Docker image for gateway

Mixnode dockerfile
Fix topology log (#962 )
2021-12-15 16:11:05 +00:00 · 2021-12-15 15:02:00 +00:00 · 2021-12-15 13:19:34 +02:00 · 2021-12-15 10:37:47 +00:00 · 2021-12-15 10:14:41 +00:00 · 2021-12-14 16:06:02 +00:00
499 changed files with 41473 additions and 12945 deletions
@@ -36,5 +36,5 @@ Cargo.* @durch @futurechimp @jstuczyn @neacsu

 # Explorer and wallet should probably get looked by the product team
 /explorer/ @nymtech/product 
-/tauri-wallet/ @nymtech/product 
+/nym-wallet/ @nymtech/product 
 /wallet-web/ @nymtech/product
@@ -9,14 +9,24 @@ on:
      - 'explorer/**'

 jobs:
+  matrix_prep:
+    runs-on: ubuntu-latest
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+    steps:
+      # creates the matrix strategy from build_matrix_includes.json
+      - uses: actions/checkout@v2
+      - id: set-matrix
+        uses: JoshuaTheMiller/conditional-build-matrix@main
+        with:
+          inputFile: '.github/workflows/build_matrix_includes.json'
+          filter: '[?runOnEvent==`${{ github.event_name }}` || runOnEvent==`always`]'
  build:
+    needs: matrix_prep
+    strategy:
+      matrix: ${{fromJson(needs.matrix_prep.outputs.matrix)}}
    runs-on: ${{ matrix.os }}
    continue-on-error: ${{ matrix.rust == 'nightly' || matrix.rust == 'beta' || matrix.os == 'windows-latest' }}
-    strategy:
-      matrix:
-        rust: [stable, beta, nightly]
-        os: [ubuntu-latest, macos-latest, windows-latest]
-
    steps:
      - name: Install Dependencies (Linux)
        run: sudo apt-get update && sudo apt-get install libwebkit2gtk-4.0-dev build-essential curl wget libssl-dev libgtk-3-dev squashfs-tools
@@ -51,6 +61,13 @@ jobs:
          command: fmt
          args: --all -- --check

+      - uses: actions-rs/clippy-check@v1
+        name: Clippy checks
+#        if: matrix.os == 'ubuntu-latest' && matrix.rust == 'stable'
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          args: --all-features
+
      - name: Run clippy
        uses: actions-rs/cargo@v1
        if: ${{ matrix.rust != 'nightly' }}
@@ -65,78 +82,21 @@ jobs:
        with:
          command: clean

-      # BUILD
-      - name: Build gateway with coconut feature
+      - name: Build all binaries with coconut enabled
        uses: actions-rs/cargo@v1
        with:
          command: build
-          args: --bin nym-gateway --features=coconut
+          args: --all --features=coconut

-      - name: Build native client with coconut feature
-        uses: actions-rs/cargo@v1
-        with:
-          command: build
-          args: --bin nym-client --features=coconut
-
-      - name: Build socks5 client with coconut feature
-        uses: actions-rs/cargo@v1
-        with:
-          command: build
-          args: --bin nym-socks5-client --features=coconut
-
-      - name: Build validator-api with coconut feature
-        uses: actions-rs/cargo@v1
-        with:
-          command: build
-          args: --bin nym-validator-api --features=coconut
-
-# TEST
-      - name: Test gateway with coconut feature
+      - name: Run all tests with coconut enabled
        uses: actions-rs/cargo@v1
        with:
          command: test
-          args: --bin nym-gateway --features=coconut
+          args: --all --features=coconut

-      - name: Test native client with coconut feature
-        uses: actions-rs/cargo@v1
-        with:
-          command: test
-          args: --bin nym-client --features=coconut
-
-      - name: Test socks5 client with coconut feature
-        uses: actions-rs/cargo@v1
-        with:
-          command: test
-          args: --bin nym-socks5-client --features=coconut
-
-      - name: Test validator-api with coconut feature
-        uses: actions-rs/cargo@v1
-        with:
-          command: test
-          args: --bin nym-validator-api --features=coconut
-
-# CLIPPY
-
-      - name: Run clippy on gateway with coconut feature
+      - name: Run clippy with coconut enabled
        uses: actions-rs/cargo@v1
+        if: ${{ matrix.rust != 'nightly' }}
        with:
          command: clippy
-          args: --bin nym-gateway --features=coconut -- -D warnings
-
-      - name: Run clippy on native client with coconut feature
-        uses: actions-rs/cargo@v1
-        with:
-          command: clippy
-          args: --bin nym-client --features=coconut -- -D warnings
-
-      - name: Run clippy on socks5 client with coconut feature
-        uses: actions-rs/cargo@v1
-        with:
-          command: clippy
-          args: --bin nym-socks5-client --features=coconut -- -D warnings
-
-      - name: Run clippy on validator-api with coconut feature
-        uses: actions-rs/cargo@v1
-        with:
-          command: clippy
-          args: --bin nym-validator-api --features=coconut -- -D warnings
+          args: --features=coconut -- -D warnings
@@ -0,0 +1,50 @@
+[
+  {
+    "os":"ubuntu-latest",
+    "rust":"stable",
+    "runOnEvent":"always"
+  },
+
+  {
+    "os":"windows-latest",
+    "rust":"stable",
+    "runOnEvent":"pull_request"
+  },
+  {
+    "os":"macos-latest",
+    "rust":"stable",
+    "runOnEvent":"pull_request"
+  },
+
+  {
+    "os":"ubuntu-latest",
+    "rust":"beta",
+    "runOnEvent":"pull_request"
+  },
+  {
+    "os":"windows-latest",
+    "rust":"beta",
+    "runOnEvent":"pull_request"
+  },
+  {
+    "os":"macos-latest",
+    "rust":"beta",
+    "runOnEvent":"pull_request"
+  },
+
+  {
+    "os":"ubuntu-latest",
+    "rust":"nightly",
+    "runOnEvent":"pull_request"
+  },
+  {
+    "os":"windows-latest",
+    "rust":"nightly",
+    "runOnEvent":"pull_request"
+  },
+  {
+    "os":"macos-latest",
+    "rust":"nightly",
+    "runOnEvent":"pull_request"
+  }
+]
@@ -1,17 +0,0 @@
-name: Clippy check
-
-on:
-  push:
-    paths-ignore:
-      - 'explorer/**'
-
-jobs:
-  clippy_check:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v1
-      - run: rustup component add clippy
-      - uses: actions-rs/clippy-check@v1
-        with:
-          token: ${{ secrets.GITHUB_TOKEN }}
-          args: --all-features 
@@ -0,0 +1,14 @@
+[
+  {
+    "rust":"stable",
+    "runOnEvent":"always"
+  },
+  {
+    "rust":"beta",
+    "runOnEvent":"pull_request"
+  },
+  {
+    "rust":"nightly",
+    "runOnEvent":"pull_request"
+  }
+]
@@ -1,4 +1,4 @@
-name: Mixnet Contract
+name: Contracts

 on:
  push:
@@ -9,14 +9,26 @@ on:
      - 'explorer/**'

 jobs:
-  mixnet-contract:
+  matrix_prep:
+    runs-on: ubuntu-latest
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+    steps:
+      # creates the matrix strategy from build_matrix_includes.json
+      - uses: actions/checkout@v2
+      - id: set-matrix
+        uses: JoshuaTheMiller/conditional-build-matrix@main
+        with:
+          inputFile: '.github/workflows/contract_matrix_includes.json'
+          filter: '[?runOnEvent==`${{ github.event_name }}` || runOnEvent==`always`]'
+  contracts:
    # since it's going to be compiled into wasm, there's absolutely
    # no point in running CI on different OS-es
    runs-on: ubuntu-latest
    continue-on-error: ${{ matrix.rust == 'nightly' }}
+    needs: matrix_prep
    strategy:
-      matrix:
-        rust: [ stable, beta, nightly ]
+      matrix: ${{fromJson(needs.matrix_prep.outputs.matrix)}}
    steps:
      - uses: actions/checkout@v2

@@ -29,22 +41,24 @@ jobs:
          components: rustfmt, clippy

      - uses: actions-rs/cargo@v1
+        env:
+          RUSTFLAGS: '-C link-arg=-s'
        with:
          command: build
-          args: --manifest-path contracts/mixnet/Cargo.toml --target wasm32-unknown-unknown
+          args: --manifest-path contracts/Cargo.toml --all --target wasm32-unknown-unknown

      - uses: actions-rs/cargo@v1
        with:
          command: test
-          args: --manifest-path contracts/mixnet/Cargo.toml
+          args: --manifest-path contracts/Cargo.toml

      - uses: actions-rs/cargo@v1
        with:
          command: fmt
-          args: --manifest-path contracts/mixnet/Cargo.toml -- --check
+          args: --manifest-path contracts/Cargo.toml --all -- --check

      - uses: actions-rs/cargo@v1
        if: ${{ matrix.rust != 'nightly' }}
        with:
          command: clippy
-          args: --manifest-path contracts/mixnet/Cargo.toml -- -D warnings
+          args: --manifest-path contracts/Cargo.toml --all -- -D warnings
@@ -11,7 +11,7 @@ defaults:

 jobs:
  build:
-    runs-on: ubuntu-latest
+    runs-on: custom-runner-linux
    steps:
      - uses: actions/checkout@v2
      - uses: actions/setup-node@v2
@@ -11,7 +11,7 @@ defaults:

 jobs:
  build:
-    runs-on: ubuntu-latest
+    runs-on: custom-runner-linux
    steps:
    - uses: actions/checkout@v2
    - name: Install rsync
@@ -22,6 +22,8 @@ jobs:
        node-version: '14'
    - run: npm install
      continue-on-error: true
+    - name: Set environment from the example
+      run: cp .env.prod .env
    - run: npm run test
      continue-on-error: true
    - run: npm run build
@@ -1,8 +1,8 @@
-name: Publish Tauri Wallet
+name: Publish Nym Wallet
 on:
  push:
    tags:
-      - tauri-wallet-*
+      - nym-wallet-*

 jobs:
  build:
@@ -3,15 +3,15 @@ name: Generate TS types
 on:
  push:
    paths-ignore:
-      - 'explorer/**'
+      - "explorer/**"
  pull_request:
    paths-ignore:
-      - 'explorer/**'
+      - "explorer/**"

 jobs:
-  tauri-wallet-types:
+  nym-wallet-types:
    runs-on: ubuntu-latest
-    if: github.event_name != 'pull_request'
+    if: ${{ github.event_name != 'pull_request' }}
    steps:
      - name: Prepare
        run: sudo apt-get update && sudo apt-get install -y libpango1.0-dev libatk1.0-dev libgdk-pixbuf2.0-dev libsoup2.4-dev librust-gdk-dev libwebkit2gtk-4.0-dev
@@ -20,10 +20,10 @@ jobs:
        with:
          toolchain: stable
      - name: Generate TS
-        run: cd tauri-wallet/src-tauri && cargo test
+        run: cd nym-wallet/src-tauri && cargo test
      - uses: EndBug/add-and-commit@v7.2.1 # https://github.com/marketplace/actions/add-commit
        with:
-          add: '["tauri-wallet"]'
-          message: '[ci skip] Generate TS types'
+          add: '["nym-wallet"]'
+          message: "[ci skip] Generate TS types"
        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -1,18 +1,18 @@
 name: Webdriverio tests for nym wallet

-on: 
- push:
+on:
+  push:
    paths:
-      - 'tauri-wallet/**'
-      
+      - "nym-wallet/**"
+
 defaults:
  run:
-    working-directory: tauri-wallet
+    working-directory: nym-wallet

 jobs:
  test:
    name: wallet tests
-    runs-on: ubuntu-latest 
+    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2

@@ -30,8 +30,8 @@ jobs:
      - name: Install minimal stable
        uses: actions-rs/toolchain@v1
        with:
-         profile: minimal
-         toolchain: stable
+          profile: minimal
+          toolchain: stable

      - name: Node v16
        uses: actions/setup-node@v1
@@ -39,32 +39,32 @@ jobs:
          node-version: 16.x

      - name: Install yarn for building application
-        run: yarn install    
+        run: yarn install

      - name: Build application
        run: yarn run webpack:build & yarn run tauri:build
-        
+
      - name: Check binary exists
        run: |
-             cd target/release/
-             (test -f nym-wallet && echo nym binary exists) || echo wallet does not exist
+          cd target/release/
+          (test -f nym-wallet && echo nym binary exists) || echo wallet does not exist

      - name: Install dependencies
        run: yarn install
-        working-directory: tauri-wallet/webdriver
+        working-directory: nym-wallet/webdriver

      - name: Remove existing user datafile
        uses: JesseTG/rm@v1.0.2
        with:
-          path: tauri-wallet/webdriver/common/data/user-data.json
+          path: nym-wallet/webdriver/common/data/user-data.json

      - name: Create user data json file
        id: create-json
        uses: jsdaniell/create-json@1.1.2
        with:
-           name: "user-data.json"
-           json: ${{ secrets.WALLET_USERDATA }}
-           dir: 'tauri-wallet/webdriver/common/data/'
+          name: "user-data.json"
+          json: ${{ secrets.WALLET_USERDATA }}
+          dir: "nym-wallet/webdriver/common/data/"

      - name: Install tauri-driver
        uses: actions-rs/cargo@v1
@@ -74,4 +74,4 @@ jobs:

      - name: Launch tests
        run: xvfb-run yarn test:runall
-        working-directory: tauri-wallet/webdriver
+        working-directory: nym-wallet/webdriver
@@ -1,9 +1,6 @@
 name: Wasm Client

 on:
-  push:
-    paths-ignore:
-      - 'explorer/**'
  pull_request:
    paths-ignore:
      - 'explorer/**'
@@ -22,10 +19,11 @@ jobs:
          override: true
          components: rustfmt, clippy

-      - uses: actions-rs/cargo@v1
-        with:
-          command: build
-          args: --manifest-path clients/webassembly/Cargo.toml --target wasm32-unknown-unknown
+# token credentials (non-coconut) don't work for wasm right now
+#      - uses: actions-rs/cargo@v1
+#        with:
+#          command: build
+#          args: --manifest-path clients/webassembly/Cargo.toml --target wasm32-unknown-unknown

      - uses: actions-rs/cargo@v1
        with:
@@ -47,4 +45,4 @@ jobs:
 #      - uses: actions-rs/cargo@v1
 #        with:
 #          command: clippy
-#          args: --manifest-path clients/webassembly/Cargo.toml --target wasm32-unknown-unknown -- -D warnings
+#          args: --manifest-path clients/webassembly/Cargo.toml --target wasm32-unknown-unknown -- -D warnings
@@ -24,8 +24,15 @@ v6-topology.json
 /explorer/downloads/topology.json
 /explorer/public/downloads/mixmining.json
 /explorer/public/downloads/topology.json
+/nym-wallet/dist/*
 /clients/validator/examples/nym-driver-example/current-contract.txt
 validator-api/v4.json
 validator-api/v6.json
 **/node_modules
 validator-api/keypair
+contracts/mixnet/code_id
+contracts/mixnet/Justfile
+contracts/mixnet/Makefile
+validator-config
+*.patch
+validator-api-config.toml
@@ -25,10 +25,12 @@ members = [
    "common/config",
    "common/credentials",
    "common/crypto",
+    "common/erc20-bridge-contract",
    "common/mixnet-contract",
    "common/mixnode-common",
    "common/network-defaults",
    "common/nonexhaustive-delayqueue",
+    "common/nymcoconut",
    "common/nymsphinx",
    "common/nymsphinx/acknowledgements",
    "common/nymsphinx/addressing",
@@ -60,6 +62,7 @@ default-members = [
    "service-providers/network-requester",
    "mixnode",
    "validator-api",
+    "explorer-api",
 ]

-exclude = ["explorer", "contracts"]
+exclude = ["explorer", "contracts", "tokenomics-py"]
@@ -0,0 +1,31 @@
+all: clippy test fmt
+clippy: clippy-main clippy-contracts clippy-wallet
+test: test-main test-contracts test-wallet
+fmt: fmt-main fmt-contracts fmt-wallet
+
+clippy-main:
+	cargo clippy
+
+clippy-contracts:
+	cargo clippy --manifest-path contracts/Cargo.toml
+
+clippy-wallet: 
+	cargo clippy --manifest-path nym-wallet/Cargo.toml
+
+test-main:
+	cargo test
+
+test-contracts:
+	cargo test --manifest-path contracts/Cargo.toml
+
+test-wallet:
+	cargo test --manifest-path nym-wallet/Cargo.toml
+
+fmt-main:
+	cargo fmt --all
+
+fmt-contracts:
+	cargo fmt --manifest-path contracts/Cargo.toml --all
+
+fmt-wallet:
+	cargo fmt --manifest-path nym-wallet/Cargo.toml --all
@@ -5,8 +5,6 @@ SPDX-License-Identifier: Apache-2.0

 ## The Nym Privacy Platform

-This repository contains the Nym mixnet.
-
 The platform is composed of multiple Rust crates. Top-level executable binary crates include:

 * nym-mixnode - shuffles [Sphinx](https://github.com/nymtech/sphinx) packets together to provide privacy against network-level attackers.
@@ -15,7 +13,7 @@ The platform is composed of multiple Rust crates. Top-level executable binary cr
 * nym-gateway - acts sort of like a mailbox for mixnet messages, removing the need for directly delivery to potentially offline or firewalled devices.
 * nym-network-monitor - sends packets through the full system to check that they are working as expected, and stores node uptime histories as the basis of a rewards system ("mixmining" or "proof-of-mixing").
 * nym-explorer - a (projected) block explorer and (existing) mixnet viewer.
-* nym-wallet (currently in development)- a desktop wallet implemented using the [Tauri](https://tauri.studio/en/docs/about/intro) framework. 
+* nym-wallet - a desktop wallet implemented using the [Tauri](https://tauri.studio/en/docs/about/intro) framework. 

 [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg?style=for-the-badge)](https://opensource.org/licenses/Apache-2.0)
 [![Build Status](https://img.shields.io/github/workflow/status/nymtech/nym/Continuous%20integration/develop?style=for-the-badge&logo=github-actions)](https://github.com/nymtech/nym/actions?query=branch%3Adevelop)
@@ -33,6 +31,45 @@ There's a `.env.sample-dev` file provided which you can rename to `.env` if you

 You can chat to us in [Keybase](https://keybase.io). Download their chat app, then click **Teams -> Join a team**. Type **nymtech.friends** into the team name and hit **continue**. For general chat, hang out in the **#general** channel. Our development takes places in the **#dev** channel. Node operators should be in the **#node-operators** channel.

+### Rewards
+
+Node, node operator and delegator rewards are determined according to the principles laid out in the section 6 of [Nym Whitepaper](https://nymtech.net/nym-whitepaper.pdf). Below is a TLDR of the variables and formulas involved in calculating the epoch rewards. Initial reward pool is set to 250 million Nym, making the circulating supply 750 million Nym.
+
+|Symbol|Definition|
+|---|---|
+|<img src="https://render.githubusercontent.com/render/math?math=R">|global share of rewards available, starts at 2% of the reward pool. 
+|<img src="https://render.githubusercontent.com/render/math?math=R_{i}">|node reward for mixnode `i`.
+|<img src="https://render.githubusercontent.com/render/math?math=\sigma_{i}">|ratio of total node stake (node bond + all delegations) to the token circulating supply.
+|<img src="https://render.githubusercontent.com/render/math?math=\lambda_{i}">|ratio of stake operator has plaged to their node to the token circulating supply.
+|<img src="https://render.githubusercontent.com/render/math?math=\omega_{i}">|fraction of total effort undertaken by node `i`, set to `1/k` in testnet Milhon.
+|<img src="https://render.githubusercontent.com/render/math?math=k">|number of nodes stakeholders are incentivised to create, set by the validators, a matter of governance. Currently determined by the `active set` size, and set to 5000 in testnet Milhon.
+|<img src="https://render.githubusercontent.com/render/math?math=\alpha">|Sybil attack resistance parameter - the higher this parameter is set the stronger the reduction in competitivness gets for a Sybil attacker.
+|<img src="https://render.githubusercontent.com/render/math?math=PM_{i}">|declared profit margin of operator `i`, defaults to 10% in testnet Milhon.
+|<img src="https://render.githubusercontent.com/render/math?math=PF_{i}">|uptime of node `i`, scaled to 0 - 1, for the rewarding epoch
+|<img src="https://render.githubusercontent.com/render/math?math=PP_{i}">|cost of operating node `i` for the duration of the rewarding eopoch, set to 40 Nym for testnet Milhon.
+
+Node reward for node `i` is determined as:
+
+<img src="https://render.githubusercontent.com/render/math?math=R_{i}=PF_{i} \cdot R \cdot (\sigma^'_{i} \cdot \omega_{i} \cdot k %2b \alpha \cdot \lambda^'_{i} \cdot \sigma^'_{i} \cdot k)/(1 %2b \alpha)">
+
+where:
+
+<img src="https://render.githubusercontent.com/render/math?math=\sigma^'_{i} = min\{\sigma_{i}, 1/k\}">
+
+and
+
+<img src="https://render.githubusercontent.com/render/math?math=\lambda^'_{i} = min\{\lambda_{i}, 1/k\}">
+
+Operator of node `i` is credited with the following amount:
+
+<img src="https://render.githubusercontent.com/render/math?math=min\{PP_{i},R_{i})\} %2b max\{0, (PM_{i} %2b (1 - PM_{i}) \cdot \lambda_{i}/\delta_{i}) \cdot (R_{i} - PP_{i})\}">
+
+Delegate with stake `s` recieves:
+
+<img src="https://render.githubusercontent.com/render/math?math=max\{0, (1-PM_{i}) \cdot (s^'/\sigma_{i}) \cdot (R_{i} - PP_{i})\}">
+
+where `s'` is stake `s` scaled over total token circulating supply.
+
 ### Licensing and copyright information

 This program is available as open source under the terms of the Apache 2.0 license. However, some elements are being licensed under CC0-1.0 and MIT. For accurate information, please check individual files.
@@ -30,3 +30,6 @@ validator-client = { path = "../../common/client-libs/validator-client" }

 [dev-dependencies]
 tempfile = "3.1.0"
+
+[features]
+coconut = []
@@ -22,7 +22,10 @@ const DEFAULT_MESSAGE_STREAM_AVERAGE_DELAY: Duration = Duration::from_millis(20)
 const DEFAULT_AVERAGE_PACKET_DELAY: Duration = Duration::from_millis(50);
 const DEFAULT_TOPOLOGY_REFRESH_RATE: Duration = Duration::from_secs(5 * 60); // every 5min
 const DEFAULT_TOPOLOGY_RESOLUTION_TIMEOUT: Duration = Duration::from_millis(5_000);
-const DEFAULT_GATEWAY_RESPONSE_TIMEOUT: Duration = Duration::from_millis(1_500);
+// Set this to a high value for now, so that we don't risk sporadic timeouts that might cause
+// bought bandwidth tokens to not have time to be spent; Once we remove the gateway from the
+// bandwidth bridging protocol, we can come back to a smaller timeout value
+const DEFAULT_GATEWAY_RESPONSE_TIMEOUT: Duration = Duration::from_secs(5 * 60);

 pub fn missing_string_value() -> String {
    MISSING_VALUE.to_string()
@@ -100,6 +103,17 @@ impl<T: NymConfig> Config<T> {
                self::Client::<T>::default_reply_encryption_key_store_path(&id);
        }

+        #[cfg(not(feature = "coconut"))]
+        if self
+            .client
+            .backup_bandwidth_token_keys_dir
+            .as_os_str()
+            .is_empty()
+        {
+            self.client.backup_bandwidth_token_keys_dir =
+                self::Client::<T>::default_backup_bandwidth_token_keys_dir(&id);
+        }
+
        self.client.id = id;
    }

@@ -111,6 +125,16 @@ impl<T: NymConfig> Config<T> {
        self.client.gateway_listener = gateway_listener.into();
    }

+    #[cfg(not(feature = "coconut"))]
+    pub fn with_eth_private_key<S: Into<String>>(&mut self, eth_private_key: S) {
+        self.client.eth_private_key = eth_private_key.into();
+    }
+
+    #[cfg(not(feature = "coconut"))]
+    pub fn with_eth_endpoint<S: Into<String>>(&mut self, eth_endpoint: S) {
+        self.client.eth_endpoint = eth_endpoint.into();
+    }
+
    pub fn set_custom_validator_apis(&mut self, validator_api_urls: Vec<Url>) {
        self.client.validator_api_urls = validator_api_urls;
    }
@@ -173,6 +197,21 @@ impl<T: NymConfig> Config<T> {
        self.client.gateway_listener.clone()
    }

+    #[cfg(not(feature = "coconut"))]
+    pub fn get_backup_bandwidth_token_keys_dir(&self) -> PathBuf {
+        self.client.backup_bandwidth_token_keys_dir.clone()
+    }
+
+    #[cfg(not(feature = "coconut"))]
+    pub fn get_eth_endpoint(&self) -> String {
+        self.client.eth_endpoint.clone()
+    }
+
+    #[cfg(not(feature = "coconut"))]
+    pub fn get_eth_private_key(&self) -> String {
+        self.client.eth_private_key.clone()
+    }
+
    // Debug getters
    pub fn get_average_packet_delay(&self) -> Duration {
        self.debug.average_packet_delay
@@ -268,6 +307,20 @@ pub struct Client<T> {
    /// Address of the gateway listener to which all client requests should be sent.
    gateway_listener: String,

+    /// Path to directory containing public/private keys used for bandwidth token purchase.
+    /// Those are saved in case of emergency, to be able to reclaim bandwidth tokens.
+    /// The public key is the name of the file, while the private key is the content.
+    #[cfg(not(feature = "coconut"))]
+    backup_bandwidth_token_keys_dir: PathBuf,
+
+    /// Ethereum private key.
+    #[cfg(not(feature = "coconut"))]
+    eth_private_key: String,
+
+    /// Address to an Ethereum full node.
+    #[cfg(not(feature = "coconut"))]
+    eth_endpoint: String,
+
    /// nym_home_directory specifies absolute path to the home nym Clients directory.
    /// It is expected to use default value and hence .toml file should not redefine this field.
    nym_root_directory: PathBuf,
@@ -292,6 +345,12 @@ impl<T: NymConfig> Default for Client<T> {
            reply_encryption_key_store_path: Default::default(),
            gateway_id: "".to_string(),
            gateway_listener: "".to_string(),
+            #[cfg(not(feature = "coconut"))]
+            backup_bandwidth_token_keys_dir: Default::default(),
+            #[cfg(not(feature = "coconut"))]
+            eth_private_key: "".to_string(),
+            #[cfg(not(feature = "coconut"))]
+            eth_endpoint: "".to_string(),
            nym_root_directory: T::default_root_directory(),
            super_struct: Default::default(),
        }
@@ -326,6 +385,11 @@ impl<T: NymConfig> Client<T> {
    fn default_reply_encryption_key_store_path(id: &str) -> PathBuf {
        T::default_data_directory(Some(id)).join("reply_key_store")
    }
+
+    #[cfg(not(feature = "coconut"))]
+    fn default_backup_bandwidth_token_keys_dir(id: &str) -> PathBuf {
+        T::default_data_directory(Some(id)).join("backup_bandwidth_token_keys")
+    }
 }

 #[derive(Debug, Default, Deserialize, PartialEq, Serialize)]
@@ -24,7 +24,7 @@ dirs = "3.0" # for determining default store directories in config
 dotenv = "0.15.0" # for obtaining environmental variables (only used for RUST_LOG for time being)
 log = "0.4" # self explanatory
 pretty_env_logger = "0.4" # for formatting log messages
-rand = {version = "0.7.3", features = ["wasm-bindgen"]} # rng-related traits + some rng implementation to use
+rand = { version = "0.7.3", features = ["wasm-bindgen"] } # rng-related traits + some rng implementation to use
 serde = { version = "1.0.104", features = ["derive"] } # for config serialization/deserialization
 sled = "0.34" # for storage of replySURB decryption keys
 tokio = { version = "1.4", features = ["rt-multi-thread", "net", "signal"] } # async runtime
@@ -44,6 +44,7 @@ topology = { path = "../../common/topology" }
 websocket-requests = { path = "websocket-requests" }
 validator-client = { path = "../../common/client-libs/validator-client" }
 version-checker = { path = "../../common/version-checker" }
+network-defaults = { path = "../../common/network-defaults" }

 [features]
 coconut = ["coconut-interface", "credentials", "gateway-requests/coconut", "gateway-client/coconut"]
@@ -3,6 +3,5 @@ module github.com/nymtech/nym/clients/native/examples/go
 go 1.14

 require (
-	github.com/btcsuite/btcutil v1.0.2 // indirect
 	github.com/gorilla/websocket v1.4.2
 )
@@ -42,6 +42,17 @@ public_encryption_key_file = '{{ client.public_encryption_key_file }}'
 # sent but not received back.
 reply_encryption_key_store_path = '{{ client.reply_encryption_key_store_path }}'

+# Path to directory containing public/private keys used for bandwidth token purchase.
+# Those are saved in case of emergency, to be able to reclaim bandwidth tokens.
+# The public key is the name of the file, while the private key is the content.
+backup_bandwidth_token_keys_dir = '{{ client.backup_bandwidth_token_keys_dir }}'
+
+# Ethereum private key.
+eth_private_key = '{{ client.eth_private_key }}'
+
+# Addess to an Ethereum full node.
+eth_endpoint = '{{ client.eth_endpoint }}'
+
 ##### additional client config options #####

 # ID of the gateway from which the client should be fetching messages.
@@ -1,8 +1,6 @@
 // Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0

-use crate::client::config::{Config, SocketType};
-use crate::websocket;
 use client_core::client::cover_traffic_stream::LoopCoverTrafficStream;
 use client_core::client::inbound_messages::{
    InputMessage, InputMessageReceiver, InputMessageSender,
@@ -24,6 +22,7 @@ use client_core::client::topology_control::{
 use client_core::config::persistence::key_pathfinder::ClientKeyPathfinder;
 use crypto::asymmetric::identity;
 use futures::channel::mpsc;
+use gateway_client::bandwidth::BandwidthController;
 use gateway_client::{
    AcknowledgementReceiver, AcknowledgementSender, GatewayClient, MixnetMessageReceiver,
    MixnetMessageSender,
@@ -35,10 +34,8 @@ use nymsphinx::anonymous_replies::ReplySurb;
 use nymsphinx::receiver::ReconstructedMessage;
 use tokio::runtime::Runtime;

-#[cfg(feature = "coconut")]
-use coconut_interface::Credential;
-#[cfg(feature = "coconut")]
-use credentials::{bandwidth::prepare_for_spending, obtain_aggregate_verification_key};
+use crate::client::config::{Config, SocketType};
+use crate::websocket;

 pub(crate) mod config;

@@ -168,31 +165,6 @@ impl NymClient {
        .start(self.runtime.handle())
    }

-    #[cfg(feature = "coconut")]
-    async fn prepare_coconut_credential(&self) -> Credential {
-        let verification_key = obtain_aggregate_verification_key(
-            &self.config.get_base().get_validator_api_endpoints(),
-        )
-        .await
-        .expect("could not obtain aggregate verification key of validators");
-
-        let bandwidth_credential = credentials::bandwidth::obtain_signature(
-            &self.key_manager.identity_keypair().public_key().to_bytes(),
-            &self.config.get_base().get_validator_api_endpoints(),
-        )
-        .await
-        .expect("could not obtain bandwidth credential");
-        // the above would presumably be loaded from a file
-
-        // the below would only be executed once we know where we want to spend it (i.e. which gateway and stuff)
-        prepare_for_spending(
-            &self.key_manager.identity_keypair().public_key().to_bytes(),
-            &bandwidth_credential,
-            &verification_key,
-        )
-        .expect("could not prepare out bandwidth credential for spending")
-    }
-
    fn start_gateway_client(
        &mut self,
        mixnet_message_sender: MixnetMessageSender,
@@ -212,7 +184,17 @@ impl NymClient {

        self.runtime.block_on(async {
            #[cfg(feature = "coconut")]
-            let coconut_credential = self.prepare_coconut_credential().await;
+            let bandwidth_controller = BandwidthController::new(
+                self.config.get_base().get_validator_api_endpoints(),
+                *self.key_manager.identity_keypair().public_key(),
+            );
+            #[cfg(not(feature = "coconut"))]
+            let bandwidth_controller = BandwidthController::new(
+                self.config.get_base().get_eth_endpoint(),
+                self.config.get_base().get_eth_private_key(),
+                self.config.get_base().get_backup_bandwidth_token_keys_dir(),
+            )
+            .expect("Could not create bandwidth controller");

            let mut gateway_client = GatewayClient::new(
                gateway_address,
@@ -222,13 +204,11 @@ impl NymClient {
                mixnet_message_sender,
                ack_sender,
                self.config.get_base().get_gateway_response_timeout(),
+                Some(bandwidth_controller),
            );

            gateway_client
-                .authenticate_and_start(
-                    #[cfg(feature = "coconut")]
-                    Some(coconut_credential),
-                )
+                .authenticate_and_start()
                .await
                .expect("could not authenticate and start up the gateway connection");

@@ -1,15 +1,23 @@
 // Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0

-use crate::client::config::Config;
-use crate::commands::override_config;
 use clap::{App, Arg, ArgMatches};
 use client_core::client::key_manager::KeyManager;
 use client_core::config::persistence::key_pathfinder::ClientKeyPathfinder;
+#[cfg(feature = "coconut")]
+use coconut_interface::{hash_to_scalar, Credential, Parameters};
 use config::NymConfig;
+#[cfg(feature = "coconut")]
+use credentials::coconut::bandwidth::{
+    obtain_signature, prepare_for_spending, BandwidthVoucherAttributes, TOTAL_ATTRIBUTES,
+};
+#[cfg(feature = "coconut")]
+use credentials::obtain_aggregate_verification_key;
 use crypto::asymmetric::{encryption, identity};
 use gateway_client::GatewayClient;
 use gateway_requests::registration::handshake::SharedKeys;
+#[cfg(feature = "coconut")]
+use network_defaults::BANDWIDTH_VALUE;
 use nymsphinx::addressing::clients::Recipient;
 use nymsphinx::addressing::nodes::NodeIdentity;
 use rand::rngs::OsRng;
@@ -21,8 +29,11 @@ use std::time::Duration;
 use topology::{filter::VersionFilterable, gateway};
 use url::Url;

+use crate::client::config::Config;
+use crate::commands::override_config;
+
 pub fn command_args<'a, 'b>() -> clap::App<'a, 'b> {
-    App::new("init")
+    let app = App::new("init")
        .about("Initialise a Nym client. Do this first!")
        .arg(Arg::with_name("id")
            .long("id")
@@ -36,9 +47,9 @@ pub fn command_args<'a, 'b>() -> clap::App<'a, 'b> {
            .takes_value(true)
        )
        .arg(Arg::with_name("validators")
-                .long("validators")
-                .help("Comma separated list of rest endpoints of the validators")
-                .takes_value(true),
+                 .long("validators")
+                 .help("Comma separated list of rest endpoints of the validators")
+                 .takes_value(true),
        )
        .arg(Arg::with_name("disable-socket")
            .long("disable-socket")
@@ -54,7 +65,51 @@ pub fn command_args<'a, 'b>() -> clap::App<'a, 'b> {
            .long("fastmode")
            .hidden(true) // this will prevent this flag from being displayed in `--help`
            .help("Mostly debug-related option to increase default traffic rate so that you would not need to modify config post init")
-        )
+        );
+    #[cfg(not(feature = "coconut"))]
+        let app = app
+        .arg(Arg::with_name("eth_endpoint")
+            .long("eth_endpoint")
+            .help("URL of an Ethereum full node that we want to use for getting bandwidth tokens from ERC20 tokens")
+            .takes_value(true)
+            .required(true))
+        .arg(Arg::with_name("eth_private_key")
+            .long("eth_private_key")
+            .help("Ethereum private key used for obtaining bandwidth tokens from ERC20 tokens")
+            .takes_value(true)
+            .required(true));
+
+    app
+}
+
+// this behaviour should definitely be changed, we shouldn't
+// need to get bandwidth credential for registration
+#[cfg(feature = "coconut")]
+async fn _prepare_temporary_credential(validators: &[Url], raw_identity: &[u8]) -> Credential {
+    let verification_key = obtain_aggregate_verification_key(validators)
+        .await
+        .expect("could not obtain aggregate verification key of validators");
+
+    let params = Parameters::new(TOTAL_ATTRIBUTES).unwrap();
+    let bandwidth_credential_attributes = BandwidthVoucherAttributes {
+        serial_number: params.random_scalar(),
+        binding_number: params.random_scalar(),
+        voucher_value: hash_to_scalar(BANDWIDTH_VALUE.to_be_bytes()),
+        voucher_info: hash_to_scalar(String::from("BandwidthVoucher").as_bytes()),
+    };
+
+    let bandwidth_credential =
+        obtain_signature(&params, &bandwidth_credential_attributes, validators)
+            .await
+            .expect("could not obtain bandwidth credential");
+
+    prepare_for_spending(
+        raw_identity,
+        &bandwidth_credential,
+        &bandwidth_credential_attributes,
+        &verification_key,
+    )
+    .expect("could not prepare out bandwidth credential for spending")
 }

 async fn register_with_gateway(
@@ -43,5 +43,14 @@ pub(crate) fn override_config(mut config: Config, matches: &ArgMatches) -> Confi
        config = config.with_port(port.unwrap());
    }

+    #[cfg(not(feature = "coconut"))]
+    if let Some(eth_endpoint) = matches.value_of("eth_endpoint") {
+        config.get_base_mut().with_eth_endpoint(eth_endpoint);
+    }
+    #[cfg(not(feature = "coconut"))]
+    if let Some(eth_private_key) = matches.value_of("eth_private_key") {
+        config.get_base_mut().with_eth_private_key(eth_private_key);
+    }
+
    config
 }
@@ -10,7 +10,7 @@ use log::*;
 use version_checker::is_minor_version_compatible;

 pub fn command_args<'a, 'b>() -> clap::App<'a, 'b> {
-    App::new("run")
+    let app = App::new("run")
        .about("Run the Nym client with provided configuration client optionally overriding set parameters")
        .arg(Arg::with_name("id")
            .long("id")
@@ -38,7 +38,19 @@ pub fn command_args<'a, 'b>() -> clap::App<'a, 'b> {
            .long("port")
            .help("Port for the socket (if applicable) to listen on")
            .takes_value(true)
-        )
+        );
+    #[cfg(not(feature = "coconut"))]
+        let app = app
+        .arg(Arg::with_name("eth_endpoint")
+            .long("eth_endpoint")
+            .help("URL of an Ethereum full node that we want to use for getting bandwidth tokens from ERC20 tokens")
+            .takes_value(true))
+        .arg(Arg::with_name("eth_private_key")
+            .long("eth_private_key")
+            .help("Ethereum private key used for obtaining bandwidth tokens from ERC20 tokens")
+            .takes_value(true));
+
+    app
 }

 // this only checks compatibility between config the binary. It does not take into consideration
@@ -1,8 +1,8 @@
 // Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0

-pub(crate) mod handler;
-pub(crate) mod listener;
-
 pub(crate) use handler::Handler;
 pub(crate) use listener::Listener;
+
+pub(crate) mod handler;
+pub(crate) mod listener;
@@ -32,13 +32,14 @@ crypto = { path = "../../common/crypto" }
 gateway-client = { path = "../../common/client-libs/gateway-client" }
 gateway-requests = { path = "../../gateway/gateway-requests" }
 nymsphinx = { path = "../../common/nymsphinx" }
-ordered-buffer = {path = "../../common/socks5/ordered-buffer"}
+ordered-buffer = { path = "../../common/socks5/ordered-buffer" }
 socks5-requests = { path = "../../common/socks5/requests" }
 topology = { path = "../../common/topology" }
 pemstore = { path = "../../common/pemstore" }
 proxy-helpers = { path = "../../common/socks5/proxy-helpers" }
 validator-client = { path = "../../common/client-libs/validator-client" }
 version-checker = { path = "../../common/version-checker" }
+network-defaults = { path = "../../common/network-defaults" }

 [features]
 coconut = ["coconut-interface", "credentials", "gateway-requests/coconut", "gateway-client/coconut"]
@@ -42,6 +42,17 @@ public_encryption_key_file = '{{ client.public_encryption_key_file }}'
 # sent but not received back.
 reply_encryption_key_store_path = '{{ client.reply_encryption_key_store_path }}'

+# Path to directory containing public/private keys used for bandwidth token purchase.
+# Those are saved in case of emergency, to be able to reclaim bandwidth tokens.
+# The public key is the name of the file, while the private key is the content.
+backup_bandwidth_token_keys_dir = '{{ client.backup_bandwidth_token_keys_dir }}'
+
+# Ethereum private key.
+eth_private_key = '{{ client.eth_private_key }}'
+
+# Addess to an Ethereum full node.
+eth_endpoint = '{{ client.eth_endpoint }}'
+
 ##### additional client config options #####

 # ID of the gateway from which the client should be fetching messages.
@@ -1,11 +1,6 @@
 // Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0

-use crate::client::config::Config;
-use crate::socks::{
-    authentication::{AuthenticationMethods, Authenticator, User},
-    server::SphinxSocksServer,
-};
 use client_core::client::cover_traffic_stream::LoopCoverTrafficStream;
 use client_core::client::inbound_messages::{
    InputMessage, InputMessageReceiver, InputMessageSender,
@@ -25,6 +20,7 @@ use client_core::client::topology_control::{
 use client_core::config::persistence::key_pathfinder::ClientKeyPathfinder;
 use crypto::asymmetric::identity;
 use futures::channel::mpsc;
+use gateway_client::bandwidth::BandwidthController;
 use gateway_client::{
    AcknowledgementReceiver, AcknowledgementSender, GatewayClient, MixnetMessageReceiver,
    MixnetMessageSender,
@@ -34,10 +30,11 @@ use nymsphinx::addressing::clients::Recipient;
 use nymsphinx::addressing::nodes::NodeIdentity;
 use tokio::runtime::Runtime;

-#[cfg(feature = "coconut")]
-use coconut_interface::Credential;
-#[cfg(feature = "coconut")]
-use credentials::{bandwidth::prepare_for_spending, obtain_aggregate_verification_key};
+use crate::client::config::Config;
+use crate::socks::{
+    authentication::{AuthenticationMethods, Authenticator, User},
+    server::SphinxSocksServer,
+};

 pub(crate) mod config;

@@ -156,31 +153,6 @@ impl NymClient {
        .start(self.runtime.handle())
    }

-    #[cfg(feature = "coconut")]
-    async fn prepare_coconut_credential(&self) -> Credential {
-        let verification_key = obtain_aggregate_verification_key(
-            &self.config.get_base().get_validator_api_endpoints(),
-        )
-        .await
-        .expect("could not obtain aggregate verification key of validators");
-
-        let bandwidth_credential = credentials::bandwidth::obtain_signature(
-            &self.key_manager.identity_keypair().public_key().to_bytes(),
-            &self.config.get_base().get_validator_api_endpoints(),
-        )
-        .await
-        .expect("could not obtain bandwidth credential");
-        // the above would presumably be loaded from a file
-
-        // the below would only be executed once we know where we want to spend it (i.e. which gateway and stuff)
-        prepare_for_spending(
-            &self.key_manager.identity_keypair().public_key().to_bytes(),
-            &bandwidth_credential,
-            &verification_key,
-        )
-        .expect("could not prepare out bandwidth credential for spending")
-    }
-
    fn start_gateway_client(
        &mut self,
        mixnet_message_sender: MixnetMessageSender,
@@ -200,7 +172,17 @@ impl NymClient {

        self.runtime.block_on(async {
            #[cfg(feature = "coconut")]
-            let coconut_credential = self.prepare_coconut_credential().await;
+            let bandwidth_controller = BandwidthController::new(
+                self.config.get_base().get_validator_api_endpoints(),
+                *self.key_manager.identity_keypair().public_key(),
+            );
+            #[cfg(not(feature = "coconut"))]
+            let bandwidth_controller = BandwidthController::new(
+                self.config.get_base().get_eth_endpoint(),
+                self.config.get_base().get_eth_private_key(),
+                self.config.get_base().get_backup_bandwidth_token_keys_dir(),
+            )
+            .expect("Could not create bandwidth controller");

            let mut gateway_client = GatewayClient::new(
                gateway_address,
@@ -210,13 +192,11 @@ impl NymClient {
                mixnet_message_sender,
                ack_sender,
                self.config.get_base().get_gateway_response_timeout(),
+                Some(bandwidth_controller),
            );

            gateway_client
-                .authenticate_and_start(
-                    #[cfg(feature = "coconut")]
-                    Some(coconut_credential),
-                )
+                .authenticate_and_start()
                .await
                .expect("could not authenticate and start up the gateway connection");

@@ -1,15 +1,23 @@
 // Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0

-use crate::client::config::Config;
-use crate::commands::override_config;
 use clap::{App, Arg, ArgMatches};
 use client_core::client::key_manager::KeyManager;
 use client_core::config::persistence::key_pathfinder::ClientKeyPathfinder;
+#[cfg(feature = "coconut")]
+use coconut_interface::{hash_to_scalar, Credential, Parameters};
 use config::NymConfig;
+#[cfg(feature = "coconut")]
+use credentials::coconut::bandwidth::{
+    obtain_signature, prepare_for_spending, BandwidthVoucherAttributes, TOTAL_ATTRIBUTES,
+};
+#[cfg(feature = "coconut")]
+use credentials::obtain_aggregate_verification_key;
 use crypto::asymmetric::{encryption, identity};
 use gateway_client::GatewayClient;
 use gateway_requests::registration::handshake::SharedKeys;
+#[cfg(feature = "coconut")]
+use network_defaults::BANDWIDTH_VALUE;
 use nymsphinx::addressing::clients::Recipient;
 use nymsphinx::addressing::nodes::NodeIdentity;
 use rand::{prelude::SliceRandom, rngs::OsRng, thread_rng};
@@ -19,8 +27,11 @@ use std::time::Duration;
 use topology::{filter::VersionFilterable, gateway};
 use url::Url;

+use crate::client::config::Config;
+use crate::commands::override_config;
+
 pub fn command_args<'a, 'b>() -> clap::App<'a, 'b> {
-    App::new("init")
+    let app = App::new("init")
        .about("Initialise a Nym client. Do this first!")
        .arg(Arg::with_name("id")
            .long("id")
@@ -40,9 +51,9 @@ pub fn command_args<'a, 'b>() -> clap::App<'a, 'b> {
            .takes_value(true)
        )
        .arg(Arg::with_name("validators")
-                .long("validators")
-                .help("Comma separated list of rest endpoints of the validators")
-                .takes_value(true),
+                 .long("validators")
+                 .help("Comma separated list of rest endpoints of the validators")
+                 .takes_value(true),
        )
        .arg(Arg::with_name("port")
            .short("p")
@@ -54,7 +65,51 @@ pub fn command_args<'a, 'b>() -> clap::App<'a, 'b> {
            .long("fastmode")
            .hidden(true) // this will prevent this flag from being displayed in `--help`
            .help("Mostly debug-related option to increase default traffic rate so that you would not need to modify config post init")
-        )
+        );
+    #[cfg(not(feature = "coconut"))]
+        let app = app
+        .arg(Arg::with_name("eth_endpoint")
+            .long("eth_endpoint")
+            .help("URL of an Ethereum full node that we want to use for getting bandwidth tokens from ERC20 tokens")
+            .takes_value(true)
+            .required(true))
+        .arg(Arg::with_name("eth_private_key")
+            .long("eth_private_key")
+            .help("Ethereum private key used for obtaining bandwidth tokens from ERC20 tokens")
+            .takes_value(true)
+            .required(true));
+
+    app
+}
+
+// this behaviour should definitely be changed, we shouldn't
+// need to get bandwidth credential for registration
+#[cfg(feature = "coconut")]
+async fn _prepare_temporary_credential(validators: &[Url], raw_identity: &[u8]) -> Credential {
+    let verification_key = obtain_aggregate_verification_key(validators)
+        .await
+        .expect("could not obtain aggregate verification key of validators");
+
+    let params = Parameters::new(TOTAL_ATTRIBUTES).unwrap();
+    let bandwidth_credential_attributes = BandwidthVoucherAttributes {
+        serial_number: params.random_scalar(),
+        binding_number: params.random_scalar(),
+        voucher_value: hash_to_scalar(BANDWIDTH_VALUE.to_be_bytes()),
+        voucher_info: hash_to_scalar("BandwidthVoucher"),
+    };
+
+    let bandwidth_credential =
+        obtain_signature(&params, &bandwidth_credential_attributes, validators)
+            .await
+            .expect("could not obtain bandwidth credential");
+
+    prepare_for_spending(
+        raw_identity,
+        &bandwidth_credential,
+        &bandwidth_credential_attributes,
+        &verification_key,
+    )
+    .expect("could not prepare out bandwidth credential for spending")
 }

 async fn register_with_gateway(
@@ -39,5 +39,14 @@ pub(crate) fn override_config(mut config: Config, matches: &ArgMatches) -> Confi
        config = config.with_port(port.unwrap());
    }

+    #[cfg(not(feature = "coconut"))]
+    if let Some(eth_endpoint) = matches.value_of("eth_endpoint") {
+        config.get_base_mut().with_eth_endpoint(eth_endpoint);
+    }
+    #[cfg(not(feature = "coconut"))]
+    if let Some(eth_private_key) = matches.value_of("eth_private_key") {
+        config.get_base_mut().with_eth_private_key(eth_private_key);
+    }
+
    config
 }
@@ -10,7 +10,7 @@ use log::*;
 use version_checker::is_minor_version_compatible;

 pub fn command_args<'a, 'b>() -> clap::App<'a, 'b> {
-    App::new("run")
+    let app = App::new("run")
        .about("Run the Nym client with provided configuration client optionally overriding set parameters")
        .arg(Arg::with_name("id")
            .long("id")
@@ -44,7 +44,19 @@ pub fn command_args<'a, 'b>() -> clap::App<'a, 'b> {
            .long("port")
            .help("Port for the socket to listen on")
            .takes_value(true)
-        )
+        );
+    #[cfg(not(feature = "coconut"))]
+    let app = app
+        .arg(Arg::with_name("eth_endpoint")
+            .long("eth_endpoint")
+            .help("URL of an Ethereum full node that we want to use for getting bandwidth tokens from ERC20 tokens")
+            .takes_value(true))
+        .arg(Arg::with_name("eth_private_key")
+            .long("eth_private_key")
+            .help("Ethereum private key used for obtaining bandwidth tokens from ERC20 tokens")
+            .takes_value(true));
+
+    app
 }

 // this only checks compatibility between config the binary. It does not take into consideration
@@ -3,21 +3,24 @@
  windows_subsystem = "windows"
 )]

+use std::sync::Arc;
+
+use tokio::sync::RwLock;
+use url::Url;
+
 use coconut_interface::{
  self, hash_to_scalar, Attribute, Credential, Parameters, Signature, Theta, VerificationKey,
 };
 use credentials::{obtain_aggregate_signature, obtain_aggregate_verification_key};
-use std::sync::Arc;
-use tokio::sync::RwLock;
-use url::Url;

 struct State {
  signatures: Vec<Signature>,
  n_attributes: u32,
  params: Parameters,
-  public_attributes_bytes: Vec<Vec<u8>>,
-  public_attributes: Vec<Attribute>,
-  private_attributes: Vec<Attribute>,
+  serial_number: Attribute,
+  binding_number: Attribute,
+  voucher_value: Attribute,
+  voucher_info: Attribute,
  aggregated_verification_key: Option<VerificationKey>,
 }

@@ -37,9 +40,10 @@ impl State {
      signatures: Vec::new(),
      n_attributes,
      params,
-      public_attributes_bytes,
-      public_attributes,
-      private_attributes,
+      serial_number: private_attributes[0],
+      binding_number: private_attributes[1],
+      voucher_value: public_attributes[0],
+      voucher_info: public_attributes[1],
      aggregated_verification_key: None,
    }
  }
@@ -63,8 +67,8 @@ async fn randomise_credential(
 ) -> Result<Vec<Signature>, String> {
  let mut state = state.write().await;
  let signature = state.signatures.remove(idx);
-  let new = signature.randomise(&state.params);
-  state.signatures.insert(idx, new);
+  let (new_signature, _) = signature.randomise(&state.params);
+  state.signatures.insert(idx, new_signature);
  Ok(state.signatures.clone())
 }

@@ -117,14 +121,15 @@ async fn prove_credential(
  let state = state.read().await;

  if let Some(signature) = state.signatures.get(idx) {
-    match coconut_interface::prove_credential(
+    match coconut_interface::prove_bandwidth_credential(
      &state.params,
      &verification_key,
      signature,
-      &state.private_attributes,
+      state.serial_number,
+      state.binding_number,
    ) {
      Ok(theta) => Ok(theta),
-      Err(e) => Err(format!("{}", e)),
+      Err(e) => Err(format!("{:?}", e)),
    }
  } else {
    Err("Got invalid Signature idx".to_string())
@@ -144,10 +149,15 @@ async fn verify_credential(

  let state = state.read().await;

+  let public_attributes_bytes = vec![
+    state.voucher_value.to_bytes().to_vec(),
+    state.voucher_info.to_bytes().to_vec(),
+  ];
+
  let credential = Credential::new(
    state.n_attributes,
    theta,
-    state.public_attributes_bytes.clone(),
+    public_attributes_bytes,
    state
      .signatures
      .get(idx)
@@ -164,11 +174,13 @@ async fn get_credential(
 ) -> Result<Vec<Signature>, String> {
  let guard = state.read().await;
  let parsed_urls = parse_url_validators(&validator_urls)?;
+  let public_attributes = vec![guard.voucher_value, guard.voucher_info];
+  let private_attributes = vec![guard.serial_number, guard.binding_number];

  let signature = obtain_aggregate_signature(
    &guard.params,
-    &guard.public_attributes,
-    &guard.private_attributes,
+    &public_attributes,
+    &private_attributes,
    &parsed_urls,
  )
  .await
@@ -1,6 +1,6 @@
-import NetClient, {INetClient} from "./net-client";
+import NetClient, { INetClient } from "./net-client";
 import {
-    StateParams,
+    ContractSettingsParams,
    Delegation,
    PagedMixDelegationsResponse,
    PagedGatewayDelegationsResponse,
@@ -10,10 +10,10 @@ import {
    Gateway,
    SendRequest
 } from "./types";
-import {Bip39, Random} from "@cosmjs/crypto";
-import {DirectSecp256k1HdWallet, EncodeObject} from "@cosmjs/proto-signing";
+import { Bip39, Random } from "@cosmjs/crypto";
+import { DirectSecp256k1HdWallet, EncodeObject } from "@cosmjs/proto-signing";
 import MixnodesCache from "./caches/mixnodes";
-import {buildFeeTable, coin, Coin, coins, StdFee} from "@cosmjs/stargate";
+import { buildFeeTable, coin, Coin, coins, StdFee } from "@cosmjs/stargate";
 import {
    ExecuteResult,
    InstantiateOptions,
@@ -32,17 +32,17 @@ import {
    nativeToPrintable
 } from "./currency";
 import GatewaysCache from "./caches/gateways";
-import QueryClient, {IQueryClient} from "./query-client";
-import {nymGasLimits, nymGasPrice} from "./stargate-helper";
-import {BroadcastTxSuccess, isBroadcastTxFailure} from "@cosmjs/stargate";
-import {makeBankMsgSend} from "./utils";
+import QueryClient, { IQueryClient } from "./query-client";
+import { nymGasLimits, nymGasPrice } from "./stargate-helper";
+import { BroadcastTxSuccess, isBroadcastTxFailure } from "@cosmjs/stargate";
+import { makeBankMsgSend } from "./utils";

 export const VALIDATOR_API_PORT = "8080";
 export const VALIDATOR_API_GATEWAYS = "v1/gateways";
 export const VALIDATOR_API_MIXNODES = "v1/mixnodes";

-export {coins, coin};
-export {Coin};
+export { coins, coin };
+export { Coin };
 export {
    displayAmountToNative,
    nativeCoinToDisplay,
@@ -52,7 +52,7 @@ export {
    MappedCoin,
    CoinMap
 }
-export {nymGasLimits, nymGasPrice}
+export { nymGasLimits, nymGasPrice }

 export default class ValidatorClient {
    private readonly client: INetClient | IQueryClient
@@ -226,12 +226,12 @@ export default class ValidatorClient {
     */
    static async mnemonicToAddress(mnemonic: string, prefix: string): Promise<string> {
        const wallet = await ValidatorClient.buildWallet(mnemonic, prefix);
-        const [{address}] = await wallet.getAccounts()
+        const [{ address }] = await wallet.getAccounts()
        return address
    }

    static async buildWallet(mnemonic: string, prefix: string): Promise<DirectSecp256k1HdWallet> {
-        const signerOptions = {prefix: prefix};
+        const signerOptions = { prefix: prefix };
        return DirectSecp256k1HdWallet.fromMnemonic(mnemonic, signerOptions);
    }

@@ -239,7 +239,7 @@ export default class ValidatorClient {
        return this.client.getBalance(address, this.denom).catch((err) => this.handleRequestFailure(err));
    }

-    async getStateParams(): Promise<StateParams> {
+    async getStateParams(): Promise<ContractSettingsParams> {
        return this.client.getStateParams(this.contractAddress).catch((err) => this.handleRequestFailure(err))
    }

@@ -293,7 +293,7 @@ export default class ValidatorClient {
     */
    async bondMixnode(mixNode: MixNode, bond: Coin): Promise<ExecuteResult> {
        if (this.client instanceof NetClient) {
-            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, {bond_mixnode: {mix_node: mixNode}}, "adding mixnode", [bond]).catch((err) => this.handleRequestFailure(err));
+            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, { bond_mixnode: { mix_node: mixNode } }, "adding mixnode", [bond]).catch((err) => this.handleRequestFailure(err));
            console.log(`account ${this.client.clientAddress} added mixnode with ${mixNode.host}`);
            return result;
        } else {
@@ -307,7 +307,7 @@ export default class ValidatorClient {
     */
    async unbondMixnode(): Promise<ExecuteResult> {
        if (this.client instanceof NetClient) {
-            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, {unbond_mixnode: {}}).catch((err) => this.handleRequestFailure(err))
+            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, { unbond_mixnode: {} }).catch((err) => this.handleRequestFailure(err))
            console.log(`account ${this.client.clientAddress} unbonded mixnode`);
            return result;
        } else {
@@ -324,7 +324,7 @@ export default class ValidatorClient {
    // requires coin type to ensure correct denomination (
    async delegateToMixnode(mixIdentity: string, amount: Coin): Promise<ExecuteResult> {
        if (this.client instanceof NetClient) {
-            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, {delegate_to_mixnode: {mix_identity: mixIdentity}}, `delegating to ${mixIdentity}`, [amount]).catch((err) => this.handleRequestFailure(err))
+            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, { delegate_to_mixnode: { mix_identity: mixIdentity } }, `delegating to ${mixIdentity}`, [amount]).catch((err) => this.handleRequestFailure(err))
            console.log(`account ${this.client.clientAddress} delegated ${amount} to mixnode ${mixIdentity}`);
            return result;
        } else {
@@ -339,7 +339,7 @@ export default class ValidatorClient {
     */
    async removeMixnodeDelegation(mixIdentity: string): Promise<ExecuteResult> {
        if (this.client instanceof NetClient) {
-            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, {undelegate_from_mixnode: {mix_identity: mixIdentity}}).catch((err) => this.handleRequestFailure(err))
+            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, { undelegate_from_mixnode: { mix_identity: mixIdentity } }).catch((err) => this.handleRequestFailure(err))
            console.log(`account ${this.client.clientAddress} removed delegation from mixnode ${mixIdentity}`);
            return result;
        } else {
@@ -356,7 +356,7 @@ export default class ValidatorClient {
    // requires coin type to ensure correct denomination (
    async delegateToGateway(gatewayIdentity: string, amount: Coin): Promise<ExecuteResult> {
        if (this.client instanceof NetClient) {
-            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, {delegate_to_gateway: {gateway_identity: gatewayIdentity}}, `delegating to ${gatewayIdentity}`, [amount]).catch((err) => this.handleRequestFailure(err))
+            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, { delegate_to_gateway: { gateway_identity: gatewayIdentity } }, `delegating to ${gatewayIdentity}`, [amount]).catch((err) => this.handleRequestFailure(err))
            console.log(`account ${this.client.clientAddress} delegated ${amount} to gateway ${gatewayIdentity}`);
            return result;
        } else {
@@ -371,7 +371,7 @@ export default class ValidatorClient {
     */
    async removeGatewayDelegation(gatewayIdentity: string): Promise<ExecuteResult> {
        if (this.client instanceof NetClient) {
-            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, {undelegate_from_gateway: {gateway_identity: gatewayIdentity}}).catch((err) => this.handleRequestFailure(err))
+            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, { undelegate_from_gateway: { gateway_identity: gatewayIdentity } }).catch((err) => this.handleRequestFailure(err))
            console.log(`account ${this.client.clientAddress} removed delegation from gateway ${gatewayIdentity}`);
            return result;
        } else {
@@ -450,7 +450,7 @@ export default class ValidatorClient {
     */
    async bondGateway(gateway: Gateway, bond: Coin): Promise<ExecuteResult> {
        if (this.client instanceof NetClient) {
-            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, {bond_gateway: {gateway: gateway}}, "adding gateway", [bond]).catch((err) => this.handleRequestFailure(err));
+            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, { bond_gateway: { gateway: gateway } }, "adding gateway", [bond]).catch((err) => this.handleRequestFailure(err));
            console.log(`account ${this.client.clientAddress} added gateway with ${gateway.host}`);
            return result;
        } else {
@@ -463,7 +463,7 @@ export default class ValidatorClient {
     */
    async unbondGateway(): Promise<ExecuteResult> {
        if (this.client instanceof NetClient) {
-            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, {unbond_gateway: {}}).catch((err) => this.handleRequestFailure(err))
+            const result = await this.client.executeContract(this.client.clientAddress, this.contractAddress, { unbond_gateway: {} }).catch((err) => this.handleRequestFailure(err))
            console.log(`account ${this.client.clientAddress} unbonded gateway`);
            return result;
        } else {
@@ -471,9 +471,9 @@ export default class ValidatorClient {
        }
    }

-    async updateStateParams(newParams: StateParams): Promise<ExecuteResult> {
+    async updateStateParams(newParams: ContractSettingsParams): Promise<ExecuteResult> {
        if (this.client instanceof NetClient) {
-            return await this.client.executeContract(this.client.clientAddress, this.contractAddress, {update_state_params: newParams}, "updating contract state").catch((err) => this.handleRequestFailure(err));
+            return await this.client.executeContract(this.client.clientAddress, this.contractAddress, { update_contract_settings: newParams }, "updating contract settings").catch((err) => this.handleRequestFailure(err));
        } else {
            throw new Error("Tried to update state params with a query client")
        }
@@ -580,7 +580,7 @@ export default class ValidatorClient {

            // the function to calculate fee for a single entry is not exposed...
            console.log(`this.denom is ${this.denom}`);
-            const table = buildFeeTable(nymGasPrice(this.prefix), {sendMultiple: nymGasLimits.send * data.length}, {sendMultiple: nymGasLimits.send * data.length})
+            const table = buildFeeTable(nymGasPrice(this.prefix), { sendMultiple: nymGasLimits.send * data.length }, { sendMultiple: nymGasLimits.send * data.length })
            const fee = table.sendMultiple
            const result = await this.client.signAndBroadcast(senderAddress, encoded, fee, memo)
            if (isBroadcastTxFailure(result)) {
@@ -80,7 +80,7 @@ export default class NetClient implements INetClient {
    }

    public static async connect(wallet: DirectSecp256k1HdWallet, url: string, prefix: string): Promise<INetClient> {
-        const [{address}] = await wallet.getAccounts();
+        const [{ address }] = await wallet.getAccounts();
        const signerOptions: SigningCosmWasmClientOptions = {
            gasPrice: nymGasPrice(prefix),
            gasLimits: nymGasLimits,
@@ -95,17 +95,17 @@ export default class NetClient implements INetClient {

    public getMixNodes(contractAddress: string, limit: number, start_after?: string): Promise<PagedMixnodeResponse> {
        if (start_after == undefined) { // TODO: check if we can take this out, I'm not sure what will happen if we send an "undefined" so I'm playing it safe here.
-            return this.cosmClient.queryContractSmart(contractAddress, {get_mix_nodes: {limit}});
+            return this.cosmClient.queryContractSmart(contractAddress, { get_mix_nodes: { limit } });
        } else {
-            return this.cosmClient.queryContractSmart(contractAddress, {get_mix_nodes: {limit, start_after}});
+            return this.cosmClient.queryContractSmart(contractAddress, { get_mix_nodes: { limit, start_after } });
        }
    }

    public getGateways(contractAddress: string, limit: number, start_after?: string): Promise<PagedGatewayResponse> {
        if (start_after == undefined) { // TODO: check if we can take this out, I'm not sure what will happen if we send an "undefined" so I'm playing it safe here.
-            return this.cosmClient.queryContractSmart(contractAddress, {get_gateways: {limit}});
+            return this.cosmClient.queryContractSmart(contractAddress, { get_gateways: { limit } });
        } else {
-            return this.cosmClient.queryContractSmart(contractAddress, {get_gateways: {limit, start_after}});
+            return this.cosmClient.queryContractSmart(contractAddress, { get_gateways: { limit, start_after } });
        }
    }

@@ -166,11 +166,11 @@ export default class NetClient implements INetClient {
    }

    public ownsMixNode(contractAddress: string, address: string): Promise<MixOwnershipResponse> {
-        return this.cosmClient.queryContractSmart(contractAddress, {owns_mixnode: {address}});
+        return this.cosmClient.queryContractSmart(contractAddress, { owns_mixnode: { address } });
    }

    public ownsGateway(contractAddress: string, address: string): Promise<GatewayOwnershipResponse> {
-        return this.cosmClient.queryContractSmart(contractAddress, {owns_gateway: {address}});
+        return this.cosmClient.queryContractSmart(contractAddress, { owns_gateway: { address } });
    }

    public getBalance(address: string, denom: string): Promise<Coin | null> {
@@ -178,7 +178,7 @@ export default class NetClient implements INetClient {
    }

    public getStateParams(contractAddress: string): Promise<StateParams> {
-        return this.cosmClient.queryContractSmart(contractAddress, {state_params: {}});
+        return this.cosmClient.queryContractSmart(contractAddress, { contract_settings_params: {} });
    }

    public executeContract(senderAddress: string, contractAddress: string, handleMsg: Record<string, unknown>, memo?: string, transferAmount?: readonly Coin[]): Promise<ExecuteResult> {
@@ -6,7 +6,7 @@ import {
    MixOwnershipResponse, PagedGatewayDelegationsResponse,
    PagedGatewayResponse, PagedMixDelegationsResponse,
    PagedMixnodeResponse,
-    StateParams
+    ContractSettingsParams
 } from "./types";

 export interface IQueryClient {
@@ -28,7 +28,7 @@ export interface IQueryClient {

    ownsGateway(contractAddress: string, address: string): Promise<GatewayOwnershipResponse>;

-    getStateParams(contractAddress: string): Promise<StateParams>;
+    getStateParams(contractAddress: string): Promise<ContractSettingsParams>;

    changeValidator(newUrl: string): Promise<void>
 }
@@ -59,17 +59,17 @@ export default class QueryClient implements IQueryClient {

    public getMixNodes(contractAddress: string, limit: number, start_after?: string): Promise<PagedMixnodeResponse> {
        if (start_after == undefined) { // TODO: check if we can take this out, I'm not sure what will happen if we send an "undefined" so I'm playing it safe here.
-            return this.cosmClient.queryContractSmart(contractAddress, {get_mix_nodes: {limit}});
+            return this.cosmClient.queryContractSmart(contractAddress, { get_mix_nodes: { limit } });
        } else {
-            return this.cosmClient.queryContractSmart(contractAddress, {get_mix_nodes: {limit, start_after}});
+            return this.cosmClient.queryContractSmart(contractAddress, { get_mix_nodes: { limit, start_after } });
        }
    }

    public getGateways(contractAddress: string, limit: number, start_after?: string): Promise<PagedGatewayResponse> {
        if (start_after == undefined) { // TODO: check if we can take this out, I'm not sure what will happen if we send an "undefined" so I'm playing it safe here.
-            return this.cosmClient.queryContractSmart(contractAddress, {get_gateways: {limit}});
+            return this.cosmClient.queryContractSmart(contractAddress, { get_gateways: { limit } });
        } else {
-            return this.cosmClient.queryContractSmart(contractAddress, {get_gateways: {limit, start_after}});
+            return this.cosmClient.queryContractSmart(contractAddress, { get_gateways: { limit, start_after } });
        }
    }

@@ -130,18 +130,18 @@ export default class QueryClient implements IQueryClient {
    }

    public ownsMixNode(contractAddress: string, address: string): Promise<MixOwnershipResponse> {
-        return this.cosmClient.queryContractSmart(contractAddress, {owns_mixnode: {address}});
+        return this.cosmClient.queryContractSmart(contractAddress, { owns_mixnode: { address } });
    }

    public ownsGateway(contractAddress: string, address: string): Promise<GatewayOwnershipResponse> {
-        return this.cosmClient.queryContractSmart(contractAddress, {owns_gateway: {address}});
+        return this.cosmClient.queryContractSmart(contractAddress, { owns_gateway: { address } });
    }

    public getBalance(address: string, stakeDenom: string): Promise<Coin | null> {
        return this.cosmClient.getBalance(address, stakeDenom);
    }

-    public getStateParams(contractAddress: string): Promise<StateParams> {
-        return this.cosmClient.queryContractSmart(contractAddress, {state_params: {}});
+    public getStateParams(contractAddress: string): Promise<ContractSettingsParams> {
+        return this.cosmClient.queryContractSmart(contractAddress, { contract_settings_params: {} });
    }
 }
@@ -42,7 +42,7 @@ export type GatewayOwnershipResponse = {
    has_gateway: boolean,
 }

-export type StateParams = {
+export type ContractSettingsParams = {
    epoch_length: number,
    // ideally I'd want to define those as `number` rather than `string`, but
    // rust-side they are defined as Uint128 and Decimal that don't have
@@ -103,7 +103,7 @@ export type MixNode = {
 export type GatewayBond = {
    owner: string
    gateway: Gateway,
-    
+
    bond_amount: Coin,
    total_delegation: Coin,
 }
@@ -3,6 +3,7 @@

 use crypto::asymmetric::{encryption, identity};
 use futures::channel::mpsc;
+use gateway_client::bandwidth::BandwidthController;
 use gateway_client::GatewayClient;
 use nymsphinx::acknowledgements::AckKey;
 use nymsphinx::addressing::clients::Recipient;
@@ -17,11 +18,6 @@ use wasm_bindgen::prelude::*;
 use wasm_bindgen_futures::spawn_local;
 use wasm_utils::{console_log, console_warn};

-#[cfg(feature = "coconut")]
-use coconut_interface::Credential;
-#[cfg(feature = "coconut")]
-use credentials::{bandwidth::prepare_for_spending, obtain_aggregate_verification_key};
-
 pub(crate) mod received_processor;

 const DEFAULT_AVERAGE_PACKET_DELAY: Duration = Duration::from_millis(200);
@@ -103,35 +99,15 @@ impl NymClient {
        self.self_recipient().to_string()
    }

-    #[cfg(feature = "coconut")]
-    async fn prepare_coconut_credential(validators: &[Url], identity_bytes: &[u8]) -> Credential {
-        let verification_key = obtain_aggregate_verification_key(validators)
-            .await
-            .expect("could not obtain aggregate verification key of validators");
-
-        let bandwidth_credential =
-            credentials::bandwidth::obtain_signature(identity_bytes, validators)
-                .await
-                .expect("could not obtain bandwidth credential");
-        // the above would presumably be loaded from a file
-
-        // the below would only be executed once we know where we want to spend it (i.e. which gateway and stuff)
-        prepare_for_spending(identity_bytes, &bandwidth_credential, &verification_key)
-            .expect("could not prepare out bandwidth credential for spending")
-    }
-
    // Right now it's impossible to have async exported functions to take `&self` rather than self
    pub async fn initial_setup(self) -> Self {
        #[cfg(feature = "coconut")]
-        let coconut_credential = {
-            let validator_server = self.validator_server.clone();
-            let identity_public_key = self.identity.public_key().clone();
-            Self::prepare_coconut_credential(
-                &vec![validator_server],
-                &identity_public_key.to_bytes(),
-            )
-            .await
-        };
+        let bandwidth_controller = Some(BandwidthController::new(
+            vec![self.validator_server.clone()],
+            *self.identity.public_key(),
+        ));
+        #[cfg(not(feature = "coconut"))]
+        let bandwidth_controller = None;

        let mut client = self.get_and_update_topology().await;
        let gateway = client.choose_gateway();
@@ -147,13 +123,11 @@ impl NymClient {
            mixnet_messages_sender,
            ack_sender,
            DEFAULT_GATEWAY_RESPONSE_TIMEOUT,
+            bandwidth_controller,
        );

        gateway_client
-            .authenticate_and_start(
-                #[cfg(feature = "coconut")]
-                Some(coconut_credential),
-            )
+            .authenticate_and_start()
            .await
            .expect("could not authenticate and start up the gateway connection");

@@ -275,7 +249,7 @@ impl NymClient {
        let validator_client = validator_client::ApiClient::new(self.validator_server.clone());

        let mixnodes = match validator_client.get_cached_active_mixnodes().await {
-            Err(err) => panic!("{}", err),
+            Err(err) => panic!("{:?}", err),
            Ok(mixes) => mixes,
        };

@@ -10,14 +10,19 @@ edition = "2018"
 # TODO: (for this and other crates), similarly to 'tokio', import only required "futures" modules rather than
 # the entire crate
 futures = "0.3"
+json = "0.12.4"
 log = "0.4"
+thiserror = "1.0"
+url = "2.2"
 rand = { version = "0.7.3", features = ["wasm-bindgen"] }

 # internal
+credentials = { path = "../../credentials" }
 crypto = { path = "../../crypto" }
 gateway-requests = { path = "../../../gateway/gateway-requests" }
 nymsphinx = { path = "../../nymsphinx" }
 coconut-interface = { path = "../../coconut-interface", optional = true }
+network-defaults = { path = "../../network-defaults" }

 [dependencies.tungstenite]
 version = "0.13"
@@ -31,6 +36,12 @@ features = ["macros", "rt", "net", "sync", "time"]
 [target."cfg(not(target_arch = \"wasm32\"))".dependencies.tokio-tungstenite]
 version = "0.14"

+[target."cfg(not(target_arch = \"wasm32\"))".dependencies.secp256k1]
+version = "0.20.3"
+
+[target."cfg(not(target_arch = \"wasm32\"))".dependencies.web3]
+version = "0.17.0"
+
 # wasm-only dependencies
 [target."cfg(target_arch = \"wasm32\")".dependencies.wasm-bindgen]
 version = "0.2"
@@ -0,0 +1,247 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+#[cfg(feature = "coconut")]
+use credentials::coconut::{
+    bandwidth::{
+        obtain_signature, prepare_for_spending, BandwidthVoucherAttributes, TOTAL_ATTRIBUTES,
+    },
+    utils::obtain_aggregate_verification_key,
+};
+#[cfg(not(feature = "coconut"))]
+use credentials::token::bandwidth::TokenCredential;
+#[cfg(not(feature = "coconut"))]
+use crypto::asymmetric::identity;
+use crypto::asymmetric::identity::PublicKey;
+use network_defaults::BANDWIDTH_VALUE;
+#[cfg(not(feature = "coconut"))]
+use network_defaults::{
+    eth_contract::ETH_JSON_ABI, ETH_BURN_FUNCTION_NAME, ETH_CONTRACT_ADDRESS, ETH_MIN_BLOCK_DEPTH,
+    TOKENS_TO_BURN,
+};
+#[cfg(not(feature = "coconut"))]
+use rand::rngs::OsRng;
+#[cfg(not(feature = "coconut"))]
+use secp256k1::SecretKey;
+#[cfg(not(feature = "coconut"))]
+use std::io::Write;
+#[cfg(not(feature = "coconut"))]
+use std::str::FromStr;
+#[cfg(not(feature = "coconut"))]
+use web3::{
+    contract::{Contract, Options},
+    transports::Http,
+    types::{Address, Bytes, U256, U64},
+    Web3,
+};
+
+use crate::error::GatewayClientError;
+
+#[cfg(not(feature = "coconut"))]
+pub fn eth_contract(web3: Web3<Http>) -> Contract<Http> {
+    Contract::from_json(
+        web3.eth(),
+        Address::from(ETH_CONTRACT_ADDRESS),
+        json::parse(ETH_JSON_ABI)
+            .expect("Invalid json abi")
+            .dump()
+            .as_bytes(),
+    )
+    .expect("Invalid json abi")
+}
+
+#[derive(Clone)]
+pub struct BandwidthController {
+    #[cfg(feature = "coconut")]
+    validator_endpoints: Vec<url::Url>,
+    #[cfg(feature = "coconut")]
+    identity: PublicKey,
+    #[cfg(not(feature = "coconut"))]
+    contract: Contract<Http>,
+    #[cfg(not(feature = "coconut"))]
+    eth_private_key: SecretKey,
+    #[cfg(not(feature = "coconut"))]
+    backup_bandwidth_token_keys_dir: std::path::PathBuf,
+}
+
+impl BandwidthController {
+    #[cfg(feature = "coconut")]
+    pub fn new(validator_endpoints: Vec<url::Url>, identity: PublicKey) -> Self {
+        BandwidthController {
+            validator_endpoints,
+            identity,
+        }
+    }
+
+    #[cfg(not(feature = "coconut"))]
+    pub fn new(
+        eth_endpoint: String,
+        eth_private_key: String,
+        backup_bandwidth_token_keys_dir: std::path::PathBuf,
+    ) -> Result<Self, GatewayClientError> {
+        // Fail early, on invalid url
+        let transport =
+            Http::new(&eth_endpoint).map_err(|_| GatewayClientError::InvalidURL(eth_endpoint))?;
+        let web3 = web3::Web3::new(transport);
+        // Fail early, on invalid abi
+        let contract = eth_contract(web3);
+        let eth_private_key = secp256k1::SecretKey::from_str(&eth_private_key)
+            .map_err(|_| GatewayClientError::InvalidEthereumPrivateKey)?;
+
+        Ok(BandwidthController {
+            contract,
+            eth_private_key,
+            backup_bandwidth_token_keys_dir,
+        })
+    }
+
+    #[cfg(not(feature = "coconut"))]
+    fn backup_keypair(&self, keypair: &identity::KeyPair) -> Result<(), GatewayClientError> {
+        std::fs::create_dir_all(&self.backup_bandwidth_token_keys_dir)?;
+        let file_path = self
+            .backup_bandwidth_token_keys_dir
+            .join(keypair.public_key().to_base58_string());
+        let mut file = std::fs::File::create(file_path)?;
+        file.write_all(&keypair.private_key().to_bytes())?;
+
+        Ok(())
+    }
+
+    #[cfg(feature = "coconut")]
+    pub async fn prepare_coconut_credential(
+        &self,
+    ) -> Result<coconut_interface::Credential, GatewayClientError> {
+        let verification_key = obtain_aggregate_verification_key(&self.validator_endpoints).await?;
+        let params = coconut_interface::Parameters::new(TOTAL_ATTRIBUTES).unwrap();
+
+        // TODO: Decide what is the value and additional info associated with the bandwidth voucher
+        let bandwidth_credential_attributes = BandwidthVoucherAttributes {
+            serial_number: params.random_scalar(),
+            binding_number: params.random_scalar(),
+            voucher_value: coconut_interface::hash_to_scalar(BANDWIDTH_VALUE.to_be_bytes()),
+            voucher_info: coconut_interface::hash_to_scalar(
+                String::from("BandwidthVoucher").as_bytes(),
+            ),
+        };
+
+        let bandwidth_credential = obtain_signature(
+            &params,
+            &bandwidth_credential_attributes,
+            &self.validator_endpoints,
+        )
+        .await?;
+        // the above would presumably be loaded from a file
+
+        // the below would only be executed once we know where we want to spend it (i.e. which gateway and stuff)
+        Ok(prepare_for_spending(
+            &self.identity.to_bytes(),
+            &bandwidth_credential,
+            &bandwidth_credential_attributes,
+            &verification_key,
+        )?)
+    }
+
+    #[cfg(not(feature = "coconut"))]
+    pub async fn prepare_token_credential(
+        &self,
+        gateway_identity: PublicKey,
+    ) -> Result<TokenCredential, GatewayClientError> {
+        let mut rng = OsRng;
+
+        let kp = identity::KeyPair::new(&mut rng);
+        self.backup_keypair(&kp)?;
+
+        let verification_key = *kp.public_key();
+        let signed_verification_key = kp.private_key().sign(&verification_key.to_bytes());
+        self.buy_token_credential(verification_key, signed_verification_key)
+            .await?;
+
+        let message: Vec<u8> = verification_key
+            .to_bytes()
+            .iter()
+            .chain(gateway_identity.to_bytes().iter())
+            .copied()
+            .collect();
+        let signature = kp.private_key().sign(&message);
+
+        Ok(TokenCredential::new(
+            verification_key,
+            gateway_identity,
+            BANDWIDTH_VALUE,
+            signature,
+        ))
+    }
+
+    #[cfg(not(feature = "coconut"))]
+    pub async fn buy_token_credential(
+        &self,
+        verification_key: PublicKey,
+        signed_verification_key: identity::Signature,
+    ) -> Result<(), GatewayClientError> {
+        // 0 means a transaction failure, 1 means success
+        let confirmations = if cfg!(debug_assertions) {
+            1
+        } else {
+            ETH_MIN_BLOCK_DEPTH
+        };
+        // 15 seconds per confirmation block + 10 seconds of network overhead
+        log::info!(
+            "Waiting for Ethereum transaction. This should take about {} seconds",
+            confirmations * 15 + 10
+        );
+        let recipt = self
+            .contract
+            .signed_call_with_confirmations(
+                ETH_BURN_FUNCTION_NAME,
+                (
+                    U256::from(TOKENS_TO_BURN),
+                    U256::from(&verification_key.to_bytes()),
+                    Bytes(signed_verification_key.to_bytes().to_vec()),
+                ),
+                Options::default(),
+                confirmations,
+                &self.eth_private_key,
+            )
+            .await?;
+        if Some(U64::from(0)) == recipt.status {
+            Err(GatewayClientError::BurnTokenError(
+                web3::Error::InvalidResponse(format!(
+                    "Transaction status is 0 (failure): {:?}",
+                    recipt.logs,
+                )),
+            ))
+        } else {
+            log::info!(
+                "Bought bandwidth on Ethereum: {} MB",
+                BANDWIDTH_VALUE / 1024 / 1024
+            );
+            Ok(())
+        }
+    }
+}
+
+#[cfg(not(feature = "coconut"))]
+#[cfg(test)]
+mod tests {
+    use network_defaults::ETH_EVENT_NAME;
+
+    use super::*;
+
+    #[test]
+    fn parse_contract() {
+        let transport =
+            Http::new("https://rinkeby.infura.io/v3/00000000000000000000000000000000").unwrap();
+        let web3 = web3::Web3::new(transport);
+        // test no panic occurs
+        eth_contract(web3);
+    }
+
+    #[test]
+    fn check_event_name_constant_against_abi() {
+        let transport =
+            Http::new("https://rinkeby.infura.io/v3/00000000000000000000000000000000").unwrap();
+        let web3 = web3::Web3::new(transport);
+        let contract = eth_contract(web3);
+        assert!(contract.abi().event(ETH_EVENT_NAME).is_ok());
+    }
+}
@@ -1,6 +1,7 @@
 // Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0

+use crate::bandwidth::BandwidthController;
 use crate::cleanup_socket_message;
 use crate::error::GatewayClientError;
 use crate::packet_router::PacketRouter;
@@ -8,6 +9,10 @@ pub use crate::packet_router::{
    AcknowledgementReceiver, AcknowledgementSender, MixnetMessageReceiver, MixnetMessageSender,
 };
 use crate::socket_state::{PartiallyDelegated, SocketState};
+#[cfg(feature = "coconut")]
+use coconut_interface::Credential;
+#[cfg(not(feature = "coconut"))]
+use credentials::token::bandwidth::TokenCredential;
 use crypto::asymmetric::identity;
 use futures::{FutureExt, SinkExt, StreamExt};
 use gateway_requests::authentication::encrypted_address::EncryptedAddressBytes;
@@ -30,15 +35,11 @@ use fluvio_wasm_timer as wasm_timer;
 #[cfg(target_arch = "wasm32")]
 use wasm_utils::websocket::JSWebsocket;

-#[cfg(feature = "coconut")]
-use coconut_interface::Credential;
-
 const DEFAULT_RECONNECTION_ATTEMPTS: usize = 10;
 const DEFAULT_RECONNECTION_BACKOFF: Duration = Duration::from_secs(5);

 pub struct GatewayClient {
    authenticated: bool,
-    #[cfg(feature = "coconut")]
    bandwidth_remaining: i64,
    gateway_address: String,
    gateway_identity: identity::PublicKey,
@@ -47,6 +48,7 @@ pub struct GatewayClient {
    connection: SocketState,
    packet_router: PacketRouter,
    response_timeout_duration: Duration,
+    bandwidth_controller: Option<BandwidthController>,

    // reconnection related variables
    /// Specifies whether client should try to reconnect to gateway on connection failure.
@@ -69,20 +71,19 @@ impl GatewayClient {
        mixnet_message_sender: MixnetMessageSender,
        ack_sender: AcknowledgementSender,
        response_timeout_duration: Duration,
+        bandwidth_controller: Option<BandwidthController>,
    ) -> Self {
        GatewayClient {
            authenticated: false,
-
-            #[cfg(feature = "coconut")]
            bandwidth_remaining: 0,
            gateway_address,
-
            gateway_identity,
            local_identity,
            shared_key,
            connection: SocketState::NotConnected,
            packet_router: PacketRouter::new(ack_sender, mixnet_message_sender),
            response_timeout_duration,
+            bandwidth_controller,
            should_reconnect_on_failure: true,
            reconnection_attempts: DEFAULT_RECONNECTION_ATTEMPTS,
            reconnection_backoff: DEFAULT_RECONNECTION_BACKOFF,
@@ -118,10 +119,7 @@ impl GatewayClient {

        GatewayClient {
            authenticated: false,
-
-            #[cfg(feature = "coconut")]
            bandwidth_remaining: 0,
-
            gateway_address,
            gateway_identity,
            local_identity,
@@ -129,6 +127,7 @@ impl GatewayClient {
            connection: SocketState::NotConnected,
            packet_router,
            response_timeout_duration,
+            bandwidth_controller: None,
            should_reconnect_on_failure: false,
            reconnection_attempts: DEFAULT_RECONNECTION_ATTEMPTS,
            reconnection_backoff: DEFAULT_RECONNECTION_BACKOFF,
@@ -139,7 +138,6 @@ impl GatewayClient {
        self.gateway_identity
    }

-    #[cfg(feature = "coconut")]
    pub fn remaining_bandwidth(&self) -> i64 {
        self.bandwidth_remaining
    }
@@ -208,14 +206,7 @@ impl GatewayClient {

        for i in 1..self.reconnection_attempts {
            info!("attempt {}...", i);
-            if self
-                .authenticate_and_start(
-                    #[cfg(feature = "coconut")]
-                    None,
-                )
-                .await
-                .is_ok()
-            {
+            if self.authenticate_and_start().await.is_ok() {
                info!("managed to reconnect!");
                return Ok(());
            }
@@ -234,13 +225,7 @@ impl GatewayClient {

        // final attempt (done separately to be able to return a proper error)
        info!("attempt {}", self.reconnection_attempts);
-        match self
-            .authenticate_and_start(
-                #[cfg(feature = "coconut")]
-                None,
-            )
-            .await
-        {
+        match self.authenticate_and_start().await {
            Ok(_) => {
                info!("managed to reconnect!");
                Ok(())
@@ -451,8 +436,12 @@ impl GatewayClient {
            ClientControlRequest::new_authenticate(self_address, encrypted_address, iv).into();

        match self.send_websocket_message(msg).await? {
-            ServerResponse::Authenticate { status } => {
+            ServerResponse::Authenticate {
+                status,
+                bandwidth_remaining,
+            } => {
                self.authenticated = status;
+                self.bandwidth_remaining = bandwidth_remaining;
                Ok(())
            }
            ServerResponse::Error { message } => Err(GatewayClientError::GatewayError(message)),
@@ -478,22 +467,15 @@ impl GatewayClient {
    }

    #[cfg(feature = "coconut")]
-    pub async fn claim_coconut_bandwidth(
+    async fn claim_coconut_bandwidth(
        &mut self,
-        coconut_credential: Credential,
+        credential: Credential,
    ) -> Result<(), GatewayClientError> {
-        if !self.authenticated {
-            return Err(GatewayClientError::NotAuthenticated);
-        }
-        if self.shared_key.is_none() {
-            return Err(GatewayClientError::NoSharedKeyAvailable);
-        }
-
        let mut rng = OsRng;
        let iv = IV::new_random(&mut rng);

        let msg = ClientControlRequest::new_enc_coconut_bandwidth_credential(
-            &coconut_credential,
+            &credential,
            self.shared_key.as_ref().unwrap(),
            iv,
        )
@@ -507,7 +489,64 @@ impl GatewayClient {
        Ok(())
    }

-    #[cfg(feature = "coconut")]
+    #[cfg(not(feature = "coconut"))]
+    async fn claim_token_bandwidth(
+        &mut self,
+        credential: TokenCredential,
+    ) -> Result<(), GatewayClientError> {
+        let mut rng = OsRng;
+
+        let iv = IV::new_random(&mut rng);
+
+        let msg = ClientControlRequest::new_enc_token_bandwidth_credential(
+            &credential,
+            self.shared_key.as_ref().unwrap(),
+            iv,
+        )
+        .into();
+        self.bandwidth_remaining = match self.send_websocket_message(msg).await? {
+            ServerResponse::Bandwidth { available_total } => Ok(available_total),
+            ServerResponse::Error { message } => Err(GatewayClientError::GatewayError(message)),
+            _ => Err(GatewayClientError::UnexpectedResponse),
+        }?;
+
+        Ok(())
+    }
+
+    pub async fn claim_bandwidth(&mut self) -> Result<(), GatewayClientError> {
+        if !self.authenticated {
+            return Err(GatewayClientError::NotAuthenticated);
+        }
+        if self.shared_key.is_none() {
+            return Err(GatewayClientError::NoSharedKeyAvailable);
+        }
+        if self.bandwidth_controller.is_none() {
+            return Err(GatewayClientError::NoBandwidthControllerAvailable);
+        }
+
+        warn!("Not enough bandwidth. Trying to get more bandwidth, this might take a while");
+
+        #[cfg(feature = "coconut")]
+        let credential = self
+            .bandwidth_controller
+            .as_ref()
+            .unwrap()
+            .prepare_coconut_credential()
+            .await?;
+        #[cfg(not(feature = "coconut"))]
+        let credential = self
+            .bandwidth_controller
+            .as_ref()
+            .unwrap()
+            .prepare_token_credential(self.gateway_identity)
+            .await?;
+
+        #[cfg(feature = "coconut")]
+        return self.claim_coconut_bandwidth(credential).await;
+        #[cfg(not(feature = "coconut"))]
+        return self.claim_token_bandwidth(credential).await;
+    }
+
    fn estimate_required_bandwidth(&self, packets: &[MixPacket]) -> i64 {
        packets
            .iter()
@@ -522,9 +561,16 @@ impl GatewayClient {
        if !self.authenticated {
            return Err(GatewayClientError::NotAuthenticated);
        }
-        #[cfg(feature = "coconut")]
-        if self.estimate_required_bandwidth(&packets) < self.bandwidth_remaining {
-            return Err(GatewayClientError::NotEnoughBandwidth);
+        if self.estimate_required_bandwidth(&packets) > self.bandwidth_remaining {
+            // Try to claim more bandwidth first, and return an error only if that is still not
+            // enough (the current granularity for bandwidth should be sufficient)
+            self.claim_bandwidth().await?;
+            if self.estimate_required_bandwidth(&packets) > self.bandwidth_remaining {
+                return Err(GatewayClientError::NotEnoughBandwidth(
+                    self.estimate_required_bandwidth(&packets),
+                    self.bandwidth_remaining,
+                ));
+            }
        }
        if !self.connection.is_established() {
            return Err(GatewayClientError::ConnectionNotEstablished);
@@ -590,9 +636,16 @@ impl GatewayClient {
        if !self.authenticated {
            return Err(GatewayClientError::NotAuthenticated);
        }
-        #[cfg(feature = "coconut")]
        if (mix_packet.sphinx_packet().len() as i64) > self.bandwidth_remaining {
-            return Err(GatewayClientError::NotEnoughBandwidth);
+            // Try to claim more bandwidth first, and return an error only if that is still not
+            // enough
+            self.claim_bandwidth().await?;
+            if (mix_packet.sphinx_packet().len() as i64) > self.bandwidth_remaining {
+                return Err(GatewayClientError::NotEnoughBandwidth(
+                    mix_packet.sphinx_packet().len() as i64,
+                    self.bandwidth_remaining,
+                ));
+            }
        }
        if !self.connection.is_established() {
            return Err(GatewayClientError::ConnectionNotEstablished);
@@ -629,10 +682,6 @@ impl GatewayClient {
        if !self.authenticated {
            return Err(GatewayClientError::NotAuthenticated);
        }
-        #[cfg(feature = "coconut")]
-        if self.bandwidth_remaining <= 0 {
-            return Err(GatewayClientError::NotEnoughBandwidth);
-        }
        if self.connection.is_partially_delegated() {
            return Ok(());
        }
@@ -660,22 +709,12 @@ impl GatewayClient {
        Ok(())
    }

-    pub async fn authenticate_and_start(
-        &mut self,
-        #[cfg(feature = "coconut")] coconut_credential: Option<Credential>,
-    ) -> Result<Arc<SharedKeys>, GatewayClientError> {
+    pub async fn authenticate_and_start(&mut self) -> Result<Arc<SharedKeys>, GatewayClientError> {
        if !self.connection.is_established() {
            self.establish_connection().await?;
        }
        let shared_key = self.perform_initial_authentication().await?;

-        #[cfg(feature = "coconut")]
-        {
-            if let Some(coconut_credential) = coconut_credential {
-                self.claim_coconut_bandwidth(coconut_credential).await?;
-            }
-        }
-
        // this call is NON-blocking
        self.start_listening_for_mixnet_messages()?;

@@ -2,39 +2,83 @@
 // SPDX-License-Identifier: Apache-2.0

 use gateway_requests::registration::handshake::error::HandshakeError;
-use std::fmt::{self, Error, Formatter};
 use std::io;
+use thiserror::Error;
 use tungstenite::Error as WsError;
 #[cfg(target_arch = "wasm32")]
 use wasm_bindgen::JsValue;
+#[cfg(not(feature = "coconut"))]
+use web3::Error as Web3Error;

-#[derive(Debug)]
+#[derive(Debug, Error)]
 pub enum GatewayClientError {
+    #[error("Connection to the gateway is not established")]
    ConnectionNotEstablished,
+
+    #[error("Gateway returned an error response - {0}")]
    GatewayError(String),
-    NetworkError(WsError),
+
+    #[error("There was a network error - {0}")]
+    NetworkError(#[from] WsError),

    // TODO: see if `JsValue` is a reasonable type for this
    #[cfg(target_arch = "wasm32")]
+    #[error("There was a network error")]
    NetworkErrorWasm(JsValue),

-    NoSharedKeyAvailable,
-    ConnectionAbruptlyClosed,
-    MalformedResponse,
-    SerializeCredential,
-    NotAuthenticated,
-    NotEnoughBandwidth,
-    UnexpectedResponse,
-    ConnectionInInvalidState,
-    RegistrationFailure(HandshakeError),
-    AuthenticationFailure,
-    Timeout,
-}
+    #[cfg(not(feature = "coconut"))]
+    #[error("Could not backup keypair - {0}")]
+    IOError(#[from] std::io::Error),

-impl From<WsError> for GatewayClientError {
-    fn from(err: WsError) -> Self {
-        GatewayClientError::NetworkError(err)
-    }
+    #[cfg(not(feature = "coconut"))]
+    #[error("Could not burn ERC20 token in Ethereum smart contract - {0}")]
+    BurnTokenError(#[from] Web3Error),
+
+    #[cfg(not(feature = "coconut"))]
+    #[error("Invalid Ethereum private key")]
+    InvalidEthereumPrivateKey,
+
+    #[error("Invalid URL - {0}")]
+    InvalidURL(String),
+
+    #[error("No shared key was provided or obtained")]
+    NoSharedKeyAvailable,
+
+    #[error("No bandwidth controller provided")]
+    NoBandwidthControllerAvailable,
+
+    #[error("Credential error - {0}")]
+    CredentialError(#[from] credentials::error::Error),
+
+    #[error("Connection was abruptly closed")]
+    ConnectionAbruptlyClosed,
+
+    #[error("Received response was malformed")]
+    MalformedResponse,
+
+    #[error("Credential could not be serialized")]
+    SerializeCredential,
+
+    #[error("Client is not authenticated")]
+    NotAuthenticated,
+
+    #[error("Client does not have enough bandwidth: estimated {0}, remaining: {1}")]
+    NotEnoughBandwidth(i64, i64),
+
+    #[error("Received an unexpected response")]
+    UnexpectedResponse,
+
+    #[error("Connection is in an invalid state - please send a bug report")]
+    ConnectionInInvalidState,
+
+    #[error("Failed to finish registration handshake - {0}")]
+    RegistrationFailure(HandshakeError),
+
+    #[error("Authentication failure")]
+    AuthenticationFailure,
+
+    #[error("Timed out")]
+    Timeout,
 }

 impl GatewayClientError {
@@ -54,60 +98,3 @@ impl GatewayClientError {
        }
    }
 }
-
-#[cfg(target_arch = "wasm32")]
-impl From<JsValue> for GatewayClientError {
-    fn from(err: JsValue) -> Self {
-        GatewayClientError::NetworkErrorWasm(err)
-    }
-}
-
-// better human readable representation of the error, mostly so that GatewayClientError
-// would implement std::error::Error
-impl fmt::Display for GatewayClientError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
-        match self {
-            GatewayClientError::ConnectionNotEstablished => {
-                write!(f, "connection to the gateway is not established")
-            }
-            GatewayClientError::NoSharedKeyAvailable => {
-                write!(f, "no shared key was provided or obtained")
-            }
-            GatewayClientError::NotAuthenticated => write!(f, "client is not authenticated"),
-
-            GatewayClientError::NetworkError(err) => {
-                write!(f, "there was a network error - {}", err)
-            }
-            #[cfg(target_arch = "wasm32")]
-            GatewayClientError::NetworkErrorWasm(err) => {
-                write!(f, "there was a network error - {:?}", err)
-            }
-
-            GatewayClientError::ConnectionAbruptlyClosed => {
-                write!(f, "connection was abruptly closed")
-            }
-            GatewayClientError::Timeout => write!(f, "timed out"),
-            GatewayClientError::MalformedResponse => write!(f, "received response was malformed"),
-            GatewayClientError::ConnectionInInvalidState => write!(
-                f,
-                "connection is in an invalid state - please send a bug report"
-            ),
-            GatewayClientError::RegistrationFailure(handshake_err) => write!(
-                f,
-                "failed to finish registration handshake - {}",
-                handshake_err
-            ),
-            GatewayClientError::AuthenticationFailure => write!(f, "authentication failure"),
-            GatewayClientError::GatewayError(err) => {
-                write!(f, "gateway returned an error response - {}", err)
-            }
-            GatewayClientError::UnexpectedResponse => write!(f, "received an unexpected response"),
-            GatewayClientError::NotEnoughBandwidth => {
-                write!(f, "client does not have enough bandwidth")
-            }
-            GatewayClientError::SerializeCredential => {
-                write!(f, "credential could not be serialized")
-            }
-        }
-    }
-}
@@ -8,6 +8,7 @@ pub use packet_router::{
 };
 use tungstenite::{protocol::Message, Error as WsError};

+pub mod bandwidth;
 pub mod client;
 pub mod error;
 pub mod packet_router;
@@ -119,7 +119,7 @@ impl PartiallyDelegated {
            }
            .is_err()
            {
-                panic!("failed to send back `mixnet_receiver_future` result on the oneshot channel")
+                warn!("failed to send back `mixnet_receiver_future` result on the oneshot channel")
            }
        };

@@ -10,6 +10,7 @@ rust-version = "1.56"
 [dependencies]
 base64 = "0.13"
 mixnet-contract = { path="../../../common/mixnet-contract" }
+vesting-contract = { path="../../../contracts/vesting" }
 serde = { version="1", features=["derive"] }
 serde_json = "1"
 reqwest = { version="0.11", features=["json"] }
@@ -26,13 +27,14 @@ network-defaults = { path = "../../network-defaults" }
 async-trait = { version = "0.1.51", optional = true }
 bip39 = { version = "1", features = ["rand"], optional = true }
 config = { path = "../../config", optional = true }
-cosmrs = { version = "0.3", features = ["rpc", "bip32", "cosmwasm"], optional = true }
+#cosmrs = { version = "0.3", features = ["rpc", "bip32", "cosmwasm"], optional = true }
+cosmrs = { git = "https://github.com/cosmos/cosmos-rust", rev="e5a1872083abb3d88fa62dda966e7f5408deba58", features = ["rpc", "bip32", "cosmwasm"], optional = true }
 prost = { version = "0.9", default-features = false, optional = true }
 flate2 = { version = "1.0.20", optional = true }
 sha2 = { version = "0.9.5", optional = true }
 itertools = { version = "0.10", optional = true }
-cosmwasm-std = { git = "https://github.com/jstuczyn/cosmwasm", branch="0.14.1-updatedk256", optional = true }
-ts-rs = "3.0"
+cosmwasm-std = { version = "1.0.0-beta2", optional = true }
+ts-rs = {version = "5.1", optional = true}

 [features]
 nymd-client = ["async-trait", "bip39", "config", "cosmrs", "prost", "flate2", "sha2", "itertools", "cosmwasm-std"]
@@ -6,13 +6,18 @@ use crate::nymd::{
    error::NymdError, CosmWasmClient, NymdClient, QueryNymdClient, SigningNymdClient,
 };
 #[cfg(feature = "nymd-client")]
-use mixnet_contract::StateParams;
+use mixnet_contract::ContractStateParams;

 use crate::{validator_api, ValidatorClientError};
 use coconut_interface::{BlindSignRequestBody, BlindedSignatureResponse, VerificationKeyResponse};
 #[cfg(feature = "nymd-client")]
-use mixnet_contract::RawDelegationData;
+use mixnet_contract::{
+    Delegation, MixnetContractVersion, MixnodeRewardingStatusResponse, RewardingIntervalResponse,
+};
 use mixnet_contract::{GatewayBond, MixNodeBond};
+
+#[cfg(feature = "nymd-client")]
+use std::str::FromStr;
 use url::Url;

 #[cfg(feature = "nymd-client")]
@@ -20,6 +25,7 @@ pub struct Config {
    api_url: Url,
    nymd_url: Url,
    mixnet_contract_address: Option<cosmrs::AccountId>,
+    vesting_contract_address: Option<cosmrs::AccountId>,

    mixnode_page_limit: Option<u32>,
    gateway_page_limit: Option<u32>,
@@ -32,10 +38,12 @@ impl Config {
        nymd_url: Url,
        api_url: Url,
        mixnet_contract_address: Option<cosmrs::AccountId>,
+        vesting_contract_address: Option<cosmrs::AccountId>,
    ) -> Self {
        Config {
            nymd_url,
            mixnet_contract_address,
+            vesting_contract_address,
            api_url,
            mixnode_page_limit: None,
            gateway_page_limit: None,
@@ -62,6 +70,7 @@ impl Config {
 #[cfg(feature = "nymd-client")]
 pub struct Client<C> {
    mixnet_contract_address: Option<cosmrs::AccountId>,
+    vesting_contract_address: Option<cosmrs::AccountId>,
    mnemonic: Option<bip39::Mnemonic>,

    mixnode_page_limit: Option<u32>,
@@ -83,11 +92,14 @@ impl Client<SigningNymdClient> {
        let nymd_client = NymdClient::connect_with_mnemonic(
            config.nymd_url.as_str(),
            config.mixnet_contract_address.clone(),
+            config.vesting_contract_address.clone(),
            mnemonic.clone(),
+            None,
        )?;

        Ok(Client {
            mixnet_contract_address: config.mixnet_contract_address,
+            vesting_contract_address: config.vesting_contract_address,
            mnemonic: Some(mnemonic),
            mixnode_page_limit: config.mixnode_page_limit,
            gateway_page_limit: config.gateway_page_limit,
@@ -101,7 +113,9 @@ impl Client<SigningNymdClient> {
        self.nymd = NymdClient::connect_with_mnemonic(
            new_endpoint.as_ref(),
            self.mixnet_contract_address.clone(),
+            self.vesting_contract_address.clone(),
            self.mnemonic.clone().unwrap(),
+            None,
        )?;
        Ok(())
    }
@@ -113,16 +127,19 @@ impl Client<QueryNymdClient> {
        let validator_api_client = validator_api::Client::new(config.api_url.clone());
        let nymd_client = NymdClient::connect(
            config.nymd_url.as_str(),
-            config
-                .mixnet_contract_address
-                .clone()
-                .ok_or(ValidatorClientError::NymdError(
-                    NymdError::NoContractAddressAvailable,
-                ))?,
+            config.mixnet_contract_address.clone().unwrap_or_else(|| {
+                cosmrs::AccountId::from_str(network_defaults::DEFAULT_MIXNET_CONTRACT_ADDRESS)
+                    .unwrap()
+            }),
+            config.vesting_contract_address.clone().unwrap_or_else(|| {
+                cosmrs::AccountId::from_str(network_defaults::DEFAULT_VESTING_CONTRACT_ADDRESS)
+                    .unwrap()
+            }),
        )?;

        Ok(Client {
            mixnet_contract_address: config.mixnet_contract_address,
+            vesting_contract_address: config.vesting_contract_address,
            mnemonic: None,
            mixnode_page_limit: config.mixnode_page_limit,
            gateway_page_limit: config.gateway_page_limit,
@@ -136,6 +153,7 @@ impl Client<QueryNymdClient> {
        self.nymd = NymdClient::connect(
            new_endpoint.as_ref(),
            self.mixnet_contract_address.clone().unwrap(),
+            self.vesting_contract_address.clone().unwrap(),
        )?;
        Ok(())
    }
@@ -165,11 +183,69 @@ impl<C> Client<C> {
        Ok(self.validator_api.get_gateways().await?)
    }

-    pub async fn get_state_params(&self) -> Result<StateParams, ValidatorClientError>
+    pub async fn get_contract_settings(&self) -> Result<ContractStateParams, ValidatorClientError>
    where
        C: CosmWasmClient + Sync,
    {
-        Ok(self.nymd.get_state_params().await?)
+        Ok(self.nymd.get_contract_settings().await?)
+    }
+
+    pub async fn get_mixnet_contract_version(&self) -> Result<MixnetContractVersion, NymdError>
+    where
+        C: CosmWasmClient + Sync,
+    {
+        Ok(self.nymd.get_mixnet_contract_version().await?)
+    }
+
+    pub async fn get_current_rewarding_interval(
+        &self,
+    ) -> Result<RewardingIntervalResponse, ValidatorClientError>
+    where
+        C: CosmWasmClient + Sync,
+    {
+        Ok(self.nymd.get_current_rewarding_interval().await?)
+    }
+
+    pub async fn get_rewarding_status(
+        &self,
+        mix_identity: mixnet_contract::IdentityKey,
+        rewarding_interval_nonce: u32,
+    ) -> Result<MixnodeRewardingStatusResponse, ValidatorClientError>
+    where
+        C: CosmWasmClient + Sync,
+    {
+        Ok(self
+            .nymd
+            .get_rewarding_status(mix_identity, rewarding_interval_nonce)
+            .await?)
+    }
+
+    pub async fn get_reward_pool(&self) -> Result<u128, ValidatorClientError>
+    where
+        C: CosmWasmClient + Sync,
+    {
+        Ok(self.nymd.get_reward_pool().await?.u128())
+    }
+
+    pub async fn get_circulating_supply(&self) -> Result<u128, ValidatorClientError>
+    where
+        C: CosmWasmClient + Sync,
+    {
+        Ok(self.nymd.get_circulating_supply().await?.u128())
+    }
+
+    pub async fn get_sybil_resistance_percent(&self) -> Result<u8, ValidatorClientError>
+    where
+        C: CosmWasmClient + Sync,
+    {
+        Ok(self.nymd.get_sybil_resistance_percent().await?)
+    }
+
+    pub async fn get_epoch_reward_percent(&self) -> Result<u8, ValidatorClientError>
+    where
+        C: CosmWasmClient + Sync,
+    {
+        Ok(self.nymd.get_epoch_reward_percent().await?)
    }

    // basically handles paging for us
@@ -249,9 +325,7 @@ impl<C> Client<C> {
        Ok(delegations)
    }

-    pub async fn get_all_nymd_mixnode_delegations(
-        &self,
-    ) -> Result<Vec<mixnet_contract::UnpackedDelegation<RawDelegationData>>, ValidatorClientError>
+    pub async fn get_all_network_delegations(&self) -> Result<Vec<Delegation>, ValidatorClientError>
    where
        C: CosmWasmClient + Sync,
    {
@@ -260,7 +334,7 @@ impl<C> Client<C> {
        loop {
            let mut paged_response = self
                .nymd
-                .get_all_mix_delegations_paged(
+                .get_all_network_delegations_paged(
                    start_after.take(),
                    self.mixnode_delegations_page_limit,
                )
@@ -277,10 +351,10 @@ impl<C> Client<C> {
        Ok(delegations)
    }

-    pub async fn get_all_nymd_reverse_mixnode_delegations(
+    pub async fn get_all_delegator_delegations(
        &self,
        delegation_owner: &cosmrs::AccountId,
-    ) -> Result<Vec<mixnet_contract::IdentityKey>, ValidatorClientError>
+    ) -> Result<Vec<Delegation>, ValidatorClientError>
    where
        C: CosmWasmClient + Sync,
    {
@@ -289,13 +363,13 @@ impl<C> Client<C> {
        loop {
            let mut paged_response = self
                .nymd
-                .get_reverse_mix_delegations_paged(
-                    mixnet_contract::Addr::unchecked(delegation_owner.as_ref()),
+                .get_delegator_delegations_paged(
+                    delegation_owner.to_string(),
                    start_after.take(),
                    self.mixnode_delegations_page_limit,
                )
                .await?;
-            delegations.append(&mut paged_response.delegated_nodes);
+            delegations.append(&mut paged_response.delegations);

            if let Some(start_after_res) = paged_response.start_next_after {
                start_after = Some(start_after_res)
@@ -307,28 +381,6 @@ impl<C> Client<C> {
        Ok(delegations)
    }

-    pub async fn get_all_nymd_mixnode_delegations_of_owner(
-        &self,
-        delegation_owner: &cosmrs::AccountId,
-    ) -> Result<Vec<mixnet_contract::Delegation>, ValidatorClientError>
-    where
-        C: CosmWasmClient + Sync,
-    {
-        let mut delegations = Vec::new();
-        for node_identity in self
-            .get_all_nymd_reverse_mixnode_delegations(delegation_owner)
-            .await?
-        {
-            let delegation = self
-                .nymd
-                .get_mix_delegation(node_identity, delegation_owner)
-                .await?;
-            delegations.push(delegation);
-        }
-
-        Ok(delegations)
-    }
-
    pub async fn blind_sign(
        &self,
        request_body: &BlindSignRequestBody,
@@ -4,7 +4,7 @@
 use crate::nymd::cosmwasm_client::helpers::create_pagination;
 use crate::nymd::cosmwasm_client::types::{
    Account, Code, CodeDetails, Contract, ContractCodeHistoryEntry, ContractCodeId,
-    SequenceResponse,
+    SequenceResponse, SimulateResponse,
 };
 use crate::nymd::error::NymdError;
 use async_trait::async_trait;
@@ -14,15 +14,19 @@ use cosmrs::proto::cosmos::auth::v1beta1::{
 use cosmrs::proto::cosmos::bank::v1beta1::{
    QueryAllBalancesRequest, QueryAllBalancesResponse, QueryBalanceRequest, QueryBalanceResponse,
 };
-use cosmrs::proto::cosmwasm::wasm::v1beta1::*;
+use cosmrs::proto::cosmos::tx::v1beta1::{
+    SimulateRequest, SimulateResponse as ProtoSimulateResponse,
+};
+use cosmrs::proto::cosmwasm::wasm::v1::*;
 use cosmrs::rpc::endpoint::block::Response as BlockResponse;
 use cosmrs::rpc::endpoint::broadcast;
 use cosmrs::rpc::endpoint::tx::Response as TxResponse;
 use cosmrs::rpc::query::Query;
 use cosmrs::rpc::{self, HttpClient, Order};
+use cosmrs::tendermint::abci::Code as AbciCode;
 use cosmrs::tendermint::abci::Transaction;
 use cosmrs::tendermint::{abci, block, chain};
-use cosmrs::{tx, AccountId, Coin, Denom};
+use cosmrs::{tx, AccountId, Coin, Denom, Tx};
 use prost::Message;
 use serde::{Deserialize, Serialize};
 use std::convert::{TryFrom, TryInto};
@@ -49,6 +53,11 @@ pub trait CosmWasmClient: rpc::Client {

        let res = self.abci_query(path, buf, None, false).await?;

+        match res.code {
+            AbciCode::Err(code) => return Err(NymdError::AbciError(code, res.log)),
+            AbciCode::Ok => (),
+        }
+
        Ok(Res::decode(res.value.as_ref())?)
    }

@@ -213,7 +222,7 @@ pub trait CosmWasmClient: rpc::Client {
    }

    async fn get_codes(&self) -> Result<Vec<Code>, NymdError> {
-        let path = Some("/cosmwasm.wasm.v1beta1.Query/Codes".parse().unwrap());
+        let path = Some("/cosmwasm.wasm.v1.Query/Codes".parse().unwrap());

        let mut raw_codes = Vec::new();
        let mut pagination = None;
@@ -240,7 +249,7 @@ pub trait CosmWasmClient: rpc::Client {
    }

    async fn get_code_details(&self, code_id: ContractCodeId) -> Result<CodeDetails, NymdError> {
-        let path = Some("/cosmwasm.wasm.v1beta1.Query/Code".parse().unwrap());
+        let path = Some("/cosmwasm.wasm.v1.Query/Code".parse().unwrap());

        let req = QueryCodeRequest { code_id };

@@ -255,11 +264,7 @@ pub trait CosmWasmClient: rpc::Client {
        }
    }
    async fn get_contracts(&self, code_id: ContractCodeId) -> Result<Vec<AccountId>, NymdError> {
-        let path = Some(
-            "/cosmwasm.wasm.v1beta1.Query/ContractsByCode"
-                .parse()
-                .unwrap(),
-        );
+        let path = Some("/cosmwasm.wasm.v1.Query/ContractsByCode".parse().unwrap());

        let mut raw_contracts = Vec::new();
        let mut pagination = None;
@@ -290,7 +295,7 @@ pub trait CosmWasmClient: rpc::Client {
    }

    async fn get_contract(&self, address: &AccountId) -> Result<Contract, NymdError> {
-        let path = Some("/cosmwasm.wasm.v1beta1.Query/ContractInfo".parse().unwrap());
+        let path = Some("/cosmwasm.wasm.v1.Query/ContractInfo".parse().unwrap());

        let req = QueryContractInfoRequest {
            address: address.to_string(),
@@ -315,11 +320,7 @@ pub trait CosmWasmClient: rpc::Client {
        &self,
        address: &AccountId,
    ) -> Result<Vec<ContractCodeHistoryEntry>, NymdError> {
-        let path = Some(
-            "/cosmwasm.wasm.v1beta1.Query/ContractHistory"
-                .parse()
-                .unwrap(),
-        );
+        let path = Some("/cosmwasm.wasm.v1.Query/ContractHistory".parse().unwrap());

        let mut raw_entries = Vec::new();
        let mut pagination = None;
@@ -353,11 +354,7 @@ pub trait CosmWasmClient: rpc::Client {
        address: &AccountId,
        query_data: Vec<u8>,
    ) -> Result<Vec<u8>, NymdError> {
-        let path = Some(
-            "/cosmwasm.wasm.v1beta1.Query/RawContractState"
-                .parse()
-                .unwrap(),
-        );
+        let path = Some("/cosmwasm.wasm.v1.Query/RawContractState".parse().unwrap());

        let req = QueryRawContractStateRequest {
            address: address.to_string(),
@@ -381,7 +378,7 @@ pub trait CosmWasmClient: rpc::Client {
        for<'a> T: Deserialize<'a>,
    {
        let path = Some(
-            "/cosmwasm.wasm.v1beta1.Query/SmartContractState"
+            "/cosmwasm.wasm.v1.Query/SmartContractState"
                .parse()
                .unwrap(),
        );
@@ -400,4 +397,27 @@ pub trait CosmWasmClient: rpc::Client {

        Ok(serde_json::from_slice(&res.data)?)
    }
+
+    // deprecation warning is due to the fact the protobuf files built were based on cosmos-sdk 0.44,
+    // where they prefer using tx_bytes directly. However, in 0.42, which we are using at the time
+    // of writing this, the option does not work
+    #[allow(deprecated)]
+    async fn query_simulate(
+        &self,
+        tx: Option<Tx>,
+        tx_bytes: Vec<u8>,
+    ) -> Result<SimulateResponse, NymdError> {
+        let path = Some("/cosmos.tx.v1beta1.Service/Simulate".parse().unwrap());
+
+        let req = SimulateRequest {
+            tx: tx.map(Into::into),
+            tx_bytes,
+        };
+
+        let res = self
+            .make_abci_query::<_, ProtoSimulateResponse>(path, req)
+            .await?;
+
+        res.try_into()
+    }
 }
@@ -29,7 +29,7 @@ pub(crate) fn find_attribute<'a>(
 ) -> Option<&'a cosmwasm_std::Attribute> {
    logs.iter()
        .flat_map(|log| log.events.iter())
-        .find(|event| event.kind == event_type)?
+        .find(|event| event.ty == event_type)?
        .attributes
        .iter()
        .find(|attr| attr.key == attribute_key)
@@ -61,7 +61,7 @@ mod tests {
        assert_eq!(parsed.len(), 1);
        assert_eq!(parsed[0].msg_index, 0);
        assert_eq!(parsed[0].events.len(), 1);
-        assert_eq!(parsed[0].events[0].kind, "message");
+        assert_eq!(parsed[0].events[0].ty, "message");
        assert_eq!(parsed[0].events[0].attributes[3].key, "code_id");
        assert_eq!(parsed[0].events[0].attributes[3].value, "1");
    }
@@ -76,12 +76,12 @@ mod tests {
        assert_eq!(parsed[2].msg_index, 2);

        assert_eq!(parsed[0].events.len(), 1);
-        assert_eq!(parsed[0].events[0].kind, "message");
+        assert_eq!(parsed[0].events[0].ty, "message");
        assert_eq!(parsed[0].events[0].attributes[3].key, "code_id");
        assert_eq!(parsed[0].events[0].attributes[3].value, "9");

        assert_eq!(parsed[2].events.len(), 1);
-        assert_eq!(parsed[2].events[0].kind, "message");
+        assert_eq!(parsed[2].events[0].ty, "message");
        assert_eq!(parsed[2].events[0].attributes[2].key, "signer");
        assert_eq!(
            parsed[2].events[0].attributes[2].value,
@@ -3,6 +3,7 @@

 use crate::nymd::error::NymdError;
 use crate::nymd::wallet::DirectSecp256k1HdWallet;
+use crate::nymd::GasPrice;
 use cosmrs::rpc::{Error as TendermintRpcError, HttpClient, HttpClientUrl};
 use std::convert::TryInto;

@@ -23,9 +24,10 @@ where
 pub fn connect_with_signer<U>(
    endpoint: U,
    signer: DirectSecp256k1HdWallet,
+    gas_price: Option<GasPrice>,
 ) -> Result<signing_client::Client, NymdError>
 where
    U: TryInto<HttpClientUrl, Error = TendermintRpcError>,
 {
-    signing_client::Client::connect_with_signer(endpoint, signer)
+    signing_client::Client::connect_with_signer(endpoint, signer, gas_price)
 }
@@ -1,37 +1,100 @@
 // Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0

+use std::convert::TryInto;
+
+use async_trait::async_trait;
+use cosmrs::bank::MsgSend;
+use cosmrs::distribution::MsgWithdrawDelegatorReward;
+use cosmrs::proto::cosmos::tx::signing::v1beta1::SignMode;
+use cosmrs::rpc::endpoint::broadcast;
+use cosmrs::rpc::{Error as TendermintRpcError, HttpClient, HttpClientUrl, SimpleRequest};
+use cosmrs::staking::{MsgDelegate, MsgUndelegate};
+use cosmrs::tx::{self, Msg, SignDoc, SignerInfo};
+use cosmrs::{cosmwasm, rpc, AccountId, Any, Coin, Tx};
+use log::debug;
+use serde::Serialize;
+use sha2::Digest;
+use sha2::Sha256;
+
 use crate::nymd::cosmwasm_client::client::CosmWasmClient;
 use crate::nymd::cosmwasm_client::helpers::{compress_wasm_code, CheckResponse};
 use crate::nymd::cosmwasm_client::logs::{self, parse_raw_logs};
 use crate::nymd::cosmwasm_client::types::*;
 use crate::nymd::error::NymdError;
+use crate::nymd::fee::{Fee, DEFAULT_SIMULATED_GAS_MULTIPLIER};
 use crate::nymd::wallet::DirectSecp256k1HdWallet;
-use async_trait::async_trait;
-use cosmrs::bank::MsgSend;
-use cosmrs::distribution::MsgWithdrawDelegatorReward;
-use cosmrs::rpc::endpoint::broadcast;
-use cosmrs::rpc::{Error as TendermintRpcError, HttpClient, HttpClientUrl, SimpleRequest};
-use cosmrs::staking::{MsgDelegate, MsgUndelegate};
-use cosmrs::tx::{Fee, Msg, SignDoc, SignerInfo};
-use cosmrs::{cosmwasm, rpc, tx, AccountId, Any, Coin};
-use log::debug;
-use serde::Serialize;
-use sha2::Digest;
-use sha2::Sha256;
-use std::convert::TryInto;
+use crate::nymd::{CosmosCoin, GasPrice};
+
+// we need to have **a** valid secp256k1 signature for simulation purposes.
+// it doesn't matter what it is as long as it parses correctly
+const DUMMY_SECP256K1_SIGNATURE: &[u8] = &[
+    54, 167, 169, 61, 100, 173, 231, 87, 1, 113, 179, 49, 102, 141, 67, 22, 170, 153, 52, 88, 178,
+    159, 200, 11, 37, 138, 76, 221, 187, 70, 104, 123, 98, 216, 190, 249, 149, 81, 1, 158, 0, 220,
+    32, 147, 101, 60, 64, 77, 44, 83, 221, 119, 170, 124, 109, 177, 73, 116, 46, 57, 102, 181, 98,
+    91,
+];

 #[async_trait]
 pub trait SigningCosmWasmClient: CosmWasmClient {
    fn signer(&self) -> &DirectSecp256k1HdWallet;

+    fn gas_price(&self) -> &GasPrice;
+
+    fn signer_public_key(&self, signer_address: &AccountId) -> Option<tx::SignerPublicKey> {
+        let signer_accounts = self.signer().try_derive_accounts().ok()?;
+        let account_from_signer = signer_accounts
+            .iter()
+            .find(|account| &account.address == signer_address)?;
+        let public_key = account_from_signer.public_key;
+        Some(public_key.into())
+    }
+
+    async fn simulate(
+        &self,
+        signer_address: &AccountId,
+        messages: Vec<Any>,
+        memo: impl Into<String> + Send + 'static,
+    ) -> Result<SimulateResponse, NymdError> {
+        let public_key = self.signer_public_key(signer_address);
+        let sequence_response = self.get_sequence(signer_address).await?;
+
+        let partial_tx = Tx {
+            body: tx::Body {
+                messages,
+                memo: memo.into(),
+                timeout_height: 0u32.into(),
+                extension_options: vec![],
+                non_critical_extension_options: vec![],
+            },
+            auth_info: tx::AuthInfo {
+                signer_infos: vec![tx::SignerInfo {
+                    public_key,
+                    mode_info: tx::ModeInfo::Single(tx::mode_info::Single {
+                        mode: SignMode::Unspecified,
+                    }),
+                    sequence: sequence_response.sequence,
+                }],
+                fee: tx::Fee::from_amount_and_gas(
+                    CosmosCoin {
+                        denom: "".parse().unwrap(),
+                        amount: 0u64.into(),
+                    },
+                    0,
+                ),
+            },
+            signatures: vec![DUMMY_SECP256K1_SIGNATURE.try_into().unwrap()],
+        };
+
+        self.query_simulate(Some(partial_tx), Vec::new()).await
+    }
+
    async fn upload(
        &self,
        sender_address: &AccountId,
        wasm_code: Vec<u8>,
        fee: Fee,
        memo: impl Into<String> + Send + 'static,
-        mut meta: Option<UploadMeta>,
    ) -> Result<UploadResult, NymdError> {
        let compressed = compress_wasm_code(&wasm_code)?;
        let compressed_size = compressed.len();
@@ -42,14 +105,6 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
        let upload_msg = cosmwasm::MsgStoreCode {
            sender: sender_address.clone(),
            wasm_byte_code: compressed,
-            source: meta
-                .as_mut()
-                .map(|meta| meta.source.take())
-                .unwrap_or_default(),
-            builder: meta
-                .as_mut()
-                .map(|meta| meta.builder.take())
-                .unwrap_or_default(),
            instantiate_permission: Default::default(),
        }
        .to_any()
@@ -61,12 +116,13 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
            .check_response()?;

        let logs = parse_raw_logs(tx_res.deliver_tx.log)?;
+        let gas_info = GasInfo::new(tx_res.deliver_tx.gas_wanted, tx_res.deliver_tx.gas_used);

        // TODO: should those strings be extracted into some constants?
        // the reason I think unwrap here is fine is that if the transaction succeeded and those
        // fields do not exist or code_id is not a number, there's no way we can recover, we're probably connected
        // to wrong validator or something
-        let code_id = logs::find_attribute(&logs, "message", "code_id")
+        let code_id = logs::find_attribute(&logs, "store_code", "code_id")
            .unwrap()
            .value
            .parse()
@@ -80,6 +136,7 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
            code_id,
            logs,
            transaction_hash: tx_res.hash,
+            gas_info,
        })
    }

@@ -111,7 +168,7 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
            // now this is a weird one. the protobuf files say this field is optional,
            // but if you omit it, the initialisation will fail CheckTx
            label: Some(label),
-            init_msg: serde_json::to_vec(msg)?,
+            msg: serde_json::to_vec(msg)?,
            funds: options.map(|options| options.funds).unwrap_or_default(),
        }
        .to_any()
@@ -123,12 +180,13 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
            .check_response()?;

        let logs = parse_raw_logs(tx_res.deliver_tx.log)?;
+        let gas_info = GasInfo::new(tx_res.deliver_tx.gas_wanted, tx_res.deliver_tx.gas_used);

        // TODO: should those strings be extracted into some constants?
        // the reason I think unwrap here is fine is that if the transaction succeeded and those
        // fields do not exist or address is malformed, there's no way we can recover, we're probably connected
        // to wrong validator or something
-        let contract_address = logs::find_attribute(&logs, "message", "contract_address")
+        let contract_address = logs::find_attribute(&logs, "instantiate", "_contract_address")
            .unwrap()
            .value
            .parse()
@@ -138,6 +196,7 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
            contract_address,
            logs,
            transaction_hash: tx_res.hash,
+            gas_info,
        })
    }

@@ -162,9 +221,12 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
            .await?
            .check_response()?;

+        let gas_info = GasInfo::new(tx_res.deliver_tx.gas_wanted, tx_res.deliver_tx.gas_used);
+
        Ok(ChangeAdminResult {
            logs: parse_raw_logs(tx_res.deliver_tx.log)?,
            transaction_hash: tx_res.hash,
+            gas_info,
        })
    }

@@ -187,9 +249,12 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
            .await?
            .check_response()?;

+        let gas_info = GasInfo::new(tx_res.deliver_tx.gas_wanted, tx_res.deliver_tx.gas_used);
+
        Ok(ChangeAdminResult {
            logs: parse_raw_logs(tx_res.deliver_tx.log)?,
            transaction_hash: tx_res.hash,
+            gas_info,
        })
    }

@@ -209,7 +274,7 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
            sender: sender_address.clone(),
            contract: contract_address.clone(),
            code_id,
-            migrate_msg: serde_json::to_vec(msg)?,
+            msg: serde_json::to_vec(msg)?,
        }
        .to_any()
        .map_err(|_| NymdError::SerializationError("MsgMigrateContract".to_owned()))?;
@@ -219,9 +284,12 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
            .await?
            .check_response()?;

+        let gas_info = GasInfo::new(tx_res.deliver_tx.gas_wanted, tx_res.deliver_tx.gas_used);
+
        Ok(MigrateResult {
            logs: parse_raw_logs(tx_res.deliver_tx.log)?,
            transaction_hash: tx_res.hash,
+            gas_info,
        })
    }

@@ -251,9 +319,12 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
            .await?
            .check_response()?;

+        let gas_info = GasInfo::new(tx_res.deliver_tx.gas_wanted, tx_res.deliver_tx.gas_used);
+
        Ok(ExecuteResult {
            logs: parse_raw_logs(tx_res.deliver_tx.log)?,
            transaction_hash: tx_res.hash,
+            gas_info,
        })
    }

@@ -288,14 +359,12 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
            .await?
            .check_response()?;

-        debug!(
-            "gas wanted: {:?}, gas used: {:?}",
-            tx_res.deliver_tx.gas_wanted, tx_res.deliver_tx.gas_used
-        );
+        let gas_info = GasInfo::new(tx_res.deliver_tx.gas_wanted, tx_res.deliver_tx.gas_used);

        Ok(ExecuteResult {
            logs: parse_raw_logs(tx_res.deliver_tx.log)?,
            transaction_hash: tx_res.hash,
+            gas_info,
        })
    }

@@ -316,7 +385,36 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
        .map_err(|_| NymdError::SerializationError("MsgSend".to_owned()))?;

        self.sign_and_broadcast_commit(sender_address, vec![send_msg], fee, memo)
-            .await
+            .await?
+            .check_response()
+    }
+
+    async fn send_tokens_multiple<I>(
+        &self,
+        sender_address: &AccountId,
+        msgs: I,
+        fee: Fee,
+        memo: impl Into<String> + Send + 'static,
+    ) -> Result<broadcast::tx_commit::Response, NymdError>
+    where
+        I: IntoIterator<Item = (AccountId, Vec<Coin>)> + Send,
+    {
+        let messages = msgs
+            .into_iter()
+            .map(|(to_address, amount)| {
+                MsgSend {
+                    from_address: sender_address.clone(),
+                    to_address,
+                    amount,
+                }
+                .to_any()
+                .map_err(|_| NymdError::SerializationError("MsgExecuteContract".to_owned()))
+            })
+            .collect::<Result<_, _>>()?;
+
+        self.sign_and_broadcast_commit(sender_address, messages, fee, memo)
+            .await?
+            .check_response()
    }

    async fn delegate_tokens(
@@ -336,7 +434,8 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
        .map_err(|_| NymdError::SerializationError("MsgDelegate".to_owned()))?;

        self.sign_and_broadcast_commit(delegator_address, vec![delegate_msg], fee, memo)
-            .await
+            .await?
+            .check_response()
    }

    async fn undelegate_tokens(
@@ -356,7 +455,8 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
        .map_err(|_| NymdError::SerializationError("MsgUndelegate".to_owned()))?;

        self.sign_and_broadcast_commit(delegator_address, vec![undelegate_msg], fee, memo)
-            .await
+            .await?
+            .check_response()
    }

    async fn withdraw_rewards(
@@ -374,7 +474,45 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
        .map_err(|_| NymdError::SerializationError("MsgWithdrawDelegatorReward".to_owned()))?;

        self.sign_and_broadcast_commit(delegator_address, vec![withdraw_msg], fee, memo)
-            .await
+            .await?
+            .check_response()
+    }
+
+    // in this particular case we cannot generalise the argument to `&str` due to lifetime constraints
+    #[allow(clippy::ptr_arg)]
+    async fn determine_transaction_fee(
+        &self,
+        signer_address: &AccountId,
+        messages: &[Any],
+        fee: Fee,
+        memo: &String,
+    ) -> Result<tx::Fee, NymdError> {
+        let fee = match fee {
+            Fee::Manual(fee) => fee,
+            Fee::Auto(multiplier) => {
+                debug!("Trying to simulate gas costs...");
+                // from what I've seen in manual testing, gas estimation does not exist if transaction
+                // fails to get executed (for example if you send 'BondMixnode" with invalid signature)
+                let gas_estimation = self
+                    .simulate(signer_address, messages.to_vec(), memo.clone())
+                    .await?
+                    .gas_info
+                    .ok_or(NymdError::GasEstimationFailure)?
+                    .gas_used;
+
+                let multiplier = multiplier.unwrap_or(DEFAULT_SIMULATED_GAS_MULTIPLIER);
+                let gas = ((gas_estimation.value() as f32 * multiplier) as u64).into();
+
+                debug!("Gas estimation: {}", gas_estimation);
+                debug!("Multiplying the estimation by {}", multiplier);
+                debug!("Final gas limit used: {}", gas);
+
+                let fee = self.gas_price() * gas;
+                tx::Fee::from_amount_and_gas(fee, gas)
+            }
+        };
+        debug!("Fee used for the transaction: {:?}", fee);
+        Ok(fee)
    }

    /// Broadcast a transaction, returning immediately.
@@ -385,6 +523,10 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
        fee: Fee,
        memo: impl Into<String> + Send + 'static,
    ) -> Result<broadcast::tx_async::Response, NymdError> {
+        let memo = memo.into();
+        let fee = self
+            .determine_transaction_fee(signer_address, &messages, fee, &memo)
+            .await?;
        let tx_raw = self.sign(signer_address, messages, fee, memo).await?;
        let tx_bytes = tx_raw
            .to_bytes()
@@ -401,6 +543,10 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
        fee: Fee,
        memo: impl Into<String> + Send + 'static,
    ) -> Result<broadcast::tx_sync::Response, NymdError> {
+        let memo = memo.into();
+        let fee = self
+            .determine_transaction_fee(signer_address, &messages, fee, &memo)
+            .await?;
        let tx_raw = self.sign(signer_address, messages, fee, memo).await?;
        let tx_bytes = tx_raw
            .to_bytes()
@@ -417,6 +563,11 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
        fee: Fee,
        memo: impl Into<String> + Send + 'static,
    ) -> Result<broadcast::tx_commit::Response, NymdError> {
+        let memo = memo.into();
+        let fee = self
+            .determine_transaction_fee(signer_address, &messages, fee, &memo)
+            .await?;
+
        let tx_raw = self.sign(signer_address, messages, fee, memo).await?;
        let tx_bytes = tx_raw
            .to_bytes()
@@ -429,7 +580,7 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
        &self,
        signer_address: &AccountId,
        messages: Vec<Any>,
-        fee: Fee,
+        fee: tx::Fee,
        memo: impl Into<String> + Send + 'static,
        signer_data: SignerData,
    ) -> Result<tx::Raw, NymdError> {
@@ -467,7 +618,7 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
        &self,
        signer_address: &AccountId,
        messages: Vec<Any>,
-        fee: Fee,
+        fee: tx::Fee,
        memo: impl Into<String> + Send + 'static,
    ) -> Result<tx::Raw, NymdError> {
        // TODO: Future optimisation: rather than grabbing current account_number and sequence
@@ -485,22 +636,28 @@ pub trait SigningCosmWasmClient: CosmWasmClient {
    }
 }

-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct Client {
    rpc_client: HttpClient,
    signer: DirectSecp256k1HdWallet,
+    gas_price: GasPrice,
 }

 impl Client {
    pub fn connect_with_signer<U>(
        endpoint: U,
        signer: DirectSecp256k1HdWallet,
+        gas_price: Option<GasPrice>,
    ) -> Result<Self, NymdError>
    where
        U: TryInto<HttpClientUrl, Error = TendermintRpcError>,
    {
        let rpc_client = HttpClient::new(endpoint)?;
-        Ok(Client { rpc_client, signer })
+        Ok(Client {
+            rpc_client,
+            signer,
+            gas_price: gas_price.unwrap_or_default(),
+        })
    }
 }

@@ -522,4 +679,8 @@ impl SigningCosmWasmClient for Client {
    fn signer(&self) -> &DirectSecp256k1HdWallet {
        &self.signer
    }
+
+    fn gas_price(&self) -> &GasPrice {
+        &self.gas_price
+    }
 }
@@ -7,15 +7,19 @@ use crate::nymd::cosmwasm_client::logs::Log;
 use crate::nymd::error::NymdError;
 use cosmrs::crypto::PublicKey;
 use cosmrs::proto::cosmos::auth::v1beta1::BaseAccount;
-use cosmrs::proto::cosmwasm::wasm::v1beta1::{
+use cosmrs::proto::cosmos::base::abci::v1beta1::{
+    GasInfo as ProtoGasInfo, Result as ProtoAbciResult,
+};
+use cosmrs::proto::cosmos::tx::v1beta1::SimulateResponse as ProtoSimulateResponse;
+use cosmrs::proto::cosmwasm::wasm::v1::{
    CodeInfoResponse, ContractCodeHistoryEntry as ProtoContractCodeHistoryEntry,
    ContractCodeHistoryOperationType, ContractInfo as ProtoContractInfo,
 };
-use cosmrs::tendermint::chain;
-use cosmrs::tx::{AccountNumber, SequenceNumber};
+use cosmrs::tendermint::{abci, chain};
+use cosmrs::tx::{AccountNumber, Gas, SequenceNumber};
 use cosmrs::{tx, AccountId, Coin};
 use serde::Serialize;
-use std::convert::TryFrom;
+use std::convert::{TryFrom, TryInto};

 pub type ContractCodeId = u64;

@@ -70,18 +74,6 @@ pub struct Code {

    /// sha256 hash of the code stored
    pub data_hash: Vec<u8>,
-
-    /// An URL to a .tar.gz archive of the source code of the contract,
-    /// which can be used to reproducibly build the Wasm bytecode.
-    ///
-    /// @see https://github.com/CosmWasm/cosmwasm-verify
-    pub source: Option<String>,
-
-    /// A docker image (including version) to reproducibly build the Wasm bytecode from the source code.
-    ///
-    /// @example ```cosmwasm/rust-optimizer:0.8.0```
-    /// @see https://github.com/CosmWasm/cosmwasm-verify
-    pub builder: Option<String>,
 }

 impl TryFrom<CodeInfoResponse> for Code {
@@ -92,31 +84,16 @@ impl TryFrom<CodeInfoResponse> for Code {
            code_id,
            creator,
            data_hash,
-            source,
-            builder,
        } = value;

        let creator = creator
            .parse()
            .map_err(|_| NymdError::MalformedAccountAddress(creator))?;

-        let source = if source.is_empty() {
-            None
-        } else {
-            Some(source)
-        };
-        let builder = if builder.is_empty() {
-            None
-        } else {
-            Some(builder)
-        };
-
        Ok(Code {
            code_id,
            creator,
            data_hash,
-            source,
-            builder,
        })
    }
 }
@@ -242,6 +219,101 @@ impl TryFrom<ProtoContractCodeHistoryEntry> for ContractCodeHistoryEntry {
    }
 }

+#[derive(Debug)]
+pub struct GasInfo {
+    /// GasWanted is the maximum units of work we allow this tx to perform.
+    pub gas_wanted: Gas,
+
+    /// GasUsed is the amount of gas actually consumed.
+    pub gas_used: Gas,
+}
+
+impl From<ProtoGasInfo> for GasInfo {
+    fn from(value: ProtoGasInfo) -> Self {
+        GasInfo {
+            gas_wanted: value.gas_wanted.into(),
+            gas_used: value.gas_used.into(),
+        }
+    }
+}
+
+impl GasInfo {
+    pub fn new(gas_wanted: Gas, gas_used: Gas) -> Self {
+        GasInfo {
+            gas_wanted,
+            gas_used,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct AbciResult {
+    /// Data is any data returned from message or handler execution. It MUST be
+    /// length prefixed in order to separate data from multiple message executions.
+    pub data: Vec<u8>,
+
+    /// Log contains the log information from message or handler execution.
+    // todo: try to parse into Log?
+    pub log: String,
+
+    /// Events contains a slice of Event objects that were emitted during message
+    /// or handler execution.
+    pub events: Vec<abci::Event>,
+}
+
+impl TryFrom<ProtoAbciResult> for AbciResult {
+    type Error = NymdError;
+
+    fn try_from(value: ProtoAbciResult) -> Result<Self, Self::Error> {
+        let mut events = Vec::with_capacity(value.events.len());
+
+        for proto_event in value.events.into_iter() {
+            let type_str = proto_event.r#type;
+
+            let mut attributes = Vec::with_capacity(proto_event.attributes.len());
+            for proto_attribute in proto_event.attributes.into_iter() {
+                let stringified_ked = String::from_utf8(proto_attribute.key)
+                    .map_err(|_| NymdError::DeserializationError("EventAttributeKey".to_owned()))?;
+                let stringified_value = String::from_utf8(proto_attribute.value)
+                    .map_err(|_| NymdError::DeserializationError("EventAttributeKey".to_owned()))?;
+
+                attributes.push(abci::tag::Tag {
+                    key: stringified_ked.parse().unwrap(),
+                    value: stringified_value.parse().unwrap(),
+                })
+            }
+
+            events.push(abci::Event {
+                type_str,
+                attributes,
+            })
+        }
+
+        Ok(AbciResult {
+            data: value.data,
+            log: value.log,
+            events,
+        })
+    }
+}
+
+#[derive(Debug)]
+pub struct SimulateResponse {
+    pub gas_info: Option<GasInfo>,
+    pub result: Option<AbciResult>,
+}
+
+impl TryFrom<ProtoSimulateResponse> for SimulateResponse {
+    type Error = NymdError;
+
+    fn try_from(value: ProtoSimulateResponse) -> Result<Self, Self::Error> {
+        Ok(SimulateResponse {
+            gas_info: value.gas_info.map(|gas_info| gas_info.into()),
+            result: value.result.map(|result| result.try_into()).transpose()?,
+        })
+    }
+}
+
 // ##############################################################################
 // types specific to the signing client (perhaps they should go to separate file)
 // ##############################################################################
@@ -254,21 +326,6 @@ pub struct SignerData {
    pub chain_id: chain::Id,
 }

-#[derive(Debug)]
-pub struct UploadMeta {
-    /// An URL to a .tar.gz archive of the source code of the contract,
-    /// which can be used to reproducibly build the Wasm bytecode.
-    ///
-    /// @see https://github.com/CosmWasm/cosmwasm-verify
-    pub source: Option<String>,
-
-    /// A docker image (including version) to reproducibly build the Wasm bytecode from the source code.
-    ///
-    /// @example ```cosmwasm/rust-optimizer:0.8.0```
-    /// @see https://github.com/CosmWasm/cosmwasm-verify
-    pub builder: Option<String>,
-}
-
 #[derive(Debug)]
 pub struct UploadResult {
    /// Size of the original wasm code in bytes
@@ -290,6 +347,8 @@ pub struct UploadResult {

    /// Transaction hash (might be used as transaction ID)
    pub transaction_hash: tx::Hash,
+
+    pub gas_info: GasInfo,
 }

 #[derive(Debug)]
@@ -316,6 +375,8 @@ pub struct InstantiateResult {

    /// Transaction hash (might be used as transaction ID)
    pub transaction_hash: tx::Hash,
+
+    pub gas_info: GasInfo,
 }

 #[derive(Debug)]
@@ -324,6 +385,8 @@ pub struct ChangeAdminResult {

    /// Transaction hash (might be used as transaction ID)
    pub transaction_hash: tx::Hash,
+
+    pub gas_info: GasInfo,
 }

 #[derive(Debug)]
@@ -332,6 +395,8 @@ pub struct MigrateResult {

    /// Transaction hash (might be used as transaction ID)
    pub transaction_hash: tx::Hash,
+
+    pub gas_info: GasInfo,
 }

 #[derive(Debug)]
@@ -340,4 +405,6 @@ pub struct ExecuteResult {

    /// Transaction hash (might be used as transaction ID)
    pub transaction_hash: tx::Hash,
+
+    pub gas_info: GasInfo,
 }
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0

 use crate::nymd::cosmwasm_client::types::ContractCodeId;
-use cosmrs::tendermint::block;
+use cosmrs::tendermint::{abci, block};
 use cosmrs::{bip32, tx, AccountId};
 use std::io;
 use thiserror::Error;
@@ -102,6 +102,12 @@ pub enum NymdError {

    #[error("The provided gas price is malformed")]
    MalformedGasPrice,
+
+    #[error("Failed to estimate gas price for the transaction")]
+    GasEstimationFailure,
+
+    #[error("Abci query failed with code {0} - {1}")]
+    AbciError(u32, abci::Log),
 }

 impl NymdError {
@@ -38,7 +38,7 @@ impl<'a> Mul<Gas> for &'a GasPrice {
        // however, realistically that is impossible to happen as the resultant value
        // would have to be way higher than our token limit of 10^15 (1 billion of tokens * 1 million for denomination)
        // and max value of u128 is approximately 10^38
-        if limit_uint128.u128() * gas_price_numerator > amount.u128() * gas_price_denominator {
+        if limit_uint128 * gas_price_numerator > amount * gas_price_denominator {
            amount += Uint128::new(1);
        }

@@ -6,9 +6,9 @@ use cosmrs::tx::{Fee, Gas};
 use cosmrs::Coin;
 use serde::{Deserialize, Serialize};
 use std::fmt;
-use ts_rs::TS;

-#[derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Hash, Serialize, Deserialize, TS)]
+#[cfg_attr(feature = "ts-rs", derive(ts_rs::TS))]
+#[derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Hash, Serialize, Deserialize)]
 pub enum Operation {
    Upload,
    Init,
@@ -17,16 +17,29 @@ pub enum Operation {
    Send,

    BondMixnode,
+    BondMixnodeOnBehalf,
    UnbondMixnode,
+    UnbondMixnodeOnBehalf,
    DelegateToMixnode,
+    DelegateToMixnodeOnBehalf,
    UndelegateFromMixnode,
+    UndelegateFromMixnodeOnBehalf,

    BondGateway,
+    BondGatewayOnBehalf,
    UnbondGateway,
-    DelegateToGateway,
-    UndelegateFromGateway,
+    UnbondGatewayOnBehalf,

-    UpdateStateParams,
+    UpdateContractSettings,
+
+    BeginMixnodeRewarding,
+    FinishMixnodeRewarding,
+
+    TrackUnbondGateway,
+    TrackUnbondMixnode,
+    WithdrawVestedCoins,
+    TrackUndelegation,
+    CreatePeriodicVestingAccount,
 }

 pub(crate) fn calculate_fee(gas_price: &GasPrice, gas_limit: Gas) -> Coin {
@@ -42,14 +55,27 @@ impl fmt::Display for Operation {
            Operation::ChangeAdmin => f.write_str("ChangeAdmin"),
            Operation::Send => f.write_str("Send"),
            Operation::BondMixnode => f.write_str("BondMixnode"),
+            Operation::BondMixnodeOnBehalf => f.write_str("BondMixnodeOnBehalf"),
            Operation::UnbondMixnode => f.write_str("UnbondMixnode"),
-            Operation::DelegateToMixnode => f.write_str("DelegateToMixnode"),
-            Operation::UndelegateFromMixnode => f.write_str("UndelegateFromMixnode"),
+            Operation::UnbondMixnodeOnBehalf => f.write_str("UnbondMixnodeOnBehalf"),
            Operation::BondGateway => f.write_str("BondGateway"),
+            Operation::BondGatewayOnBehalf => f.write_str("BondGatewayOnBehalf"),
            Operation::UnbondGateway => f.write_str("UnbondGateway"),
-            Operation::DelegateToGateway => f.write_str("DelegateToGateway"),
-            Operation::UndelegateFromGateway => f.write_str("UndelegateFromGateway"),
-            Operation::UpdateStateParams => f.write_str("UpdateStateParams"),
+            Operation::UnbondGatewayOnBehalf => f.write_str("UnbondGatewayOnBehalf"),
+            Operation::DelegateToMixnode => f.write_str("DelegateToMixnode"),
+            Operation::DelegateToMixnodeOnBehalf => f.write_str("DelegateToMixnodeOnBehalf"),
+            Operation::UndelegateFromMixnode => f.write_str("UndelegateFromMixnode"),
+            Operation::UndelegateFromMixnodeOnBehalf => {
+                f.write_str("UndelegateFromMixnodeOnBehalf")
+            }
+            Operation::UpdateContractSettings => f.write_str("UpdateContractSettings"),
+            Operation::BeginMixnodeRewarding => f.write_str("BeginMixnodeRewarding"),
+            Operation::FinishMixnodeRewarding => f.write_str("FinishMixnodeRewarding"),
+            Operation::TrackUnbondGateway => f.write_str("TrackUnbondGateway"),
+            Operation::TrackUnbondMixnode => f.write_str("TrackUnbondMixnode"),
+            Operation::WithdrawVestedCoins => f.write_str("WithdrawVestedCoins"),
+            Operation::TrackUndelegation => f.write_str("TrackUndelegation"),
+            Operation::CreatePeriodicVestingAccount => f.write_str("CreatePeriodicVestingAccount"),
        }
    }
 }
@@ -58,23 +84,34 @@ impl Operation {
    // TODO: some value tweaking
    pub fn default_gas_limit(&self) -> Gas {
        match self {
-            Operation::Upload => 2_500_000u64.into(),
+            Operation::Upload => 3_000_000u64.into(),
            Operation::Init => 500_000u64.into(),
            Operation::Migrate => 200_000u64.into(),
            Operation::ChangeAdmin => 80_000u64.into(),
            Operation::Send => 80_000u64.into(),

            Operation::BondMixnode => 175_000u64.into(),
+            Operation::BondMixnodeOnBehalf => 200_000u64.into(),
            Operation::UnbondMixnode => 175_000u64.into(),
+            Operation::UnbondMixnodeOnBehalf => 175_000u64.into(),
            Operation::DelegateToMixnode => 175_000u64.into(),
+            Operation::DelegateToMixnodeOnBehalf => 175_000u64.into(),
            Operation::UndelegateFromMixnode => 175_000u64.into(),
+            Operation::UndelegateFromMixnodeOnBehalf => 175_000u64.into(),

            Operation::BondGateway => 175_000u64.into(),
+            Operation::BondGatewayOnBehalf => 200_000u64.into(),
            Operation::UnbondGateway => 175_000u64.into(),
-            Operation::DelegateToGateway => 175_000u64.into(),
-            Operation::UndelegateFromGateway => 175_000u64.into(),
+            Operation::UnbondGatewayOnBehalf => 200_000u64.into(),

-            Operation::UpdateStateParams => 175_000u64.into(),
+            Operation::UpdateContractSettings => 175_000u64.into(),
+            Operation::BeginMixnodeRewarding => 175_000u64.into(),
+            Operation::FinishMixnodeRewarding => 175_000u64.into(),
+            Operation::TrackUnbondGateway => 175_000u64.into(),
+            Operation::TrackUnbondMixnode => 175_000u64.into(),
+            Operation::WithdrawVestedCoins => 175_000u64.into(),
+            Operation::TrackUndelegation => 175_000u64.into(),
+            Operation::CreatePeriodicVestingAccount => 175_000u64.into(),
        }
    }

@@ -88,9 +125,8 @@ impl Operation {
        Fee::from_amount_and_gas(fee, gas_limit)
    }

-    pub(crate) fn determine_fee(&self, gas_price: &GasPrice, gas_limit: Option<Gas>) -> Fee {
-        let gas_limit = gas_limit.unwrap_or_else(|| self.default_gas_limit());
-        Self::determine_custom_fee(gas_price, gas_limit)
+    pub fn default_fee(&self, gas_price: &GasPrice) -> Fee {
+        Self::determine_custom_fee(gas_price, self.default_gas_limit())
    }
 }

@@ -0,0 +1,33 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+use cosmrs::tx;
+
+pub mod gas_price;
+pub mod helpers;
+
+pub const DEFAULT_SIMULATED_GAS_MULTIPLIER: f32 = 1.3;
+
+#[derive(Debug, Clone)]
+pub enum Fee {
+    Manual(tx::Fee),
+    Auto(Option<f32>),
+}
+
+impl From<tx::Fee> for Fee {
+    fn from(fee: tx::Fee) -> Self {
+        Fee::Manual(fee)
+    }
+}
+
+impl From<f32> for Fee {
+    fn from(multiplier: f32) -> Self {
+        Fee::Auto(Some(multiplier))
+    }
+}
+
+impl Default for Fee {
+    fn default() -> Self {
+        Fee::Auto(Some(DEFAULT_SIMULATED_GAS_MULTIPLIER))
+    }
+}
@@ -0,0 +1,8 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+mod vesting_query_client;
+mod vesting_signing_client;
+
+pub use vesting_query_client::VestingQueryClient;
+pub use vesting_signing_client::VestingSigningClient;
@@ -0,0 +1,176 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+pub use crate::nymd::cosmwasm_client::client::CosmWasmClient;
+use crate::nymd::error::NymdError;
+use crate::nymd::NymdClient;
+use async_trait::async_trait;
+use cosmwasm_std::{Coin, Timestamp};
+use vesting_contract::messages::QueryMsg as VestingQueryMsg;
+
+#[async_trait]
+pub trait VestingQueryClient {
+    async fn locked_coins(
+        &self,
+        address: &str,
+        block_time: Option<Timestamp>,
+    ) -> Result<Coin, NymdError>;
+
+    async fn spendable_coins(
+        &self,
+        vesting_account_address: &str,
+        block_time: Option<Timestamp>,
+    ) -> Result<Coin, NymdError>;
+
+    async fn vested_coins(
+        &self,
+        vesting_account_address: &str,
+        block_time: Option<Timestamp>,
+    ) -> Result<Coin, NymdError>;
+
+    async fn vesting_coins(
+        &self,
+        vesting_account_address: &str,
+        block_time: Option<Timestamp>,
+    ) -> Result<Coin, NymdError>;
+
+    async fn vesting_start_time(
+        &self,
+        vesting_account_address: &str,
+    ) -> Result<Timestamp, NymdError>;
+
+    async fn vesting_end_time(&self, vesting_account_address: &str)
+        -> Result<Timestamp, NymdError>;
+
+    async fn original_vesting(&self, vesting_account_address: &str) -> Result<Coin, NymdError>;
+
+    async fn delegated_free(
+        &self,
+        vesting_account_address: &str,
+        block_time: Option<Timestamp>,
+    ) -> Result<Coin, NymdError>;
+
+    async fn delegated_vesting(
+        &self,
+        vesting_account_address: &str,
+        block_time: Option<Timestamp>,
+    ) -> Result<Coin, NymdError>;
+}
+
+#[async_trait]
+impl<C: CosmWasmClient + Sync + Send> VestingQueryClient for NymdClient<C> {
+    async fn locked_coins(
+        &self,
+        vesting_account_address: &str,
+        block_time: Option<Timestamp>,
+    ) -> Result<Coin, NymdError> {
+        let request = VestingQueryMsg::LockedCoins {
+            vesting_account_address: vesting_account_address.to_string(),
+            block_time,
+        };
+        self.client
+            .query_contract_smart(self.vesting_contract_address()?, &request)
+            .await
+    }
+
+    async fn spendable_coins(
+        &self,
+        vesting_account_address: &str,
+        block_time: Option<Timestamp>,
+    ) -> Result<Coin, NymdError> {
+        let request = VestingQueryMsg::SpendableCoins {
+            vesting_account_address: vesting_account_address.to_string(),
+            block_time,
+        };
+        self.client
+            .query_contract_smart(self.vesting_contract_address()?, &request)
+            .await
+    }
+    async fn vested_coins(
+        &self,
+        vesting_account_address: &str,
+        block_time: Option<Timestamp>,
+    ) -> Result<Coin, NymdError> {
+        let request = VestingQueryMsg::GetVestedCoins {
+            vesting_account_address: vesting_account_address.to_string(),
+            block_time,
+        };
+        self.client
+            .query_contract_smart(self.vesting_contract_address()?, &request)
+            .await
+    }
+    async fn vesting_coins(
+        &self,
+        vesting_account_address: &str,
+        block_time: Option<Timestamp>,
+    ) -> Result<Coin, NymdError> {
+        let request = VestingQueryMsg::GetVestingCoins {
+            vesting_account_address: vesting_account_address.to_string(),
+            block_time,
+        };
+        self.client
+            .query_contract_smart(self.vesting_contract_address()?, &request)
+            .await
+    }
+
+    async fn vesting_start_time(
+        &self,
+        vesting_account_address: &str,
+    ) -> Result<Timestamp, NymdError> {
+        let request = VestingQueryMsg::GetStartTime {
+            vesting_account_address: vesting_account_address.to_string(),
+        };
+        self.client
+            .query_contract_smart(self.vesting_contract_address()?, &request)
+            .await
+    }
+
+    async fn vesting_end_time(
+        &self,
+        vesting_account_address: &str,
+    ) -> Result<Timestamp, NymdError> {
+        let request = VestingQueryMsg::GetEndTime {
+            vesting_account_address: vesting_account_address.to_string(),
+        };
+        self.client
+            .query_contract_smart(self.vesting_contract_address()?, &request)
+            .await
+    }
+
+    async fn original_vesting(&self, vesting_account_address: &str) -> Result<Coin, NymdError> {
+        let request = VestingQueryMsg::GetOriginalVesting {
+            vesting_account_address: vesting_account_address.to_string(),
+        };
+        self.client
+            .query_contract_smart(self.vesting_contract_address()?, &request)
+            .await
+    }
+
+    async fn delegated_free(
+        &self,
+        vesting_account_address: &str,
+        block_time: Option<Timestamp>,
+    ) -> Result<Coin, NymdError> {
+        let request = VestingQueryMsg::GetDelegatedFree {
+            vesting_account_address: vesting_account_address.to_string(),
+            block_time,
+        };
+        self.client
+            .query_contract_smart(self.vesting_contract_address()?, &request)
+            .await
+    }
+
+    async fn delegated_vesting(
+        &self,
+        vesting_account_address: &str,
+        block_time: Option<Timestamp>,
+    ) -> Result<Coin, NymdError> {
+        let request = VestingQueryMsg::GetDelegatedVesting {
+            vesting_account_address: vesting_account_address.to_string(),
+            block_time,
+        };
+        self.client
+            .query_contract_smart(self.vesting_contract_address()?, &request)
+            .await
+    }
+}
@@ -0,0 +1,294 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+pub use crate::nymd::cosmwasm_client::signing_client::SigningCosmWasmClient;
+use crate::nymd::cosmwasm_client::types::ExecuteResult;
+use crate::nymd::error::NymdError;
+use crate::nymd::fee::helpers::Operation;
+use crate::nymd::{cosmwasm_coin_to_cosmos_coin, NymdClient};
+use async_trait::async_trait;
+use cosmwasm_std::Coin;
+use mixnet_contract::{Gateway, IdentityKey, IdentityKeyRef, MixNode};
+use vesting_contract::messages::ExecuteMsg as VestingExecuteMsg;
+
+#[async_trait]
+pub trait VestingSigningClient {
+    async fn vesting_bond_gateway(
+        &self,
+        gateway: Gateway,
+        owner_signature: &str,
+        pledge: Coin,
+    ) -> Result<ExecuteResult, NymdError>;
+
+    async fn vesting_unbond_gateway(&self) -> Result<ExecuteResult, NymdError>;
+
+    async fn vesting_track_unbond_gateway(
+        &self,
+        owner: &str,
+        amount: Coin,
+    ) -> Result<ExecuteResult, NymdError>;
+
+    async fn vesting_bond_mixnode(
+        &self,
+        mix_node: MixNode,
+        owner_signature: &str,
+        pledge: Coin,
+    ) -> Result<ExecuteResult, NymdError>;
+    async fn vesting_unbond_mixnode(&self) -> Result<ExecuteResult, NymdError>;
+
+    async fn vesting_track_unbond_mixnode(
+        &self,
+        owner: &str,
+        amount: Coin,
+    ) -> Result<ExecuteResult, NymdError>;
+
+    async fn withdraw_vested_coins(&self, amount: Coin) -> Result<ExecuteResult, NymdError>;
+
+    async fn vesting_track_undelegation(
+        &self,
+        address: &str,
+        mix_identity: IdentityKey,
+        amount: Coin,
+    ) -> Result<ExecuteResult, NymdError>;
+
+    async fn vesting_delegate_to_mixnode<'a>(
+        &self,
+        mix_identity: IdentityKeyRef<'a>,
+        amount: &Coin,
+    ) -> Result<ExecuteResult, NymdError>;
+
+    async fn vesting_undelegate_from_mixnode<'a>(
+        &self,
+        mix_identity: IdentityKeyRef<'a>,
+    ) -> Result<ExecuteResult, NymdError>;
+
+    async fn create_periodic_vesting_account(
+        &self,
+        address: &str,
+        start_time: Option<u64>,
+        amount: Coin,
+    ) -> Result<ExecuteResult, NymdError>;
+}
+
+#[async_trait]
+impl<C: SigningCosmWasmClient + Sync + Send> VestingSigningClient for NymdClient<C> {
+    async fn vesting_bond_gateway(
+        &self,
+        gateway: Gateway,
+        owner_signature: &str,
+        pledge: Coin,
+    ) -> Result<ExecuteResult, NymdError> {
+        let fee = self.operation_fee(Operation::BondGateway);
+        let req = VestingExecuteMsg::BondGateway {
+            gateway,
+            owner_signature: owner_signature.to_string(),
+        };
+        self.client
+            .execute(
+                self.address(),
+                self.vesting_contract_address()?,
+                &req,
+                fee,
+                "VestingContract::BondGateway",
+                vec![cosmwasm_coin_to_cosmos_coin(pledge)],
+            )
+            .await
+    }
+
+    async fn vesting_unbond_gateway(&self) -> Result<ExecuteResult, NymdError> {
+        let fee = self.operation_fee(Operation::UnbondGateway);
+        let req = VestingExecuteMsg::UnbondGateway {};
+        self.client
+            .execute(
+                self.address(),
+                self.vesting_contract_address()?,
+                &req,
+                fee,
+                "VestingContract::UnbondGateway",
+                vec![],
+            )
+            .await
+    }
+
+    async fn vesting_track_unbond_gateway(
+        &self,
+        owner: &str,
+        amount: Coin,
+    ) -> Result<ExecuteResult, NymdError> {
+        let fee = self.operation_fee(Operation::TrackUnbondGateway);
+        let req = VestingExecuteMsg::TrackUnbondGateway {
+            owner: owner.to_string(),
+            amount,
+        };
+        self.client
+            .execute(
+                self.address(),
+                self.vesting_contract_address()?,
+                &req,
+                fee,
+                "VestingContract::TrackUnbondGateway",
+                vec![],
+            )
+            .await
+    }
+
+    async fn vesting_bond_mixnode(
+        &self,
+        mix_node: MixNode,
+        owner_signature: &str,
+        pledge: Coin,
+    ) -> Result<ExecuteResult, NymdError> {
+        let fee = self.operation_fee(Operation::BondMixnode);
+        let req = VestingExecuteMsg::BondMixnode {
+            mix_node,
+            owner_signature: owner_signature.to_string(),
+        };
+        self.client
+            .execute(
+                self.address(),
+                self.vesting_contract_address()?,
+                &req,
+                fee,
+                "VestingContract::BondMixnode",
+                vec![cosmwasm_coin_to_cosmos_coin(pledge)],
+            )
+            .await
+    }
+
+    async fn vesting_unbond_mixnode(&self) -> Result<ExecuteResult, NymdError> {
+        let fee = self.operation_fee(Operation::UnbondMixnode);
+        let req = VestingExecuteMsg::UnbondMixnode {};
+        self.client
+            .execute(
+                self.address(),
+                self.vesting_contract_address()?,
+                &req,
+                fee,
+                "VestingContract::UnbondMixnode",
+                vec![],
+            )
+            .await
+    }
+
+    async fn vesting_track_unbond_mixnode(
+        &self,
+        owner: &str,
+        amount: Coin,
+    ) -> Result<ExecuteResult, NymdError> {
+        let fee = self.operation_fee(Operation::TrackUnbondMixnode);
+        let req = VestingExecuteMsg::TrackUnbondMixnode {
+            owner: owner.to_string(),
+            amount,
+        };
+        self.client
+            .execute(
+                self.address(),
+                self.vesting_contract_address()?,
+                &req,
+                fee,
+                "VestingContract::TrackUnbondMixnode",
+                vec![],
+            )
+            .await
+    }
+
+    async fn withdraw_vested_coins(&self, amount: Coin) -> Result<ExecuteResult, NymdError> {
+        let fee = self.operation_fee(Operation::WithdrawVestedCoins);
+        let req = VestingExecuteMsg::WithdrawVestedCoins { amount };
+        self.client
+            .execute(
+                self.address(),
+                self.vesting_contract_address()?,
+                &req,
+                fee,
+                "VestingContract::WithdrawVested",
+                vec![],
+            )
+            .await
+    }
+
+    async fn vesting_track_undelegation(
+        &self,
+        address: &str,
+        mix_identity: IdentityKey,
+        amount: Coin,
+    ) -> Result<ExecuteResult, NymdError> {
+        let fee = self.operation_fee(Operation::TrackUndelegation);
+        let req = VestingExecuteMsg::TrackUndelegation {
+            owner: address.to_string(),
+            mix_identity,
+            amount,
+        };
+        self.client
+            .execute(
+                self.address(),
+                self.vesting_contract_address()?,
+                &req,
+                fee,
+                "VestingContract::TrackUndelegation",
+                vec![],
+            )
+            .await
+    }
+    async fn vesting_delegate_to_mixnode<'a>(
+        &self,
+        mix_identity: IdentityKeyRef<'a>,
+        amount: &Coin,
+    ) -> Result<ExecuteResult, NymdError> {
+        let fee = self.operation_fee(Operation::DelegateToMixnode);
+        let req = VestingExecuteMsg::DelegateToMixnode {
+            mix_identity: mix_identity.into(),
+        };
+        self.client
+            .execute(
+                self.address(),
+                self.vesting_contract_address()?,
+                &req,
+                fee,
+                "VestingContract::DeledateToMixnode",
+                vec![cosmwasm_coin_to_cosmos_coin(amount.to_owned())],
+            )
+            .await
+    }
+    async fn vesting_undelegate_from_mixnode<'a>(
+        &self,
+        mix_identity: IdentityKeyRef<'a>,
+    ) -> Result<ExecuteResult, NymdError> {
+        let fee = self.operation_fee(Operation::UndelegateFromMixnode);
+        let req = VestingExecuteMsg::UndelegateFromMixnode {
+            mix_identity: mix_identity.into(),
+        };
+        self.client
+            .execute(
+                self.address(),
+                self.vesting_contract_address()?,
+                &req,
+                fee,
+                "VestingContract::UndelegateFromMixnode",
+                vec![],
+            )
+            .await
+    }
+    async fn create_periodic_vesting_account(
+        &self,
+        address: &str,
+        start_time: Option<u64>,
+        amount: Coin,
+    ) -> Result<ExecuteResult, NymdError> {
+        let fee = self.operation_fee(Operation::CreatePeriodicVestingAccount);
+        let req = VestingExecuteMsg::CreateAccount {
+            address: address.to_string(),
+            start_time,
+        };
+        self.client
+            .execute(
+                self.address(),
+                self.vesting_contract_address()?,
+                &req,
+                fee,
+                "VestingContract::CreatePeriodicVestingAccount",
+                vec![cosmwasm_coin_to_cosmos_coin(amount)],
+            )
+            .await
+    }
+}
@@ -10,7 +10,7 @@ use cosmrs::tx::SignDoc;
 use cosmrs::{tx, AccountId};

 /// Derivation information required to derive a keypair and an address from a mnemonic.
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 struct Secp256k1Derivation {
    hd_path: DerivationPath,
    prefix: String,
@@ -40,7 +40,7 @@ impl AccountData {

 type Secp256k1Keypair = (SigningKey, PublicKey);

-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct DirectSecp256k1HdWallet {
    /// Base secret
    secret: bip39::Mnemonic,
@@ -8,4 +8,4 @@ description = "Crutch library until there is proper SerDe support for coconut st
 serde = { version = "1.0", features = ["derive"] }
 getset = "0.1.1"

-coconut-rs = { git = "https://github.com/nymtech/coconut.git", branch = "0.5.0" }
+nymcoconut = {path = "../nymcoconut" }
@@ -4,7 +4,7 @@
 use getset::{CopyGetters, Getters};
 use serde::{Deserialize, Serialize};

-pub use coconut_rs::*;
+pub use nymcoconut::*;

 #[derive(Serialize, Deserialize, Getters, CopyGetters, Clone)]
 pub struct Credential {
@@ -42,7 +42,7 @@ impl Credential {
            .iter()
            .map(hash_to_scalar)
            .collect::<Vec<Attribute>>();
-        coconut_rs::verify_credential(&params, verification_key, &self.theta, &public_attributes)
+        nymcoconut::verify_credential(&params, verification_key, &self.theta, &public_attributes)
    }
 }

@@ -84,7 +84,7 @@ pub struct BlindSignRequestBody {
    #[getset(get = "pub")]
    blind_sign_request: BlindSignRequest,
    #[getset(get = "pub")]
-    public_key: coconut_rs::PublicKey,
+    public_key: nymcoconut::PublicKey,
    public_attributes: Vec<String>,
    #[getset(get = "pub")]
    total_params: u32,
@@ -92,13 +92,13 @@ pub struct BlindSignRequestBody {

 impl BlindSignRequestBody {
    pub fn new(
-        blind_sign_request: BlindSignRequest,
-        public_key: &coconut_rs::PublicKey,
+        blind_sign_request: &BlindSignRequest,
+        public_key: &nymcoconut::PublicKey,
        public_attributes: &[Attribute],
        total_params: u32,
    ) -> BlindSignRequestBody {
        BlindSignRequestBody {
-            blind_sign_request,
+            blind_sign_request: blind_sign_request.clone(),
            public_key: public_key.clone(),
            public_attributes: public_attributes
                .iter()
@@ -11,4 +11,6 @@ url = "2.2"

 # I guess temporarily until we get serde support in coconut up and running
 coconut-interface = { path = "../coconut-interface" }
+crypto = { path = "../crypto" }
+network-defaults = { path = "../network-defaults" }
 validator-client = { path = "../client-libs/validator-client" }
@@ -1,48 +0,0 @@
-// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
-// SPDX-License-Identifier: Apache-2.0
-
-// for time being assume the bandwidth credential consists of public identity of the requester
-// and private (though known... just go along with it) infinite bandwidth value
-// right now this has no double-spending protection, spender binding, etc
-// it's the simplest possible case
-
-use url::Url;
-
-use crate::error::Error;
-use crate::utils::{obtain_aggregate_signature, prepare_credential_for_spending};
-use coconut_interface::{hash_to_scalar, Credential, Parameters, Signature, VerificationKey};
-
-const BANDWIDTH_VALUE: u64 = 10 * 1024 * 1024 * 1024; // 10 GB
-
-pub const PUBLIC_ATTRIBUTES: u32 = 1;
-pub const PRIVATE_ATTRIBUTES: u32 = 1;
-pub const TOTAL_ATTRIBUTES: u32 = PUBLIC_ATTRIBUTES + PRIVATE_ATTRIBUTES;
-
-// TODO: this definitely has to be moved somewhere else. It's just a temporary solution
-pub async fn obtain_signature(raw_identity: &[u8], validators: &[Url]) -> Result<Signature, Error> {
-    let public_attributes = vec![hash_to_scalar(BANDWIDTH_VALUE.to_be_bytes())];
-    let private_attributes = vec![hash_to_scalar(raw_identity)];
-
-    let params = Parameters::new(TOTAL_ATTRIBUTES)?;
-
-    obtain_aggregate_signature(&params, &public_attributes, &private_attributes, validators).await
-}
-
-pub fn prepare_for_spending(
-    raw_identity: &[u8],
-    signature: &Signature,
-    verification_key: &VerificationKey,
-) -> Result<Credential, Error> {
-    let public_attributes = vec![BANDWIDTH_VALUE.to_be_bytes().to_vec()];
-    let private_attributes = vec![raw_identity.to_vec()];
-
-    let params = Parameters::new(TOTAL_ATTRIBUTES)?;
-
-    prepare_credential_for_spending(
-        &params,
-        public_attributes,
-        private_attributes,
-        signature,
-        verification_key,
-    )
-}
@@ -0,0 +1,77 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+// for time being assume the bandwidth credential consists of public identity of the requester
+// and private (though known... just go along with it) infinite bandwidth value
+// right now this has no double-spending protection, spender binding, etc
+// it's the simplest possible case
+
+use coconut_interface::{
+    Credential, Parameters, PrivateAttribute, PublicAttribute, Signature, VerificationKey,
+};
+use network_defaults::BANDWIDTH_VALUE;
+use url::Url;
+
+use crate::error::Error;
+
+use super::utils::{obtain_aggregate_signature, prepare_credential_for_spending};
+
+pub const PUBLIC_ATTRIBUTES: u32 = 2;
+pub const PRIVATE_ATTRIBUTES: u32 = 2;
+pub const TOTAL_ATTRIBUTES: u32 = PUBLIC_ATTRIBUTES + PRIVATE_ATTRIBUTES;
+
+pub struct BandwidthVoucherAttributes {
+    // a random secret value generated by the client used for double-spending detection
+    pub serial_number: PrivateAttribute,
+    // a random secret value generated by the client used to bind multiple credentials together
+    pub binding_number: PrivateAttribute,
+    // the value (e.g., bandwidth) encoded in this voucher
+    pub voucher_value: PublicAttribute,
+    // a field with public information, e.g., type of voucher, epoch etc.
+    pub voucher_info: PublicAttribute,
+}
+
+impl BandwidthVoucherAttributes {
+    pub fn get_public_attributes(&self) -> Vec<PublicAttribute> {
+        vec![self.voucher_value, self.voucher_info]
+    }
+
+    pub fn get_private_attributes(&self) -> Vec<PrivateAttribute> {
+        vec![self.serial_number, self.binding_number]
+    }
+}
+
+// TODO: this definitely has to be moved somewhere else. It's just a temporary solution
+pub async fn obtain_signature(
+    params: &Parameters,
+    attributes: &BandwidthVoucherAttributes,
+    validators: &[Url],
+) -> Result<Signature, Error> {
+    let public_attributes = attributes.get_public_attributes();
+    let private_attributes = attributes.get_private_attributes();
+
+    obtain_aggregate_signature(params, &public_attributes, &private_attributes, validators).await
+}
+
+pub fn prepare_for_spending(
+    raw_identity: &[u8],
+    signature: &Signature,
+    attributes: &BandwidthVoucherAttributes,
+    verification_key: &VerificationKey,
+) -> Result<Credential, Error> {
+    let public_attributes = vec![
+        raw_identity.to_vec(),
+        BANDWIDTH_VALUE.to_be_bytes().to_vec(),
+    ];
+
+    let params = Parameters::new(TOTAL_ATTRIBUTES)?;
+
+    prepare_credential_for_spending(
+        &params,
+        public_attributes,
+        attributes.serial_number,
+        attributes.binding_number,
+        signature,
+        verification_key,
+    )
+}
@@ -0,0 +1,5 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+pub mod bandwidth;
+pub mod utils;
@@ -1,14 +1,16 @@
 // Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0

-use crate::error::Error;
 use coconut_interface::{
-    aggregate_signature_shares, aggregate_verification_keys, hash_to_scalar, prepare_blind_sign,
-    prove_credential, Attribute, BlindSignRequestBody, Credential, Parameters, Signature,
+    aggregate_signature_shares, aggregate_verification_keys, prepare_blind_sign,
+    prove_bandwidth_credential, Attribute, BlindSignRequestBody, Credential, Parameters, Signature,
    SignatureShare, VerificationKey,
 };
 use url::Url;

+use crate::coconut::bandwidth::PRIVATE_ATTRIBUTES;
+use crate::error::Error;
+
 /// Contacts all provided validators and then aggregate their verification keys.
 ///
 /// # Arguments
@@ -63,17 +65,18 @@ async fn obtain_partial_credential(
    public_attributes: &[Attribute],
    private_attributes: &[Attribute],
    client: &validator_client::ApiClient,
+    validator_vk: &VerificationKey,
 ) -> Result<Signature, Error> {
    let elgamal_keypair = coconut_interface::elgamal_keygen(params);
    let blind_sign_request = prepare_blind_sign(
        params,
-        elgamal_keypair.public_key(),
+        &elgamal_keypair,
        private_attributes,
        public_attributes,
    )?;

    let blind_sign_request_body = BlindSignRequestBody::new(
-        blind_sign_request,
+        &blind_sign_request,
        elgamal_keypair.public_key(),
        public_attributes,
        (public_attributes.len() + private_attributes.len()) as u32,
@@ -83,7 +86,17 @@ async fn obtain_partial_credential(
        .blind_sign(&blind_sign_request_body)
        .await?
        .blinded_signature;
-    Ok(blinded_signature.unblind(elgamal_keypair.private_key()))
+
+    let unblinded_signature = blinded_signature.unblind(
+        params,
+        elgamal_keypair.private_key(),
+        validator_vk,
+        private_attributes,
+        public_attributes,
+        &blind_sign_request.get_commitment_hash(),
+    )?;
+
+    Ok(unblinded_signature)
 }

 pub async fn obtain_aggregate_signature(
@@ -97,40 +110,76 @@ pub async fn obtain_aggregate_signature(
    }

    let mut shares = Vec::with_capacity(validators.len());
+    let mut validators_partial_vks: Vec<VerificationKey> = Vec::with_capacity(validators.len());

    let mut client = validator_client::ApiClient::new(validators[0].clone());
-    let first =
-        obtain_partial_credential(params, public_attributes, private_attributes, &client).await?;
+    let validator_partial_vk = client.get_coconut_verification_key().await?;
+    validators_partial_vks.push(validator_partial_vk.key.clone());
+
+    let first = obtain_partial_credential(
+        params,
+        public_attributes,
+        private_attributes,
+        &client,
+        &validator_partial_vk.key,
+    )
+    .await?;
    shares.push(SignatureShare::new(first, 0));

    for (id, validator_url) in validators.iter().enumerate().skip(1) {
        client.change_validator_api(validator_url.clone());
-        let signature =
-            obtain_partial_credential(params, public_attributes, private_attributes, &client)
-                .await?;
+        let validator_partial_vk = client.get_coconut_verification_key().await?;
+        validators_partial_vks.push(validator_partial_vk.key.clone());
+        let signature = obtain_partial_credential(
+            params,
+            public_attributes,
+            private_attributes,
+            &client,
+            &validator_partial_vk.key,
+        )
+        .await?;
        let share = SignatureShare::new(signature, id as u64);
        shares.push(share)
    }

-    Ok(aggregate_signature_shares(&shares)?)
+    let mut attributes = Vec::with_capacity(private_attributes.len() + public_attributes.len());
+    attributes.extend_from_slice(private_attributes);
+    attributes.extend_from_slice(public_attributes);
+
+    let mut indices: Vec<u64> = Vec::with_capacity(validators_partial_vks.len());
+    for i in 1..validators_partial_vks.len() {
+        indices.push(i as u64);
+    }
+    let verification_key =
+        aggregate_verification_keys(&validators_partial_vks, Some(indices.as_ref()))?;
+
+    Ok(aggregate_signature_shares(
+        params,
+        &verification_key,
+        &attributes,
+        &shares,
+    )?)
 }

 // TODO: better type flow
 pub fn prepare_credential_for_spending(
    params: &Parameters,
    public_attributes: Vec<Vec<u8>>,
-    private_attributes: Vec<Vec<u8>>,
+    serial_number: Attribute,
+    binding_number: Attribute,
    signature: &Signature,
    verification_key: &VerificationKey,
 ) -> Result<Credential, Error> {
-    let private_attributes = private_attributes
-        .iter()
-        .map(hash_to_scalar)
-        .collect::<Vec<Attribute>>();
-    let theta = prove_credential(params, verification_key, signature, &private_attributes)?;
+    let theta = prove_bandwidth_credential(
+        params,
+        verification_key,
+        signature,
+        serial_number,
+        binding_number,
+    )?;

    Ok(Credential::new(
-        (public_attributes.len() + private_attributes.len()) as u32,
+        (public_attributes.len() + PRIVATE_ATTRIBUTES as usize) as u32,
        theta,
        public_attributes,
        signature,
@@ -1,8 +1,8 @@
 // Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0

-pub mod bandwidth;
+pub mod coconut;
 pub mod error;
-mod utils;
+pub mod token;

-pub use utils::{obtain_aggregate_signature, obtain_aggregate_verification_key};
+pub use coconut::utils::{obtain_aggregate_signature, obtain_aggregate_verification_key};
@@ -0,0 +1,140 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+use crypto::asymmetric::identity::{PublicKey, Signature, PUBLIC_KEY_LENGTH, SIGNATURE_LENGTH};
+
+use crate::error::Error;
+use std::convert::TryInto;
+
+#[cfg(not(feature = "coconut"))]
+pub struct TokenCredential {
+    verification_key: PublicKey,
+    gateway_identity: PublicKey,
+    bandwidth: u64,
+    signature: Signature,
+}
+
+#[cfg(not(feature = "coconut"))]
+impl TokenCredential {
+    pub fn new(
+        verification_key: PublicKey,
+        gateway_identity: PublicKey,
+        bandwidth: u64,
+        signature: Signature,
+    ) -> Self {
+        TokenCredential {
+            verification_key,
+            gateway_identity,
+            bandwidth,
+            signature,
+        }
+    }
+
+    pub fn verification_key(&self) -> PublicKey {
+        self.verification_key
+    }
+
+    pub fn gateway_identity(&self) -> PublicKey {
+        self.gateway_identity
+    }
+
+    pub fn bandwidth(&self) -> u64 {
+        self.bandwidth
+    }
+
+    pub fn signature_bytes(&self) -> [u8; 64] {
+        self.signature.to_bytes()
+    }
+
+    pub fn verify_signature(&self) -> bool {
+        let message: Vec<u8> = self
+            .verification_key
+            .to_bytes()
+            .iter()
+            .chain(self.gateway_identity.to_bytes().iter())
+            .copied()
+            .collect();
+        self.verification_key
+            .verify(&message, &self.signature)
+            .is_ok()
+    }
+
+    pub fn to_bytes(&self) -> Vec<u8> {
+        self.verification_key
+            .to_bytes()
+            .iter()
+            .chain(self.gateway_identity.to_bytes().iter())
+            .chain(self.bandwidth.to_be_bytes().iter())
+            .chain(self.signature.to_bytes().iter())
+            .copied()
+            .collect()
+    }
+
+    pub fn from_bytes(b: &[u8]) -> Result<Self, Error> {
+        if b.len() != 2 * PUBLIC_KEY_LENGTH + 8 + SIGNATURE_LENGTH {
+            return Err(Error::BandwidthCredentialError);
+        }
+        let verification_key = PublicKey::from_bytes(&b[..PUBLIC_KEY_LENGTH])
+            .map_err(|_| Error::BandwidthCredentialError)?;
+        let gateway_identity = PublicKey::from_bytes(&b[PUBLIC_KEY_LENGTH..2 * PUBLIC_KEY_LENGTH])
+            .map_err(|_| Error::BandwidthCredentialError)?;
+        let bandwidth = u64::from_be_bytes(
+            b[2 * PUBLIC_KEY_LENGTH..2 * PUBLIC_KEY_LENGTH + 8]
+                .try_into()
+                // unwrapping is safe because we know we have 8 bytes
+                .unwrap(),
+        );
+        let signature = Signature::from_bytes(&b[2 * PUBLIC_KEY_LENGTH + 8..])
+            .map_err(|_| Error::BandwidthCredentialError)?;
+        Ok(TokenCredential {
+            verification_key,
+            gateway_identity,
+            bandwidth,
+            signature,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[cfg(not(feature = "coconut"))]
+    #[test]
+    fn token_serde() {
+        // pre-generated, valid values
+        let verification_key = PublicKey::from_bytes(&[
+            103, 105, 71, 177, 149, 245, 26, 32, 73, 121, 76, 50, 94, 88, 119, 231, 91, 229, 167,
+            56, 39, 62, 185, 39, 83, 246, 153, 27, 17, 155, 109, 73,
+        ])
+        .unwrap();
+        let gateway_identity = PublicKey::from_bytes(&[
+            37, 113, 137, 189, 157, 82, 35, 2, 187, 136, 61, 119, 98, 5, 245, 82, 46, 124, 67, 45,
+            165, 255, 53, 222, 185, 252, 6, 148, 128, 15, 206, 19,
+        ])
+        .unwrap();
+        let signature = Signature::from_bytes(&[
+            117, 251, 162, 217, 57, 2, 50, 210, 206, 81, 236, 90, 74, 201, 69, 237, 240, 247, 214,
+            158, 220, 89, 235, 222, 85, 134, 73, 73, 8, 60, 25, 39, 183, 28, 83, 193, 31, 174, 25,
+            24, 38, 215, 205, 228, 159, 135, 35, 4, 171, 59, 100, 157, 12, 249, 77, 52, 143, 4, 32,
+            28, 147, 70, 182, 14,
+        ])
+        .unwrap();
+        let credential = TokenCredential::new(verification_key, gateway_identity, 1024, signature);
+        let serialized_credential = credential.to_bytes();
+        let deserialized_credential = TokenCredential::from_bytes(&serialized_credential).unwrap();
+        assert_eq!(
+            credential.verification_key,
+            deserialized_credential.verification_key
+        );
+        assert_eq!(
+            credential.gateway_identity,
+            deserialized_credential.gateway_identity
+        );
+        assert_eq!(credential.bandwidth, deserialized_credential.bandwidth);
+        assert_eq!(
+            credential.signature.to_bytes(),
+            deserialized_credential.signature.to_bytes()
+        );
+    }
+}
@@ -0,0 +1,4 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+pub mod bandwidth;
@@ -1,7 +1,7 @@
 // Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0

-use ed25519_dalek::ed25519::signature::Signature as SignatureTrait;
+pub use ed25519_dalek::ed25519::signature::Signature as SignatureTrait;
 pub use ed25519_dalek::SignatureError;
 pub use ed25519_dalek::{Verifier, PUBLIC_KEY_LENGTH, SECRET_KEY_LENGTH, SIGNATURE_LENGTH};
 use nymsphinx_types::{DestinationAddressBytes, DESTINATION_ADDRESS_LENGTH};
@@ -10,33 +10,33 @@ use rand::{CryptoRng, RngCore};
 use std::fmt::{self, Display, Formatter};

 #[derive(Debug)]
-pub enum KeyRecoveryError {
+pub enum Ed25519RecoveryError {
    MalformedBytes(SignatureError),
    MalformedString(bs58::decode::Error),
 }

-impl From<SignatureError> for KeyRecoveryError {
+impl From<SignatureError> for Ed25519RecoveryError {
    fn from(err: SignatureError) -> Self {
-        KeyRecoveryError::MalformedBytes(err)
+        Ed25519RecoveryError::MalformedBytes(err)
    }
 }

-impl From<bs58::decode::Error> for KeyRecoveryError {
+impl From<bs58::decode::Error> for Ed25519RecoveryError {
    fn from(err: bs58::decode::Error) -> Self {
-        KeyRecoveryError::MalformedString(err)
+        Ed25519RecoveryError::MalformedString(err)
    }
 }

-impl fmt::Display for KeyRecoveryError {
+impl fmt::Display for Ed25519RecoveryError {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        match self {
-            KeyRecoveryError::MalformedBytes(err) => write!(f, "malformed bytes - {}", err),
-            KeyRecoveryError::MalformedString(err) => write!(f, "malformed string - {}", err),
+            Ed25519RecoveryError::MalformedBytes(err) => write!(f, "malformed bytes - {}", err),
+            Ed25519RecoveryError::MalformedString(err) => write!(f, "malformed string - {}", err),
        }
    }
 }

-impl std::error::Error for KeyRecoveryError {}
+impl std::error::Error for Ed25519RecoveryError {}

 /// Keypair for usage in ed25519 EdDSA.
 pub struct KeyPair {
@@ -62,7 +62,7 @@ impl KeyPair {
        &self.public_key
    }

-    pub fn from_bytes(priv_bytes: &[u8], pub_bytes: &[u8]) -> Result<Self, KeyRecoveryError> {
+    pub fn from_bytes(priv_bytes: &[u8], pub_bytes: &[u8]) -> Result<Self, Ed25519RecoveryError> {
        Ok(KeyPair {
            private_key: PrivateKey::from_bytes(priv_bytes)?,
            public_key: PublicKey::from_bytes(pub_bytes)?,
@@ -115,7 +115,7 @@ impl PublicKey {
        self.0.to_bytes()
    }

-    pub fn from_bytes(b: &[u8]) -> Result<Self, KeyRecoveryError> {
+    pub fn from_bytes(b: &[u8]) -> Result<Self, Ed25519RecoveryError> {
        Ok(PublicKey(ed25519_dalek::PublicKey::from_bytes(b)?))
    }

@@ -123,7 +123,7 @@ impl PublicKey {
        bs58::encode(self.to_bytes()).into_string()
    }

-    pub fn from_base58_string<I: AsRef<[u8]>>(val: I) -> Result<Self, KeyRecoveryError> {
+    pub fn from_base58_string<I: AsRef<[u8]>>(val: I) -> Result<Self, Ed25519RecoveryError> {
        let bytes = bs58::decode(val).into_vec()?;
        Self::from_bytes(&bytes)
    }
@@ -134,7 +134,7 @@ impl PublicKey {
 }

 impl PemStorableKey for PublicKey {
-    type Error = KeyRecoveryError;
+    type Error = Ed25519RecoveryError;

    fn pem_type() -> &'static str {
        "ED25519 PUBLIC KEY"
@@ -170,7 +170,7 @@ impl PrivateKey {
        self.0.to_bytes()
    }

-    pub fn from_bytes(b: &[u8]) -> Result<Self, KeyRecoveryError> {
+    pub fn from_bytes(b: &[u8]) -> Result<Self, Ed25519RecoveryError> {
        Ok(PrivateKey(ed25519_dalek::SecretKey::from_bytes(b)?))
    }

@@ -178,7 +178,7 @@ impl PrivateKey {
        bs58::encode(&self.to_bytes()).into_string()
    }

-    pub fn from_base58_string<I: AsRef<[u8]>>(val: I) -> Result<Self, KeyRecoveryError> {
+    pub fn from_base58_string<I: AsRef<[u8]>>(val: I) -> Result<Self, Ed25519RecoveryError> {
        let bytes = bs58::decode(val).into_vec()?;
        Self::from_bytes(&bytes)
    }
@@ -192,7 +192,7 @@ impl PrivateKey {
 }

 impl PemStorableKey for PrivateKey {
-    type Error = KeyRecoveryError;
+    type Error = Ed25519RecoveryError;

    fn pem_type() -> &'static str {
        "ED25519 PRIVATE KEY"
@@ -211,11 +211,20 @@ impl PemStorableKey for PrivateKey {
 pub struct Signature(ed25519_dalek::Signature);

 impl Signature {
+    pub fn to_base58_string(&self) -> String {
+        bs58::encode(&self.to_bytes()).into_string()
+    }
+
+    pub fn from_base58_string<I: AsRef<[u8]>>(val: I) -> Result<Self, Ed25519RecoveryError> {
+        let bytes = bs58::decode(val).into_vec()?;
+        Self::from_bytes(&bytes)
+    }
+
    pub fn to_bytes(&self) -> [u8; SIGNATURE_LENGTH] {
        self.0.to_bytes()
    }

-    pub fn from_bytes(bytes: &[u8]) -> Result<Self, SignatureError> {
+    pub fn from_bytes(bytes: &[u8]) -> Result<Self, Ed25519RecoveryError> {
        Ok(Signature(ed25519_dalek::Signature::from_bytes(bytes)?))
    }
 }
@@ -0,0 +1,10 @@
+[package]
+name = "erc20-bridge-contract"
+version = "0.1.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+schemars = "0.8"
+serde = { version = "1.0.103", default-features = false, features = ["derive"] }
@@ -0,0 +1,45 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+
+// Serializable structures for what we find in common/crypto
+#[derive(Serialize, Deserialize, Copy, Clone, Debug, PartialEq, JsonSchema)]
+pub struct PublicKey([u8; 32]);
+
+impl PublicKey {
+    pub fn new(bytes: [u8; 32]) -> Self {
+        PublicKey(bytes)
+    }
+    pub fn to_bytes(&self) -> [u8; 32] {
+        self.0
+    }
+}
+
+impl AsRef<[u8]> for PublicKey {
+    #[inline]
+    fn as_ref(&self) -> &[u8] {
+        &self.0
+    }
+}
+
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
+pub struct Signature([u8; 32], [u8; 32]);
+
+impl Signature {
+    pub fn new(bytes: [u8; 64]) -> Self {
+        let mut sig1 = [0u8; 32];
+        let mut sig2 = [0u8; 32];
+        sig1.copy_from_slice(&bytes[..32]);
+        sig2.copy_from_slice(&bytes[32..]);
+
+        Signature(sig1, sig2)
+    }
+    pub fn to_bytes(&self) -> [u8; 64] {
+        let mut res = [0u8; 64];
+        res[..32].copy_from_slice(&self.0);
+        res[32..].copy_from_slice(&self.1);
+        res
+    }
+}
@@ -0,0 +1,3 @@
+pub mod keys;
+pub mod msg;
+pub mod payment;
@@ -0,0 +1,30 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+
+use crate::keys::PublicKey;
+use crate::payment::LinkPaymentData;
+
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
+pub struct InstantiateMsg {}
+
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
+#[serde(rename_all = "snake_case")]
+pub enum ExecuteMsg {
+    LinkPayment { data: LinkPaymentData },
+}
+
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
+#[serde(rename_all = "snake_case")]
+pub enum QueryMsg {
+    GetPayments {
+        limit: Option<u32>,
+        start_after: Option<PublicKey>,
+    },
+}
+
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
+#[serde(rename_all = "snake_case")]
+pub struct MigrateMsg {}
@@ -0,0 +1,73 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+
+use crate::keys::{PublicKey, Signature};
+
+#[derive(Clone, Debug, Deserialize, PartialEq, Serialize, JsonSchema)]
+pub struct Payment {
+    verification_key: PublicKey,
+    gateway_identity: PublicKey,
+    bandwidth: u64,
+}
+
+impl Payment {
+    pub fn new(verification_key: PublicKey, gateway_identity: PublicKey, bandwidth: u64) -> Self {
+        Payment {
+            verification_key,
+            gateway_identity,
+            bandwidth,
+        }
+    }
+
+    pub fn verification_key(&self) -> PublicKey {
+        self.verification_key
+    }
+}
+
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
+pub struct LinkPaymentData {
+    pub verification_key: PublicKey,
+    pub gateway_identity: PublicKey,
+    pub bandwidth: u64,
+    pub signature: Signature,
+}
+
+impl LinkPaymentData {
+    pub fn new(
+        verification_key: [u8; 32],
+        gateway_identity: [u8; 32],
+        bandwidth: u64,
+        signature: [u8; 64],
+    ) -> Self {
+        LinkPaymentData {
+            verification_key: PublicKey::new(verification_key),
+            gateway_identity: PublicKey::new(gateway_identity),
+            bandwidth,
+            signature: Signature::new(signature),
+        }
+    }
+}
+
+#[derive(Clone, Debug, Deserialize, PartialEq, Serialize, JsonSchema)]
+pub struct PagedPaymentResponse {
+    pub payments: Vec<Payment>,
+    pub per_page: usize,
+    pub start_next_after: Option<PublicKey>,
+}
+
+impl PagedPaymentResponse {
+    pub fn new(
+        payments: Vec<Payment>,
+        per_page: usize,
+        start_next_after: Option<PublicKey>,
+    ) -> Self {
+        PagedPaymentResponse {
+            payments,
+            per_page,
+            start_next_after,
+        }
+    }
+}
@@ -7,11 +7,17 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

 [dependencies]
-# this branch is identical to 0.14.1 with addition of updated k256 dependency required to help poor cargo choose correct version
-cosmwasm-std = { git = "https://github.com/jstuczyn/cosmwasm", branch="0.14.1-updatedk256" }
-#cosmwasm-std = { version = "0.14.1" }
+cosmwasm-std = "1.0.0-beta2"

 serde = { version = "1.0", features = ["derive"] }
 serde_repr = "0.1"
 schemars = "0.8"
-ts-rs = "3.0"
+ts-rs = { version = "5.1", optional = true }
+thiserror = "1.0"
+network-defaults = { path = "../network-defaults" }
+fixed = { version = "1.1", features = ["serde"] }
+az = "1.1"
+log = "0.4.14"
+
+[features]
+default = []
@@ -1,3 +1,6 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
 // due to code generated by JsonSchema
 #![allow(clippy::field_reassign_with_default)]

@@ -7,51 +10,41 @@ use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 use std::fmt::Display;

-#[derive(Clone, Debug, Deserialize, PartialEq, Serialize, JsonSchema)]
-pub struct UnpackedDelegation<T> {
+#[derive(Clone, Debug, Deserialize, Serialize, PartialEq, JsonSchema)]
+pub struct Delegation {
    pub owner: Addr,
    pub node_identity: IdentityKey,
-    pub delegation_data: T,
-}
-
-impl<T> UnpackedDelegation<T> {
-    pub fn new(owner: Addr, node_identity: IdentityKey, delegation_data: T) -> Self {
-        UnpackedDelegation {
-            owner,
-            node_identity,
-            delegation_data,
-        }
-    }
-}
-
-#[derive(Clone, Debug, Deserialize, PartialEq, Serialize, JsonSchema)]
-pub struct RawDelegationData {
-    pub amount: Uint128,
+    pub amount: Coin,
    pub block_height: u64,
-}
-
-impl RawDelegationData {
-    pub fn new(amount: Uint128, block_height: u64) -> Self {
-        RawDelegationData {
-            amount,
-            block_height,
-        }
-    }
-}
-
-#[derive(Clone, Debug, Deserialize, PartialEq, Serialize, JsonSchema)]
-pub struct Delegation {
-    owner: Addr,
-    amount: Coin,
-    block_height: u64,
+    pub proxy: Option<Addr>, // proxy address used to delegate the funds on behalf of anouther address
 }

 impl Delegation {
-    pub fn new(owner: Addr, amount: Coin, block_height: u64) -> Self {
+    pub fn new(
+        owner: Addr,
+        node_identity: IdentityKey,
+        amount: Coin,
+        block_height: u64,
+        proxy: Option<Addr>,
+    ) -> Self {
        Delegation {
            owner,
+            node_identity,
            amount,
            block_height,
+            proxy,
+        }
+    }
+
+    // TODO: change that to use .joined_key() and return Vec<u8>
+    pub fn storage_key(&self) -> (IdentityKey, Addr) {
+        (self.node_identity(), self.owner())
+    }
+
+    pub fn increment_amount(&mut self, amount: Uint128, at_height: Option<u64>) {
+        self.amount.amount += amount;
+        if let Some(at_height) = at_height {
+            self.block_height = at_height;
        }
    }

@@ -59,6 +52,10 @@ impl Delegation {
        &self.amount
    }

+    pub fn node_identity(&self) -> IdentityKey {
+        self.node_identity.clone()
+    }
+
    pub fn owner(&self) -> Addr {
        self.owner.clone()
    }
@@ -72,65 +69,56 @@ impl Display for Delegation {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
        write!(
            f,
-            "{} {} delegated by {} at block {}",
-            self.amount.amount, self.amount.denom, self.owner, self.block_height
+            "{} delegated towards {} by {} at block {}",
+            self.amount, self.node_identity, self.owner, self.block_height
        )
    }
 }

 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize, JsonSchema)]
 pub struct PagedMixDelegationsResponse {
-    pub node_identity: IdentityKey,
    pub delegations: Vec<Delegation>,
-    pub start_next_after: Option<Addr>,
+    pub start_next_after: Option<String>,
 }

 impl PagedMixDelegationsResponse {
-    pub fn new(
-        node_identity: IdentityKey,
-        delegations: Vec<Delegation>,
-        start_next_after: Option<Addr>,
-    ) -> Self {
+    pub fn new(delegations: Vec<Delegation>, start_next_after: Option<Addr>) -> Self {
        PagedMixDelegationsResponse {
-            node_identity,
            delegations,
-            start_next_after,
+            start_next_after: start_next_after.map(|s| s.to_string()),
        }
    }
 }

 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize, JsonSchema)]
-pub struct PagedReverseMixDelegationsResponse {
-    pub delegation_owner: Addr,
-    pub delegated_nodes: Vec<IdentityKey>,
+pub struct PagedDelegatorDelegationsResponse {
+    pub delegations: Vec<Delegation>,
    pub start_next_after: Option<IdentityKey>,
 }

-impl PagedReverseMixDelegationsResponse {
-    pub fn new(
-        delegation_owner: Addr,
-        delegated_nodes: Vec<IdentityKey>,
-        start_next_after: Option<IdentityKey>,
-    ) -> Self {
-        PagedReverseMixDelegationsResponse {
-            delegation_owner,
-            delegated_nodes,
+impl PagedDelegatorDelegationsResponse {
+    pub fn new(delegations: Vec<Delegation>, start_next_after: Option<IdentityKey>) -> Self {
+        PagedDelegatorDelegationsResponse {
+            delegations,
            start_next_after,
        }
    }
 }

 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize, JsonSchema)]
-pub struct PagedAllDelegationsResponse<T> {
-    pub delegations: Vec<UnpackedDelegation<T>>,
-    pub start_next_after: Option<Vec<u8>>,
+pub struct PagedAllDelegationsResponse {
+    pub delegations: Vec<Delegation>,
+    pub start_next_after: Option<(IdentityKey, String)>,
 }

-impl<T> PagedAllDelegationsResponse<T> {
-    pub fn new(delegations: Vec<UnpackedDelegation<T>>, start_next_after: Option<Vec<u8>>) -> Self {
+impl PagedAllDelegationsResponse {
+    pub fn new(
+        delegations: Vec<Delegation>,
+        start_next_after: Option<(IdentityKey, Addr)>,
+    ) -> Self {
        PagedAllDelegationsResponse {
            delegations,
-            start_next_after,
+            start_next_after: start_next_after.map(|(id, addr)| (id, addr.to_string())),
        }
    }
 }
@@ -0,0 +1,9 @@
+use thiserror::Error;
+
+#[derive(Error, Debug, PartialEq)]
+pub enum MixnetContractError {
+    #[error("Overflow Error")]
+    OverflowError(#[from] cosmwasm_std::OverflowError),
+    #[error("reward_blockstamp field not set, set_reward_blockstamp must be called before attempting to issue rewards")]
+    BlockstampNotSet,
+}
@@ -7,9 +7,9 @@ use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 use std::cmp::Ordering;
 use std::fmt::Display;
-use ts_rs::TS;

-#[derive(Clone, Debug, Deserialize, PartialEq, PartialOrd, Serialize, JsonSchema, TS)]
+#[cfg_attr(feature = "ts-rs", derive(ts_rs::TS))]
+#[derive(Clone, Debug, Deserialize, PartialEq, PartialOrd, Serialize, JsonSchema)]
 pub struct Gateway {
    pub host: String,
    pub mix_port: u16,
@@ -23,19 +23,27 @@ pub struct Gateway {

 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize, JsonSchema)]
 pub struct GatewayBond {
-    pub bond_amount: Coin,
+    pub pledge_amount: Coin,
    pub owner: Addr,
    pub block_height: u64,
    pub gateway: Gateway,
+    pub proxy: Option<Addr>,
 }

 impl GatewayBond {
-    pub fn new(bond_amount: Coin, owner: Addr, block_height: u64, gateway: Gateway) -> Self {
+    pub fn new(
+        pledge_amount: Coin,
+        owner: Addr,
+        block_height: u64,
+        gateway: Gateway,
+        proxy: Option<Addr>,
+    ) -> Self {
        GatewayBond {
-            bond_amount,
+            pledge_amount,
            owner,
            block_height,
            gateway,
+            proxy,
        }
    }

@@ -43,8 +51,8 @@ impl GatewayBond {
        &self.gateway.identity_key
    }

-    pub fn bond_amount(&self) -> Coin {
-        self.bond_amount.clone()
+    pub fn pledge_amount(&self) -> Coin {
+        self.pledge_amount.clone()
    }

    pub fn owner(&self) -> &Addr {
@@ -59,17 +67,17 @@ impl GatewayBond {
 impl PartialOrd for GatewayBond {
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        // first remove invalid cases
-        if self.bond_amount.denom != other.bond_amount.denom {
+        if self.pledge_amount.denom != other.pledge_amount.denom {
            return None;
        }

-        // try to order by total bond
-        let bond_cmp = self
-            .bond_amount
+        // try to order by total pledge
+        let pledge_cmp = self
+            .pledge_amount
            .amount
-            .partial_cmp(&other.bond_amount.amount)?;
-        if bond_cmp != Ordering::Equal {
-            return Some(bond_cmp);
+            .partial_cmp(&other.pledge_amount.amount)?;
+        if pledge_cmp != Ordering::Equal {
+            return Some(pledge_cmp);
        }

        // then check block height
@@ -94,7 +102,10 @@ impl Display for GatewayBond {
        write!(
            f,
            "amount: {} {}, owner: {}, identity: {}",
-            self.bond_amount.amount, self.bond_amount.denom, self.owner, self.gateway.identity_key
+            self.pledge_amount.amount,
+            self.pledge_amount.denom,
+            self.owner,
+            self.gateway.identity_key
        )
    }
 }
@@ -123,7 +134,7 @@ impl PagedGatewayResponse {
 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize, JsonSchema)]
 pub struct GatewayOwnershipResponse {
    pub address: Addr,
-    pub has_gateway: bool,
+    pub gateway: Option<GatewayBond>,
 }

 #[cfg(test)]
@@ -150,38 +161,43 @@ mod tests {
        let _0foos = Coin::new(0, "foo");

        let gate1 = GatewayBond {
-            bond_amount: _150foos.clone(),
+            pledge_amount: _150foos.clone(),
            owner: Addr::unchecked("foo1"),
            block_height: 100,
            gateway: gateway_fixture(),
+            proxy: None,
        };

        let gate2 = GatewayBond {
-            bond_amount: _150foos,
+            pledge_amount: _150foos,
            owner: Addr::unchecked("foo2"),
            block_height: 120,
            gateway: gateway_fixture(),
+            proxy: None,
        };

        let gate3 = GatewayBond {
-            bond_amount: _50foos,
+            pledge_amount: _50foos,
            owner: Addr::unchecked("foo3"),
            block_height: 120,
            gateway: gateway_fixture(),
+            proxy: None,
        };

        let gate4 = GatewayBond {
-            bond_amount: _140foos,
+            pledge_amount: _140foos,
            owner: Addr::unchecked("foo4"),
            block_height: 120,
            gateway: gateway_fixture(),
+            proxy: None,
        };

        let gate5 = GatewayBond {
-            bond_amount: _0foos,
+            pledge_amount: _0foos,
            owner: Addr::unchecked("foo5"),
            block_height: 120,
            gateway: gateway_fixture(),
+            proxy: None,
        };

        // summary:
@@ -2,17 +2,20 @@
 // SPDX-License-Identifier: Apache-2.0

 mod delegation;
+pub mod error;
 mod gateway;
-mod mixnode;
+pub mod mixnode;
 mod msg;
 mod types;

+pub const MIXNODE_DELEGATORS_PAGE_LIMIT: usize = 250;
+
 pub use cosmwasm_std::{Addr, Coin};
 pub use delegation::{
-    Delegation, PagedAllDelegationsResponse, PagedMixDelegationsResponse,
-    PagedReverseMixDelegationsResponse, RawDelegationData, UnpackedDelegation,
+    Delegation, PagedAllDelegationsResponse, PagedDelegatorDelegationsResponse,
+    PagedMixDelegationsResponse,
 };
 pub use gateway::{Gateway, GatewayBond, GatewayOwnershipResponse, PagedGatewayResponse};
 pub use mixnode::{Layer, MixNode, MixNodeBond, MixOwnershipResponse, PagedMixnodeResponse};
-pub use msg::{ExecuteMsg, InstantiateMsg, MigrateMsg, QueryMsg};
-pub use types::{IdentityKey, IdentityKeyRef, LayerDistribution, SphinxKey, StateParams};
+pub use msg::*;
+pub use types::*;
@@ -2,15 +2,24 @@
 #![allow(clippy::field_reassign_with_default)]

 use crate::{IdentityKey, SphinxKey};
-use cosmwasm_std::{coin, Addr, Coin};
+use az::CheckedCast;
+use cosmwasm_std::{coin, Addr, Coin, Uint128};
+use log::error;
+use network_defaults::DEFAULT_OPERATOR_EPOCH_COST;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 use serde_repr::{Deserialize_repr, Serialize_repr};
 use std::cmp::Ordering;
 use std::fmt::Display;
-use ts_rs::TS;

-#[derive(Clone, Debug, Deserialize, PartialEq, PartialOrd, Serialize, JsonSchema, TS)]
+type U128 = fixed::types::U75F53; // u128 with 18 significant digits
+
+fixed::const_fixed_from_int! {
+    const ONE: U128 = 1;
+}
+
+#[cfg_attr(feature = "ts-rs", derive(ts_rs::TS))]
+#[derive(Clone, Debug, Deserialize, PartialEq, PartialOrd, Serialize, JsonSchema)]
 pub struct MixNode {
    pub host: String,
    pub mix_port: u16,
@@ -20,6 +29,7 @@ pub struct MixNode {
    /// Base58 encoded ed25519 EdDSA public key.
    pub identity_key: IdentityKey,
    pub version: String,
+    pub profit_margin_percent: u8,
 }

 #[derive(
@@ -43,40 +53,258 @@ pub enum Layer {
    Three = 3,
 }

+#[derive(Debug, Clone, JsonSchema, PartialEq, Serialize, Deserialize, Copy)]
+pub struct NodeRewardParams {
+    period_reward_pool: Uint128,
+    rewarded_set_size: Uint128,
+    active_set_size: Uint128,
+    reward_blockstamp: u64,
+    circulating_supply: Uint128,
+    uptime: Uint128,
+    sybil_resistance_percent: u8,
+    in_active_set: bool,
+    active_set_work_factor: u8,
+}
+
+impl NodeRewardParams {
+    #[allow(clippy::too_many_arguments)]
+    pub fn new(
+        period_reward_pool: u128,
+        rewarded_set_size: u128,
+        active_set_size: u128,
+        reward_blockstamp: u64,
+        circulating_supply: u128,
+        uptime: u128,
+        sybil_resistance_percent: u8,
+        in_active_set: bool,
+        active_set_work_factor: u8,
+    ) -> NodeRewardParams {
+        NodeRewardParams {
+            period_reward_pool: Uint128::new(period_reward_pool),
+            rewarded_set_size: Uint128::new(rewarded_set_size),
+            active_set_size: Uint128::new(active_set_size),
+            reward_blockstamp,
+            circulating_supply: Uint128::new(circulating_supply),
+            uptime: Uint128::new(uptime),
+            sybil_resistance_percent,
+            in_active_set,
+            active_set_work_factor,
+        }
+    }
+
+    pub fn omega(&self) -> U128 {
+        // As per keybase://chat/nymtech#tokeneconomics/1179
+        let denom = self.active_set_work_factor() * U128::from_num(self.rewarded_set_size())
+            - (self.active_set_work_factor() - ONE) * U128::from_num(self.idle_nodes().u128());
+
+        if self.in_active_set() {
+            // work_active = factor / (factor * self.network.k[month] - (factor - 1) * idle_nodes)
+            self.active_set_work_factor() / denom * self.rewarded_set_size()
+        } else {
+            // work_idle = 1 / (factor * self.network.k[month] - (factor - 1) * idle_nodes)
+            ONE / denom * self.rewarded_set_size()
+        }
+    }
+
+    pub fn idle_nodes(&self) -> Uint128 {
+        self.rewarded_set_size - self.active_set_size
+    }
+
+    pub fn active_set_work_factor(&self) -> U128 {
+        U128::from_num(self.active_set_work_factor)
+    }
+
+    pub fn in_active_set(&self) -> bool {
+        self.in_active_set
+    }
+
+    pub fn performance(&self) -> U128 {
+        U128::from_num(self.uptime.u128()) / U128::from_num(100)
+    }
+
+    pub fn operator_cost(&self) -> U128 {
+        U128::from_num(self.uptime.u128() / 100u128 * DEFAULT_OPERATOR_EPOCH_COST as u128)
+    }
+
+    pub fn set_reward_blockstamp(&mut self, blockstamp: u64) {
+        self.reward_blockstamp = blockstamp;
+    }
+
+    pub fn period_reward_pool(&self) -> u128 {
+        self.period_reward_pool.u128()
+    }
+
+    pub fn rewarded_set_size(&self) -> u128 {
+        self.rewarded_set_size.u128()
+    }
+
+    pub fn circulating_supply(&self) -> u128 {
+        self.circulating_supply.u128()
+    }
+
+    pub fn reward_blockstamp(&self) -> u64 {
+        self.reward_blockstamp
+    }
+
+    pub fn uptime(&self) -> u128 {
+        self.uptime.u128()
+    }
+
+    pub fn one_over_k(&self) -> U128 {
+        ONE / U128::from_num(self.rewarded_set_size.u128())
+    }
+
+    pub fn alpha(&self) -> U128 {
+        U128::from_num(self.sybil_resistance_percent) / U128::from_num(100)
+    }
+}
+
+// cosmwasm's limited serde doesn't work with U128 directly
+#[allow(non_snake_case)]
+pub mod fixed_U128_as_string {
+    use super::U128;
+    use serde::de::Error;
+    use serde::Deserialize;
+    use std::str::FromStr;
+
+    pub fn serialize<S>(val: &U128, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        let s = (*val).to_string();
+        serializer.serialize_str(&s)
+    }
+
+    pub fn deserialize<'de, D>(deserializer: D) -> Result<U128, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let s = String::deserialize(deserializer)?;
+        U128::from_str(&s).map_err(|err| {
+            D::Error::custom(format!(
+                "failed to deserialize U128 with its string representation - {}",
+                err
+            ))
+        })
+    }
+}
+
+// everything required to reward delegator of given mixnode
+#[derive(Debug, Clone, Copy, Serialize, Deserialize, JsonSchema)]
+pub struct DelegatorRewardParams {
+    node_reward_params: NodeRewardParams,
+
+    // to be completely honest I don't understand all consequences of using `#[schemars(with = "String")]`
+    // for U128 here, but it seems that CosmWasm is using the same attribute for their Uint128
+    #[schemars(with = "String")]
+    #[serde(with = "fixed_U128_as_string")]
+    sigma: U128,
+    #[schemars(with = "String")]
+    #[serde(with = "fixed_U128_as_string")]
+    profit_margin: U128,
+    #[schemars(with = "String")]
+    #[serde(with = "fixed_U128_as_string")]
+    node_profit: U128,
+}
+
+impl DelegatorRewardParams {
+    pub fn new(mixnode_bond: &MixNodeBond, node_reward_params: NodeRewardParams) -> Self {
+        DelegatorRewardParams {
+            sigma: mixnode_bond.sigma(&node_reward_params),
+            profit_margin: mixnode_bond.profit_margin(),
+            node_profit: mixnode_bond.node_profit(&node_reward_params),
+            node_reward_params,
+        }
+    }
+
+    pub fn determine_delegation_reward(&self, delegation_amount: Uint128) -> u128 {
+        // change all values into their fixed representations
+        let delegation_amount = U128::from_num(delegation_amount.u128());
+        let circulating_supply = U128::from_num(self.node_reward_params.circulating_supply());
+
+        let scaled_delegation_amount = delegation_amount / circulating_supply;
+        let delegator_reward =
+            (ONE - self.profit_margin) * scaled_delegation_amount / self.sigma * self.node_profit;
+
+        let reward = delegator_reward.max(U128::ZERO);
+        if let Some(int_reward) = reward.checked_cast() {
+            int_reward
+        } else {
+            error!(
+                "Could not cast delegator reward ({}) to u128, returning 0",
+                reward,
+            );
+            0u128
+        }
+    }
+
+    pub fn node_reward_params(&self) -> &NodeRewardParams {
+        &self.node_reward_params
+    }
+}
+
+#[derive(Debug)]
+pub struct NodeRewardResult {
+    reward: U128,
+    lambda: U128,
+    sigma: U128,
+}
+
+impl NodeRewardResult {
+    pub fn reward(&self) -> U128 {
+        self.reward
+    }
+
+    pub fn lambda(&self) -> U128 {
+        self.lambda
+    }
+
+    pub fn sigma(&self) -> U128 {
+        self.sigma
+    }
+}
+
 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize, JsonSchema)]
 pub struct MixNodeBond {
-    pub bond_amount: Coin,
+    pub pledge_amount: Coin,
    pub total_delegation: Coin,
    pub owner: Addr,
    pub layer: Layer,
    pub block_height: u64,
    pub mix_node: MixNode,
+    pub proxy: Option<Addr>,
 }

 impl MixNodeBond {
    pub fn new(
-        bond_amount: Coin,
+        pledge_amount: Coin,
        owner: Addr,
        layer: Layer,
        block_height: u64,
        mix_node: MixNode,
+        proxy: Option<Addr>,
    ) -> Self {
        MixNodeBond {
-            total_delegation: coin(0, &bond_amount.denom),
-            bond_amount,
+            total_delegation: coin(0, &pledge_amount.denom),
+            pledge_amount,
            owner,
            layer,
            block_height,
            mix_node,
+            proxy,
        }
    }

+    pub fn profit_margin(&self) -> U128 {
+        U128::from_num(self.mix_node.profit_margin_percent) / U128::from_num(100)
+    }
+
    pub fn identity(&self) -> &String {
        &self.mix_node.identity_key
    }

-    pub fn bond_amount(&self) -> Coin {
-        self.bond_amount.clone()
+    pub fn pledge_amount(&self) -> Coin {
+        self.pledge_amount.clone()
    }

    pub fn owner(&self) -> &Addr {
@@ -86,38 +314,138 @@ impl MixNodeBond {
    pub fn mix_node(&self) -> &MixNode {
        &self.mix_node
    }
+
+    pub fn total_stake(&self) -> Option<u128> {
+        if self.pledge_amount.denom != self.total_delegation.denom {
+            None
+        } else {
+            Some(self.pledge_amount.amount.u128() + self.total_delegation.amount.u128())
+        }
+    }
+
+    pub fn total_delegation(&self) -> Coin {
+        self.total_delegation.clone()
+    }
+
+    pub fn pledge_to_circulating_supply(&self, circulating_supply: u128) -> U128 {
+        U128::from_num(self.pledge_amount().amount.u128()) / U128::from_num(circulating_supply)
+    }
+
+    pub fn total_bond_to_circulating_supply(&self, circulating_supply: u128) -> U128 {
+        U128::from_num(self.pledge_amount().amount.u128() + self.total_delegation().amount.u128())
+            / U128::from_num(circulating_supply)
+    }
+
+    pub fn lambda(&self, params: &NodeRewardParams) -> U128 {
+        // Ratio of a bond to the token circulating supply
+        let pledge_to_circulating_supply_ratio =
+            self.pledge_to_circulating_supply(params.circulating_supply());
+        pledge_to_circulating_supply_ratio.min(params.one_over_k())
+    }
+
+    pub fn sigma(&self, params: &NodeRewardParams) -> U128 {
+        // Ratio of a delegation to the the token circulating supply
+        let total_bond_to_circulating_supply_ratio =
+            self.total_bond_to_circulating_supply(params.circulating_supply());
+        total_bond_to_circulating_supply_ratio.min(params.one_over_k())
+    }
+
+    pub fn reward(&self, params: &NodeRewardParams) -> NodeRewardResult {
+        let lambda = self.lambda(params);
+        let sigma = self.sigma(params);
+
+        let reward = params.performance()
+            * params.period_reward_pool()
+            * (sigma * params.omega()
+                + params.alpha() * lambda * sigma * params.rewarded_set_size())
+            / (ONE + params.alpha());
+
+        NodeRewardResult {
+            reward,
+            lambda,
+            sigma,
+        }
+    }
+
+    pub fn node_profit(&self, params: &NodeRewardParams) -> U128 {
+        if self.reward(params).reward() < params.operator_cost() {
+            U128::from_num(0)
+        } else {
+            self.reward(params).reward() - params.operator_cost()
+        }
+    }
+
+    pub fn operator_reward(&self, params: &NodeRewardParams) -> u128 {
+        let reward = self.reward(params);
+        let profit = if reward.reward < params.operator_cost() {
+            U128::from_num(0)
+        } else {
+            reward.reward - params.operator_cost()
+        };
+        let operator_base_reward = reward.reward.min(params.operator_cost());
+        let operator_reward = (self.profit_margin()
+            + (ONE - self.profit_margin()) * reward.lambda / reward.sigma)
+            * profit;
+
+        let reward = (operator_reward + operator_base_reward).max(U128::from_num(0));
+
+        if let Some(int_reward) = reward.checked_cast() {
+            int_reward
+        } else {
+            error!(
+                "Could not cast reward ({}) to u128, returning 0 - mixnode {}",
+                reward,
+                self.identity()
+            );
+            0u128
+        }
+    }
+
+    pub fn sigma_ratio(&self, params: &NodeRewardParams) -> U128 {
+        if self.total_bond_to_circulating_supply(params.circulating_supply()) < params.one_over_k()
+        {
+            self.total_bond_to_circulating_supply(params.circulating_supply())
+        } else {
+            params.one_over_k()
+        }
+    }
+
+    pub fn reward_delegation(&self, delegation_amount: Uint128, params: &NodeRewardParams) -> u128 {
+        let reward_params = DelegatorRewardParams::new(self, *params);
+        reward_params.determine_delegation_reward(delegation_amount)
+    }
 }

 impl PartialOrd for MixNodeBond {
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        // first remove invalid cases
-        if self.bond_amount.denom != self.total_delegation.denom {
+        if self.pledge_amount.denom != self.total_delegation.denom {
            return None;
        }

-        if other.bond_amount.denom != other.total_delegation.denom {
+        if other.pledge_amount.denom != other.total_delegation.denom {
            return None;
        }

-        if self.bond_amount.denom != other.bond_amount.denom {
+        if self.pledge_amount.denom != other.pledge_amount.denom {
            return None;
        }

        // try to order by total bond + delegation
-        let total_cmp = (self.bond_amount.amount + self.total_delegation.amount)
-            .partial_cmp(&(self.bond_amount.amount + self.total_delegation.amount))?;
+        let total_cmp = (self.pledge_amount.amount + self.total_delegation.amount)
+            .partial_cmp(&(self.pledge_amount.amount + self.total_delegation.amount))?;

        if total_cmp != Ordering::Equal {
            return Some(total_cmp);
        }

        // then if those are equal, prefer higher bond over delegation
-        let bond_cmp = self
-            .bond_amount
+        let pledge_cmp = self
+            .pledge_amount
            .amount
-            .partial_cmp(&other.bond_amount.amount)?;
-        if bond_cmp != Ordering::Equal {
-            return Some(bond_cmp);
+            .partial_cmp(&other.pledge_amount.amount)?;
+        if pledge_cmp != Ordering::Equal {
+            return Some(pledge_cmp);
        }

        // then look at delegation (I'm not sure we can get here, but better safe than sorry)
@@ -156,7 +484,10 @@ impl Display for MixNodeBond {
        write!(
            f,
            "amount: {} {}, owner: {}, identity: {}",
-            self.bond_amount.amount, self.bond_amount.denom, self.owner, self.mix_node.identity_key
+            self.pledge_amount.amount,
+            self.pledge_amount.denom,
+            self.owner,
+            self.mix_node.identity_key
        )
    }
 }
@@ -185,7 +516,7 @@ impl PagedMixnodeResponse {
 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize, JsonSchema)]
 pub struct MixOwnershipResponse {
    pub address: Addr,
-    pub has_node: bool,
+    pub mixnode: Option<MixNodeBond>,
 }

 #[cfg(test)]
@@ -201,6 +532,7 @@ mod tests {
            sphinx_key: "sphinxkey".to_string(),
            identity_key: "identitykey".to_string(),
            version: "0.11.0".to_string(),
+            profit_margin_percent: 10,
        }
    }

@@ -211,48 +543,53 @@ mod tests {
        let _0foos = Coin::new(0, "foo");

        let mix1 = MixNodeBond {
-            bond_amount: _150foos.clone(),
+            pledge_amount: _150foos.clone(),
            total_delegation: _50foos.clone(),
            owner: Addr::unchecked("foo1"),
            layer: Layer::One,
            block_height: 100,
            mix_node: mixnode_fixture(),
+            proxy: None,
        };

        let mix2 = MixNodeBond {
-            bond_amount: _150foos.clone(),
+            pledge_amount: _150foos.clone(),
            total_delegation: _50foos.clone(),
            owner: Addr::unchecked("foo2"),
            layer: Layer::One,
            block_height: 120,
            mix_node: mixnode_fixture(),
+            proxy: None,
        };

        let mix3 = MixNodeBond {
-            bond_amount: _50foos,
+            pledge_amount: _50foos,
            total_delegation: _150foos.clone(),
            owner: Addr::unchecked("foo3"),
            layer: Layer::One,
            block_height: 120,
            mix_node: mixnode_fixture(),
+            proxy: None,
        };

        let mix4 = MixNodeBond {
-            bond_amount: _150foos.clone(),
+            pledge_amount: _150foos.clone(),
            total_delegation: _0foos.clone(),
            owner: Addr::unchecked("foo4"),
            layer: Layer::One,
            block_height: 120,
            mix_node: mixnode_fixture(),
+            proxy: None,
        };

        let mix5 = MixNodeBond {
-            bond_amount: _0foos,
+            pledge_amount: _0foos,
            total_delegation: _150foos,
            owner: Addr::unchecked("foo5"),
            layer: Layer::One,
            block_height: 120,
            mix_node: mixnode_fixture(),
+            proxy: None,
        };

        // summary:
@@ -1,27 +1,31 @@
 // Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0

-use crate::StateParams;
+use crate::mixnode::NodeRewardParams;
+use crate::ContractStateParams;
 use crate::{Gateway, IdentityKey, MixNode};
-use cosmwasm_std::Addr;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};

 #[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
-pub struct InstantiateMsg {}
+pub struct InstantiateMsg {
+    pub rewarding_validator_address: String,
+}

 #[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
 #[serde(rename_all = "snake_case")]
 pub enum ExecuteMsg {
    BondMixnode {
        mix_node: MixNode,
+        owner_signature: String,
    },
    UnbondMixnode {},
    BondGateway {
        gateway: Gateway,
+        owner_signature: String,
    },
    UnbondGateway {},
-    UpdateStateParams(StateParams),
+    UpdateContractStateParams(ContractStateParams),

    DelegateToMixnode {
        mix_identity: IdentityKey,
@@ -31,16 +35,59 @@ pub enum ExecuteMsg {
        mix_identity: IdentityKey,
    },

+    BeginMixnodeRewarding {
+        // nonce of the current rewarding interval
+        rewarding_interval_nonce: u32,
+    },
+
+    FinishMixnodeRewarding {
+        // nonce of the current rewarding interval
+        rewarding_interval_nonce: u32,
+    },
+
    RewardMixnode {
        identity: IdentityKey,
        // percentage value in range 0-100
-        uptime: u32,
+        params: NodeRewardParams,
+
+        // nonce of the current rewarding interval
+        rewarding_interval_nonce: u32,
+    },
+    RewardNextMixDelegators {
+        mix_identity: IdentityKey,
+        // nonce of the current rewarding interval
+        rewarding_interval_nonce: u32,
+    },
+    DelegateToMixnodeOnBehalf {
+        mix_identity: IdentityKey,
+        delegate: String,
+    },
+    UndelegateFromMixnodeOnBehalf {
+        mix_identity: IdentityKey,
+        delegate: String,
+    },
+    BondMixnodeOnBehalf {
+        mix_node: MixNode,
+        owner: String,
+        owner_signature: String,
+    },
+    UnbondMixnodeOnBehalf {
+        owner: String,
+    },
+    BondGatewayOnBehalf {
+        gateway: Gateway,
+        owner: String,
+        owner_signature: String,
+    },
+    UnbondGatewayOnBehalf {
+        owner: String,
    },
 }

 #[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
 #[serde(rename_all = "snake_case")]
 pub enum QueryMsg {
+    GetContractVersion {},
    GetMixNodes {
        limit: Option<u32>,
        start_after: Option<IdentityKey>,
@@ -50,31 +97,49 @@ pub enum QueryMsg {
        limit: Option<u32>,
    },
    OwnsMixnode {
-        address: Addr,
+        address: String,
    },
    OwnsGateway {
-        address: Addr,
+        address: String,
    },
    StateParams {},
-    GetMixDelegations {
+    CurrentRewardingInterval {},
+    // gets all [paged] delegations in the entire network
+    // TODO: do we even want that?
+    GetAllNetworkDelegations {
+        start_after: Option<(IdentityKey, String)>,
+        limit: Option<u32>,
+    },
+    // gets all [paged] delegations associated with particular mixnode
+    GetMixnodeDelegations {
        mix_identity: IdentityKey,
-        start_after: Option<Addr>,
+        // since `start_after` is user-provided input, we can't use `Addr` as we
+        // can't guarantee it's validated.
+        start_after: Option<String>,
        limit: Option<u32>,
    },
-    GetAllMixDelegations {
-        start_after: Option<Vec<u8>>,
-        limit: Option<u32>,
-    },
-    GetReverseMixDelegations {
-        delegation_owner: Addr,
+    // gets all [paged] delegations associated with particular delegator
+    GetDelegatorDelegations {
+        // since `delegator` is user-provided input, we can't use `Addr` as we
+        // can't guarantee it's validated.
+        delegator: String,
        start_after: Option<IdentityKey>,
        limit: Option<u32>,
    },
-    GetMixDelegation {
+    // gets delegation associated with particular mixnode, delegator pair
+    GetDelegationDetails {
        mix_identity: IdentityKey,
-        address: Addr,
+        delegator: String,
    },
    LayerDistribution {},
+    GetRewardPool {},
+    GetCirculatingSupply {},
+    GetEpochRewardPercent {},
+    GetSybilResistancePercent {},
+    GetRewardingStatus {
+        mix_identity: IdentityKey,
+        rewarding_interval_nonce: u32,
+    },
 }

 #[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
@@ -1,8 +1,9 @@
 // Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0

+use crate::mixnode::DelegatorRewardParams;
 use crate::Layer;
-use cosmwasm_std::{Decimal, Uint128};
+use cosmwasm_std::{Addr, Uint128};
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 use std::fmt::{self, Display, Formatter};
@@ -26,42 +27,111 @@ impl LayerDistribution {
    }
 }

-#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
-pub struct StateParams {
-    pub epoch_length: u32, // length of an epoch, expressed in hours
-
-    pub minimum_mixnode_bond: Uint128, // minimum amount a mixnode must bond to get into the system
-    pub minimum_gateway_bond: Uint128, // minimum amount a gateway must bond to get into the system
-
-    pub mixnode_bond_reward_rate: Decimal, // annual reward rate, expressed as a decimal like 1.25
-    pub mixnode_delegation_reward_rate: Decimal, // annual reward rate, expressed as a decimal like 1.25
-    pub mixnode_active_set_size: u32,
+#[derive(Debug, Default, Serialize, Deserialize, Copy, Clone, Eq, PartialEq)]
+pub struct RewardingIntervalResponse {
+    pub current_rewarding_interval_starting_block: u64,
+    pub current_rewarding_interval_nonce: u32,
+    pub rewarding_in_progress: bool,
 }

-impl Display for StateParams {
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
+pub struct ContractStateParams {
+    // so currently epoch_length is being unused and validator API performs rewarding
+    // based on its own epoch length config value. I guess that's fine for time being
+    // however, in the future, the contract constant should be controlling it instead.
+    // pub epoch_length: u32, // length of a rewarding epoch/interval, expressed in hours
+    pub minimum_mixnode_pledge: Uint128, // minimum amount a mixnode must pledge to get into the system
+    pub minimum_gateway_pledge: Uint128, // minimum amount a gateway must pledge to get into the system
+
+    // number of mixnode that are going to get rewarded during current rewarding interval (k_m)
+    // based on overall demand for private bandwidth-
+    pub mixnode_rewarded_set_size: u32,
+
+    // subset of rewarded mixnodes that are actively receiving mix traffic
+    // used to handle shorter-term (e.g. hourly) fluctuations of demand
+    pub mixnode_active_set_size: u32,
+    pub active_set_work_factor: u8,
+}
+
+impl Display for ContractStateParams {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        write!(f, "Contract state parameters: [ ")?;
-        write!(f, "epoch length: {}; ", self.epoch_length)?;
-        write!(f, "minimum mixnode bond: {}; ", self.minimum_mixnode_bond)?;
-        write!(f, "minimum gateway bond: {}; ", self.minimum_gateway_bond)?;
        write!(
            f,
-            "mixnode bond reward rate: {}; ",
-            self.mixnode_bond_reward_rate
+            "minimum mixnode pledge: {}; ",
+            self.minimum_mixnode_pledge
        )?;
        write!(
            f,
-            "mixnode delegation reward rate: {}; ",
-            self.mixnode_delegation_reward_rate
+            "minimum gateway pledge: {}; ",
+            self.minimum_gateway_pledge
+        )?;
+        write!(
+            f,
+            "mixnode rewarded set size: {}",
+            self.mixnode_rewarded_set_size
        )?;
        write!(
            f,
            "mixnode active set size: {}",
            self.mixnode_active_set_size
+        )?;
+        write!(
+            f,
+            "mixnode active set work factor: {}",
+            self.active_set_work_factor
        )
    }
 }

+#[derive(Default, Debug, Serialize, Deserialize, PartialEq)]
+pub struct RewardingResult {
+    pub operator_reward: Uint128,
+    pub total_delegator_reward: Uint128,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct PendingDelegatorRewarding {
+    // keep track of the running rewarding results so we'd known how much was the operator and its delegators rewarded
+    pub running_results: RewardingResult,
+
+    pub next_start: Addr,
+
+    pub rewarding_params: DelegatorRewardParams,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub enum RewardingStatus {
+    Complete(RewardingResult),
+    PendingNextDelegatorPage(PendingDelegatorRewarding),
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct MixnodeRewardingStatusResponse {
+    pub status: Option<RewardingStatus>,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct MixnetContractVersion {
+    // VERGEN_BUILD_TIMESTAMP
+    pub build_timestamp: String,
+
+    // VERGEN_BUILD_SEMVER
+    pub build_version: String,
+
+    // VERGEN_GIT_SHA
+    pub commit_sha: String,
+
+    // VERGEN_GIT_COMMIT_TIMESTAMP
+    pub commit_timestamp: String,
+
+    // VERGEN_GIT_BRANCH
+    pub commit_branch: String,
+
+    // VERGEN_RUSTC_SEMVER
+    pub rustc_version: String,
+}
+
 // type aliases for better reasoning about available data
 pub type IdentityKey = String;
 pub type IdentityKeyRef<'a> = &'a str;
@@ -7,6 +7,7 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

 [dependencies]
+hex-literal = "0.3.3"
 serde = {version = "1.0", features = ["derive"]}
 url = "2.2"
 time = { version = "0.3", features = ["macros"] }
@@ -0,0 +1,132 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+// This should be modified whenever an updated Ethereum contract is uploaded
+pub const ETH_JSON_ABI: &str = r#"
+[
+  {
+    "inputs": [
+      {
+        "internalType": "contract ERC20Burnable",
+        "name": "_erc20",
+        "type": "address"
+      }
+    ],
+    "stateMutability": "nonpayable",
+    "type": "constructor"
+  },
+  {
+    "anonymous": false,
+    "inputs": [
+      {
+        "indexed": false,
+        "internalType": "uint256",
+        "name": "Bandwidth",
+        "type": "uint256"
+      },
+      {
+        "indexed": true,
+        "internalType": "uint256",
+        "name": "VerificationKey",
+        "type": "uint256"
+      },
+      {
+        "indexed": false,
+        "internalType": "bytes",
+        "name": "SignedVerificationKey",
+        "type": "bytes"
+      }
+    ],
+    "name": "Burned",
+    "type": "event"
+  },
+  {
+    "anonymous": false,
+    "inputs": [
+      {
+        "indexed": true,
+        "internalType": "address",
+        "name": "previousOwner",
+        "type": "address"
+      },
+      {
+        "indexed": true,
+        "internalType": "address",
+        "name": "newOwner",
+        "type": "address"
+      }
+    ],
+    "name": "OwnershipTransferred",
+    "type": "event"
+  },
+  {
+    "inputs": [
+      {
+        "internalType": "uint256",
+        "name": "amount",
+        "type": "uint256"
+      },
+      {
+        "internalType": "uint256",
+        "name": "verificationKey",
+        "type": "uint256"
+      },
+      {
+        "internalType": "bytes",
+        "name": "signedVerificationKey",
+        "type": "bytes"
+      }
+    ],
+    "name": "burnTokenForAccessCode",
+    "outputs": [],
+    "stateMutability": "nonpayable",
+    "type": "function"
+  },
+  {
+    "inputs": [],
+    "name": "erc20",
+    "outputs": [
+      {
+        "internalType": "contract ERC20Burnable",
+        "name": "",
+        "type": "address"
+      }
+    ],
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "inputs": [],
+    "name": "owner",
+    "outputs": [
+      {
+        "internalType": "address",
+        "name": "",
+        "type": "address"
+      }
+    ],
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "inputs": [],
+    "name": "renounceOwnership",
+    "outputs": [],
+    "stateMutability": "nonpayable",
+    "type": "function"
+  },
+  {
+    "inputs": [
+      {
+        "internalType": "address",
+        "name": "newOwner",
+        "type": "address"
+      }
+    ],
+    "name": "transferOwnership",
+    "outputs": [],
+    "stateMutability": "nonpayable",
+    "type": "function"
+  }
+]
+        "#;
@@ -5,6 +5,8 @@ use std::time::Duration;
 use time::OffsetDateTime;
 use url::Url;

+pub mod eth_contract;
+
 #[derive(Debug, Serialize, Deserialize, Clone)]
 pub struct ValidatorDetails {
    // it is assumed those values are always valid since they're being provided in our defaults file
@@ -61,7 +63,25 @@ pub fn default_api_endpoints() -> Vec<Url> {
 }

 pub const DEFAULT_MIXNET_CONTRACT_ADDRESS: &str = "punk10pyejy66429refv3g35g2t7am0was7yalwrzen";
-pub const NETWORK_MONITOR_ADDRESS: &str = "punk1v9qauwdq5terag6uvfsdytcs2d0sdmfdy7hgk3";
+pub const DEFAULT_VESTING_CONTRACT_ADDRESS: &str = "";
+pub const REWARDING_VALIDATOR_ADDRESS: &str = "punk1v9qauwdq5terag6uvfsdytcs2d0sdmfdy7hgk3";
+
+/// How much bandwidth (in bytes) one token can buy
+const BYTES_PER_TOKEN: u64 = 1024 * 1024 * 1024;
+/// How many ERC20 tokens should be burned to buy bandwidth
+pub const TOKENS_TO_BURN: u64 = 10;
+/// Default bandwidth (in bytes) that we try to buy
+pub const BANDWIDTH_VALUE: u64 = TOKENS_TO_BURN * BYTES_PER_TOKEN;
+
+// Ethereum constants used for token bridge
+pub const ETH_CONTRACT_ADDRESS: [u8; 20] =
+    hex_literal::hex!("9fEE3e28c17dbB87310A51F13C4fbf4331A6f102");
+pub const ETH_MIN_BLOCK_DEPTH: usize = 7;
+pub const COSMOS_CONTRACT_ADDRESS: &str = "punk1jld76tqw4wnpfenmay2xkv86nr3j0w426eka82";
+// Name of the event triggered by the eth contract. If the event name is changed,
+// this would also need to be changed; It is currently tested against the json abi
+pub const ETH_EVENT_NAME: &str = "Burned";
+pub const ETH_BURN_FUNCTION_NAME: &str = "burnTokenForAccessCode";

 /// Defaults Cosmos Hub/ATOM path
 pub const COSMOS_DERIVATION_PATH: &str = "m/44'/118'/0'/0/0";
@@ -93,4 +113,11 @@ pub const VALIDATOR_API_VERSION: &str = "v1";

 // REWARDING
 pub const DEFAULT_FIRST_EPOCH_START: OffsetDateTime = time::macros::datetime!(2021-08-23 12:00 UTC);
-pub const DEFAULT_EPOCH_LENGTH: Duration = Duration::from_secs(24 * 60 * 60); // 24h
+pub const DEFAULT_EPOCH_LENGTH: Duration = Duration::from_secs(24 * 60 * 60 * 30); // 30 days
+/// We'll be assuming a few more things, profit margin and cost function. Since we don't have relialable package measurement, we'll be using uptime. We'll also set the value of 1 Nym to 1 $, to be able to translate epoch costs to Nyms. We'll also assume a cost of 40$ per epoch(month), converting that to Nym at our 1$ rate translates to 40_000_000 uNyms
+pub const DEFAULT_OPERATOR_EPOCH_COST: u64 = 40_000_000; // 40$/(30 days) at 1 Nym == 1$
+
+// TODO: is there a way to get this from the chain
+pub const TOTAL_SUPPLY: u128 = 1_000_000_000_000_000;
+
+pub const DEFAULT_PROFIT_MARGIN: u8 = 10;
@@ -0,0 +1,43 @@
+[package]
+name = "nymcoconut"
+version = "0.5.0"
+authors = ["Jedrzej Stuczynski <andrew@nymtech.net>", "Ania Piotrowska <ania@nymtech.net>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+bls12_381 = { version = "0.5", default-features = false, features = ["pairings", "alloc", "experimental"] }
+itertools = "0.10"
+digest = "0.9"
+rand = "0.8"
+thiserror = "1.0"
+serde = "1.0"
+serde_derive = "1.0"
+bs58 = "0.4.0"
+sha2 = "0.9"
+
+[dependencies.ff]
+version = "0.10"
+default-features = false
+
+[dependencies.group]
+version = "0.10"
+default-features = false
+
+[dev-dependencies]
+criterion = { version="0.3", features=["html_reports"] }
+doc-comment = "0.3"
+
+[dev-dependencies.bincode]
+version = "1"
+
+#[[bench]]
+#name = "benchmarks"
+#harness = false
+
+[features]
+default = []
+
+[target.'cfg(target_env = "wasm32-unknown-unknown")'.dependencies]
+getrandom = { version="0.2", features=["js"] }
@@ -0,0 +1,322 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+use core::ops::{Deref, Mul};
+use std::convert::TryFrom;
+use std::convert::TryInto;
+
+use bls12_381::{G1Projective, Scalar};
+use group::Curve;
+use serde_derive::{Deserialize, Serialize};
+
+use crate::error::{CoconutError, Result};
+use crate::scheme::setup::Parameters;
+use crate::traits::{Base58, Bytable};
+use crate::utils::{try_deserialize_g1_projective, try_deserialize_scalar};
+
+/// Type alias for the ephemeral key generated during ElGamal encryption
+pub type EphemeralKey = Scalar;
+
+/// Two G1 points representing ElGamal ciphertext
+#[derive(Debug)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct Ciphertext(pub(crate) G1Projective, pub(crate) G1Projective);
+
+impl TryFrom<&[u8]> for Ciphertext {
+    type Error = CoconutError;
+
+    fn try_from(bytes: &[u8]) -> Result<Ciphertext> {
+        if bytes.len() != 96 {
+            return Err(CoconutError::Deserialization(format!(
+                "Ciphertext must be exactly 96 bytes, got {}",
+                bytes.len()
+            )));
+        }
+
+        let c1_bytes: &[u8; 48] = &bytes[..48].try_into().unwrap();
+        let c2_bytes: &[u8; 48] = &bytes[48..].try_into().unwrap();
+
+        let c1 = try_deserialize_g1_projective(
+            c1_bytes,
+            CoconutError::Deserialization("Failed to deserialize compressed c1".to_string()),
+        )?;
+        let c2 = try_deserialize_g1_projective(
+            c2_bytes,
+            CoconutError::Deserialization("Failed to deserialize compressed c2".to_string()),
+        )?;
+
+        Ok(Ciphertext(c1, c2))
+    }
+}
+
+impl Ciphertext {
+    pub fn c1(&self) -> &G1Projective {
+        &self.0
+    }
+
+    pub fn c2(&self) -> &G1Projective {
+        &self.1
+    }
+
+    pub fn to_bytes(&self) -> [u8; 96] {
+        let mut bytes = [0u8; 96];
+        bytes[..48].copy_from_slice(&self.0.to_affine().to_compressed());
+        bytes[48..].copy_from_slice(&self.1.to_affine().to_compressed());
+        bytes
+    }
+
+    pub fn from_bytes(bytes: &[u8]) -> Result<Ciphertext> {
+        Ciphertext::try_from(bytes)
+    }
+}
+
+/// PrivateKey used in the ElGamal encryption scheme to recover the plaintext
+#[derive(Debug)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct PrivateKey(pub(crate) Scalar);
+
+impl PrivateKey {
+    /// Decrypt takes the ElGamal encryption of a message and returns a point on the G1 curve
+    /// that represents original h^m.
+    pub fn decrypt(&self, ciphertext: &Ciphertext) -> G1Projective {
+        let (c1, c2) = &(ciphertext.0, ciphertext.1);
+
+        // (gamma^k * h^m) / (g1^{d * k})   |   note: gamma = g1^d
+        c2 - c1 * self.0
+    }
+
+    pub fn public_key(&self, params: &Parameters) -> PublicKey {
+        PublicKey(params.gen1() * self.0)
+    }
+
+    pub fn to_bytes(&self) -> [u8; 32] {
+        self.0.to_bytes()
+    }
+
+    pub fn from_bytes(bytes: &[u8; 32]) -> Result<PrivateKey> {
+        try_deserialize_scalar(
+            bytes,
+            CoconutError::Deserialization(
+                "Failed to deserialize ElGamal private key - it was not in the canonical form"
+                    .to_string(),
+            ),
+        )
+        .map(PrivateKey)
+    }
+}
+
+impl Bytable for PrivateKey {
+    fn to_byte_vec(&self) -> Vec<u8> {
+        self.to_bytes().to_vec()
+    }
+
+    fn try_from_byte_slice(slice: &[u8]) -> Result<Self> {
+        PrivateKey::from_bytes(slice.try_into().unwrap())
+    }
+}
+
+impl Base58 for PrivateKey {}
+
+// TODO: perhaps be more explicit and apart from gamma also store generator and group order?
+/// PublicKey used in the ElGamal encryption scheme to produce the ciphertext
+#[derive(Debug, Clone)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct PublicKey(G1Projective);
+
+impl PublicKey {
+    /// Encrypt encrypts the given message in the form of h^m,
+    /// where h is a point on the G1 curve using the given public key.
+    /// The random k is returned alongside the encryption
+    /// as it is required by the Coconut Scheme to create proofs of knowledge.
+    pub fn encrypt(
+        &self,
+        params: &Parameters,
+        h: &G1Projective,
+        msg: &Scalar,
+    ) -> (Ciphertext, EphemeralKey) {
+        let k = params.random_scalar();
+        // c1 = g1^k
+        let c1 = params.gen1() * k;
+        // c2 = gamma^k * h^m
+        let c2 = self.0 * k + h * msg;
+
+        (Ciphertext(c1, c2), k)
+    }
+
+    pub fn to_bytes(&self) -> [u8; 48] {
+        self.to_byte_vec().try_into().unwrap()
+    }
+
+    pub fn from_bytes(bytes: &[u8; 48]) -> Result<PublicKey> {
+        Ok(PublicKey::try_from(bytes.to_vec().as_slice()).unwrap())
+    }
+}
+
+impl Bytable for PublicKey {
+    fn to_byte_vec(&self) -> Vec<u8> {
+        self.0.to_affine().to_compressed().into()
+    }
+
+    fn try_from_byte_slice(slice: &[u8]) -> Result<Self> {
+        Ok(PublicKey::from_bytes(slice.try_into().unwrap()).unwrap())
+    }
+}
+
+impl TryFrom<&[u8]> for PublicKey {
+    type Error = CoconutError;
+
+    fn try_from(slice: &[u8]) -> Result<PublicKey> {
+        try_deserialize_g1_projective(
+            slice.try_into().unwrap(),
+            CoconutError::Deserialization(
+                "Failed to deserialize compressed ElGamal public key".to_string(),
+            ),
+        )
+        .map(PublicKey)
+    }
+}
+
+impl Base58 for PublicKey {}
+
+impl Deref for PublicKey {
+    type Target = G1Projective;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl<'a, 'b> Mul<&'b Scalar> for &'a PublicKey {
+    type Output = G1Projective;
+
+    fn mul(self, rhs: &'b Scalar) -> Self::Output {
+        self.0 * rhs
+    }
+}
+
+#[derive(Serialize, Deserialize)]
+/// A convenient wrapper for both keys of the ElGamal keypair
+pub struct ElGamalKeyPair {
+    private_key: PrivateKey,
+    public_key: PublicKey,
+}
+
+impl ElGamalKeyPair {
+    pub fn public_key(&self) -> &PublicKey {
+        &self.public_key
+    }
+
+    pub fn private_key(&self) -> &PrivateKey {
+        &self.private_key
+    }
+}
+
+/// Generate a fresh ElGamal keypair using the group generator specified by the provided [Parameters]
+pub fn elgamal_keygen(params: &Parameters) -> ElGamalKeyPair {
+    let private_key = params.random_scalar();
+    let gamma = params.gen1() * private_key;
+
+    ElGamalKeyPair {
+        private_key: PrivateKey(private_key),
+        public_key: PublicKey(gamma),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn keygen() {
+        let params = Parameters::default();
+        let keypair = super::elgamal_keygen(&params);
+
+        let expected = params.gen1() * keypair.private_key.0;
+        let gamma = keypair.public_key.0;
+        assert_eq!(
+            expected, gamma,
+            "Public key, gamma, should be equal to g1^d, where d is the private key"
+        );
+    }
+
+    #[test]
+    fn encryption() {
+        let params = Parameters::default();
+        let keypair = super::elgamal_keygen(&params);
+
+        let r = params.random_scalar();
+        let h = params.gen1() * r;
+        let m = params.random_scalar();
+
+        let (ciphertext, ephemeral_key) = keypair.public_key.encrypt(&params, &h, &m);
+
+        let expected_c1 = params.gen1() * ephemeral_key;
+        assert_eq!(expected_c1, ciphertext.0, "c1 should be equal to g1^k");
+
+        let expected_c2 = keypair.public_key.0 * ephemeral_key + h * m;
+        assert_eq!(
+            expected_c2, ciphertext.1,
+            "c2 should be equal to gamma^k * h^m"
+        );
+    }
+
+    #[test]
+    fn decryption() {
+        let params = Parameters::default();
+        let keypair = super::elgamal_keygen(&params);
+
+        let r = params.random_scalar();
+        let h = params.gen1() * r;
+        let m = params.random_scalar();
+
+        let (ciphertext, _) = keypair.public_key.encrypt(&params, &h, &m);
+        let dec = keypair.private_key.decrypt(&ciphertext);
+
+        let expected = h * m;
+        assert_eq!(
+            expected, dec,
+            "after ElGamal decryption, original h^m should be obtained"
+        );
+    }
+
+    #[test]
+    fn private_key_bytes_roundtrip() {
+        let params = Parameters::default();
+        let private_key = PrivateKey(params.random_scalar());
+        let bytes = private_key.to_bytes();
+
+        // also make sure it is equivalent to the internal scalar's bytes
+        assert_eq!(private_key.0.to_bytes(), bytes);
+        assert_eq!(private_key, PrivateKey::from_bytes(&bytes).unwrap())
+    }
+
+    #[test]
+    fn public_key_bytes_roundtrip() {
+        let params = Parameters::default();
+        let r = params.random_scalar();
+        let public_key = PublicKey(params.gen1() * r);
+        let bytes = public_key.to_bytes();
+
+        // also make sure it is equivalent to the internal g1 compressed bytes
+        assert_eq!(public_key.0.to_affine().to_compressed(), bytes);
+        assert_eq!(public_key, PublicKey::from_bytes(&bytes).unwrap())
+    }
+
+    #[test]
+    fn ciphertext_bytes_roundtrip() {
+        let params = Parameters::default();
+        let r = params.random_scalar();
+        let s = params.random_scalar();
+        let ciphertext = Ciphertext(params.gen1() * r, params.gen1() * s);
+        let bytes = ciphertext.to_bytes();
+
+        // also make sure it is equivalent to the internal g1 compressed bytes concatenated
+        let expected_bytes = [
+            ciphertext.0.to_affine().to_compressed(),
+            ciphertext.1.to_affine().to_compressed(),
+        ]
+        .concat();
+        assert_eq!(expected_bytes, bytes);
+        assert_eq!(ciphertext, Ciphertext::try_from(&bytes[..]).unwrap())
+    }
+}
@@ -0,0 +1,53 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+use thiserror::Error;
+
+/// A `Result` alias where the `Err` case is `coconut_rs::Error`.
+pub type Result<T> = std::result::Result<T, CoconutError>;
+
+#[derive(Error, Debug)]
+pub enum CoconutError {
+    #[error("Setup error: {0}")]
+    Setup(String),
+
+    #[error("encountered error during keygen")]
+    Keygen,
+
+    #[error("Issuance related error: {0}")]
+    Issuance(String),
+
+    #[error("Tried to prepare blind sign request for higher than specified number of attributes (max: {}, requested: {})", max, requested)]
+    IssuanceMaxAttributes { max: usize, requested: usize },
+
+    #[error("Interpolation error: {0}")]
+    Interpolation(String),
+
+    #[error("Aggregation error: {0}")]
+    Aggregation(String),
+
+    #[error("Unblind error: {0}")]
+    Unblind(String),
+
+    #[error("Verification error: {0}")]
+    Verification(String),
+
+    #[error("Deserialization error: {0}")]
+    Deserialization(String),
+
+    #[error(
+        "Deserailization error, expected at least {} bytes, got {}",
+        min,
+        actual
+    )]
+    DeserializationMinLength { min: usize, actual: usize },
+
+    #[error("Tried to deserialize {object} with bytes of invalid length. Expected {actual} < {} or {modulus_target} % {modulus} == 0")]
+    DeserializationInvalidLength {
+        actual: usize,
+        target: usize,
+        modulus_target: usize,
+        modulus: usize,
+        object: String,
+    },
+}
@@ -0,0 +1,15 @@
+use crate::{BlindSignRequest, BlindedSignature, Bytable, Theta};
+
+macro_rules! impl_clone {
+    ($struct:ident) => {
+        impl Clone for $struct {
+            fn clone(&self) -> Self {
+                Self::try_from_byte_slice(&self.to_byte_vec()).unwrap()
+            }
+        }
+    };
+}
+
+impl_clone!(BlindSignRequest);
+impl_clone!(BlindedSignature);
+impl_clone!(Theta);
@@ -0,0 +1,2 @@
+mod clone;
+mod serde;
@@ -0,0 +1,56 @@
+use crate::elgamal::PrivateKey;
+use crate::scheme::SecretKey;
+use crate::{
+    Base58, BlindSignRequest, BlindedSignature, PublicKey, Signature, Theta, VerificationKey,
+};
+use serde::de::Unexpected;
+use serde::{de::Error, de::Visitor, Deserialize, Deserializer, Serialize, Serializer};
+use std::fmt;
+
+macro_rules! impl_serde {
+    ($struct:ident, $visitor:ident) => {
+        pub struct $visitor {}
+
+        impl Serialize for $struct {
+            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+            where
+                S: Serializer,
+            {
+                serializer.serialize_str(&self.to_bs58())
+            }
+        }
+
+        impl<'de> Visitor<'de> for $visitor {
+            type Value = $struct;
+
+            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                write!(formatter, "A base58 encoded struct")
+            }
+
+            fn visit_str<E: Error>(self, s: &str) -> Result<Self::Value, E> {
+                match $struct::try_from_bs58(s) {
+                    Ok(x) => Ok(x),
+                    Err(_) => Err(Error::invalid_value(Unexpected::Str(s), &self)),
+                }
+            }
+        }
+
+        impl<'de> Deserialize<'de> for $struct {
+            fn deserialize<D>(deserializer: D) -> Result<$struct, D::Error>
+            where
+                D: Deserializer<'de>,
+            {
+                deserializer.deserialize_str($visitor {})
+            }
+        }
+    };
+}
+
+impl_serde!(SecretKey, V1);
+impl_serde!(VerificationKey, V2);
+impl_serde!(PublicKey, V3);
+impl_serde!(PrivateKey, V4);
+impl_serde!(BlindSignRequest, V5);
+impl_serde!(BlindedSignature, V6);
+impl_serde!(Signature, V7);
+impl_serde!(Theta, V8);
@@ -0,0 +1,57 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+use std::convert::TryInto;
+
+use bls12_381::Scalar;
+
+pub use elgamal::elgamal_keygen;
+pub use elgamal::ElGamalKeyPair;
+pub use elgamal::PublicKey;
+pub use error::CoconutError;
+pub use scheme::aggregation::aggregate_signature_shares;
+pub use scheme::aggregation::aggregate_verification_keys;
+pub use scheme::issuance::blind_sign;
+pub use scheme::issuance::prepare_blind_sign;
+pub use scheme::issuance::BlindSignRequest;
+pub use scheme::keygen::ttp_keygen;
+pub use scheme::keygen::KeyPair;
+pub use scheme::keygen::VerificationKey;
+pub use scheme::setup::setup;
+pub use scheme::setup::Parameters;
+pub use scheme::verification::prove_bandwidth_credential;
+pub use scheme::verification::verify_credential;
+pub use scheme::verification::Theta;
+pub use scheme::BlindedSignature;
+pub use scheme::Signature;
+pub use scheme::SignatureShare;
+pub use traits::Base58;
+pub use utils::hash_to_scalar;
+
+use crate::traits::Bytable;
+
+pub mod elgamal;
+mod error;
+mod impls;
+mod proofs;
+mod scheme;
+#[cfg(test)]
+mod tests;
+mod traits;
+mod utils;
+
+pub type Attribute = Scalar;
+pub type PrivateAttribute = Attribute;
+pub type PublicAttribute = Attribute;
+
+impl Bytable for Attribute {
+    fn to_byte_vec(&self) -> Vec<u8> {
+        self.to_bytes().to_vec()
+    }
+
+    fn try_from_byte_slice(slice: &[u8]) -> Result<Self, CoconutError> {
+        Ok(Attribute::from_bytes(slice.try_into().unwrap()).unwrap())
+    }
+}
+
+impl Base58 for Attribute {}
@@ -0,0 +1,663 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+// TODO: look at https://crates.io/crates/merlin to perhaps use it instead?
+
+use std::borrow::Borrow;
+use std::convert::TryInto;
+
+use bls12_381::{G1Projective, G2Projective, Scalar};
+use digest::generic_array::typenum::Unsigned;
+use digest::Digest;
+use group::GroupEncoding;
+use itertools::izip;
+use sha2::Sha256;
+
+use crate::elgamal::Ciphertext;
+use crate::error::{CoconutError, Result};
+use crate::scheme::setup::Parameters;
+use crate::scheme::VerificationKey;
+use crate::utils::{hash_g1, try_deserialize_scalar, try_deserialize_scalar_vec};
+use crate::{elgamal, Attribute, ElGamalKeyPair};
+
+// as per the reference python implementation
+type ChallengeDigest = Sha256;
+
+#[derive(Debug)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct ProofCmCs {
+    challenge: Scalar,
+    response_opening: Scalar,
+    response_private_elgamal_key: Scalar,
+    response_keys: Vec<Scalar>,
+    response_attributes: Vec<Scalar>,
+}
+
+// note: this is slightly different from the reference python implementation
+// as we omit the unnecessary string conversion. Instead we concatenate byte
+// representations together and hash that.
+// note2: G1 and G2 elements are using their compressed representations
+// and as per the bls12-381 library all elements are using big-endian form
+/// Generates a Scalar [or Fp] challenge by hashing a number of elliptic curve points.  
+fn compute_challenge<D, I, B>(iter: I) -> Scalar
+where
+    D: Digest,
+    I: Iterator<Item = B>,
+    B: AsRef<[u8]>,
+{
+    let mut h = D::new();
+    for point_representation in iter {
+        h.update(point_representation);
+    }
+    let digest = h.finalize();
+
+    // TODO: I don't like the 0 padding here (though it's what we've been using before,
+    // but we never had a security audit anyway...)
+    // instead we could maybe use the `from_bytes` variant and adding some suffix
+    // when computing the digest until we produce a valid scalar.
+    let mut bytes = [0u8; 64];
+    let pad_size = 64usize
+        .checked_sub(D::OutputSize::to_usize())
+        .unwrap_or_default();
+
+    bytes[pad_size..].copy_from_slice(&digest);
+
+    Scalar::from_bytes_wide(&bytes)
+}
+
+fn produce_response(witness: &Scalar, challenge: &Scalar, secret: &Scalar) -> Scalar {
+    witness - challenge * secret
+}
+
+// note: it's caller's responsibility to ensure witnesses.len() = secrets.len()
+fn produce_responses<S>(witnesses: &[Scalar], challenge: &Scalar, secrets: &[S]) -> Vec<Scalar>
+where
+    S: Borrow<Scalar>,
+{
+    debug_assert_eq!(witnesses.len(), secrets.len());
+
+    witnesses
+        .iter()
+        .zip(secrets.iter())
+        .map(|(w, x)| produce_response(w, challenge, x.borrow()))
+        .collect()
+}
+
+impl ProofCmCs {
+    /// Construct non-interactive zero-knowledge proof of correctness of the ciphertexts and the commitment
+    /// using the Fiat-Shamir heuristic.
+    pub(crate) fn construct(
+        params: &Parameters,
+        elgamal_keypair: &ElGamalKeyPair,
+        ephemeral_keys: &[elgamal::EphemeralKey],
+        commitment: &G1Projective,
+        commitment_opening: &Scalar,
+        private_attributes: &[Attribute],
+        priv_attributes_ciphertexts: &[Ciphertext],
+    ) -> Self {
+        // note: this is only called from `prepare_blind_sign` that already checks
+        // whether private attributes are non-empty and whether we don't have too many
+        // attributes in total to sign.
+        // we also know, due to the single call place, that ephemeral_keys.len() == private_attributes.len()
+
+        // witness creation
+
+        let witness_commitment_opening = params.random_scalar();
+        let witness_private_elgamal_key = params.random_scalar();
+        let witness_keys = params.n_random_scalars(ephemeral_keys.len());
+        let witness_attributes = params.n_random_scalars(private_attributes.len());
+
+        // recompute h
+        let h = hash_g1(commitment.to_bytes());
+        let hs_bytes = params
+            .gen_hs()
+            .iter()
+            .map(|h| h.to_bytes())
+            .collect::<Vec<_>>();
+
+        let g1 = params.gen1();
+
+        // compute commitments
+        let commitment_private_key_elgamal = g1 * witness_private_elgamal_key;
+
+        // Aw[i] = (wk[i] * g1)
+        let commitment_keys1_bytes = witness_keys
+            .iter()
+            .map(|wk_i| g1 * wk_i)
+            .map(|witness| witness.to_bytes())
+            .collect::<Vec<_>>();
+
+        // Bw[i] = (wm[i] * h) + (wk[i] * gamma)
+        let commitment_keys2_bytes = witness_keys
+            .iter()
+            .zip(witness_attributes.iter())
+            .map(|(wk_i, wm_i)| elgamal_keypair.public_key() * wk_i + h * wm_i)
+            .map(|witness| witness.to_bytes())
+            .collect::<Vec<_>>();
+
+        // zkp commitment for the attributes commitment cm
+        // Ccm = (wr * g1) + (wm[0] * hs[0]) + ... + (wm[i] * hs[i])
+        let commitment_attributes = g1 * witness_commitment_opening
+            + witness_attributes
+                .iter()
+                .zip(params.gen_hs().iter())
+                .map(|(wm_i, hs_i)| hs_i * wm_i)
+                .sum::<G1Projective>();
+
+        let ciphertexts_bytes = priv_attributes_ciphertexts
+            .iter()
+            .map(|c| c.to_bytes())
+            .collect::<Vec<_>>();
+
+        // compute challenge
+        let challenge = compute_challenge::<ChallengeDigest, _, _>(
+            std::iter::once(params.gen1().to_bytes().as_ref())
+                .chain(hs_bytes.iter().map(|hs| hs.as_ref()))
+                .chain(std::iter::once(h.to_bytes().as_ref()))
+                .chain(std::iter::once(
+                    elgamal_keypair.public_key().to_bytes().as_ref(),
+                ))
+                .chain(std::iter::once(commitment.to_bytes().as_ref()))
+                .chain(std::iter::once(commitment_attributes.to_bytes().as_ref()))
+                .chain(std::iter::once(
+                    commitment_private_key_elgamal.to_bytes().as_ref(),
+                ))
+                .chain(commitment_keys1_bytes.iter().map(|aw| aw.as_ref()))
+                .chain(commitment_keys2_bytes.iter().map(|bw| bw.as_ref()))
+                .chain(ciphertexts_bytes.iter().map(|c| c.as_ref())),
+        );
+
+        // Responses
+        let response_opening =
+            produce_response(&witness_commitment_opening, &challenge, commitment_opening);
+        let response_private_elgamal_key = produce_response(
+            &witness_private_elgamal_key,
+            &challenge,
+            &elgamal_keypair.private_key().0,
+        );
+        let response_keys = produce_responses(&witness_keys, &challenge, ephemeral_keys);
+        let response_attributes = produce_responses(
+            &witness_attributes,
+            &challenge,
+            &private_attributes.iter().collect::<Vec<_>>(),
+        );
+
+        ProofCmCs {
+            challenge,
+            response_opening,
+            response_private_elgamal_key,
+            response_keys,
+            response_attributes,
+        }
+    }
+
+    pub(crate) fn verify(
+        &self,
+        params: &Parameters,
+        pub_key: &elgamal::PublicKey,
+        commitment: &G1Projective,
+        attributes_ciphertexts: &[elgamal::Ciphertext],
+    ) -> bool {
+        if self.response_keys.len() != attributes_ciphertexts.len() {
+            return false;
+        }
+
+        // recompute h
+        let h = hash_g1(commitment.to_bytes());
+        let g1 = params.gen1();
+
+        let hs_bytes = params
+            .gen_hs()
+            .iter()
+            .map(|h| h.to_bytes())
+            .collect::<Vec<_>>();
+
+        // recompute witnesses commitments
+        let commitment_private_key_elgamal =
+            pub_key * &self.challenge + g1 * self.response_private_elgamal_key;
+
+        // Aw[i] = (c * c1[i]) + (rk[i] * g1)
+        let commitment_keys1_bytes = attributes_ciphertexts
+            .iter()
+            .map(|ciphertext| ciphertext.c1())
+            .zip(self.response_keys.iter())
+            .map(|(c1, res_k)| c1 * self.challenge + g1 * res_k)
+            .map(|witness| witness.to_bytes())
+            .collect::<Vec<_>>();
+
+        // Bw[i] = (c * c2[i]) + (rk[i] * gamma) + (rm[i] * h)
+        let commitment_keys2_bytes = izip!(
+            attributes_ciphertexts
+                .iter()
+                .map(|ciphertext| ciphertext.c2()),
+            self.response_keys.iter(),
+            self.response_attributes.iter()
+        )
+        .map(|(c2, res_key, res_attr)| c2 * self.challenge + pub_key * res_key + h * res_attr)
+        .map(|witness| witness.to_bytes())
+        .collect::<Vec<_>>();
+
+        // Cw = (cm * c) + (rr * g1) + (rm[0] * hs[0]) + ... + (rm[n] * hs[n])
+        let commitment_attributes = commitment * self.challenge
+            + g1 * self.response_opening
+            + self
+                .response_attributes
+                .iter()
+                .zip(params.gen_hs().iter())
+                .map(|(res_attr, hs)| hs * res_attr)
+                .sum::<G1Projective>();
+
+        let ciphertexts_bytes = attributes_ciphertexts
+            .iter()
+            .map(|c| c.to_bytes())
+            .collect::<Vec<_>>();
+
+        // re-compute the challenge
+        let challenge = compute_challenge::<ChallengeDigest, _, _>(
+            std::iter::once(params.gen1().to_bytes().as_ref())
+                .chain(hs_bytes.iter().map(|hs| hs.as_ref()))
+                .chain(std::iter::once(h.to_bytes().as_ref()))
+                .chain(std::iter::once(pub_key.to_bytes().as_ref()))
+                .chain(std::iter::once(commitment.to_bytes().as_ref()))
+                .chain(std::iter::once(commitment_attributes.to_bytes().as_ref()))
+                .chain(std::iter::once(
+                    commitment_private_key_elgamal.to_bytes().as_ref(),
+                ))
+                .chain(commitment_keys1_bytes.iter().map(|aw| aw.as_ref()))
+                .chain(commitment_keys2_bytes.iter().map(|bw| bw.as_ref()))
+                .chain(ciphertexts_bytes.iter().map(|c| c.as_ref())),
+        );
+
+        challenge == self.challenge
+    }
+
+    // challenge || response opening || response private elgamal key || keys len || response keys || attributes len || response attributes
+    pub(crate) fn to_bytes(&self) -> Vec<u8> {
+        let keys_len = self.response_keys.len() as u64;
+        let attributes_len = self.response_attributes.len() as u64;
+
+        let mut bytes = Vec::with_capacity(16 + (keys_len + attributes_len + 3) as usize * 32);
+
+        bytes.extend_from_slice(&self.challenge.to_bytes());
+        bytes.extend_from_slice(&self.response_opening.to_bytes());
+        bytes.extend_from_slice(&self.response_private_elgamal_key.to_bytes());
+        bytes.extend_from_slice(&keys_len.to_le_bytes());
+
+        for rk in &self.response_keys {
+            bytes.extend_from_slice(&rk.to_bytes());
+        }
+
+        bytes.extend_from_slice(&attributes_len.to_le_bytes());
+
+        for rm in &self.response_attributes {
+            bytes.extend_from_slice(&rm.to_bytes());
+        }
+
+        bytes
+    }
+
+    pub(crate) fn from_bytes(bytes: &[u8]) -> Result<Self> {
+        // at the very minimum there must be a single attribute being proven
+        if bytes.len() < 32 * 5 + 16 || (bytes.len() - 16) % 32 != 0 {
+            return Err(
+                CoconutError::Deserialization(
+                    "tried to deserialize proof of ciphertexts and commitment with bytes of invalid length".to_string())
+            );
+        }
+
+        let mut idx = 0;
+        let challenge_bytes = bytes[idx..idx + 32].try_into().unwrap();
+        idx += 32;
+        let response_opening_bytes = bytes[idx..idx + 32].try_into().unwrap();
+        idx += 32;
+        let response_private_elgamal_key_bytes = bytes[idx..idx + 32].try_into().unwrap();
+        idx += 32;
+
+        let challenge = try_deserialize_scalar(
+            &challenge_bytes,
+            CoconutError::Deserialization("Failed to deserialize challenge".to_string()),
+        )?;
+        let response_opening = try_deserialize_scalar(
+            &response_opening_bytes,
+            CoconutError::Deserialization(
+                "Failed to deserialize the response to the random".to_string(),
+            ),
+        )?;
+        let response_private_elgamal_key = try_deserialize_scalar(
+            &response_private_elgamal_key_bytes,
+            CoconutError::Deserialization(
+                "Failed to deserialize the response to the private ElGamal key".to_string(),
+            ),
+        )?;
+
+        let rk_len = u64::from_le_bytes(bytes[idx..idx + 8].try_into().unwrap());
+        idx += 8;
+        if bytes[idx..].len() < rk_len as usize * 32 + 8 {
+            return Err(
+                CoconutError::Deserialization(
+                    "tried to deserialize proof of ciphertexts and commitment with insufficient number of bytes provided".to_string()),
+            );
+        }
+
+        let rk_end = idx + rk_len as usize * 32;
+        let response_keys = try_deserialize_scalar_vec(
+            rk_len,
+            &bytes[idx..rk_end],
+            CoconutError::Deserialization("Failed to deserialize keys response".to_string()),
+        )?;
+
+        let rm_len = u64::from_le_bytes(bytes[rk_end..rk_end + 8].try_into().unwrap());
+        let response_attributes = try_deserialize_scalar_vec(
+            rm_len,
+            &bytes[rk_end + 8..],
+            CoconutError::Deserialization("Failed to deserialize attributes response".to_string()),
+        )?;
+
+        Ok(ProofCmCs {
+            challenge,
+            response_opening,
+            response_private_elgamal_key,
+            response_keys,
+            response_attributes,
+        })
+    }
+}
+
+#[derive(Debug)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct ProofKappaZeta {
+    // c
+    challenge: Scalar,
+
+    // responses
+    response_serial_number: Scalar,
+    response_binding_number: Scalar,
+    response_blinder: Scalar,
+}
+
+impl ProofKappaZeta {
+    pub(crate) fn construct(
+        params: &Parameters,
+        verification_key: &VerificationKey,
+        serial_number: &Attribute,
+        binding_number: &Attribute,
+        blinding_factor: &Scalar,
+        blinded_message: &G2Projective,
+        blinded_serial_number: &G2Projective,
+    ) -> Self {
+        // create the witnesses
+        let witness_blinder = params.random_scalar();
+        let witness_serial_number = params.random_scalar();
+        let witness_binding_number = params.random_scalar();
+        let witness_attributes = vec![witness_serial_number, witness_binding_number];
+
+        let beta_bytes = verification_key
+            .beta
+            .iter()
+            .map(|beta_i| beta_i.to_bytes())
+            .collect::<Vec<_>>();
+
+        // witnesses commitments
+        // Aw = g2 * wt + alpha + beta[0] * wm[0] + ... + beta[i] * wm[i]
+        let commitment_kappa = params.gen2() * witness_blinder
+            + verification_key.alpha
+            + witness_attributes
+                .iter()
+                .zip(verification_key.beta.iter())
+                .map(|(wm_i, beta_i)| beta_i * wm_i)
+                .sum::<G2Projective>();
+
+        // zeta is the public value associated with the serial number
+        let commitment_zeta = params.gen2() * witness_serial_number;
+
+        let challenge = compute_challenge::<ChallengeDigest, _, _>(
+            std::iter::once(params.gen2().to_bytes().as_ref())
+                .chain(std::iter::once(blinded_message.to_bytes().as_ref()))
+                .chain(std::iter::once(blinded_serial_number.to_bytes().as_ref()))
+                .chain(std::iter::once(verification_key.alpha.to_bytes().as_ref()))
+                .chain(beta_bytes.iter().map(|b| b.as_ref()))
+                .chain(std::iter::once(commitment_kappa.to_bytes().as_ref()))
+                .chain(std::iter::once(commitment_zeta.to_bytes().as_ref())),
+        );
+
+        // responses
+        let response_blinder = produce_response(&witness_blinder, &challenge, blinding_factor);
+        let response_serial_number =
+            produce_response(&witness_serial_number, &challenge, serial_number);
+        let response_binding_number =
+            produce_response(&witness_binding_number, &challenge, binding_number);
+
+        ProofKappaZeta {
+            challenge,
+            response_serial_number,
+            response_binding_number,
+            response_blinder,
+        }
+    }
+
+    pub(crate) fn private_attributes_len(&self) -> usize {
+        2
+    }
+
+    pub(crate) fn verify(
+        &self,
+        params: &Parameters,
+        verification_key: &VerificationKey,
+        kappa: &G2Projective,
+        zeta: &G2Projective,
+    ) -> bool {
+        let beta_bytes = verification_key
+            .beta
+            .iter()
+            .map(|beta_i| beta_i.to_bytes())
+            .collect::<Vec<_>>();
+
+        let response_attributes = vec![self.response_serial_number, self.response_binding_number];
+        // re-compute witnesses commitments
+        // Aw = (c * kappa) + (rt * g2) + ((1 - c) * alpha) + (rm[0] * beta[0]) + ... + (rm[i] * beta[i])
+        let commitment_kappa = kappa * self.challenge
+            + params.gen2() * self.response_blinder
+            + verification_key.alpha * (Scalar::one() - self.challenge)
+            + response_attributes
+                .iter()
+                .zip(verification_key.beta.iter())
+                .map(|(priv_attr, beta_i)| beta_i * priv_attr)
+                .sum::<G2Projective>();
+
+        // zeta is the public value associated with the serial number
+        let commitment_zeta = zeta * self.challenge + params.gen2() * self.response_serial_number;
+
+        // compute the challenge
+        let challenge = compute_challenge::<ChallengeDigest, _, _>(
+            std::iter::once(params.gen2().to_bytes().as_ref())
+                .chain(std::iter::once(kappa.to_bytes().as_ref()))
+                .chain(std::iter::once(zeta.to_bytes().as_ref()))
+                .chain(std::iter::once(verification_key.alpha.to_bytes().as_ref()))
+                .chain(beta_bytes.iter().map(|b| b.as_ref()))
+                .chain(std::iter::once(commitment_kappa.to_bytes().as_ref()))
+                .chain(std::iter::once(commitment_zeta.to_bytes().as_ref())),
+        );
+
+        challenge == self.challenge
+    }
+
+    // challenge || response serial number || response binding number || repose blinder
+    pub(crate) fn to_bytes(&self) -> Vec<u8> {
+        let attributes_len = 2; // because we have serial number and the binding number
+        let mut bytes = Vec::with_capacity((1 + attributes_len + 1) as usize * 32);
+
+        bytes.extend_from_slice(&self.challenge.to_bytes());
+        bytes.extend_from_slice(&self.response_serial_number.to_bytes());
+        bytes.extend_from_slice(&self.response_binding_number.to_bytes());
+
+        bytes.extend_from_slice(&self.response_blinder.to_bytes());
+
+        bytes
+    }
+
+    pub(crate) fn from_bytes(bytes: &[u8]) -> Result<Self> {
+        // at the very minimum there must be a single attribute being proven
+        if bytes.len() < 32 * 4 || (bytes.len()) % 32 != 0 {
+            return Err(CoconutError::DeserializationInvalidLength {
+                actual: bytes.len(),
+                modulus_target: bytes.len(),
+                modulus: 32,
+                object: "kappa and zeta".to_string(),
+                target: 32 * 4,
+            });
+        }
+
+        let challenge_bytes = bytes[..32].try_into().unwrap();
+        let challenge = try_deserialize_scalar(
+            &challenge_bytes,
+            CoconutError::Deserialization("Failed to deserialize challenge".to_string()),
+        )?;
+
+        let serial_number_bytes = &bytes[32..64].try_into().unwrap();
+        let response_serial_number = try_deserialize_scalar(
+            serial_number_bytes,
+            CoconutError::Deserialization("failed to deserialize the serial number".to_string()),
+        )?;
+
+        let binding_number_bytes = &bytes[64..96].try_into().unwrap();
+        let response_binding_number = try_deserialize_scalar(
+            binding_number_bytes,
+            CoconutError::Deserialization("failed to deserialize the binding number".to_string()),
+        )?;
+
+        let blinder_bytes = bytes[96..].try_into().unwrap();
+        let response_blinder = try_deserialize_scalar(
+            &blinder_bytes,
+            CoconutError::Deserialization("failed to deserialize the blinder".to_string()),
+        )?;
+
+        Ok(ProofKappaZeta {
+            challenge,
+            response_serial_number,
+            response_binding_number,
+            response_blinder,
+        })
+    }
+}
+
+// proof builder:
+// - commitment
+// - challenge
+// - responses
+
+#[cfg(test)]
+mod tests {
+    use group::Group;
+    use rand::thread_rng;
+
+    use crate::scheme::issuance::{compute_attribute_encryption, compute_commitment_hash};
+    use crate::scheme::keygen::keygen;
+    use crate::scheme::setup::setup;
+    use crate::scheme::verification::{compute_kappa, compute_zeta};
+
+    use super::*;
+
+    #[test]
+    fn proof_cm_cs_bytes_roundtrip() {
+        let mut rng = thread_rng();
+        let mut params = setup(1).unwrap();
+
+        let elgamal_keypair = elgamal::elgamal_keygen(&params);
+        let private_attributes = params.n_random_scalars(1);
+
+        // we don't care about 'correctness' of the proof. only whether we can correctly recover it from bytes
+        let cm = G1Projective::random(&mut rng);
+        let r = params.random_scalar();
+
+        let commitment_hash = compute_commitment_hash(cm);
+        let (attributes_ciphertexts, _): (Vec<_>, Vec<_>) = compute_attribute_encryption(
+            &params,
+            private_attributes.as_ref(),
+            elgamal_keypair.public_key(),
+            commitment_hash,
+        );
+        let ephemeral_keys = params.n_random_scalars(1);
+
+        // 0 public 1 private
+        let pi_s = ProofCmCs::construct(
+            &mut params,
+            &elgamal_keypair,
+            &ephemeral_keys,
+            &cm,
+            &r,
+            &private_attributes,
+            &*attributes_ciphertexts,
+        );
+
+        let bytes = pi_s.to_bytes();
+        assert_eq!(ProofCmCs::from_bytes(&bytes).unwrap(), pi_s);
+
+        // 2 private
+        let private_attributes = params.n_random_scalars(2);
+        let ephemeral_keys = params.n_random_scalars(2);
+
+        let pi_s = ProofCmCs::construct(
+            &mut params,
+            &elgamal_keypair,
+            &ephemeral_keys,
+            &cm,
+            &r,
+            &private_attributes,
+            &*attributes_ciphertexts,
+        );
+
+        let bytes = pi_s.to_bytes();
+        assert_eq!(ProofCmCs::from_bytes(&bytes).unwrap(), pi_s);
+    }
+
+    #[test]
+    fn proof_kappa_zeta_bytes_roundtrip() {
+        let mut params = setup(4).unwrap();
+
+        let keypair = keygen(&mut params);
+
+        // we don't care about 'correctness' of the proof. only whether we can correctly recover it from bytes
+        let serial_number = params.random_scalar();
+        let binding_number = params.random_scalar();
+        let private_attributes = vec![serial_number, binding_number];
+
+        let r = params.random_scalar();
+        let kappa = compute_kappa(&params, &keypair.verification_key(), &private_attributes, r);
+        let zeta = compute_zeta(&params, serial_number);
+
+        // 0 public 2 private
+        let pi_v = ProofKappaZeta::construct(
+            &mut params,
+            &keypair.verification_key(),
+            &serial_number,
+            &binding_number,
+            &r,
+            &kappa,
+            &zeta,
+        );
+
+        let proof_bytes = pi_v.to_bytes();
+
+        let proof_from_bytes = ProofKappaZeta::from_bytes(&proof_bytes).unwrap();
+        assert_eq!(proof_from_bytes, pi_v);
+
+        // 2 public 2 private
+        let mut params = setup(4).unwrap();
+        let keypair = keygen(&mut params);
+
+        let pi_v = ProofKappaZeta::construct(
+            &mut params,
+            &keypair.verification_key(),
+            &serial_number,
+            &binding_number,
+            &r,
+            &kappa,
+            &zeta,
+        );
+
+        let proof_bytes = pi_v.to_bytes();
+
+        let proof_from_bytes = ProofKappaZeta::from_bytes(&proof_bytes).unwrap();
+        assert_eq!(proof_from_bytes, pi_v);
+    }
+}
@@ -0,0 +1,377 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+use core::iter::Sum;
+use core::ops::Mul;
+
+use bls12_381::{G2Prepared, G2Projective, Scalar};
+use group::Curve;
+use itertools::Itertools;
+
+use crate::error::{CoconutError, Result};
+use crate::scheme::verification::check_bilinear_pairing;
+use crate::scheme::{PartialSignature, Signature, SignatureShare, SignerIndex, VerificationKey};
+use crate::utils::perform_lagrangian_interpolation_at_origin;
+use crate::{Attribute, Parameters};
+
+pub(crate) trait Aggregatable: Sized {
+    fn aggregate(aggregatable: &[Self], indices: Option<&[SignerIndex]>) -> Result<Self>;
+
+    fn check_unique_indices(indices: &[SignerIndex]) -> bool {
+        // if aggregation is a threshold one, all indices should be unique
+        indices.iter().unique_by(|&index| index).count() == indices.len()
+    }
+}
+
+// includes `VerificationKey`
+impl<T> Aggregatable for T
+where
+    T: Sum,
+    for<'a> T: Sum<&'a T>,
+    for<'a> &'a T: Mul<Scalar, Output = T>,
+{
+    fn aggregate(aggregatable: &[T], indices: Option<&[u64]>) -> Result<T> {
+        if aggregatable.is_empty() {
+            return Err(CoconutError::Aggregation("Empty set of values".to_string()));
+        }
+
+        if let Some(indices) = indices {
+            if !Self::check_unique_indices(indices) {
+                return Err(CoconutError::Aggregation("Non-unique indices".to_string()));
+            }
+            perform_lagrangian_interpolation_at_origin(indices, aggregatable)
+        } else {
+            // non-threshold
+            Ok(aggregatable.iter().sum())
+        }
+    }
+}
+
+impl Aggregatable for PartialSignature {
+    fn aggregate(sigs: &[PartialSignature], indices: Option<&[u64]>) -> Result<Signature> {
+        let h = sigs
+            .get(0)
+            .ok_or_else(|| CoconutError::Aggregation("Empty set of signatures".to_string()))?
+            .sig1();
+
+        // TODO: is it possible to avoid this allocation?
+        let sigmas = sigs.iter().map(|sig| *sig.sig2()).collect::<Vec<_>>();
+        let aggr_sigma = Aggregatable::aggregate(&sigmas, indices)?;
+
+        Ok(Signature(*h, aggr_sigma))
+    }
+}
+
+/// Ensures all provided verification keys were generated to verify the same number of attributes.
+fn check_same_key_size(keys: &[VerificationKey]) -> bool {
+    keys.iter().map(|vk| vk.beta.len()).all_equal()
+}
+
+pub fn aggregate_verification_keys(
+    keys: &[VerificationKey],
+    indices: Option<&[SignerIndex]>,
+) -> Result<VerificationKey> {
+    if !check_same_key_size(keys) {
+        return Err(CoconutError::Aggregation(
+            "Verification keys are of different sizes".to_string(),
+        ));
+    }
+    Aggregatable::aggregate(keys, indices)
+}
+
+pub fn aggregate_signatures(
+    params: &Parameters,
+    verification_key: &VerificationKey,
+    attributes: &[Attribute],
+    signatures: &[PartialSignature],
+    indices: Option<&[SignerIndex]>,
+) -> Result<Signature> {
+    // aggregate the signature
+
+    let signature = match Aggregatable::aggregate(signatures, indices) {
+        Ok(res) => res,
+        Err(err) => return Err(err),
+    };
+
+    // Verify the signature
+    let alpha = verification_key.alpha;
+
+    let tmp = attributes
+        .iter()
+        .zip(verification_key.beta.iter())
+        .map(|(attr, beta_i)| beta_i * attr)
+        .sum::<G2Projective>();
+
+    if !check_bilinear_pairing(
+        &signature.0.to_affine(),
+        &G2Prepared::from((alpha + tmp).to_affine()),
+        &signature.1.to_affine(),
+        params.prepared_miller_g2(),
+    ) {
+        return Err(CoconutError::Aggregation(
+            "Verification of the aggregated signature failed".to_string(),
+        ));
+    }
+    Ok(signature)
+}
+
+pub fn aggregate_signature_shares(
+    params: &Parameters,
+    verification_key: &VerificationKey,
+    attributes: &[Attribute],
+    shares: &[SignatureShare],
+) -> Result<Signature> {
+    let (signatures, indices): (Vec<_>, Vec<_>) = shares
+        .iter()
+        .map(|share| (*share.signature(), share.index()))
+        .unzip();
+
+    aggregate_signatures(
+        params,
+        verification_key,
+        attributes,
+        &signatures,
+        Some(&indices),
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use bls12_381::G1Projective;
+    use group::Group;
+
+    use crate::scheme::issuance::sign;
+    use crate::scheme::keygen::ttp_keygen;
+    use crate::scheme::setup::Parameters;
+    use crate::scheme::verification::verify;
+
+    use super::*;
+
+    #[test]
+    fn key_aggregation_works_for_any_subset_of_keys() {
+        let mut params = Parameters::new(2).unwrap();
+        let keypairs = ttp_keygen(&mut params, 3, 5).unwrap();
+
+        let vks = keypairs
+            .into_iter()
+            .map(|keypair| keypair.verification_key())
+            .collect::<Vec<_>>();
+
+        let aggr_vk1 = aggregate_verification_keys(&vks[..3], Some(&[1, 2, 3])).unwrap();
+        let aggr_vk2 = aggregate_verification_keys(&vks[2..], Some(&[3, 4, 5])).unwrap();
+
+        assert_eq!(aggr_vk1, aggr_vk2);
+
+        // TODO: should those two actually work or not?
+        // aggregating threshold+1
+        let aggr_more = aggregate_verification_keys(&vks[1..], Some(&[2, 3, 4, 5])).unwrap();
+        assert_eq!(aggr_vk1, aggr_more);
+
+        // aggregating all
+        let aggr_all = aggregate_verification_keys(&vks, Some(&[1, 2, 3, 4, 5])).unwrap();
+        assert_eq!(aggr_all, aggr_vk1);
+
+        // not taking enough points (threshold was 3)
+        let aggr_not_enough = aggregate_verification_keys(&vks[..2], Some(&[1, 2])).unwrap();
+        assert_ne!(aggr_not_enough, aggr_vk1);
+
+        // taking wrong index
+        let aggr_bad = aggregate_verification_keys(&vks[2..], Some(&[42, 123, 100])).unwrap();
+        assert_ne!(aggr_vk1, aggr_bad);
+    }
+
+    #[test]
+    fn key_aggregation_doesnt_work_for_empty_set_of_keys() {
+        let keys: Vec<VerificationKey> = vec![];
+        assert!(aggregate_verification_keys(&keys, None).is_err());
+    }
+
+    #[test]
+    fn key_aggregation_doesnt_work_if_indices_have_invalid_length() {
+        let keys = vec![VerificationKey::identity(3)];
+
+        assert!(aggregate_verification_keys(&keys, Some(&[])).is_err());
+        assert!(aggregate_verification_keys(&keys, Some(&[1, 2])).is_err());
+    }
+
+    #[test]
+    fn key_aggregation_doesnt_work_for_non_unique_indices() {
+        let keys = vec![VerificationKey::identity(3), VerificationKey::identity(3)];
+
+        assert!(aggregate_verification_keys(&keys, Some(&[1, 1])).is_err());
+    }
+
+    #[test]
+    fn key_aggregation_doesnt_work_for_keys_of_different_size() {
+        let keys = vec![VerificationKey::identity(3), VerificationKey::identity(1)];
+
+        assert!(aggregate_verification_keys(&keys, None).is_err())
+    }
+
+    #[test]
+    fn signature_aggregation_works_for_any_subset_of_signatures() {
+        let mut params = Parameters::new(2).unwrap();
+        let attributes = params.n_random_scalars(2);
+
+        let keypairs = ttp_keygen(&mut params, 3, 5).unwrap();
+
+        let (sks, vks): (Vec<_>, Vec<_>) = keypairs
+            .into_iter()
+            .map(|keypair| (keypair.secret_key(), keypair.verification_key()))
+            .unzip();
+
+        let sigs = sks
+            .iter()
+            .map(|sk| sign(&mut params, sk, &attributes).unwrap())
+            .collect::<Vec<_>>();
+
+        // aggregating (any) threshold works
+        let aggr_vk_1 = aggregate_verification_keys(&vks[..3], Some(&[1, 2, 3])).unwrap();
+        let aggr_sig1 = aggregate_signatures(
+            &params,
+            &aggr_vk_1,
+            &attributes,
+            &sigs[..3],
+            Some(&[1, 2, 3]),
+        )
+        .unwrap();
+
+        let aggr_vk_2 = aggregate_verification_keys(&vks[2..], Some(&[3, 4, 5])).unwrap();
+        let aggr_sig2 = aggregate_signatures(
+            &params,
+            &aggr_vk_1,
+            &attributes,
+            &sigs[2..],
+            Some(&[3, 4, 5]),
+        )
+        .unwrap();
+        assert_eq!(aggr_sig1, aggr_sig2);
+
+        // verify credential for good measure
+        assert!(verify(&params, &aggr_vk_1, &attributes, &aggr_sig1));
+        assert!(verify(&params, &aggr_vk_2, &attributes, &aggr_sig2));
+
+        // aggregating threshold+1 works
+        let aggr_vk_more = aggregate_verification_keys(&vks[1..], Some(&[2, 3, 4, 5])).unwrap();
+        let aggr_more = aggregate_signatures(
+            &params,
+            &aggr_vk_more,
+            &attributes,
+            &sigs[1..],
+            Some(&[2, 3, 4, 5]),
+        )
+        .unwrap();
+        assert_eq!(aggr_sig1, aggr_more);
+
+        // aggregating all
+        let aggr_vk_all = aggregate_verification_keys(&vks, Some(&[1, 2, 3, 4, 5])).unwrap();
+        let aggr_all = aggregate_signatures(
+            &params,
+            &aggr_vk_all,
+            &attributes,
+            &sigs,
+            Some(&[1, 2, 3, 4, 5]),
+        )
+        .unwrap();
+        assert_eq!(aggr_all, aggr_sig1);
+
+        // not taking enough points (threshold was 3) should fail
+        let aggr_vk_not_enough = aggregate_verification_keys(&vks[..2], Some(&[1, 2])).unwrap();
+        let aggr_not_enough = aggregate_signatures(
+            &params,
+            &aggr_vk_not_enough,
+            &attributes,
+            &sigs[..2],
+            Some(&[1, 2]),
+        )
+        .unwrap();
+        assert_ne!(aggr_not_enough, aggr_sig1);
+
+        // taking wrong index should fail
+        let aggr_vk_bad = aggregate_verification_keys(&vks[2..], Some(&[1, 2, 3])).unwrap();
+        assert!(aggregate_signatures(
+            &params,
+            &aggr_vk_bad,
+            &attributes,
+            &sigs[2..],
+            Some(&[42, 123, 100]),
+        )
+        .is_err());
+    }
+
+    fn random_signature() -> Signature {
+        let mut rng = rand::thread_rng();
+        Signature(
+            G1Projective::random(&mut rng),
+            G1Projective::random(&mut rng),
+        )
+    }
+
+    #[test]
+    fn signature_aggregation_doesnt_work_for_empty_set_of_signatures() {
+        let signatures: Vec<Signature> = vec![];
+        let mut params = Parameters::new(2).unwrap();
+        let attributes = params.n_random_scalars(2);
+        let keypairs = ttp_keygen(&mut params, 3, 5).unwrap();
+
+        let (_, vks): (Vec<_>, Vec<_>) = keypairs
+            .into_iter()
+            .map(|keypair| (keypair.secret_key(), keypair.verification_key()))
+            .unzip();
+
+        let aggr_vk_all = aggregate_verification_keys(&vks, None).unwrap();
+        assert!(
+            aggregate_signatures(&params, &aggr_vk_all, &attributes, &signatures, None).is_err()
+        );
+    }
+
+    #[test]
+    fn signature_aggregation_doesnt_work_if_indices_have_invalid_length() {
+        let signatures = vec![random_signature()];
+        let mut params = Parameters::new(2).unwrap();
+        let attributes = params.n_random_scalars(2);
+        let keypairs = ttp_keygen(&mut params, 3, 5).unwrap();
+        let (_, vks): (Vec<_>, Vec<_>) = keypairs
+            .into_iter()
+            .map(|keypair| (keypair.secret_key(), keypair.verification_key()))
+            .unzip();
+        let aggr_vk_all = aggregate_verification_keys(&vks, None).unwrap();
+
+        assert!(
+            aggregate_signatures(&params, &aggr_vk_all, &attributes, &signatures, Some(&[]))
+                .is_err()
+        );
+        assert!(aggregate_signatures(
+            &params,
+            &aggr_vk_all,
+            &attributes,
+            &signatures,
+            Some(&[1, 2]),
+        )
+        .is_err());
+    }
+
+    #[test]
+    fn signature_aggregation_doesnt_work_for_non_unique_indices() {
+        let signatures = vec![random_signature(), random_signature()];
+        let mut params = Parameters::new(2).unwrap();
+        let attributes = params.n_random_scalars(2);
+        let keypairs = ttp_keygen(&mut params, 3, 5).unwrap();
+        let (_, vks): (Vec<_>, Vec<_>) = keypairs
+            .into_iter()
+            .map(|keypair| (keypair.secret_key(), keypair.verification_key()))
+            .unzip();
+        let aggr_vk_all = aggregate_verification_keys(&vks, None).unwrap();
+
+        assert!(aggregate_signatures(
+            &params,
+            &aggr_vk_all,
+            &attributes,
+            &signatures,
+            Some(&[1, 1]),
+        )
+        .is_err());
+    }
+
+    // TODO: test for aggregating non-threshold keys
+}
@@ -0,0 +1,382 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+use std::convert::TryFrom;
+use std::convert::TryInto;
+
+use bls12_381::{G1Affine, G1Projective, Scalar};
+use group::{Curve, GroupEncoding};
+
+use crate::elgamal::{Ciphertext, EphemeralKey};
+use crate::error::{CoconutError, Result};
+use crate::proofs::ProofCmCs;
+use crate::scheme::setup::Parameters;
+use crate::scheme::BlindedSignature;
+use crate::scheme::SecretKey;
+/// Creates a Coconut Signature under a given secret key on a set of public attributes only.
+#[cfg(test)]
+use crate::Signature;
+use crate::{elgamal, Attribute, ElGamalKeyPair};
+// TODO: possibly completely remove those two functions.
+// They only exist to have a simpler and smaller code snippets to test
+// basic functionalities.
+use crate::traits::{Base58, Bytable};
+use crate::utils::{hash_g1, try_deserialize_g1_projective};
+
+// TODO NAMING: double check this one
+// Lambda
+#[derive(Debug)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct BlindSignRequest {
+    // cm
+    commitment: G1Projective,
+    // h
+    commitment_hash: G1Projective,
+    // c
+    private_attributes_ciphertexts: Vec<elgamal::Ciphertext>,
+    // pi_s
+    pi_s: ProofCmCs,
+}
+
+impl TryFrom<&[u8]> for BlindSignRequest {
+    type Error = CoconutError;
+
+    fn try_from(bytes: &[u8]) -> Result<BlindSignRequest> {
+        if bytes.len() < 48 + 48 + 8 + 96 {
+            return Err(CoconutError::DeserializationMinLength {
+                min: 48 + 48 + 8 + 96,
+                actual: bytes.len(),
+            });
+        }
+
+        let mut j = 0;
+        let commitment_bytes_len = 48;
+        let commitment_hash_bytes_len = 48;
+
+        let cm_bytes = bytes[..j + commitment_bytes_len].try_into().unwrap();
+        let commitment = try_deserialize_g1_projective(
+            &cm_bytes,
+            CoconutError::Deserialization(
+                "Failed to deserialize compressed commitment".to_string(),
+            ),
+        )?;
+        j += commitment_bytes_len;
+
+        let cm_hash_bytes = bytes[j..j + commitment_hash_bytes_len].try_into().unwrap();
+        let commitment_hash = try_deserialize_g1_projective(
+            &cm_hash_bytes,
+            CoconutError::Deserialization(
+                "Failed to deserialize compressed commitment hash".to_string(),
+            ),
+        )?;
+        j += commitment_hash_bytes_len;
+
+        let c_len = u64::from_le_bytes(bytes[j..j + 8].try_into().unwrap());
+        j += 8;
+        if bytes[j..].len() < c_len as usize * 96 {
+            return Err(CoconutError::DeserializationMinLength {
+                min: c_len as usize * 96,
+                actual: bytes[56..].len(),
+            });
+        }
+
+        let mut private_attributes_ciphertexts = Vec::with_capacity(c_len as usize);
+        for i in 0..c_len as usize {
+            let start = j + i * 96;
+            let end = start + 96;
+            private_attributes_ciphertexts.push(Ciphertext::try_from(&bytes[start..end])?)
+        }
+
+        let pi_s = ProofCmCs::from_bytes(&bytes[j + c_len as usize * 96..])?;
+
+        Ok(BlindSignRequest {
+            commitment,
+            commitment_hash,
+            private_attributes_ciphertexts,
+            pi_s,
+        })
+    }
+}
+
+impl Bytable for BlindSignRequest {
+    fn to_byte_vec(&self) -> Vec<u8> {
+        let cm_bytes = self.commitment.to_affine().to_compressed();
+        let cm_hash_bytes = self.commitment_hash.to_affine().to_compressed();
+        let c_len = self.private_attributes_ciphertexts.len() as u64;
+        let proof_bytes = self.pi_s.to_bytes();
+
+        let mut bytes = Vec::with_capacity(48 + 48 + 8 + c_len as usize * 96 + proof_bytes.len());
+
+        bytes.extend_from_slice(&cm_bytes);
+        bytes.extend_from_slice(&cm_hash_bytes);
+        bytes.extend_from_slice(&c_len.to_le_bytes());
+        for c in &self.private_attributes_ciphertexts {
+            bytes.extend_from_slice(&c.to_bytes());
+        }
+
+        bytes.extend_from_slice(&proof_bytes);
+
+        bytes
+    }
+
+    fn try_from_byte_slice(slice: &[u8]) -> Result<Self> {
+        BlindSignRequest::from_bytes(slice)
+    }
+}
+
+impl Base58 for BlindSignRequest {}
+
+impl BlindSignRequest {
+    fn verify_proof(&self, params: &Parameters, pub_key: &elgamal::PublicKey) -> bool {
+        self.pi_s.verify(
+            params,
+            pub_key,
+            &self.commitment,
+            &self.private_attributes_ciphertexts,
+        )
+    }
+
+    pub fn get_commitment_hash(&self) -> G1Projective {
+        self.commitment_hash
+    }
+
+    pub fn to_bytes(&self) -> Vec<u8> {
+        self.to_byte_vec()
+    }
+
+    pub fn from_bytes(bytes: &[u8]) -> Result<BlindSignRequest> {
+        BlindSignRequest::try_from(bytes)
+    }
+}
+
+pub fn compute_private_attributes_commitment(
+    params: &Parameters,
+    private_attributes: &[Attribute],
+    hs: &[G1Affine],
+) -> (Scalar, G1Projective) {
+    let commitment_opening = params.random_scalar();
+
+    // Produces h0 ^ m0 * h1^m1 * .... * hn^mn
+    // where m0, m1, ...., mn are private attributes
+    let attr_cm = private_attributes
+        .iter()
+        .zip(hs)
+        .map(|(&m, h)| h * m)
+        .sum::<G1Projective>();
+
+    // Produces g1^r * h0 ^ m0 * h1^m1 * .... * hn^mn
+    let commitment = params.gen1() * commitment_opening + attr_cm;
+    (commitment_opening, commitment)
+}
+
+pub fn compute_commitment_hash(commitment: G1Projective) -> G1Projective {
+    hash_g1(commitment.to_bytes())
+}
+
+pub fn compute_attribute_encryption(
+    params: &Parameters,
+    private_attributes: &[Attribute],
+    pub_key: &elgamal::PublicKey,
+    commitment_hash: G1Projective,
+) -> (Vec<Ciphertext>, Vec<EphemeralKey>) {
+    private_attributes
+        .iter()
+        .map(|m| pub_key.encrypt(params, &commitment_hash, m))
+        .unzip()
+}
+
+/// Builds cryptographic material required for blind sign.
+pub fn prepare_blind_sign(
+    params: &Parameters,
+    elgamal_keypair: &ElGamalKeyPair,
+    private_attributes: &[Attribute],
+    public_attributes: &[Attribute],
+) -> Result<BlindSignRequest> {
+    if private_attributes.is_empty() {
+        return Err(CoconutError::Issuance(
+            "Tried to prepare blind sign request for an empty set of private attributes"
+                .to_string(),
+        ));
+    }
+
+    let hs = params.gen_hs();
+    if private_attributes.len() + public_attributes.len() > hs.len() {
+        return Err(CoconutError::IssuanceMaxAttributes {
+            max: hs.len(),
+            requested: private_attributes.len() + public_attributes.len(),
+        });
+    }
+
+    let (commitment_opening, commitment) =
+        compute_private_attributes_commitment(params, private_attributes, hs);
+
+    // Compute the challenge as the commitment hash
+    let commitment_hash = compute_commitment_hash(commitment);
+    // build ElGamal encryption
+    let (private_attributes_ciphertexts, ephemeral_keys): (Vec<_>, Vec<_>) =
+        compute_attribute_encryption(
+            params,
+            private_attributes,
+            elgamal_keypair.public_key(),
+            commitment_hash,
+        );
+
+    let pi_s = ProofCmCs::construct(
+        params,
+        elgamal_keypair,
+        &ephemeral_keys,
+        &commitment,
+        &commitment_opening,
+        private_attributes,
+        &*private_attributes_ciphertexts,
+    );
+
+    Ok(BlindSignRequest {
+        commitment,
+        commitment_hash,
+        private_attributes_ciphertexts,
+        pi_s,
+    })
+}
+
+pub fn blind_sign(
+    params: &Parameters,
+    signing_secret_key: &SecretKey,
+    prover_pub_key: &elgamal::PublicKey,
+    blind_sign_request: &BlindSignRequest,
+    public_attributes: &[Attribute],
+) -> Result<BlindedSignature> {
+    let num_private = blind_sign_request.private_attributes_ciphertexts.len();
+    let hs = params.gen_hs();
+
+    if num_private + public_attributes.len() > hs.len() {
+        return Err(CoconutError::IssuanceMaxAttributes {
+            max: hs.len(),
+            requested: num_private + public_attributes.len(),
+        });
+    }
+
+    // Verify the commitment hash
+    let h = hash_g1(blind_sign_request.commitment.to_bytes());
+    if !(h == blind_sign_request.commitment_hash) {
+        return Err(CoconutError::Issuance(
+            "Failed to verify the commitment hash".to_string(),
+        ));
+    }
+
+    // Verify the ZK proof
+    if !blind_sign_request.verify_proof(params, prover_pub_key) {
+        return Err(CoconutError::Issuance(
+            "Failed to verify the proof of knowledge".to_string(),
+        ));
+    }
+
+    // in python implementation there are n^2 G1 multiplications, let's do it with a single one instead.
+    // i.e. compute h ^ (pub_m[0] * y[m + 1] + ... + pub_m[n] * y[m + n]) directly (where m is number of PRIVATE attributes)
+    // rather than ((h ^ pub_m[0]) ^ y[m + 1] , (h ^ pub_m[1]) ^ y[m + 2] , ...).sum() separately
+    let signed_public = h * public_attributes
+        .iter()
+        .zip(signing_secret_key.ys.iter().skip(num_private))
+        .map(|(attr, yi)| attr * yi)
+        .sum::<Scalar>();
+
+    // c1[0] ^ y[0] * ... * c1[m] ^ y[m]
+    let sig_1 = blind_sign_request
+        .private_attributes_ciphertexts
+        .iter()
+        .map(|ciphertext| ciphertext.c1())
+        .zip(signing_secret_key.ys.iter())
+        .map(|(c1, yi)| c1 * yi)
+        .sum();
+
+    // h ^ x + c2[0] ^ y[0] + ... c2[m] ^ y[m] + h ^ (pub_m[0] * y[m + 1] + ... + pub_m[n] * y[m + n])
+    let sig_2 = blind_sign_request
+        .private_attributes_ciphertexts
+        .iter()
+        .map(|ciphertext| ciphertext.c2())
+        .zip(signing_secret_key.ys.iter())
+        .map(|(c2, yi)| c2 * yi)
+        .chain(std::iter::once(h * signing_secret_key.x))
+        .chain(std::iter::once(signed_public))
+        .sum();
+
+    Ok(BlindedSignature(h, elgamal::Ciphertext(sig_1, sig_2)))
+}
+
+#[cfg(test)]
+pub fn sign(
+    params: &mut Parameters,
+    secret_key: &SecretKey,
+    public_attributes: &[Attribute],
+) -> Result<Signature> {
+    if public_attributes.len() > secret_key.ys.len() {
+        return Err(CoconutError::IssuanceMaxAttributes {
+            max: secret_key.ys.len(),
+            requested: public_attributes.len(),
+        });
+    }
+
+    // TODO: why in the python implementation this hash onto the curve is present
+    // while it's not used in the paper? the paper uses random exponent instead.
+    // (the python implementation hashes string representation of all attributes onto the curve,
+    // but I think the same can be achieved by just summing the attributes thus avoiding the unnecessary
+    // transformation. If I'm wrong, please correct me.)
+    let attributes_sum = public_attributes.iter().sum::<Scalar>();
+    let h = hash_g1((params.gen1() * attributes_sum).to_bytes());
+
+    // x + m0 * y0 + m1 * y1 + ... mn * yn
+    let exponent = secret_key.x
+        + public_attributes
+            .iter()
+            .zip(secret_key.ys.iter())
+            .map(|(m_i, y_i)| m_i * y_i)
+            .sum::<Scalar>();
+
+    let sig2 = h * exponent;
+    Ok(Signature(h, sig2))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn blind_sign_request_bytes_roundtrip() {
+        let mut params = Parameters::new(1).unwrap();
+        let public_attributes = params.n_random_scalars(0);
+        let private_attributes = params.n_random_scalars(1);
+        let elgamal_keypair = elgamal::elgamal_keygen(&params);
+
+        let lambda = prepare_blind_sign(
+            &mut params,
+            &elgamal_keypair,
+            &private_attributes,
+            &public_attributes,
+        )
+        .unwrap();
+
+        let bytes = lambda.to_bytes();
+        println!("{:?}", bytes.len());
+        assert_eq!(
+            BlindSignRequest::try_from(bytes.as_slice()).unwrap(),
+            lambda
+        );
+
+        let mut params = Parameters::new(4).unwrap();
+        let public_attributes = params.n_random_scalars(2);
+        let private_attributes = params.n_random_scalars(2);
+        let lambda = prepare_blind_sign(
+            &mut params,
+            &elgamal_keypair,
+            &private_attributes,
+            &public_attributes,
+        )
+        .unwrap();
+
+        let bytes = lambda.to_bytes();
+        assert_eq!(
+            BlindSignRequest::try_from(bytes.as_slice()).unwrap(),
+            lambda
+        );
+    }
+}
@@ -0,0 +1,539 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+use core::borrow::Borrow;
+use core::iter::Sum;
+use core::ops::{Add, Mul};
+use std::convert::TryFrom;
+use std::convert::TryInto;
+
+use bls12_381::{G2Projective, Scalar};
+use group::Curve;
+use serde_derive::{Deserialize, Serialize};
+
+use crate::error::{CoconutError, Result};
+use crate::scheme::aggregation::aggregate_verification_keys;
+use crate::scheme::setup::Parameters;
+use crate::scheme::SignerIndex;
+use crate::traits::Bytable;
+use crate::utils::{
+    try_deserialize_g2_projective, try_deserialize_scalar, try_deserialize_scalar_vec, Polynomial,
+};
+use crate::Base58;
+
+#[derive(Debug, Clone)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct SecretKey {
+    pub(crate) x: Scalar,
+    pub(crate) ys: Vec<Scalar>,
+}
+
+impl TryFrom<&[u8]> for SecretKey {
+    type Error = CoconutError;
+
+    fn try_from(bytes: &[u8]) -> Result<SecretKey> {
+        if bytes.len() < 32 * 2 + 8 || (bytes.len() - 8) % 32 != 0 {
+            return Err(CoconutError::DeserializationInvalidLength {
+                actual: bytes.len(),
+                modulus_target: bytes.len() - 8,
+                target: 32 * 2 + 8,
+                modulus: 32,
+                object: "secret key".to_string(),
+            });
+        }
+
+        // this conversion will not fail as we are taking the same length of data
+        let x_bytes: [u8; 32] = bytes[..32].try_into().unwrap();
+        let ys_len = u64::from_le_bytes(bytes[32..40].try_into().unwrap());
+        let actual_ys_len = (bytes.len() - 40) / 32;
+
+        if ys_len as usize != actual_ys_len {
+            return Err(CoconutError::Deserialization(format!(
+                "Tried to deserialize secret key with inconsistent ys len (expected {}, got {})",
+                ys_len, actual_ys_len
+            )));
+        }
+
+        let x = try_deserialize_scalar(
+            &x_bytes,
+            CoconutError::Deserialization("Failed to deserialize secret key scalar".to_string()),
+        )?;
+        let ys = try_deserialize_scalar_vec(
+            ys_len,
+            &bytes[40..],
+            CoconutError::Deserialization("Failed to deserialize secret key scalars".to_string()),
+        )?;
+
+        Ok(SecretKey { x, ys })
+    }
+}
+
+impl SecretKey {
+    /// Derive verification key using this secret key.
+    pub fn verification_key(&self, params: &Parameters) -> VerificationKey {
+        let g2 = params.gen2();
+        VerificationKey {
+            alpha: g2 * self.x,
+            beta: self.ys.iter().map(|y| g2 * y).collect(),
+        }
+    }
+
+    // x || ys.len() || ys
+    pub fn to_bytes(&self) -> Vec<u8> {
+        let ys_len = self.ys.len() as u64;
+        let mut bytes = Vec::with_capacity(8 + (ys_len + 1) as usize * 32);
+
+        bytes.extend_from_slice(&self.x.to_bytes());
+        bytes.extend_from_slice(&ys_len.to_le_bytes());
+        for y in self.ys.iter() {
+            bytes.extend_from_slice(&y.to_bytes())
+        }
+        bytes
+    }
+
+    pub fn from_bytes(bytes: &[u8]) -> Result<SecretKey> {
+        SecretKey::try_from(bytes)
+    }
+}
+
+impl Bytable for SecretKey {
+    fn to_byte_vec(&self) -> Vec<u8> {
+        self.to_bytes()
+    }
+
+    fn try_from_byte_slice(slice: &[u8]) -> Result<Self> {
+        SecretKey::try_from(slice)
+    }
+}
+
+impl Base58 for SecretKey {}
+
+// TODO: perhaps change points to affine representation
+// to make verification slightly more efficient?
+#[derive(Debug, PartialEq, Clone)]
+pub struct VerificationKey {
+    // TODO add gen2 as per the paper or imply it from the fact library is using bls381?
+    pub(crate) alpha: G2Projective,
+    pub(crate) beta: Vec<G2Projective>,
+}
+
+impl TryFrom<&[u8]> for VerificationKey {
+    type Error = CoconutError;
+
+    fn try_from(bytes: &[u8]) -> Result<VerificationKey> {
+        if bytes.len() < 96 * 2 + 8 || (bytes.len() - 8) % 96 != 0 {
+            return Err(CoconutError::DeserializationInvalidLength {
+                actual: bytes.len(),
+                modulus_target: bytes.len() - 8,
+                target: 96 * 2 + 8,
+                modulus: 96,
+                object: "secret key".to_string(),
+            });
+        }
+
+        // this conversion will not fail as we are taking the same length of data
+        let alpha_bytes: [u8; 96] = bytes[..96].try_into().unwrap();
+        let beta_len = u64::from_le_bytes(bytes[96..104].try_into().unwrap());
+        let actual_beta_len = (bytes.len() - 104) / 96;
+
+        if beta_len as usize != actual_beta_len {
+            return Err(
+                CoconutError::Deserialization(
+                    format!("Tried to deserialize verification key with inconsistent beta len (expected {}, got {})",
+                            beta_len, actual_beta_len
+                    )));
+        }
+
+        let alpha = try_deserialize_g2_projective(
+            &alpha_bytes,
+            CoconutError::Deserialization(
+                "Failed to deserialize verification key G2 point (alpha)".to_string(),
+            ),
+        )?;
+
+        let mut beta = Vec::with_capacity(actual_beta_len);
+        for i in 0..actual_beta_len {
+            let start = 104 + i * 96;
+            let end = start + 96;
+            let beta_i_bytes = bytes[start..end].try_into().unwrap();
+            let beta_i = try_deserialize_g2_projective(
+                &beta_i_bytes,
+                CoconutError::Deserialization(
+                    "Failed to deserialize verification key G2 point (beta)".to_string(),
+                ),
+            )?;
+
+            beta.push(beta_i)
+        }
+
+        Ok(VerificationKey { alpha, beta })
+    }
+}
+
+impl<'b> Add<&'b VerificationKey> for VerificationKey {
+    type Output = VerificationKey;
+
+    #[inline]
+    fn add(self, rhs: &'b VerificationKey) -> VerificationKey {
+        // If you're trying to add two keys together that were created
+        // for different number of attributes, just panic as it's a
+        // nonsense operation.
+        assert_eq!(
+            self.beta.len(),
+            rhs.beta.len(),
+            "trying to add verification keys generated for different number of attributes"
+        );
+
+        VerificationKey {
+            alpha: self.alpha + rhs.alpha,
+            beta: self
+                .beta
+                .iter()
+                .zip(rhs.beta.iter())
+                .map(|(self_beta, rhs_beta)| self_beta + rhs_beta)
+                .collect(),
+        }
+    }
+}
+
+impl<'a> Mul<Scalar> for &'a VerificationKey {
+    type Output = VerificationKey;
+
+    #[inline]
+    fn mul(self, rhs: Scalar) -> Self::Output {
+        VerificationKey {
+            alpha: self.alpha * rhs,
+            beta: self.beta.iter().map(|b_i| b_i * rhs).collect(),
+        }
+    }
+}
+
+impl<T> Sum<T> for VerificationKey
+where
+    T: Borrow<VerificationKey>,
+{
+    #[inline]
+    fn sum<I>(iter: I) -> Self
+    where
+        I: Iterator<Item = T>,
+    {
+        let mut peekable = iter.peekable();
+        let head_attributes = match peekable.peek() {
+            Some(head) => head.borrow().beta.len(),
+            None => {
+                // TODO: this is a really weird edge case. You're trying to sum an EMPTY iterator
+                // of VerificationKey. So should it panic here or just return some nonsense value?
+                return VerificationKey::identity(0);
+            }
+        };
+
+        peekable.fold(VerificationKey::identity(head_attributes), |acc, item| {
+            acc + item.borrow()
+        })
+    }
+}
+
+impl VerificationKey {
+    /// Create a (kinda) identity verification key using specified
+    /// number of 'beta' elements
+    pub(crate) fn identity(beta_size: usize) -> Self {
+        VerificationKey {
+            alpha: G2Projective::identity(),
+            beta: vec![G2Projective::identity(); beta_size],
+        }
+    }
+
+    pub fn aggregate(sigs: &[Self], indices: Option<&[SignerIndex]>) -> Result<Self> {
+        aggregate_verification_keys(sigs, indices)
+    }
+
+    pub fn alpha(&self) -> &G2Projective {
+        &self.alpha
+    }
+
+    pub fn beta(&self) -> &Vec<G2Projective> {
+        &self.beta
+    }
+
+    pub fn to_bytes(&self) -> Vec<u8> {
+        let beta_len = self.beta.len() as u64;
+        let mut bytes = Vec::with_capacity(8 + (beta_len + 1) as usize * 96);
+
+        bytes.extend_from_slice(&self.alpha.to_affine().to_compressed());
+        bytes.extend_from_slice(&beta_len.to_le_bytes());
+        for beta in self.beta.iter() {
+            bytes.extend_from_slice(&beta.to_affine().to_compressed())
+        }
+        bytes
+    }
+
+    pub fn from_bytes(bytes: &[u8]) -> Result<VerificationKey> {
+        VerificationKey::try_from(bytes)
+    }
+}
+
+impl Bytable for VerificationKey {
+    fn to_byte_vec(&self) -> Vec<u8> {
+        self.to_bytes()
+    }
+
+    fn try_from_byte_slice(slice: &[u8]) -> Result<Self> {
+        VerificationKey::try_from(slice)
+    }
+}
+
+impl Base58 for VerificationKey {}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct KeyPair {
+    secret_key: SecretKey,
+    verification_key: VerificationKey,
+
+    /// Optional index value specifying polynomial point used during threshold key generation.
+    pub index: Option<SignerIndex>,
+}
+
+impl KeyPair {
+    const MARKER_BYTES: &'static [u8] = b"coconutkeypair";
+
+    pub fn secret_key(&self) -> SecretKey {
+        self.secret_key.clone()
+    }
+
+    pub fn verification_key(&self) -> VerificationKey {
+        self.verification_key.clone()
+    }
+
+    pub fn to_bytes(&self) -> Vec<u8> {
+        // Schema is coconutkeypair[14]|secret_key_len[8]|secret_key[secret_key_len]|verification_key_len[8]|verification_key[verification_key_len]|signer_index[8] - optional
+        self.to_byte_vec()
+    }
+
+    pub fn from_bytes(bytes: &[u8]) -> Result<Self> {
+        KeyPair::try_from_byte_slice(bytes)
+    }
+}
+
+impl Bytable for KeyPair {
+    fn to_byte_vec(&self) -> Vec<u8> {
+        // Schema is coconutkeypair[14]|secret_key_len[8]|secret_key[secret_key_len]|verification_key_len[8]|verification_key[verification_key_len]|signer_index[8] - optional
+        let mut byts = vec![];
+        let secret_key_bytes = self.secret_key.to_bytes();
+        let secret_key_len = (secret_key_bytes.len() as u64).to_le_bytes();
+        let verification_key_bytes = self.verification_key.to_bytes();
+        let verification_key_len = (verification_key_bytes.len() as u64).to_le_bytes();
+        byts.extend_from_slice(Self::MARKER_BYTES);
+        byts.extend_from_slice(&secret_key_len);
+        byts.extend_from_slice(&secret_key_bytes);
+        byts.extend_from_slice(&verification_key_len);
+        byts.extend_from_slice(&verification_key_bytes);
+        if let Some(index) = self.index {
+            byts.extend_from_slice(&index.to_le_bytes())
+        }
+        byts
+    }
+
+    fn try_from_byte_slice(slice: &[u8]) -> Result<Self> {
+        KeyPair::try_from(slice)
+    }
+}
+
+impl Base58 for KeyPair {}
+
+impl TryFrom<&[u8]> for KeyPair {
+    type Error = CoconutError;
+
+    fn try_from(bytes: &[u8]) -> Result<KeyPair> {
+        let header_len = Self::MARKER_BYTES.len();
+
+        // we must be able to at the very least read the length of secret key which is past the header
+        // and is 8 bytes long
+        if bytes.len() < header_len + 8 {
+            return Err(CoconutError::DeserializationMinLength {
+                min: header_len + 8,
+                actual: bytes.len(),
+            });
+        }
+
+        let secret_key_len =
+            u64::from_le_bytes(bytes[header_len..header_len + 8].try_into().unwrap()) as usize;
+        let secret_key_start = header_len + 8;
+
+        let secret_key =
+            SecretKey::try_from(&bytes[secret_key_start..secret_key_start + secret_key_len])?;
+
+        // we must be able to read the length of verification key
+        if bytes.len() < secret_key_start + secret_key_len + 8 {
+            return Err(CoconutError::DeserializationMinLength {
+                min: secret_key_start + secret_key_len + 8,
+                actual: bytes.len(),
+            });
+        }
+
+        let verification_key_len = u64::from_le_bytes(
+            bytes[secret_key_start + secret_key_len..secret_key_start + secret_key_len + 8]
+                .try_into()
+                .unwrap(),
+        ) as usize;
+        let verification_key_start = secret_key_start + secret_key_len + 8;
+
+        let verification_key = VerificationKey::try_from(
+            &bytes[verification_key_start..verification_key_start + verification_key_len],
+        )?;
+        let consumed_bytes = verification_key_start + verification_key_len;
+        let index = if consumed_bytes < bytes.len() && [consumed_bytes..].len() == 8 {
+            Some(u64::from_le_bytes(
+                bytes[consumed_bytes..consumed_bytes + 8]
+                    .try_into()
+                    .unwrap(),
+            ))
+        } else {
+            None
+        };
+        Ok(KeyPair {
+            secret_key,
+            verification_key,
+            index,
+        })
+    }
+}
+
+/// Generate a single Coconut keypair ((x, y0, y1...), (g2^x, g2^y0, ...)).
+/// It is not suitable for threshold credentials as all subsequent calls to `keygen` generate keys
+/// that are independent of each other.
+#[cfg(test)]
+pub fn keygen(params: &Parameters) -> KeyPair {
+    let attributes = params.gen_hs().len();
+
+    let x = params.random_scalar();
+    let ys = params.n_random_scalars(attributes);
+
+    let secret_key = SecretKey { x, ys };
+    let verification_key = secret_key.verification_key(params);
+
+    KeyPair {
+        secret_key,
+        verification_key,
+        index: None,
+    }
+}
+
+/// Generate a set of n Coconut keypairs [((x, y0, y1...), (g2^x, g2^y0, ...)), ...],
+/// such that they support threshold aggregation by `threshold` number of parties.
+/// It is expected that this procedure is executed by a Trusted Third Party.
+pub fn ttp_keygen(
+    params: &Parameters,
+    threshold: u64,
+    num_authorities: u64,
+) -> Result<Vec<KeyPair>> {
+    if threshold == 0 {
+        return Err(CoconutError::Setup(
+            "Tried to generate threshold keys with a 0 threshold value".to_string(),
+        ));
+    }
+
+    if threshold > num_authorities {
+        return Err(
+            CoconutError::Setup(
+                "Tried to generate threshold keys for threshold value being higher than number of the signing authorities".to_string(),
+            ));
+    }
+
+    let attributes = params.gen_hs().len();
+
+    // generate polynomials
+    let v = Polynomial::new_random(params, threshold - 1);
+    let ws = (0..attributes)
+        .map(|_| Polynomial::new_random(params, threshold - 1))
+        .collect::<Vec<_>>();
+
+    // TODO: potentially if we had some known authority identifier we could use that instead
+    // of the increasing (1,2,3,...) sequence
+    let polynomial_indices = (1..=num_authorities).collect::<Vec<_>>();
+
+    // generate polynomial shares
+    let x = polynomial_indices
+        .iter()
+        .map(|&id| v.evaluate(&Scalar::from(id)));
+    let ys = polynomial_indices.iter().map(|&id| {
+        ws.iter()
+            .map(|w| w.evaluate(&Scalar::from(id)))
+            .collect::<Vec<_>>()
+    });
+
+    // finally set the keys
+    let secret_keys = x.zip(ys).map(|(x, ys)| SecretKey { x, ys });
+
+    let keypairs = secret_keys
+        .zip(polynomial_indices.iter())
+        .map(|(secret_key, index)| {
+            let verification_key = secret_key.verification_key(params);
+            KeyPair {
+                secret_key,
+                verification_key,
+                index: Some(*index),
+            }
+        })
+        .collect();
+
+    Ok(keypairs)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::scheme::setup::setup;
+
+    use super::*;
+
+    #[test]
+    fn keypair_bytes_roundtrip() {
+        let mut params1 = setup(1).unwrap();
+        let mut params5 = setup(5).unwrap();
+
+        let keypair1 = keygen(&mut params1);
+        let keypair5 = keygen(&mut params5);
+
+        let bytes1 = keypair1.to_bytes();
+        let bytes5 = keypair5.to_bytes();
+
+        assert_eq!(KeyPair::from_bytes(&bytes1).unwrap(), keypair1);
+        assert_eq!(KeyPair::from_bytes(&bytes5).unwrap(), keypair5);
+    }
+
+    #[test]
+    fn secret_key_bytes_roundtrip() {
+        let mut params1 = setup(1).unwrap();
+        let mut params5 = setup(5).unwrap();
+
+        let keypair1 = keygen(&mut params1);
+        let keypair5 = keygen(&mut params5);
+
+        let bytes1 = keypair1.secret_key.to_bytes();
+        let bytes5 = keypair5.secret_key.to_bytes();
+
+        assert_eq!(SecretKey::from_bytes(&bytes1).unwrap(), keypair1.secret_key);
+        assert_eq!(SecretKey::from_bytes(&bytes5).unwrap(), keypair5.secret_key);
+    }
+
+    #[test]
+    fn verification_key_bytes_roundtrip() {
+        let mut params1 = setup(1).unwrap();
+        let mut params5 = setup(5).unwrap();
+
+        let keypair1 = &keygen(&mut params1);
+        let keypair5 = &keygen(&mut params5);
+
+        let bytes1: Vec<u8> = keypair1.verification_key.to_bytes();
+        let bytes5: Vec<u8> = keypair5.verification_key.to_bytes();
+
+        assert_eq!(
+            VerificationKey::try_from(bytes1.as_slice()).unwrap(),
+            keypair1.verification_key
+        );
+        assert_eq!(
+            VerificationKey::try_from(bytes5.as_slice()).unwrap(),
+            keypair5.verification_key
+        );
+    }
+}
@@ -0,0 +1,661 @@
+// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
+// SPDX-License-Identifier: Apache-2.0
+
+// TODO: implement https://crates.io/crates/signature traits?
+
+use std::convert::TryFrom;
+use std::convert::TryInto;
+
+use bls12_381::{G1Projective, G2Prepared, G2Projective, Scalar};
+use group::Curve;
+
+pub use keygen::{SecretKey, VerificationKey};
+
+use crate::elgamal::Ciphertext;
+use crate::error::{CoconutError, Result};
+use crate::scheme::setup::Parameters;
+use crate::scheme::verification::check_bilinear_pairing;
+use crate::traits::{Base58, Bytable};
+use crate::utils::try_deserialize_g1_projective;
+use crate::{elgamal, Attribute};
+
+pub mod aggregation;
+pub mod issuance;
+pub mod keygen;
+pub mod setup;
+pub mod verification;
+
+pub type SignerIndex = u64;
+
+// (h, s)
+#[derive(Debug, Clone, Copy)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct Signature(pub(crate) G1Projective, pub(crate) G1Projective);
+
+pub type PartialSignature = Signature;
+
+impl TryFrom<&[u8]> for Signature {
+    type Error = CoconutError;
+
+    fn try_from(bytes: &[u8]) -> Result<Signature> {
+        if bytes.len() != 96 {
+            return Err(CoconutError::Deserialization(format!(
+                "Signature must be exactly 96 bytes, got {}",
+                bytes.len()
+            )));
+        }
+
+        let sig1_bytes: &[u8; 48] = &bytes[..48].try_into().expect("Slice size != 48");
+        let sig2_bytes: &[u8; 48] = &bytes[48..].try_into().expect("Slice size != 48");
+
+        let sig1 = try_deserialize_g1_projective(
+            sig1_bytes,
+            CoconutError::Deserialization("Failed to deserialize compressed sig1".to_string()),
+        )?;
+
+        let sig2 = try_deserialize_g1_projective(
+            sig2_bytes,
+            CoconutError::Deserialization("Failed to deserialize compressed sig2".to_string()),
+        )?;
+
+        Ok(Signature(sig1, sig2))
+    }
+}
+
+impl Signature {
+    pub(crate) fn sig1(&self) -> &G1Projective {
+        &self.0
+    }
+
+    pub(crate) fn sig2(&self) -> &G1Projective {
+        &self.1
+    }
+
+    pub fn randomise(&self, params: &Parameters) -> (Signature, Scalar) {
+        let r = params.random_scalar();
+        let r_prime = params.random_scalar();
+        let h_prime = self.0 * r_prime;
+        let s_prime = (self.1 * r_prime) + (h_prime * r);
+        (Signature(h_prime, s_prime), r)
+    }
+
+    pub fn to_bytes(self) -> [u8; 96] {
+        let mut bytes = [0u8; 96];
+        bytes[..48].copy_from_slice(&self.0.to_affine().to_compressed());
+        bytes[48..].copy_from_slice(&self.1.to_affine().to_compressed());
+        bytes
+    }
+
+    pub fn from_bytes(bytes: &[u8]) -> Result<Signature> {
+        Signature::try_from(bytes)
+    }
+}
+
+impl Bytable for Signature {
+    fn to_byte_vec(&self) -> Vec<u8> {
+        self.to_bytes().to_vec()
+    }
+
+    fn try_from_byte_slice(slice: &[u8]) -> Result<Self> {
+        Signature::from_bytes(slice)
+    }
+}
+
+impl Base58 for Signature {}
+
+#[derive(Debug)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct BlindedSignature(G1Projective, elgamal::Ciphertext);
+
+impl Bytable for BlindedSignature {
+    fn to_byte_vec(&self) -> Vec<u8> {
+        self.to_bytes().to_vec()
+    }
+
+    fn try_from_byte_slice(slice: &[u8]) -> Result<Self> {
+        Self::from_bytes(slice)
+    }
+}
+
+impl Base58 for BlindedSignature {}
+
+impl TryFrom<&[u8]> for BlindedSignature {
+    type Error = CoconutError;
+
+    fn try_from(bytes: &[u8]) -> Result<BlindedSignature> {
+        if bytes.len() != 144 {
+            return Err(CoconutError::Deserialization(format!(
+                "BlindedSignature must be exactly 144 bytes, got {}",
+                bytes.len()
+            )));
+        }
+
+        let h_bytes: &[u8; 48] = &bytes[..48].try_into().expect("Slice size != 48");
+
+        let h = try_deserialize_g1_projective(
+            h_bytes,
+            CoconutError::Deserialization("Failed to deserialize compressed h".to_string()),
+        )?;
+        let c_tilde = Ciphertext::try_from(&bytes[48..])?;
+
+        Ok(BlindedSignature(h, c_tilde))
+    }
+}
+
+impl BlindedSignature {
+    pub fn unblind(
+        &self,
+        params: &Parameters,
+        private_key: &elgamal::PrivateKey,
+        partial_verification_key: &VerificationKey,
+        private_attributes: &[Attribute],
+        public_attributes: &[Attribute],
+        commitment_hash: &G1Projective,
+    ) -> Result<Signature> {
+        // parse the signature
+        let h = &self.0;
+        let c = &self.1;
+        let sig2 = private_key.decrypt(c);
+
+        // Verify the commitment hash
+        if !(commitment_hash == h) {
+            return Err(CoconutError::Unblind(
+                "Verification of commitment hash from signature failed".to_string(),
+            ));
+        }
+
+        let alpha = partial_verification_key.alpha;
+
+        let tmp = private_attributes
+            .iter()
+            .chain(public_attributes.iter())
+            .zip(partial_verification_key.beta.iter())
+            .map(|(attr, beta_i)| beta_i * attr)
+            .sum::<G2Projective>();
+
+        // Verify the signature share
+        if !check_bilinear_pairing(
+            &h.to_affine(),
+            &G2Prepared::from((alpha + tmp).to_affine()),
+            &sig2.to_affine(),
+            params.prepared_miller_g2(),
+        ) {
+            return Err(CoconutError::Unblind(
+                "Verification of signature share failed".to_string(),
+            ));
+        }
+
+        Ok(Signature(self.0, sig2))
+    }
+
+    pub fn to_bytes(&self) -> [u8; 144] {
+        let mut bytes = [0u8; 144];
+        bytes[..48].copy_from_slice(&self.0.to_affine().to_compressed());
+        bytes[48..].copy_from_slice(&self.1.to_bytes());
+        bytes
+    }
+
+    pub fn from_bytes(bytes: &[u8]) -> Result<BlindedSignature> {
+        BlindedSignature::try_from(bytes)
+    }
+}
+
+// perhaps this should take signature by reference? we'll see how it goes
+pub struct SignatureShare {
+    signature: Signature,
+    index: SignerIndex,
+}
+
+impl SignatureShare {
+    pub fn new(signature: Signature, index: SignerIndex) -> Self {
+        SignatureShare { signature, index }
+    }
+
+    pub fn signature(&self) -> &Signature {
+        &self.signature
+    }
+
+    pub fn index(&self) -> SignerIndex {
+        self.index
+    }
+
+    // pub fn aggregate(shares: &[Self]) -> Result<Signature> {
+    //     aggregate_signature_shares(shares)
+    // }
+}
+
+#[cfg(test)]
+mod tests {
+    use group::GroupEncoding;
+
+    use crate::hash_to_scalar;
+    use crate::scheme::aggregation::{aggregate_signatures, aggregate_verification_keys};
+    use crate::scheme::issuance::{blind_sign, prepare_blind_sign, sign};
+    use crate::scheme::keygen::{keygen, ttp_keygen};
+    use crate::scheme::verification::{prove_bandwidth_credential, verify, verify_credential};
+    use crate::utils::hash_g1;
+
+    use super::*;
+
+    #[test]
+    fn unblind_returns_error_if_integrity_check_on_commitment_hash_fails() {
+        let mut params = Parameters::new(2).unwrap();
+        let private_attributes = params.n_random_scalars(2 as usize);
+        let elgamal_keypair = elgamal::elgamal_keygen(&mut params);
+
+        let lambda =
+            prepare_blind_sign(&mut params, &elgamal_keypair, &private_attributes, &[]).unwrap();
+
+        let keypair1 = keygen(&mut params);
+
+        let sig1 = blind_sign(
+            &mut params,
+            &keypair1.secret_key(),
+            elgamal_keypair.public_key(),
+            &lambda,
+            &[],
+        )
+        .unwrap();
+
+        let wrong_commitment_opening = params.random_scalar();
+        let wrong_commitment = params.gen1() * wrong_commitment_opening;
+        let fake_commitment_hash = hash_g1(wrong_commitment.to_bytes());
+        assert!(sig1
+            .unblind(
+                &params,
+                elgamal_keypair.private_key(),
+                &keypair1.verification_key(),
+                &private_attributes,
+                &[],
+                &fake_commitment_hash,
+            )
+            .is_err());
+    }
+
+    #[test]
+    fn unblind_returns_error_if_signature_verification_fails() {
+        let mut params = Parameters::new(2).unwrap();
+        let private_attributes = vec![hash_to_scalar("Attribute1"), hash_to_scalar("Attribute2")];
+        let private_attributes2 = vec![hash_to_scalar("Attribute3"), hash_to_scalar("Attribute4")];
+        let elgamal_keypair = elgamal::elgamal_keygen(&mut params);
+
+        let lambda =
+            prepare_blind_sign(&mut params, &elgamal_keypair, &private_attributes, &[]).unwrap();
+
+        let keypair1 = keygen(&mut params);
+
+        let sig1 = blind_sign(
+            &mut params,
+            &keypair1.secret_key(),
+            elgamal_keypair.public_key(),
+            &lambda,
+            &[],
+        )
+        .unwrap();
+
+        assert!(sig1
+            .unblind(
+                &params,
+                elgamal_keypair.private_key(),
+                &keypair1.verification_key(),
+                &private_attributes2,
+                &[],
+                &lambda.get_commitment_hash(),
+            )
+            .is_err());
+    }
+
+    #[test]
+    fn verification_on_two_private_attributes() {
+        let mut params = Parameters::new(2).unwrap();
+        let serial_number = params.random_scalar();
+        let binding_number = params.random_scalar();
+        let private_attributes = vec![serial_number, binding_number];
+        let elgamal_keypair = elgamal::elgamal_keygen(&mut params);
+
+        let keypair1 = keygen(&mut params);
+        let keypair2 = keygen(&mut params);
+
+        let lambda =
+            prepare_blind_sign(&mut params, &elgamal_keypair, &private_attributes, &[]).unwrap();
+
+        let sig1 = blind_sign(
+            &mut params,
+            &keypair1.secret_key(),
+            elgamal_keypair.public_key(),
+            &lambda,
+            &[],
+        )
+        .unwrap()
+        .unblind(
+            &params,
+            elgamal_keypair.private_key(),
+            &keypair1.verification_key(),
+            &private_attributes,
+            &[],
+            &lambda.get_commitment_hash(),
+        )
+        .unwrap();
+
+        let sig2 = blind_sign(
+            &mut params,
+            &keypair2.secret_key(),
+            elgamal_keypair.public_key(),
+            &lambda,
+            &[],
+        )
+        .unwrap()
+        .unblind(
+            &params,
+            elgamal_keypair.private_key(),
+            &keypair2.verification_key(),
+            &private_attributes,
+            &[],
+            &lambda.get_commitment_hash(),
+        )
+        .unwrap();
+
+        let theta1 = prove_bandwidth_credential(
+            &mut params,
+            &keypair1.verification_key(),
+            &sig1,
+            serial_number,
+            binding_number,
+        )
+        .unwrap();
+
+        let theta2 = prove_bandwidth_credential(
+            &mut params,
+            &keypair2.verification_key(),
+            &sig2,
+            serial_number,
+            binding_number,
+        )
+        .unwrap();
+
+        assert!(verify_credential(
+            &params,
+            &keypair1.verification_key(),
+            &theta1,
+            &[],
+        ));
+
+        assert!(verify_credential(
+            &params,
+            &keypair2.verification_key(),
+            &theta2,
+            &[],
+        ));
+
+        assert!(!verify_credential(
+            &params,
+            &keypair1.verification_key(),
+            &theta2,
+            &[],
+        ));
+    }
+
+    #[test]
+    fn verification_on_two_public_attributes() {
+        let mut params = Parameters::new(2).unwrap();
+        let attributes = params.n_random_scalars(2);
+
+        let keypair1 = keygen(&mut params);
+        let keypair2 = keygen(&mut params);
+        let sig1 = sign(&mut params, &keypair1.secret_key(), &attributes).unwrap();
+        let sig2 = sign(&mut params, &keypair2.secret_key(), &attributes).unwrap();
+
+        assert!(verify(
+            &params,
+            &keypair1.verification_key(),
+            &attributes,
+            &sig1,
+        ));
+
+        assert!(!verify(
+            &params,
+            &keypair2.verification_key(),
+            &attributes,
+            &sig1,
+        ));
+
+        assert!(!verify(
+            &params,
+            &keypair1.verification_key(),
+            &attributes,
+            &sig2,
+        ));
+    }
+
+    #[test]
+    fn verification_on_two_public_and_two_private_attributes() {
+        let mut params = Parameters::new(4).unwrap();
+        let public_attributes = params.n_random_scalars(2);
+        let serial_number = params.random_scalar();
+        let binding_number = params.random_scalar();
+        let private_attributes = vec![serial_number, binding_number];
+        let elgamal_keypair = elgamal::elgamal_keygen(&mut params);
+
+        let keypair1 = keygen(&mut params);
+        let keypair2 = keygen(&mut params);
+
+        let lambda = prepare_blind_sign(
+            &mut params,
+            &elgamal_keypair,
+            &private_attributes,
+            &public_attributes,
+        )
+        .unwrap();
+
+        let sig1 = blind_sign(
+            &mut params,
+            &keypair1.secret_key(),
+            elgamal_keypair.public_key(),
+            &lambda,
+            &public_attributes,
+        )
+        .unwrap()
+        .unblind(
+            &params,
+            elgamal_keypair.private_key(),
+            &keypair1.verification_key(),
+            &private_attributes,
+            &public_attributes,
+            &lambda.get_commitment_hash(),
+        )
+        .unwrap();
+
+        let sig2 = blind_sign(
+            &mut params,
+            &keypair2.secret_key(),
+            elgamal_keypair.public_key(),
+            &lambda,
+            &public_attributes,
+        )
+        .unwrap()
+        .unblind(
+            &params,
+            elgamal_keypair.private_key(),
+            &keypair2.verification_key(),
+            &private_attributes,
+            &public_attributes,
+            &lambda.get_commitment_hash(),
+        )
+        .unwrap();
+
+        let theta1 = prove_bandwidth_credential(
+            &mut params,
+            &keypair1.verification_key(),
+            &sig1,
+            serial_number,
+            binding_number,
+        )
+        .unwrap();
+
+        let theta2 = prove_bandwidth_credential(
+            &mut params,
+            &keypair2.verification_key(),
+            &sig2,
+            serial_number,
+            binding_number,
+        )
+        .unwrap();
+
+        assert!(verify_credential(
+            &params,
+            &keypair1.verification_key(),
+            &theta1,
+            &public_attributes,
+        ));
+
+        assert!(verify_credential(
+            &params,
+            &keypair2.verification_key(),
+            &theta2,
+            &public_attributes,
+        ));
+
+        assert!(!verify_credential(
+            &params,
+            &keypair1.verification_key(),
+            &theta2,
+            &public_attributes,
+        ));
+    }
+
+    #[test]
+    fn verification_on_two_public_and_two_private_attributes_from_two_signers() {
+        let mut params = Parameters::new(4).unwrap();
+        let public_attributes = params.n_random_scalars(2);
+        let serial_number = params.random_scalar();
+        let binding_number = params.random_scalar();
+        let private_attributes = vec![serial_number, binding_number];
+        let elgamal_keypair = elgamal::elgamal_keygen(&params);
+
+        let keypairs = ttp_keygen(&mut params, 2, 3).unwrap();
+
+        let lambda = prepare_blind_sign(
+            &mut params,
+            &elgamal_keypair,
+            &private_attributes,
+            &public_attributes,
+        )
+        .unwrap();
+
+        let sigs = keypairs
+            .iter()
+            .map(|keypair| {
+                blind_sign(
+                    &mut params,
+                    &keypair.secret_key(),
+                    elgamal_keypair.public_key(),
+                    &lambda,
+                    &public_attributes,
+                )
+                .unwrap()
+                .unblind(
+                    &params,
+                    elgamal_keypair.private_key(),
+                    &keypair.verification_key(),
+                    &private_attributes,
+                    &public_attributes,
+                    &lambda.get_commitment_hash(),
+                )
+                .unwrap()
+            })
+            .collect::<Vec<_>>();
+
+        let vks = keypairs
+            .into_iter()
+            .map(|keypair| keypair.verification_key())
+            .collect::<Vec<_>>();
+
+        let mut attributes = Vec::with_capacity(private_attributes.len() + public_attributes.len());
+        attributes.extend_from_slice(&private_attributes);
+        attributes.extend_from_slice(&public_attributes);
+
+        let aggr_vk = aggregate_verification_keys(&vks[..2], Some(&[1, 2])).unwrap();
+        let aggr_sig =
+            aggregate_signatures(&params, &aggr_vk, &attributes, &sigs[..2], Some(&[1, 2]))
+                .unwrap();
+
+        let theta = prove_bandwidth_credential(
+            &mut params,
+            &aggr_vk,
+            &aggr_sig,
+            serial_number,
+            binding_number,
+        )
+        .unwrap();
+
+        assert!(verify_credential(
+            &params,
+            &aggr_vk,
+            &theta,
+            &public_attributes,
+        ));
+
+        // taking different subset of keys and credentials
+        let aggr_vk = aggregate_verification_keys(&vks[1..], Some(&[2, 3])).unwrap();
+        let aggr_sig =
+            aggregate_signatures(&params, &aggr_vk, &attributes, &sigs[1..], Some(&[2, 3]))
+                .unwrap();
+
+        let theta = prove_bandwidth_credential(
+            &mut params,
+            &aggr_vk,
+            &aggr_sig,
+            serial_number,
+            binding_number,
+        )
+        .unwrap();
+
+        assert!(verify_credential(
+            &params,
+            &aggr_vk,
+            &theta,
+            &public_attributes,
+        ));
+    }
+
+    #[test]
+    fn signature_bytes_roundtrip() {
+        let params = Parameters::default();
+        let r = params.random_scalar();
+        let s = params.random_scalar();
+        let signature = Signature(params.gen1() * r, params.gen1() * s);
+        let bytes = signature.to_bytes();
+
+        // also make sure it is equivalent to the internal g1 compressed bytes concatenated
+        let expected_bytes = [
+            signature.0.to_affine().to_compressed(),
+            signature.1.to_affine().to_compressed(),
+        ]
+        .concat();
+        assert_eq!(expected_bytes, bytes);
+        assert_eq!(signature, Signature::try_from(&bytes[..]).unwrap())
+    }
+
+    #[test]
+    fn blinded_signature_bytes_roundtrip() {
+        let params = Parameters::default();
+        let r = params.random_scalar();
+        let s = params.random_scalar();
+        let t = params.random_scalar();
+        let blinded_sig = BlindedSignature(
+            params.gen1() * t,
+            Ciphertext(params.gen1() * r, params.gen1() * s),
+        );
+        let bytes = blinded_sig.to_bytes();
+
+        // also make sure it is equivalent to the internal g1 compressed bytes concatenated
+        let expected_bytes = [
+            blinded_sig.0.to_affine().to_compressed(),
+            blinded_sig.1 .0.to_affine().to_compressed(),
+            blinded_sig.1 .1.to_affine().to_compressed(),
+        ]
+        .concat();
+        assert_eq!(expected_bytes, bytes);
+        assert_eq!(blinded_sig, BlindedSignature::try_from(&bytes[..]).unwrap())
+    }
+}
--- a/Show More
+++ b/Show More