chore: remove legacy gateway key compatibility (#5531 )

* removed aes128ctr key between client and gateway * removed deprecated code and all references to the legacy aes128ctr key * clippy * post rebase fixes
deprecated unpaginated /issued-ticketbooks-challenge request (#5555 )
2025-03-04 16:42:29 +00:00 · 2025-03-04 16:42:08 +00:00 · 2025-03-04 14:59:00 +00:00 · 2025-03-04 14:56:50 +00:00 · 2025-03-04 12:55:45 +00:00 · 2025-03-04 11:00:24 +00:00
453 changed files with 13566 additions and 13998 deletions
@@ -26,6 +26,7 @@ jobs:
    runs-on: ${{ matrix.platform }}
    env:
      CARGO_TERM_COLOR: always
+      RUSTUP_PERMIT_COPY_RENAME: 1
    steps:
      - uses: actions/checkout@v4

@@ -12,6 +12,7 @@ jobs:
    runs-on: arc-ubuntu-22.04
    env:
      CARGO_TERM_COLOR: always
+      RUSTUP_PERMIT_COPY_RENAME: 1
    steps:
      - name: Check out repository code
        uses: actions/checkout@v4
@@ -37,6 +37,7 @@ jobs:
    env:
      CARGO_TERM_COLOR: always
      IPINFO_API_TOKEN: ${{ secrets.IPINFO_API_TOKEN }}
+      RUSTUP_PERMIT_COPY_RENAME: 1
    steps:
      - name: Install Dependencies (Linux)
        run: sudo apt-get update && sudo apt-get -y install libwebkit2gtk-4.0-dev build-essential curl wget libssl-dev libgtk-3-dev libudev-dev squashfs-tools protobuf-compiler
@@ -54,6 +55,20 @@ jobs:
          override: true
          components: rustfmt, clippy

+      # To avoid running out of disk space, skip generating debug symbols
+      - name: Set debug to false (unix)
+        if: contains(matrix.os, 'ubuntu') || contains(matrix.os, 'mac')
+        run: |
+          sed -i.bak 's/\[profile.dev\]/\[profile.dev\]\ndebug = false/' Cargo.toml
+          git diff
+
+      - name: Set debug to false (win)
+        if: contains(matrix.os, 'windows')
+        shell: pwsh
+        run: |
+          (Get-Content Cargo.toml) -replace '\[profile.dev\]', "`$&`ndebug = false" | Set-Content Cargo.toml
+          git diff
+
      - name: Check formatting
        uses: actions-rs/cargo@v1
        with:
@@ -9,6 +9,8 @@ on:
    paths:
      - 'contracts/**'
      - 'common/**'
+      - 'Cargo.lock'
+      - 'Cargo.toml'
      - '.github/workflows/ci-contracts.yml'

 jobs:
@@ -30,6 +30,12 @@ jobs:
          override: true
          components: rustfmt, clippy

+      - name: Set debug to false
+        working-directory: nym-wallet
+        run: |
+          sed -i.bak '1s/^/\[profile.dev\]\ndebug = false\n\n/' Cargo.toml
+          git diff
+
      - name: Build all binaries
        uses: actions-rs/cargo@v1
        with:
@@ -45,6 +45,11 @@ jobs:
      - name: Install wasm-bindgen-cli
        run: cargo install wasm-bindgen-cli

+      - name: Set debug to false
+        run: |
+          sed -i.bak 's/\[profile.dev\]/\[profile.dev\]\ndebug = false/' Cargo.toml
+          git diff
+
      - name: "Build"
        run: make sdk-wasm-build

@@ -4,6 +4,212 @@ Post 1.0.0 release, the changelog format is based on [Keep a Changelog](https://

 ## [Unreleased]

+## [2025.4-dorina] (2025-03-04)
+
+- fixed sphinx version metrics registration ([#5546])
+- Feature/chain status api ([#5539])
+- Add SURBs soft threshold ([#5535])
+- Simplify IPR v8 ([#5532])
+- Shared instance for DNS AsyncResolver ([#5523])
+- merge #5512 again after reverting due to incorrect rebase ([#5520])
+- cherry-pick 17d3ff2d775f61aee381d90a304ed416c08f33fc onto dorina ([#5519])
+- cherry-pick 6e5d0dac1b75413c5f09122b0d953f8ec6ef48df onto dorina ([#5518])
+- chore: workspace global panic preventing lints ([#5512])
+- bugfix: dont query for ecash apis unless necessary when spending ticketbooks ([#5508])
+- bugfix: bound check when recovering a reply SURB ([#5502])
+- chore: removed all old coconut code ([#5500])
+- IPR request types v8 ([#5498])
+- Support static routes for HTTP requests ([#5487])
+- build(deps): bump the patch-updates group across 1 directory with 3 updates ([#5482])
+- added missing import to doctest ([#5480])
+- adjusted TestSetup::new_complex to ensure bonded node's existence ([#5478])
+- Trigger contracts CI on main workspace Cargo changes ([#5477])
+- build(deps): bump http from 1.1.0 to 1.2.0 ([#5472])
+- build(deps): bump utoipa-swagger-ui from 8.0.3 to 8.1.0 ([#5471])
+- build(deps): bump colored from 2.1.0 to 2.2.0 ([#5470])
+- build(deps): bump celes from 2.4.0 to 2.5.0 ([#5469])
+- build(deps): bump the patch-updates group with 2 updates ([#5467])
+- build(deps): bump elliptic from 6.5.4 to 6.6.1 in /docker/typescript_client/upload_contract ([#5463])
+- Run cargo autoinherit ([#5460])
+- Fix clippy::precedence ([#5457])
+- Provide Interval context with node descriptor endpoints ([#5456])
+- fix: update fx average rate calcs to ignore 0 values ([#5454])
+- Feature/add gbp currency ([#5453])
+- Add helper to extract a list of sqlite files with journal files wal/shm ([#5452])
+- Add a middleware layer to the nym api allowing for data compression ([#5451])
+- Condense core API functionalities and enable gzip decompression for reqwest payloads ([#5450])
+- build(deps): bump uniffi_build from 0.25.3 to 0.29.0 ([#5448])
+- Upgrade tower to 0.5.2 ([#5446])
+- build(deps): bump hickory-proto from 0.24.2 to 0.24.3 ([#5444])
+- Seedable clients ([#5440])
+- build(deps): bump the patch-updates group across 1 directory with 10 updates ([#5439])
+- Remove all recv_with_delay and add shutdown condition to loops in client-core ([#5435])
+- Disable the test for checking the remaining bandwidth in nym-node-status-api ([#5425])
+- Dz nym node stats ([#5418])
+- build(deps): bump hyper from 1.4.1 to 1.6.0 ([#5416])
+- build(deps): bump publicsuffix from 2.2.3 to 2.3.0 ([#5367])
+- Nymnode entrypoint docker ([#5300])
+
+[#5546]: https://github.com/nymtech/nym/pull/5546
+[#5539]: https://github.com/nymtech/nym/pull/5539
+[#5535]: https://github.com/nymtech/nym/pull/5535
+[#5532]: https://github.com/nymtech/nym/pull/5532
+[#5523]: https://github.com/nymtech/nym/pull/5523
+[#5520]: https://github.com/nymtech/nym/pull/5520
+[#5519]: https://github.com/nymtech/nym/pull/5519
+[#5518]: https://github.com/nymtech/nym/pull/5518
+[#5512]: https://github.com/nymtech/nym/pull/5512
+[#5508]: https://github.com/nymtech/nym/pull/5508
+[#5502]: https://github.com/nymtech/nym/pull/5502
+[#5500]: https://github.com/nymtech/nym/pull/5500
+[#5498]: https://github.com/nymtech/nym/pull/5498
+[#5487]: https://github.com/nymtech/nym/pull/5487
+[#5482]: https://github.com/nymtech/nym/pull/5482
+[#5480]: https://github.com/nymtech/nym/pull/5480
+[#5478]: https://github.com/nymtech/nym/pull/5478
+[#5477]: https://github.com/nymtech/nym/pull/5477
+[#5472]: https://github.com/nymtech/nym/pull/5472
+[#5471]: https://github.com/nymtech/nym/pull/5471
+[#5470]: https://github.com/nymtech/nym/pull/5470
+[#5469]: https://github.com/nymtech/nym/pull/5469
+[#5467]: https://github.com/nymtech/nym/pull/5467
+[#5463]: https://github.com/nymtech/nym/pull/5463
+[#5460]: https://github.com/nymtech/nym/pull/5460
+[#5457]: https://github.com/nymtech/nym/pull/5457
+[#5456]: https://github.com/nymtech/nym/pull/5456
+[#5454]: https://github.com/nymtech/nym/pull/5454
+[#5453]: https://github.com/nymtech/nym/pull/5453
+[#5452]: https://github.com/nymtech/nym/pull/5452
+[#5451]: https://github.com/nymtech/nym/pull/5451
+[#5450]: https://github.com/nymtech/nym/pull/5450
+[#5448]: https://github.com/nymtech/nym/pull/5448
+[#5446]: https://github.com/nymtech/nym/pull/5446
+[#5444]: https://github.com/nymtech/nym/pull/5444
+[#5440]: https://github.com/nymtech/nym/pull/5440
+[#5439]: https://github.com/nymtech/nym/pull/5439
+[#5435]: https://github.com/nymtech/nym/pull/5435
+[#5425]: https://github.com/nymtech/nym/pull/5425
+[#5418]: https://github.com/nymtech/nym/pull/5418
+[#5416]: https://github.com/nymtech/nym/pull/5416
+[#5367]: https://github.com/nymtech/nym/pull/5367
+[#5300]: https://github.com/nymtech/nym/pull/5300
+
+## [2025.3-ruta] (2025-02-10)
+
+- Push down forget me to client configs ([#5431])
+- Fix statistics shutdown ([#5426])
+- Make wait_for_graceful_shutdown to be pub ([#5424])
+- Upgrade to thiserror 2.0 ([#5414])
+- build(deps): bump the patch-updates group across 1 directory with 9 updates ([#5406])
+- Relocate a validator api function ([#5401])
+- Send shutdown instead of panic when reaching max fail ([#5398])
+- Change Explorer URL to new smooshed nodes ([#5396])
+- reduce log severity for checking topology validity ([#5395])
+- MixnetClient can send ClientRequests ([#5381])
+- Fix missing path triggers for CI ([#5380])
+- Uncouple storage reference for bandwidth client ([#5372])
+- build(deps): bump tokio from 1.40.0 to 1.43.0 ([#5370])
+- DNS resolver configuration for internal HTTP client lookups ([#5355])
+- Update README.md ([#5328])
+- Update README.md ([#5327])
+
+[#5431]: https://github.com/nymtech/nym/pull/5431
+[#5426]: https://github.com/nymtech/nym/pull/5426
+[#5424]: https://github.com/nymtech/nym/pull/5424
+[#5414]: https://github.com/nymtech/nym/pull/5414
+[#5406]: https://github.com/nymtech/nym/pull/5406
+[#5401]: https://github.com/nymtech/nym/pull/5401
+[#5398]: https://github.com/nymtech/nym/pull/5398
+[#5396]: https://github.com/nymtech/nym/pull/5396
+[#5395]: https://github.com/nymtech/nym/pull/5395
+[#5381]: https://github.com/nymtech/nym/pull/5381
+[#5380]: https://github.com/nymtech/nym/pull/5380
+[#5372]: https://github.com/nymtech/nym/pull/5372
+[#5370]: https://github.com/nymtech/nym/pull/5370
+[#5355]: https://github.com/nymtech/nym/pull/5355
+[#5328]: https://github.com/nymtech/nym/pull/5328
+[#5327]: https://github.com/nymtech/nym/pull/5327
+
+## [2025.2-hu] (2025-02-04)
+
+- Feature/remove double spending bloomfilter ([#5417])
+- HU - Downgrade harmless log message from info to debug ([#5405])
+- lower default ticket verification quorum to 0.7 ([#5404])
+- Downgrade harmless log message from info to debug ([#5403])
+- Redirect from mixnode page to nodes page ([#5397])
+- chore :update version of chain watcher and validator rewarder ([#5394])
+- bugfix: correctly handle ingore epoch roles flag ([#5390])
+- bugfix: terminate mixnet socket listener on shutdown ([#5389])
+- feat: make client ignore dual mode nodes by default ([#5388])
+- Handle ecash network errors differently ([#5378])
+- Remove empty ephemeral keys ([#5376])
+- fixed sql migration for adding default message timestamp ([#5374])
+- Bind to [::] on nym-node for both IP versions ([#5361])
+- exposed NymApiClient method for obtaining node performance history ([#5360])
+- Client gateway selection ([#5358])
+- chore: refresh wasm sdk ([#5353])
+- chore: update indexed_db_futures ([#5347])
+- build(deps): bump mikefarah/yq from 4.44.6 to 4.45.1 ([#5342])
+- updated cosmrs and tendermint-rpc to their most recent versions ([#5339])
+- build(deps): bump ts-rs from 10.0.0 to 10.1.0 ([#5338])
+- build(deps): bump tempfile from 3.14.0 to 3.15.0 ([#5337])
+- build(deps): bump the patch-updates group with 8 updates ([#5336])
+- feature: introduce /load endpoint for self-reported quantised NymNode load ([#5326])
+- feature: `CancellationToken`-based shutdowns ([#5325])
+- Use expect in geodata test to give error message on failure ([#5314])
+- feature: periodically remove stale gateway messages ([#5312])
+- build(deps): bump the patch-updates group across 1 directory with 35 updates ([#5310])
+- Add dependabot assignes for the root cargo ecosystem ([#5297])
+- Move tun constants to network defaults ([#5286])
+- Include IPINFO_API_TOKEN in nightly CI ([#5285])
+- Nyx Chain Watcher ([#5274])
+- bugfix: remove unnecessary arguments for nym-api swagger endpoints ([#5272])
+- feature: nym topology revamp ([#5271])
+- Add windows to CI builds ([#5269])
+- http-api-client: deduplicate code ([#5267])
+- build(deps): bump http from 1.1.0 to 1.2.0 ([#5228])
+- NS API: add mixnet scraper ([#5200])
+- build(deps): bump criterion from 0.4.0 to 0.5.1 ([#4911])
+
+[#5417]: https://github.com/nymtech/nym/pull/5417
+[#5405]: https://github.com/nymtech/nym/pull/5405
+[#5404]: https://github.com/nymtech/nym/pull/5404
+[#5403]: https://github.com/nymtech/nym/pull/5403
+[#5397]: https://github.com/nymtech/nym/pull/5397
+[#5394]: https://github.com/nymtech/nym/pull/5394
+[#5390]: https://github.com/nymtech/nym/pull/5390
+[#5389]: https://github.com/nymtech/nym/pull/5389
+[#5388]: https://github.com/nymtech/nym/pull/5388
+[#5378]: https://github.com/nymtech/nym/pull/5378
+[#5376]: https://github.com/nymtech/nym/pull/5376
+[#5374]: https://github.com/nymtech/nym/pull/5374
+[#5361]: https://github.com/nymtech/nym/pull/5361
+[#5360]: https://github.com/nymtech/nym/pull/5360
+[#5358]: https://github.com/nymtech/nym/pull/5358
+[#5353]: https://github.com/nymtech/nym/pull/5353
+[#5347]: https://github.com/nymtech/nym/pull/5347
+[#5342]: https://github.com/nymtech/nym/pull/5342
+[#5339]: https://github.com/nymtech/nym/pull/5339
+[#5338]: https://github.com/nymtech/nym/pull/5338
+[#5337]: https://github.com/nymtech/nym/pull/5337
+[#5336]: https://github.com/nymtech/nym/pull/5336
+[#5326]: https://github.com/nymtech/nym/pull/5326
+[#5325]: https://github.com/nymtech/nym/pull/5325
+[#5314]: https://github.com/nymtech/nym/pull/5314
+[#5312]: https://github.com/nymtech/nym/pull/5312
+[#5310]: https://github.com/nymtech/nym/pull/5310
+[#5297]: https://github.com/nymtech/nym/pull/5297
+[#5286]: https://github.com/nymtech/nym/pull/5286
+[#5285]: https://github.com/nymtech/nym/pull/5285
+[#5274]: https://github.com/nymtech/nym/pull/5274
+[#5272]: https://github.com/nymtech/nym/pull/5272
+[#5271]: https://github.com/nymtech/nym/pull/5271
+[#5269]: https://github.com/nymtech/nym/pull/5269
+[#5267]: https://github.com/nymtech/nym/pull/5267
+[#5228]: https://github.com/nymtech/nym/pull/5228
+[#5200]: https://github.com/nymtech/nym/pull/5200
+[#4911]: https://github.com/nymtech/nym/pull/4911
+
 ## [2025.1-reeses] (2025-01-15)

 - Feture/legacy alert ([#5346])
@@ -48,7 +48,6 @@ members = [
    "common/credentials-interface",
    "common/crypto",
    "common/dkg",
-    "common/ecash-double-spending",
    "common/ecash-time",
    "common/execute",
    "common/exit-policy",
@@ -67,7 +66,6 @@ members = [
    "common/nym-id",
    "common/nym-metrics",
    "common/nym_offline_compact_ecash",
-    "common/nymcoconut",
    "common/nymsphinx",
    "common/nymsphinx/acknowledgements",
    "common/nymsphinx/addressing",
@@ -188,40 +186,43 @@ readme = "README.md"

 [workspace.dependencies]
 addr = "0.15.6"
+aead = "0.5.2"
 aes = "0.8.1"
 aes-gcm = "0.10.1"
 aes-gcm-siv = "0.11.1"
-aead = "0.5.2"
-anyhow = "1.0.95"
+ammonia = "4"
+anyhow = "1.0.97"
 arc-swap = "1.7.1"
 argon2 = "0.5.0"
-async-trait = "0.1.85"
-axum-client-ip = "0.6.1"
+async-trait = "0.1.87"
 axum = "0.7.5"
+axum-client-ip = "0.6.1"
 axum-extra = "0.9.4"
+axum-test = "16.2.0"
 base64 = "0.22.1"
+base85rs = "0.1.3"
 bincode = "1.3.3"
 bip39 = { version = "2.0.0", features = ["zeroize"] }
 bit-vec = "0.7.0"                                     # can we unify those?
 bitvec = "1.0.0"
-blake3 = "1.5.5"
+blake3 = "1.6.1"
 bloomfilter = "1.0.14"
 bs58 = "0.5.1"
 bytecodec = "0.4.15"
 bytes = "1.7.2"
 cargo_metadata = "0.18.1"
-celes = "2.4.0"
+celes = "2.5.0"
 cfg-if = "1.0.0"
 chacha20 = "0.9.0"
 chacha20poly1305 = "0.10.1"
-chrono = "0.4.39"
+chrono = "0.4.40"
 cipher = "0.4.3"
-clap = "4.5.26"
+clap = "4.5.31"
 clap_complete = "4.5"
 clap_complete_fig = "4.5"
-colored = "2.0"
-comfy-table = "7.1.3"
-console = "0.15.10"
+colored = "2.2"
+comfy-table = "7.1.4"
+console = "0.15.11"
 console-subscriber = "0.1.1"
 console_error_panic_hook = "0.1"
 const-str = "0.5.6"
@@ -240,50 +241,50 @@ doc-comment = "0.3"
 dotenvy = "0.15.6"
 ecdsa = "0.16"
 ed25519-dalek = "2.1"
-etherparse = "0.13.0"
+env_logger = "0.11.6"
 envy = "0.4"
+etherparse = "0.13.0"
 eyre = "0.6.9"
 fastrand = "2.1.1"
-flate2 = "1.0.35"
+flate2 = "1.1.0"
 futures = "0.3.31"
 futures-util = "0.3"
 generic-array = "0.14.7"
 getrandom = "0.2.10"
-getset = "0.1.3"
+getset = "0.1.5"
 handlebars = "3.5.5"
 headers = "0.4.0"
 hex = "0.4.3"
 hex-literal = "0.3.3"
-hickory-resolver = "0.24.2"
+hickory-resolver = "0.24.4"
 hkdf = "0.12.3"
 hmac = "0.12.1"
 http = "1"
 http-body-util = "0.1"
 httpcodec = "0.2.3"
+human-repr = "1.1.0"
 humantime = "2.1.0"
 humantime-serde = "1.1.1"
-human-repr = "1.1.0"
-hyper = "1.4.1"
+hyper = "1.6.0"
 hyper-util = "0.1"
-indicatif = "0.17.9"
+indicatif = "0.17.11"
 inquire = "0.6.2"
 ip_network = "0.4.1"
 ipnetwork = "0.20"
 isocountry = "0.3.2"
-itertools = "0.13.0"
+itertools = "0.14.0"
 k256 = "0.13"
 lazy_static = "1.5.0"
 ledger-transport = "0.10.0"
 ledger-transport-hid = "0.10.0"
 log = "0.4"
 maxminddb = "0.23.0"
-rs_merkle = "1.4.2"
 mime = "0.3.17"
 moka = { version = "0.12", features = ["future"] }
 nix = "0.27.1"
 notify = "5.1.0"
 okapi = "0.7.0"
-once_cell = "1.20.2"
+once_cell = "1.20.3"
 opentelemetry = "0.19.0"
 opentelemetry-jaeger = "0.18.0"
 parking_lot = "0.12.3"
@@ -292,7 +293,7 @@ petgraph = "0.6.5"
 pin-project = "1.1"
 pin-project-lite = "0.2.16"
 pretty_env_logger = "0.4.0"
-publicsuffix = "2.2.3"
+publicsuffix = "2.3.0"
 quote = "1"
 rand = "0.8.5"
 rand_chacha = "0.3"
@@ -306,20 +307,21 @@ reqwest = { version = "0.12.4", default-features = false }
 rocket = "0.5.0"
 rocket_cors = "0.6.0"
 rocket_okapi = "0.8.0"
+rs_merkle = "1.4.2"
 safer-ffi = "0.1.13"
-schemars = "0.8.21"
-semver = "1.0.24"
+schemars = "0.8.22"
+semver = "1.0.25"
 serde = "1.0.217"
-serde_bytes = "0.11.15"
+serde_bytes = "0.11.16"
 serde_derive = "1.0"
-serde_json = "1.0.135"
-serde_json_path = "0.7.1"
+serde_json = "1.0.140"
+serde_json_path = "0.7.2"
 serde_repr = "0.1"
 serde_with = "3.9.0"
 serde_yaml = "0.9.25"
 sha2 = "0.10.8"
 si-scale = "0.2.3"
-sphinx-packet = "0.1.1"
+sphinx-packet = "=0.4.0" # make sure to use version 0.4.0 (or higher) that has removed backwards compatibility
 sqlx = "0.7.4"
 strum = "0.26"
 strum_macros = "0.26"
@@ -327,29 +329,32 @@ subtle-encoding = "0.5"
 syn = "1"
 sysinfo = "0.33.0"
 tap = "1.0.1"
-tar = "0.4.43"
+tar = "0.4.44"
 tempfile = "3.15"
-thiserror = "1.0.64"
+thiserror = "2.0"
 time = "0.3.37"
-tokio = "1.39"
+tokio = "1.43"
+tokio-postgres = "0.7"
 tokio-stream = "0.1.17"
 tokio-test = "0.4.4"
 tokio-tun = "0.11.5"
 tokio-tungstenite = { version = "0.20.1" }
 tokio-util = "0.7.13"
-toml = "0.8.19"
-tower = "0.4.13"
+toml = "0.8.20"
+tower = "0.5.2"
 tower-http = "0.5.2"
 tracing = "0.1.41"
+tracing-log = "0.2"
 tracing-opentelemetry = "0.19.0"
 tracing-subscriber = "0.3.19"
 tracing-tree = "0.2.2"
-tracing-log = "0.2"
 ts-rs = "10.1.0"
 tungstenite = { version = "0.20.1", default-features = false }
+uniffi = "0.29.0"
+uniffi_build = "0.29.0"
 url = "2.5"
 utoipa = "5.2"
-utoipa-swagger-ui = "8.0"
+utoipa-swagger-ui = "8.1"
 utoipauto = "0.2"
 uuid = "*"
 vergen = { version = "=8.3.1", default-features = false }
@@ -385,10 +390,10 @@ cw4 = { version = "=1.1.2" }
 cw-controllers = { version = "=1.1.0" }

 # cosmrs-related
-bip32 = { version = "0.5.2", default-features = false }
+bip32 = { version = "0.5.3", default-features = false }


-cosmrs = { version = "0.21.0" }
+cosmrs = { version = "0.21.1" }
 tendermint = "0.40.0"
 tendermint-rpc = "0.40.0"
 prost = { version = "0.13", default-features = false }
@@ -432,3 +437,13 @@ opt-level = 'z'
 [profile.release.package.mix-fetch-wasm]
 # lto = true
 opt-level = 'z'
+
+[workspace.lints.clippy]
+unwrap_used = "deny"
+expect_used = "deny"
+todo = "deny"
+dbg_macro = "deny"
+exit = "deny"
+panic = "deny"
+unimplemented = "deny"
+unreachable = "deny"
@@ -1,6 +1,6 @@
 [package]
 name = "nym-client"
-version = "1.1.46"
+version = "1.1.49"
 authors = ["Dave Hrycyszyn <futurechimp@users.noreply.github.com>", "Jędrzej Stuczyński <andrew@nymtech.net>"]
 description = "Implementation of the Nym Client"
 edition = "2021"
@@ -56,7 +56,7 @@ pub fn default_data_directory<P: AsRef<Path>>(id: P) -> PathBuf {
        .join(DEFAULT_DATA_DIR)
 }

-#[derive(Debug, Deserialize, PartialEq, Serialize)]
+#[derive(Debug, Deserialize, PartialEq, Serialize, Clone)]
 pub struct Config {
    #[serde(flatten)]
    pub base: BaseClientConfig,
@@ -94,6 +94,10 @@ impl CliClientConfig for Config {
 }

 impl Config {
+    pub fn base(&self) -> BaseClientConfig {
+        self.base.clone()
+    }
+
    pub fn new<S: AsRef<str>>(id: S) -> Self {
        Config {
            base: BaseClientConfig::new(id.as_ref(), env!("CARGO_PKG_VERSION")),
@@ -209,7 +213,7 @@ impl SocketType {
    }
 }

-#[derive(Debug, Deserialize, PartialEq, Eq, Serialize)]
+#[derive(Debug, Deserialize, PartialEq, Eq, Serialize, Clone)]
 #[serde(default, deny_unknown_fields)]
 pub struct Socket {
    pub socket_type: SocketType,
@@ -107,5 +107,8 @@ enabled = {{ debug.stats_reporting.enabled }}
 provider_address = '{{ debug.stats_reporting.provider_address }}'
 reporting_interval = '{{ debug.stats_reporting.reporting_interval }}'

+[debug.forget_me]
+client = {{ debug.forget_me.client }}
+stats = {{ debug.forget_me.stats }}

 "#;
@@ -20,7 +20,7 @@ pub use nym_sphinx::addressing::clients::Recipient;

 pub mod config;

-type NativeClientBuilder<'a> = BaseClientBuilder<'a, QueryHttpRpcNyxdClient, OnDiskPersistent>;
+type NativeClientBuilder = BaseClientBuilder<QueryHttpRpcNyxdClient, OnDiskPersistent>;

 pub struct SocketClient {
    /// Client configuration options, including, among other things, packet sending rates,
@@ -32,6 +32,10 @@ pub struct SocketClient {
 }

 impl SocketClient {
+    pub fn config(&self) -> Config {
+        self.config.clone()
+    }
+
    pub fn new(config: Config, custom_mixnet: Option<PathBuf>) -> Self {
        SocketClient {
            config,
@@ -45,7 +49,7 @@ impl SocketClient {
        client_output: ClientOutput,
        client_state: ClientState,
        self_address: &Recipient,
-        shutdown: nym_task::TaskClient,
+        task_client: nym_task::TaskClient,
        packet_type: PacketType,
    ) {
        info!("Starting websocket listener...");
@@ -73,10 +77,15 @@ impl SocketClient {
            shared_lane_queue_lengths,
            reply_controller_sender,
            Some(packet_type),
+            task_client.fork("websocket_handler"),
        );

-        websocket::Listener::new(config.socket.host, config.socket.listening_port)
-            .start(websocket_handler, shutdown);
+        websocket::Listener::new(
+            config.socket.host,
+            config.socket.listening_port,
+            task_client.with_suffix("websocket_listener"),
+        )
+        .start(websocket_handler);
    }

    /// blocking version of `start_socket` method. Will run forever (or until SIGINT is sent)
@@ -108,8 +117,9 @@ impl SocketClient {
        let storage = self.initialise_storage().await?;
        let user_agent = nym_bin_common::bin_info!().into();

-        let mut base_client = BaseClientBuilder::new(&self.config.base, storage, dkg_query_client)
-            .with_user_agent(user_agent);
+        let mut base_client =
+            BaseClientBuilder::new(self.config().base(), storage, dkg_query_client)
+                .with_user_agent(user_agent);

        if let Some(custom_mixnet) = &self.custom_mixnet {
            base_client = base_client.with_stored_topology(custom_mixnet)?;
@@ -82,6 +82,7 @@ impl From<Init> for OverrideConfig {
            nyxd_urls: init_config.common_args.nyxd_urls,
            enabled_credentials_mode: init_config.common_args.enabled_credentials_mode,
            stats_reporting_address: init_config.common_args.stats_reporting_address,
+            forget_me: init_config.common_args.forget_me.into(),
        }
    }
 }
@@ -16,6 +16,7 @@ use nym_bin_common::completions::{fig_generate, ArgShell};
 use nym_client::client::Recipient;
 use nym_client_core::cli_helpers::CliClient;
 use nym_client_core::client::base_client::storage::migration_helpers::v1_1_33;
+use nym_client_core::config::ForgetMe;
 use nym_config::OptionalSet;
 use std::error::Error;
 use std::net::IpAddr;
@@ -106,6 +107,7 @@ pub(crate) struct OverrideConfig {
    nyxd_urls: Option<Vec<url::Url>>,
    enabled_credentials_mode: Option<bool>,
    stats_reporting_address: Option<Recipient>,
+    forget_me: ForgetMe,
 }

 pub(crate) async fn execute(args: Cli) -> Result<(), Box<dyn Error + Send + Sync>> {
@@ -133,6 +135,7 @@ pub(crate) fn override_config(config: Config, args: OverrideConfig) -> Config {
            args.fastmode,
        )
        .with_base(BaseClientConfig::with_disabled_cover_traffic, args.no_cover)
+        .with_base(BaseClientConfig::with_forget_me, args.forget_me)
        .with_optional(Config::with_port, args.port)
        .with_optional(Config::with_host, args.host)
        .with_optional_custom_env_ext(
@@ -41,6 +41,7 @@ impl From<Run> for OverrideConfig {
            nyxd_urls: run_config.common_args.nyxd_urls,
            enabled_credentials_mode: run_config.common_args.enabled_credentials_mode,
            stats_reporting_address: run_config.common_args.stats_reporting_address,
+            forget_me: run_config.common_args.forget_me.into(),
        }
    }
 }
@@ -19,6 +19,7 @@ use nym_sphinx::receiver::ReconstructedMessage;
 use nym_task::connections::{
    ConnectionCommand, ConnectionCommandSender, ConnectionId, LaneQueueLengths, TransmissionLane,
 };
+use nym_task::TaskClient;
 use std::time::Duration;
 use tokio::net::TcpStream;
 use tokio::time::Instant;
@@ -43,9 +44,11 @@ pub(crate) struct HandlerBuilder {
    lane_queue_lengths: LaneQueueLengths,
    reply_controller_sender: ReplyControllerSender,
    packet_type: Option<PacketType>,
+    task_client: TaskClient,
 }

 impl HandlerBuilder {
+    #[allow(clippy::too_many_arguments)]
    pub(crate) fn new(
        msg_input: InputMessageSender,
        client_connection_tx: ConnectionCommandSender,
@@ -54,6 +57,7 @@ impl HandlerBuilder {
        lane_queue_lengths: LaneQueueLengths,
        reply_controller_sender: ReplyControllerSender,
        packet_type: Option<PacketType>,
+        task_client: TaskClient,
    ) -> Self {
        Self {
            msg_input,
@@ -63,11 +67,14 @@ impl HandlerBuilder {
            lane_queue_lengths,
            reply_controller_sender,
            packet_type,
+            task_client,
        }
    }

    // TODO: make sure we only ever have one active handler
    pub fn create_active_handler(&self) -> Handler {
+        let mut task_client = self.task_client.fork("active_handler");
+        task_client.disarm();
        Handler {
            msg_input: self.msg_input.clone(),
            client_connection_tx: self.client_connection_tx.clone(),
@@ -78,6 +85,7 @@ impl HandlerBuilder {
            lane_queue_lengths: self.lane_queue_lengths.clone(),
            reply_controller_sender: self.reply_controller_sender.clone(),
            packet_type: self.packet_type,
+            task_client,
        }
    }
 }
@@ -92,16 +100,18 @@ pub(crate) struct Handler {
    lane_queue_lengths: LaneQueueLengths,
    reply_controller_sender: ReplyControllerSender,
    packet_type: Option<PacketType>,
+    task_client: TaskClient,
 }

 impl Drop for Handler {
    fn drop(&mut self) {
-        if self
+        if let Err(err) = self
            .buffer_requester
            .unbounded_send(ReceivedBufferMessage::ReceiverDisconnect)
-            .is_err()
        {
-            error!("we failed to disconnect the receiver from the buffer! presumably the shutdown procedure has been initiated!")
+            if !self.task_client.is_shutdown_poll() {
+                error!("failed to disconnect the receiver from the buffer: {err}");
+            }
        }
    }
 }
@@ -125,10 +135,23 @@ impl Handler {
        };

        // get the number of pending replies waiting for reply surbs
-        let reply_queue_length = self
+        let reply_queue_length = match self
            .reply_controller_sender
            .get_lane_queue_length(connection_id)
-            .await;
+            .await
+        {
+            Ok(length) => length,
+            Err(err) => {
+                if !self.task_client.is_shutdown_poll() {
+                    error!(
+                        "Failed to get reply queue length for connection {connection_id}: {err}"
+                    );
+                }
+                // We're just going to assume that the queue is empty, and I think that's okay
+                // during shutdown.
+                0
+            }
+        };

        let queue_length = base_length + reply_queue_length;

@@ -168,10 +191,11 @@ impl Handler {

        // the ack control is now responsible for chunking, etc.
        let input_msg = InputMessage::new_regular(recipient, message, lane, self.packet_type);
-        self.msg_input
-            .send(input_msg)
-            .await
-            .expect("InputMessageReceiver has stopped receiving!");
+        if let Err(err) = self.msg_input.send(input_msg).await {
+            if !self.task_client.is_shutdown_poll() {
+                error!("Failed to send message to the input buffer: {err}");
+            }
+        }

        // Only reply back with a `LaneQueueLength` if the sender providided a connection id
        let TransmissionLane::ConnectionId(connection_id) = lane else {
@@ -200,10 +224,11 @@ impl Handler {

        let input_msg =
            InputMessage::new_anonymous(recipient, message, reply_surbs, lane, self.packet_type);
-        self.msg_input
-            .send(input_msg)
-            .await
-            .expect("InputMessageReceiver has stopped receiving!");
+        if let Err(err) = self.msg_input.send(input_msg).await {
+            if !self.task_client.is_shutdown_poll() {
+                error!("Failed to send anonymous message to the input buffer: {err}");
+            }
+        }

        // Only reply back with a `LaneQueueLength` if the sender providided a connection id
        let TransmissionLane::ConnectionId(connection_id) = lane else {
@@ -227,10 +252,11 @@ impl Handler {
        });

        let input_msg = InputMessage::new_reply(recipient_tag, message, lane, self.packet_type);
-        self.msg_input
-            .send(input_msg)
-            .await
-            .expect("InputMessageReceiver has stopped receiving!");
+        if let Err(err) = self.msg_input.send(input_msg).await {
+            if !self.task_client.is_shutdown_poll() {
+                error!("Failed to send reply message to the input buffer: {err}");
+            }
+        }

        // Only reply back with a `LaneQueueLength` if the sender providided a connection id
        let TransmissionLane::ConnectionId(connection_id) = lane else {
@@ -245,9 +271,14 @@ impl Handler {
    }

    fn handle_closed_connection(&self, connection_id: u64) -> Option<ServerResponse> {
-        self.client_connection_tx
+        if let Err(err) = self
+            .client_connection_tx
            .unbounded_send(ConnectionCommand::Close(connection_id))
-            .unwrap();
+        {
+            if !self.task_client.is_shutdown_poll() {
+                error!("Failed to send close connection command: {err}");
+            }
+        }
        None
    }

@@ -362,11 +393,10 @@ impl Handler {
        }
    }

-    async fn listen_for_requests(
-        &mut self,
-        mut msg_receiver: ReconstructedMessagesReceiver,
-        mut task_client: nym_task::TaskClient,
-    ) {
+    async fn listen_for_requests(&mut self, mut msg_receiver: ReconstructedMessagesReceiver) {
+        let mut task_client = self.task_client.fork("select");
+        task_client.disarm();
+
        while !task_client.is_shutdown() {
            tokio::select! {
                // we can either get a client request from the websocket
@@ -415,15 +445,7 @@ impl Handler {
    }

    // consume self to make sure `drop` is called after this is done
-    pub(crate) async fn handle_connection(
-        mut self,
-        socket: TcpStream,
-        mut task_client: nym_task::TaskClient,
-    ) {
-        // We don't want a crash in the connection handler to trigger a shutdown of the whole
-        // process.
-        task_client.disarm();
-
+    pub(crate) async fn handle_connection(mut self, socket: TcpStream) {
        let ws_stream = match accept_async(socket).await {
            Ok(ws_stream) => ws_stream,
            Err(err) => {
@@ -436,14 +458,18 @@ impl Handler {
        let (reconstructed_sender, reconstructed_receiver) = mpsc::unbounded();

        // tell the buffer to start sending stuff to us
-        self.buffer_requester
-            .unbounded_send(ReceivedBufferMessage::ReceiverAnnounce(
-                reconstructed_sender,
-            ))
-            .expect("the buffer request failed!");
+        if let Err(err) =
+            self.buffer_requester
+                .unbounded_send(ReceivedBufferMessage::ReceiverAnnounce(
+                    reconstructed_sender,
+                ))
+        {
+            if !self.task_client.is_shutdown_poll() {
+                error!("failed to announce the receiver to the buffer: {err}");
+            }
+        }

-        self.listen_for_requests(reconstructed_receiver, task_client)
-            .await;
+        self.listen_for_requests(reconstructed_receiver).await;
    }
 }

@@ -3,6 +3,7 @@

 use super::handler::HandlerBuilder;
 use log::*;
+use nym_task::TaskClient;
 use std::net::IpAddr;
 use std::{net::SocketAddr, process, sync::Arc};
 use tokio::io::AsyncWriteExt;
@@ -22,21 +23,19 @@ impl State {
 pub(crate) struct Listener {
    address: SocketAddr,
    state: State,
+    task_client: TaskClient,
 }

 impl Listener {
-    pub(crate) fn new(host: IpAddr, port: u16) -> Self {
+    pub(crate) fn new(host: IpAddr, port: u16, task_client: TaskClient) -> Self {
        Listener {
            address: SocketAddr::new(host, port),
            state: State::AwaitingConnection,
+            task_client,
        }
    }

-    pub(crate) async fn run(
-        &mut self,
-        handler: HandlerBuilder,
-        mut task_client: nym_task::TaskClient,
-    ) {
+    pub(crate) async fn run(&mut self, handler: HandlerBuilder) {
        let tcp_listener = match tokio::net::TcpListener::bind(self.address).await {
            Ok(listener) => listener,
            Err(err) => {
@@ -47,11 +46,11 @@ impl Listener {

        let notify = Arc::new(Notify::new());

-        loop {
+        while !self.task_client.is_shutdown() {
            tokio::select! {
                // When the handler finishes we check if shutdown is signalled
                _ = notify.notified() => {
-                    if task_client.is_shutdown() {
+                    if self.task_client.is_shutdown() {
                        log::trace!("Websocket listener: detected shutdown after connection closed");
                        break;
                    }
@@ -60,7 +59,7 @@ impl Listener {
                }
                // ... but when there is no connected client at the time of shutdown being
                // signalled, we handle it here.
-                _ = task_client.recv() => {
+                _ = self.task_client.recv() => {
                    if !self.state.is_connected() {
                        log::trace!("Not connected: shutting down");
                        break;
@@ -88,9 +87,8 @@ impl Listener {
                                // hanging because the executor doesn't come back here
                                let notify_clone = Arc::clone(&notify);
                                let fresh_handler = handler.create_active_handler();
-                                let task_client_handler = task_client.clone();
                                tokio::spawn(async move {
-                                    fresh_handler.handle_connection(socket, task_client_handler).await;
+                                    fresh_handler.handle_connection(socket).await;
                                    notify_clone.notify_one();
                                });
                                self.state = State::Connected;
@@ -104,13 +102,9 @@ impl Listener {
        log::debug!("Websocket listener: Exiting");
    }

-    pub(crate) fn start(
-        mut self,
-        handler: HandlerBuilder,
-        shutdown: nym_task::TaskClient,
-    ) -> JoinHandle<()> {
+    pub(crate) fn start(mut self, handler: HandlerBuilder) -> JoinHandle<()> {
        info!("Running websocket on {:?}", self.address.to_string());

-        tokio::spawn(async move { self.run(handler, shutdown).await })
+        tokio::spawn(async move { self.run(handler).await })
    }
 }
@@ -1,6 +1,6 @@
 [package]
 name = "nym-socks5-client"
-version = "1.1.46"
+version = "1.1.49"
 authors = ["Dave Hrycyszyn <futurechimp@users.noreply.github.com>"]
 description = "A SOCKS5 localhost proxy that converts incoming messages to Sphinx and sends them to a Nym address"
 edition = "2021"
@@ -93,6 +93,7 @@ impl From<Init> for OverrideConfig {
            enabled_credentials_mode: init_config.common_args.enabled_credentials_mode,
            outfox: false,
            stats_reporting_address: init_config.common_args.stats_reporting_address,
+            forget_me: init_config.common_args.forget_me.into(),
        }
    }
 }
@@ -17,7 +17,7 @@ use nym_bin_common::completions::{fig_generate, ArgShell};
 use nym_client_core::cli_helpers::CliClient;
 use nym_client_core::client::base_client::storage::migration_helpers::v1_1_33;
 use nym_client_core::client::topology_control::geo_aware_provider::CountryGroup;
-use nym_client_core::config::{GroupBy, TopologyStructure};
+use nym_client_core::config::{ForgetMe, GroupBy, TopologyStructure};
 use nym_config::OptionalSet;
 use nym_sphinx::addressing::Recipient;
 use nym_sphinx::params::{PacketSize, PacketType};
@@ -113,6 +113,7 @@ pub(crate) struct OverrideConfig {
    enabled_credentials_mode: Option<bool>,
    outfox: bool,
    stats_reporting_address: Option<Recipient>,
+    forget_me: ForgetMe,
 }

 pub(crate) async fn execute(args: Cli) -> Result<(), Box<dyn Error + Send + Sync>> {
@@ -179,6 +180,7 @@ pub(crate) fn override_config(config: Config, args: OverrideConfig) -> Config {
            BaseClientConfig::with_topology_structure,
            topology_structure,
        )
+        .with_base(BaseClientConfig::with_forget_me, args.forget_me)
        .with_optional(Config::with_anonymous_replies, args.use_anonymous_replies)
        .with_optional(Config::with_port, args.port)
        .with_optional(Config::with_ip, args.ip)
@@ -65,6 +65,7 @@ impl From<Run> for OverrideConfig {
            enabled_credentials_mode: run_config.common_args.enabled_credentials_mode,
            outfox: run_config.outfox,
            stats_reporting_address: run_config.common_args.stats_reporting_address,
+            forget_me: run_config.common_args.forget_me.into(),
        }
    }
 }
@@ -113,4 +113,8 @@ enabled = {{ core.debug.stats_reporting.enabled }}
 provider_address = '{{ core.debug.stats_reporting.provider_address }}'
 reporting_interval = '{{ core.debug.stats_reporting.reporting_interval }}'

+[core.debug.forget_me]
+client = {{ core.debug.forget_me.client }}
+stats = {{ core.debug.forget_me.stats }}
+
 "#;
@@ -1,2 +1,3 @@
 allow-unwrap-in-tests = true
 allow-expect-in-tests = true
+allow-panic-in-tests = true
@@ -60,7 +60,7 @@ impl From<IpAddr> for IpPair {
            std::net::IpAddr::V4(ipv4_addr) => (ipv4_addr.octets()[2], ipv4_addr.octets()[3]),
            std::net::IpAddr::V6(ipv6_addr) => (ipv6_addr.octets()[14], ipv6_addr.octets()[15]),
        };
-        let last_bytes = (before_last_byte as u16) << 8 | last_byte as u16;
+        let last_bytes = ((before_last_byte as u16) << 8) | last_byte as u16;
        let ipv4 = Ipv4Addr::new(
            WG_TUN_DEVICE_IP_ADDRESS_V4.octets()[0],
            WG_TUN_DEVICE_IP_ADDRESS_V4.octets()[1],
@@ -105,26 +105,24 @@ impl<C, St: Storage> BandwidthController<C, St> {
    async fn get_aggregate_verification_key(
        &self,
        epoch_id: EpochId,
-        apis: &mut ApiClientsWrapper,
+        ecash_apis: &mut ApiClientsWrapper<'_, C>,
    ) -> Result<VerificationKeyAuth, BandwidthControllerError>
    where
        C: DkgQueryClient + Sync + Send,
        <St as Storage>::StorageError: Send + Sync + 'static,
    {
-        let ecash_apis = apis.get_or_init(epoch_id, &self.client).await?;
        get_aggregate_verification_key(&self.storage, epoch_id, ecash_apis).await
    }

    async fn get_coin_index_signatures(
        &self,
        epoch_id: EpochId,
-        apis: &mut ApiClientsWrapper,
+        ecash_apis: &mut ApiClientsWrapper<'_, C>,
    ) -> Result<Vec<AnnotatedCoinIndexSignature>, BandwidthControllerError>
    where
        C: DkgQueryClient + Sync + Send,
        <St as Storage>::StorageError: Send + Sync + 'static,
    {
-        let ecash_apis = apis.get_or_init(epoch_id, &self.client).await?;
        get_coin_index_signatures(&self.storage, epoch_id, ecash_apis).await
    }

@@ -132,13 +130,12 @@ impl<C, St: Storage> BandwidthController<C, St> {
        &self,
        epoch_id: EpochId,
        expiration_date: Date,
-        apis: &mut ApiClientsWrapper,
+        ecash_apis: &mut ApiClientsWrapper<'_, C>,
    ) -> Result<Vec<AnnotatedExpirationDateSignature>, BandwidthControllerError>
    where
        C: DkgQueryClient + Sync + Send,
        <St as Storage>::StorageError: Send + Sync + 'static,
    {
-        let ecash_apis = apis.get_or_init(epoch_id, &self.client).await?;
        get_expiration_date_signatures(&self.storage, epoch_id, expiration_date, ecash_apis).await
    }

@@ -154,7 +151,7 @@ impl<C, St: Storage> BandwidthController<C, St> {
    {
        let epoch_id = retrieved_ticketbook.ticketbook.epoch_id();
        let expiration_date = retrieved_ticketbook.ticketbook.expiration_date();
-        let mut api_clients = Default::default();
+        let mut api_clients = ApiClientsWrapper::new(&self.client, epoch_id);

        let verification_key = self
            .get_aggregate_verification_key(epoch_id, &mut api_clients)
@@ -21,30 +21,67 @@ use rand::thread_rng;
 use std::fmt::Display;
 use std::future::Future;

-// it really doesn't need the RwLock because it's never moved across tasks,
-// but we need all the Send/Sync action
-#[derive(Default)]
-pub(crate) struct ApiClientsWrapper(Option<Vec<EcashApiClient>>);
-
-impl ApiClientsWrapper {
-    pub(crate) async fn get_or_init<C>(
+pub(crate) trait EcashClientsProvider {
+    async fn try_get_ecash_clients(
        &mut self,
+    ) -> Result<Vec<EcashApiClient>, BandwidthControllerError>;
+}
+
+impl EcashClientsProvider for Vec<EcashApiClient> {
+    async fn try_get_ecash_clients(
+        &mut self,
+    ) -> Result<Vec<EcashApiClient>, BandwidthControllerError> {
+        Ok(self.clone())
+    }
+}
+
+impl<C> EcashClientsProvider for &mut ApiClientsWrapper<'_, C>
+where
+    C: DkgQueryClient + Sync + Send,
+{
+    async fn try_get_ecash_clients(
+        &mut self,
+    ) -> Result<Vec<EcashApiClient>, BandwidthControllerError> {
+        self.clients().await
+    }
+}
+
+pub(crate) enum ApiClientsWrapper<'a, C> {
+    Uninitialised {
+        query_client: &'a C,
        epoch_id: EpochId,
-        dkg_client: &C,
-    ) -> Result<Vec<EcashApiClient>, BandwidthControllerError>
+    },
+    Cached {
+        clients: Vec<EcashApiClient>,
+    },
+}
+
+impl<'a, C> ApiClientsWrapper<'a, C> {
+    pub(crate) fn new(query_client: &'a C, epoch_id: EpochId) -> Self {
+        ApiClientsWrapper::Uninitialised {
+            query_client,
+            epoch_id,
+        }
+    }
+
+    async fn clients(&mut self) -> Result<Vec<EcashApiClient>, BandwidthControllerError>
    where
        C: DkgQueryClient + Sync + Send,
    {
-        if let Some(cached) = &self.0 {
-            return Ok(cached.clone());
+        match self {
+            ApiClientsWrapper::Uninitialised {
+                query_client,
+                epoch_id,
+            } => {
+                let clients = all_ecash_api_clients(*query_client, *epoch_id).await?;
+                *self = ApiClientsWrapper::Cached {
+                    clients: clients.clone(),
+                };
+
+                Ok(clients)
+            }
+            ApiClientsWrapper::Cached { clients } => Ok(clients.clone()),
        }
-
-        let clients = all_ecash_api_clients(dkg_client, epoch_id).await?;
-
-        // technically we don't have to be cloning all the clients here, but it's way simpler than
-        // dealing with locking and whatnot given the performance penalty is negligible
-        self.0 = Some(clients.clone());
-        Ok(clients)
    }
 }

@@ -76,7 +113,7 @@ where
 pub(crate) async fn get_aggregate_verification_key<St>(
    storage: &St,
    epoch_id: EpochId,
-    ecash_apis: Vec<EcashApiClient>,
+    mut ecash_apis: impl EcashClientsProvider,
 ) -> Result<VerificationKeyAuth, BandwidthControllerError>
 where
    St: Storage,
@@ -90,6 +127,8 @@ where
        return Ok(stored);
    };

+    let ecash_apis = ecash_apis.try_get_ecash_clients().await?;
+
    let master_vk = query_random_apis_until_success(
        ecash_apis,
        |api| async move { api.api_client.master_verification_key(Some(epoch_id)).await },
@@ -115,7 +154,7 @@ where
 pub(crate) async fn get_coin_index_signatures<St>(
    storage: &St,
    epoch_id: EpochId,
-    ecash_apis: Vec<EcashApiClient>,
+    mut ecash_apis: impl EcashClientsProvider,
 ) -> Result<Vec<AnnotatedCoinIndexSignature>, BandwidthControllerError>
 where
    St: Storage,
@@ -129,6 +168,8 @@ where
        return Ok(stored);
    };

+    let ecash_apis = ecash_apis.try_get_ecash_clients().await?;
+
    let index_sigs = query_random_apis_until_success(
        ecash_apis,
        |api| async move {
@@ -159,7 +200,7 @@ pub(crate) async fn get_expiration_date_signatures<St>(
    storage: &St,
    epoch_id: EpochId,
    expiration_date: Date,
-    ecash_apis: Vec<EcashApiClient>,
+    mut ecash_apis: impl EcashClientsProvider,
 ) -> Result<Vec<AnnotatedExpirationDateSignature>, BandwidthControllerError>
 where
    St: Storage,
@@ -173,6 +214,8 @@ where
        return Ok(stored);
    };

+    let ecash_apis = ecash_apis.try_get_ecash_clients().await?;
+
    let expiration_sigs = query_random_apis_until_success(
        ecash_apis,
        |api| async move {
@@ -40,6 +40,7 @@ nym-crypto = { path = "../crypto" }
 nym-explorer-client = { path = "../../explorer-api/explorer-client" }
 nym-gateway-client = { path = "../client-libs/gateway-client" }
 nym-gateway-requests = { path = "../gateway-requests" }
+nym-http-api-client = { path = "../http-api-client" }
 nym-metrics = { path = "../nym-metrics" }
 nym-nonexhaustive-delayqueue = { path = "../nonexhaustive-delayqueue" }
 nym-sphinx = { path = "../nymsphinx" }
@@ -45,6 +45,7 @@ const DEFAULT_COVER_TRAFFIC_PRIMARY_SIZE_RATIO: f64 = 0.70;
 // clients/client-core/src/client/replies/reply_storage/surb_storage.rs
 const DEFAULT_MINIMUM_REPLY_SURB_STORAGE_THRESHOLD: usize = 10;
 const DEFAULT_MAXIMUM_REPLY_SURB_STORAGE_THRESHOLD: usize = 200;
+const DEFAULT_MINIMUM_REPLY_SURB_THRESHOLD_BUFFER: usize = 0;

 // define how much to request at once
 // clients/client-core/src/client/replies/reply_controller.rs
@@ -145,6 +146,11 @@ impl Config {
        self
    }

+    pub fn with_forget_me(mut self, forget_me: ForgetMe) -> Self {
+        self.debug.forget_me = forget_me;
+        self
+    }
+
    // TODO: this should be refactored properly
    // as of 12.09.23 the below is true (not sure how this comment will rot in the future)
    // medium_toggle:
@@ -517,7 +523,7 @@ impl Default for Acknowledgements {
 }

 #[derive(Debug, Clone, Copy, Deserialize, PartialEq, Serialize)]
-#[serde(default, deny_unknown_fields)]
+#[serde(default)]
 pub struct Topology {
    /// The uniform delay every which clients are querying the directory server
    /// to try to obtain a compatible network topology to send sphinx packets through.
@@ -558,6 +564,10 @@ pub struct Topology {
    /// Specifies whether this client should ignore the current epoch role of the target egress node
    /// when constructing the final hop packets.
    pub ignore_egress_epoch_role: bool,
+
+    /// Specifies whether this client should ignore the current epoch role of the ingress node
+    /// when attempting to establish new connection
+    pub ignore_ingress_epoch_role: bool,
 }

 #[allow(clippy::large_enum_variant)]
@@ -595,7 +605,9 @@ impl Default for Topology {
            minimum_mixnode_performance: DEFAULT_MIN_MIXNODE_PERFORMANCE,
            minimum_gateway_performance: DEFAULT_MIN_GATEWAY_PERFORMANCE,
            use_extended_topology: false,
-            ignore_egress_epoch_role: false,
+
+            ignore_egress_epoch_role: true,
+            ignore_ingress_epoch_role: true,
        }
    }
 }
@@ -610,6 +622,10 @@ pub struct ReplySurbs {
    /// Defines the maximum number of reply surbs the client wants to keep in its storage at any times.
    pub maximum_reply_surb_storage_threshold: usize,

+    /// Defines the soft threshold ontop of the minimum reply surb storage threshold for when the client
+    /// should proactively request additional reply surbs.
+    pub minimum_reply_surb_threshold_buffer: usize,
+
    /// Defines the minimum number of reply surbs the client would request.
    pub minimum_reply_surb_request_size: u32,

@@ -649,6 +665,7 @@ impl Default for ReplySurbs {
        ReplySurbs {
            minimum_reply_surb_storage_threshold: DEFAULT_MINIMUM_REPLY_SURB_STORAGE_THRESHOLD,
            maximum_reply_surb_storage_threshold: DEFAULT_MAXIMUM_REPLY_SURB_STORAGE_THRESHOLD,
+            minimum_reply_surb_threshold_buffer: DEFAULT_MINIMUM_REPLY_SURB_THRESHOLD_BUFFER,
            minimum_reply_surb_request_size: DEFAULT_MINIMUM_REPLY_SURB_REQUEST_SIZE,
            maximum_reply_surb_request_size: DEFAULT_MAXIMUM_REPLY_SURB_REQUEST_SIZE,
            maximum_allowed_reply_surb_request_size: DEFAULT_MAXIMUM_ALLOWED_SURB_REQUEST_SIZE,
@@ -713,6 +730,9 @@ pub struct DebugConfig {

    /// Defines all configuration options related to stats reporting.
    pub stats_reporting: StatsReporting,
+
+    /// Defines all configuration options related to the forget me flag.
+    pub forget_me: ForgetMe,
 }

 impl DebugConfig {
@@ -735,6 +755,69 @@ impl Default for DebugConfig {
            topology: Default::default(),
            reply_surbs: Default::default(),
            stats_reporting: Default::default(),
+            forget_me: Default::default(),
+        }
+    }
+}
+
+#[derive(Clone, Default, Debug, Deserialize, PartialEq, Serialize, Copy)]
+pub struct ForgetMe {
+    client: bool,
+    stats: bool,
+}
+
+impl From<bool> for ForgetMe {
+    fn from(value: bool) -> Self {
+        if value {
+            Self::new_all()
+        } else {
+            Self::new_none()
+        }
+    }
+}
+
+impl ForgetMe {
+    pub fn new_all() -> Self {
+        Self {
+            client: true,
+            stats: true,
+        }
+    }
+
+    pub fn new_client() -> Self {
+        Self {
+            client: true,
+            stats: false,
+        }
+    }
+
+    pub fn new_stats() -> Self {
+        Self {
+            client: false,
+            stats: true,
+        }
+    }
+
+    pub fn new(client: bool, stats: bool) -> Self {
+        Self { client, stats }
+    }
+
+    pub fn any(&self) -> bool {
+        self.client || self.stats
+    }
+
+    pub fn client(&self) -> bool {
+        self.client
+    }
+
+    pub fn stats(&self) -> bool {
+        self.stats
+    }
+
+    pub fn new_none() -> Self {
+        Self {
+            client: false,
+            stats: false,
        }
    }
 }
@@ -181,8 +181,9 @@ impl From<ConfigV5> for Config {
                    maximum_reply_surb_age: value.debug.reply_surbs.maximum_reply_surb_age,
                    maximum_reply_key_age: value.debug.reply_surbs.maximum_reply_key_age,
                    surb_mix_hops: value.debug.reply_surbs.surb_mix_hops,
+                    ..Default::default()
                },
-                stats_reporting: Default::default(),
+                ..Default::default()
            },
        }
    }
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2025 - Nym Technologies SA <contact@nymtech.net>
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+-- make aes256gcm column non-nullable and drop any gateways that still use the legacy keys
+-- (since they'd be unusable after this change)
+CREATE TABLE remote_gateway_details_tmp
+(
+    gateway_id_bs58            TEXT NOT NULL UNIQUE PRIMARY KEY REFERENCES registered_gateway (gateway_id_bs58),
+    derived_aes256_gcm_siv_key BLOB NOT NULL,
+    gateway_owner_address      TEXT,
+    gateway_listener           TEXT NOT NULL
+);
+
+INSERT INTO remote_gateway_details_tmp (gateway_id_bs58, derived_aes256_gcm_siv_key, gateway_owner_address,
+                                        gateway_listener)
+SELECT gateway_id_bs58, derived_aes256_gcm_siv_key, gateway_owner_address, gateway_listener
+FROM remote_gateway_details
+WHERE derived_aes256_gcm_siv_key IS NOT NULL;
+
+DROP TABLE remote_gateway_details;
+ALTER TABLE remote_gateway_details_tmp
+    RENAME TO remote_gateway_details;
@@ -156,48 +156,26 @@ impl StorageManager {

    pub(crate) async fn set_remote_gateway_details(
        &self,
-        remote: &RawRemoteGatewayDetails,
+        gateway_id_bs58: String,
+        derived_aes256_gcm_siv_key: &[u8],
+        gateway_owner_address: Option<String>,
+        gateway_listener: String,
    ) -> Result<(), sqlx::Error> {
        sqlx::query!(
            r#"
-                INSERT INTO remote_gateway_details(gateway_id_bs58, derived_aes128_ctr_blake3_hmac_keys_bs58, derived_aes256_gcm_siv_key, gateway_owner_address, gateway_listener)
-                VALUES (?, ?, ?, ?, ?)
+                INSERT INTO remote_gateway_details(gateway_id_bs58, derived_aes256_gcm_siv_key, gateway_owner_address, gateway_listener)
+                VALUES (?, ?, ?, ?)
            "#,
-            remote.gateway_id_bs58,
-            remote.derived_aes128_ctr_blake3_hmac_keys_bs58,
-            remote.derived_aes256_gcm_siv_key,
-            remote.gateway_owner_address,
-            remote.gateway_listener,
+            gateway_id_bs58,
+            derived_aes256_gcm_siv_key,
+            gateway_owner_address,
+            gateway_listener,
        )
            .execute(&self.connection_pool)
            .await?;
        Ok(())
    }

-    pub(crate) async fn update_remote_gateway_key(
-        &self,
-        gateway_id_bs58: &str,
-        derived_aes128_ctr_blake3_hmac_keys_bs58: Option<&str>,
-        derived_aes256_gcm_siv_key: Option<&[u8]>,
-    ) -> Result<(), sqlx::Error> {
-        sqlx::query!(
-            r#"
-                UPDATE remote_gateway_details
-                SET
-                    derived_aes128_ctr_blake3_hmac_keys_bs58 = ?,
-                    derived_aes256_gcm_siv_key = ?
-                WHERE gateway_id_bs58 = ?
-            "#,
-            derived_aes128_ctr_blake3_hmac_keys_bs58,
-            derived_aes256_gcm_siv_key,
-            gateway_id_bs58
-        )
-        .execute(&self.connection_pool)
-        .await?;
-
-        Ok(())
-    }
-
    pub(crate) async fn remove_remote_gateway_details(
        &self,
        gateway_id: &str,
@@ -8,7 +8,6 @@ use crate::{
 use async_trait::async_trait;
 use manager::StorageManager;
 use nym_crypto::asymmetric::ed25519;
-use nym_gateway_requests::SharedSymmetricKey;
 use std::path::Path;

 pub mod error;
@@ -119,9 +118,16 @@ impl GatewaysDetailsStore for OnDiskGatewaysDetails {

        match &details.details {
            GatewayDetails::Remote(remote_details) => {
-                let raw_details = remote_details.into();
                self.manager
-                    .set_remote_gateway_details(&raw_details)
+                    .set_remote_gateway_details(
+                        remote_details.gateway_id.to_base58_string(),
+                        remote_details.shared_key.as_bytes(),
+                        remote_details
+                            .gateway_owner_address
+                            .as_ref()
+                            .map(|o| o.to_string()),
+                        remote_details.gateway_listener.to_string(),
+                    )
                    .await?;
            }
            GatewayDetails::Custom(custom_details) => {
@@ -134,21 +140,6 @@ impl GatewaysDetailsStore for OnDiskGatewaysDetails {
        Ok(())
    }

-    async fn upgrade_stored_remote_gateway_key(
-        &self,
-        gateway_id: ed25519::PublicKey,
-        updated_key: &SharedSymmetricKey,
-    ) -> Result<(), Self::StorageError> {
-        self.manager
-            .update_remote_gateway_key(
-                &gateway_id.to_base58_string(),
-                None,
-                Some(updated_key.as_bytes()),
-            )
-            .await?;
-        Ok(())
-    }
-
    // ideally all of those should be run under a storage tx to ensure storage consistency,
    // but at that point it's fine
    async fn remove_gateway_details(&self, gateway_id: &str) -> Result<(), Self::StorageError> {
@@ -2,10 +2,8 @@
 // SPDX-License-Identifier: Apache-2.0

 use crate::types::{ActiveGateway, GatewayRegistration};
-use crate::{BadGateway, GatewayDetails, GatewaysDetailsStore};
+use crate::{BadGateway, GatewaysDetailsStore};
 use async_trait::async_trait;
-use nym_crypto::asymmetric::ed25519::PublicKey;
-use nym_gateway_requests::{SharedGatewayKey, SharedSymmetricKey};
 use std::collections::HashMap;
 use std::sync::Arc;
 use thiserror::Error;
@@ -96,29 +94,6 @@ impl GatewaysDetailsStore for InMemGatewaysDetails {
        Ok(())
    }

-    async fn upgrade_stored_remote_gateway_key(
-        &self,
-        gateway_id: PublicKey,
-        updated_key: &SharedSymmetricKey,
-    ) -> Result<(), Self::StorageError> {
-        let mut guard = self.inner.write().await;
-
-        #[allow(clippy::unwrap_used)]
-        if let Some(target) = guard.gateways.get_mut(&gateway_id.to_string()) {
-            let GatewayDetails::Remote(details) = &mut target.details else {
-                return Ok(());
-            };
-            assert_eq!(Arc::strong_count(&details.shared_key), 1);
-
-            // eh. that's nasty, but it's only ever used for ephemeral clients so should be fine for now...
-            details.shared_key = Arc::new(SharedGatewayKey::Current(
-                SharedSymmetricKey::try_from_bytes(updated_key.as_bytes()).unwrap(),
-            ))
-        }
-
-        Ok(())
-    }
-
    async fn remove_gateway_details(&self, gateway_id: &str) -> Result<(), Self::StorageError> {
        let mut guard = self.inner.write().await;
        if let Some(active) = guard.active_gateway.as_ref() {
@@ -6,7 +6,6 @@

 use async_trait::async_trait;
 use nym_crypto::asymmetric::identity;
-use nym_gateway_requests::SharedSymmetricKey;
 use std::error::Error;

 pub mod backend;
@@ -62,12 +61,6 @@ pub trait GatewaysDetailsStore {
        details: &GatewayRegistration,
    ) -> Result<(), Self::StorageError>;

-    async fn upgrade_stored_remote_gateway_key(
-        &self,
-        gateway_id: identity::PublicKey,
-        updated_key: &SharedSymmetricKey,
-    ) -> Result<(), Self::StorageError>;
-
    /// Remove given gateway details from the underlying store.
    async fn remove_gateway_details(&self, gateway_id: &str) -> Result<(), Self::StorageError>;
 }
@@ -4,10 +4,9 @@
 use crate::BadGateway;
 use cosmrs::AccountId;
 use nym_crypto::asymmetric::identity;
-use nym_gateway_requests::shared_key::{LegacySharedKeys, SharedGatewayKey, SharedSymmetricKey};
+use nym_gateway_requests::shared_key::SharedSymmetricKey;
 use serde::{Deserialize, Serialize};
 use std::fmt::{Display, Formatter};
-use std::ops::Deref;
 use std::str::FromStr;
 use std::sync::Arc;
 use time::OffsetDateTime;
@@ -65,7 +64,7 @@ impl From<GatewayDetails> for GatewayRegistration {
 impl GatewayDetails {
    pub fn new_remote(
        gateway_id: identity::PublicKey,
-        shared_key: Arc<SharedGatewayKey>,
+        shared_key: Arc<SharedSymmetricKey>,
        gateway_owner_address: Option<AccountId>,
        gateway_listener: Url,
    ) -> Self {
@@ -88,7 +87,7 @@ impl GatewayDetails {
        }
    }

-    pub fn shared_key(&self) -> Option<&SharedGatewayKey> {
+    pub fn shared_key(&self) -> Option<&SharedSymmetricKey> {
        match self {
            GatewayDetails::Remote(details) => Some(&details.shared_key),
            GatewayDetails::Custom(_) => None,
@@ -168,8 +167,7 @@ pub struct RegisteredGateway {
 #[cfg_attr(feature = "sqlx", derive(sqlx::FromRow))]
 pub struct RawRemoteGatewayDetails {
    pub gateway_id_bs58: String,
-    pub derived_aes128_ctr_blake3_hmac_keys_bs58: Option<String>,
-    pub derived_aes256_gcm_siv_key: Option<Vec<u8>>,
+    pub derived_aes256_gcm_siv_key: Vec<u8>,
    pub gateway_owner_address: Option<String>,
    pub gateway_listener: String,
 }
@@ -186,35 +184,11 @@ impl TryFrom<RawRemoteGatewayDetails> for RemoteGatewayDetails {
                }
            })?;

-        let shared_key =
-            match (
-                &value.derived_aes256_gcm_siv_key,
-                &value.derived_aes128_ctr_blake3_hmac_keys_bs58,
-            ) {
-                (None, None) => {
-                    return Err(BadGateway::MissingSharedKey {
-                        gateway_id: value.gateway_id_bs58.clone(),
-                    })
-                }
-                (Some(aes256gcm_siv), _) => {
-                    let current_key =
-                        SharedSymmetricKey::try_from_bytes(aes256gcm_siv).map_err(|source| {
-                            BadGateway::MalformedSharedKeys {
-                                gateway_id: value.gateway_id_bs58.clone(),
-                                source,
-                            }
-                        })?;
-                    SharedGatewayKey::Current(current_key)
-                }
-                (None, Some(aes128ctr_hmac)) => {
-                    let legacy_key = LegacySharedKeys::try_from_base58_string(aes128ctr_hmac)
-                        .map_err(|source| BadGateway::MalformedSharedKeys {
-                            gateway_id: value.gateway_id_bs58.clone(),
-                            source,
-                        })?;
-                    SharedGatewayKey::Legacy(legacy_key)
-                }
-            };
+        let shared_key = SharedSymmetricKey::try_from_bytes(&value.derived_aes256_gcm_siv_key)
+            .map_err(|source| BadGateway::MalformedSharedKeys {
+                gateway_id: value.gateway_id_bs58.clone(),
+                source,
+            })?;

        let gateway_owner_address = value
            .gateway_owner_address
@@ -247,29 +221,11 @@ impl TryFrom<RawRemoteGatewayDetails> for RemoteGatewayDetails {
    }
 }

-impl<'a> From<&'a RemoteGatewayDetails> for RawRemoteGatewayDetails {
-    fn from(value: &'a RemoteGatewayDetails) -> Self {
-        let (derived_aes128_ctr_blake3_hmac_keys_bs58, derived_aes256_gcm_siv_key) =
-            match value.shared_key.deref() {
-                SharedGatewayKey::Current(key) => (None, Some(key.to_bytes())),
-                SharedGatewayKey::Legacy(key) => (Some(key.to_base58_string()), None),
-            };
-
-        RawRemoteGatewayDetails {
-            gateway_id_bs58: value.gateway_id.to_base58_string(),
-            derived_aes128_ctr_blake3_hmac_keys_bs58,
-            derived_aes256_gcm_siv_key,
-            gateway_owner_address: value.gateway_owner_address.as_ref().map(|o| o.to_string()),
-            gateway_listener: value.gateway_listener.to_string(),
-        }
-    }
-}
-
 #[derive(Debug, Clone)]
 pub struct RemoteGatewayDetails {
    pub gateway_id: identity::PublicKey,

-    pub shared_key: Arc<SharedGatewayKey>,
+    pub shared_key: Arc<SharedSymmetricKey>,

    pub gateway_owner_address: Option<AccountId>,

@@ -120,6 +120,7 @@ where
            &core.client.nym_api_urls,
            user_agent,
            core.debug.topology.minimum_gateway_performance,
+            core.debug.topology.ignore_ingress_epoch_role,
        )
        .await?
    };
@@ -93,6 +93,10 @@ pub struct CommonClientInitArgs {
    /// Sets the address to report statistics
    #[cfg_attr(feature = "cli", clap(long, hide = true))]
    pub stats_reporting_address: Option<Recipient>,
+
+    /// Sets the forget me flag
+    #[cfg_attr(feature = "cli", clap(long, hide = true, default_value_t = false))]
+    pub forget_me: bool,
 }

 pub struct InitResultsWithConfig<T> {
@@ -175,6 +179,7 @@ where
            &core.client.nym_api_urls,
            user_agent,
            core.debug.topology.minimum_gateway_performance,
+            core.debug.topology.ignore_ingress_epoch_role,
        )
        .await?
    };
@@ -61,4 +61,8 @@ pub struct CommonClientRunArgs {
    /// Sets the address to report statistics
    #[cfg_attr(feature = "cli", clap(long, hide = true))]
    pub stats_reporting_address: Option<Recipient>,
+
+    /// Sets the forget me flag
+    #[cfg_attr(feature = "cli", clap(long, hide = true, default_value_t = false))]
+    pub forget_me: bool,
 }
@@ -1,6 +1,7 @@
 // Copyright 2022-2023 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0

+use super::mix_traffic::ClientRequestSender;
 use super::received_buffer::ReceivedBufferMessage;
 use super::statistics_control::StatisticsControl;
 use crate::client::base_client::storage::helpers::store_client_keys;
@@ -31,13 +32,15 @@ use crate::init::{
    setup_gateway,
    types::{GatewaySetup, InitialisationResult},
 };
-use crate::{config, spawn_future, ForgetMe};
+use crate::{config, spawn_future};
 use futures::channel::mpsc;
 use log::*;
 use nym_bandwidth_controller::BandwidthController;
+use nym_client_core_config_types::ForgetMe;
 use nym_client_core_gateways_storage::{GatewayDetails, GatewaysDetailsStore};
 use nym_credential_storage::storage::Storage as CredentialStorage;
 use nym_crypto::asymmetric::{encryption, identity};
+use nym_crypto::hkdf::DerivationMaterial;
 use nym_gateway_client::client::config::GatewayClientConfig;
 use nym_gateway_client::{
    AcknowledgementReceiver, GatewayClient, GatewayConfig, MixnetMessageReceiver, PacketRouter,
@@ -175,8 +178,8 @@ impl From<bool> for CredentialsToggle {
    }
 }

-pub struct BaseClientBuilder<'a, C, S: MixnetClientStorage> {
-    config: &'a Config,
+pub struct BaseClientBuilder<C, S: MixnetClientStorage> {
+    config: Config,
    client_store: S,
    dkg_query_client: Option<C>,

@@ -191,19 +194,19 @@ pub struct BaseClientBuilder<'a, C, S: MixnetClientStorage> {
    #[cfg(unix)]
    connection_fd_callback: Option<Arc<dyn Fn(RawFd) + Send + Sync>>,

-    forget_me: ForgetMe,
+    derivation_material: Option<DerivationMaterial>,
 }

-impl<'a, C, S> BaseClientBuilder<'a, C, S>
+impl<C, S> BaseClientBuilder<C, S>
 where
    S: MixnetClientStorage + 'static,
    C: DkgQueryClient + Send + Sync + 'static,
 {
    pub fn new(
-        base_config: &'a Config,
+        base_config: Config,
        client_store: S,
        dkg_query_client: Option<C>,
-    ) -> BaseClientBuilder<'a, C, S> {
+    ) -> BaseClientBuilder<C, S> {
        BaseClientBuilder {
            config: base_config,
            client_store,
@@ -216,13 +219,22 @@ where
            setup_method: GatewaySetup::MustLoad { gateway_id: None },
            #[cfg(unix)]
            connection_fd_callback: None,
-            forget_me: Default::default(),
+            derivation_material: None,
        }
    }

+    #[must_use]
+    pub fn with_derivation_material(
+        mut self,
+        derivation_material: Option<DerivationMaterial>,
+    ) -> Self {
+        self.derivation_material = derivation_material;
+        self
+    }
+
    #[must_use]
    pub fn with_forget_me(mut self, forget_me: &ForgetMe) -> Self {
-        self.forget_me = forget_me.clone();
+        self.config.debug.forget_me = *forget_me;
        self
    }

@@ -298,7 +310,7 @@ where
        topology_accessor: TopologyAccessor,
        mix_tx: BatchMixMessageSender,
        stats_tx: ClientStatsSender,
-        shutdown: TaskClient,
+        task_client: TaskClient,
    ) {
        info!("Starting loop cover traffic stream...");

@@ -311,9 +323,10 @@ where
            debug_config.traffic,
            debug_config.cover_traffic,
            stats_tx,
+            task_client,
        );

-        stream.start_with_shutdown(shutdown);
+        stream.start();
    }

    #[allow(clippy::too_many_arguments)]
@@ -328,7 +341,7 @@ where
        reply_controller_receiver: ReplyControllerReceiver,
        lane_queue_lengths: LaneQueueLengths,
        client_connection_rx: ConnectionCommandReceiver,
-        shutdown: TaskClient,
+        task_client: TaskClient,
        packet_type: PacketType,
        stats_tx: ClientStatsSender,
    ) {
@@ -346,8 +359,9 @@ where
            lane_queue_lengths,
            client_connection_rx,
            stats_tx,
+            task_client,
        )
-        .start_with_shutdown(shutdown, packet_type);
+        .start(packet_type);
    }

    // buffer controlling all messages fetched from provider
@@ -370,8 +384,9 @@ where
                reply_key_storage,
                reply_controller_sender,
                metrics_reporter,
+                shutdown,
            );
-        controller.start_with_shutdown(shutdown)
+        controller.start()
    }

    #[allow(clippy::too_many_arguments)]
@@ -379,7 +394,6 @@ where
        config: &Config,
        initialisation_result: InitialisationResult,
        bandwidth_controller: Option<BandwidthController<C, S::CredentialStore>>,
-        details_store: &S::GatewaysDetailsStore,
        packet_router: PacketRouter,
        stats_reporter: ClientStatsSender,
        #[cfg(unix)] connection_fd_callback: Option<Arc<dyn Fn(RawFd) + Send + Sync>>,
@@ -388,7 +402,6 @@ where
    where
        <S::KeyStore as KeyStore>::StorageError: Send + Sync + 'static,
        <S::CredentialStore as CredentialStorage>::StorageError: Send + Sync + 'static,
-        <S::GatewaysDetailsStore as GatewaysDetailsStore>::StorageError: Sync + Send,
    {
        let managed_keys = initialisation_result.client_keys;
        let GatewayDetails::Remote(details) = initialisation_result.gateway_registration.details
@@ -443,31 +456,13 @@ where
        // we need to:
        // - perform handshake (reg or auth)
        // - check for key upgrade
-        // - maybe perform another upgrade handshake
        // - check for bandwidth
        // - start background tasks
-        let auth_res = gateway_client
+        let _auth_res = gateway_client
            .perform_initial_authentication()
            .await
            .map_err(gateway_failure)?;

-        if auth_res.requires_key_upgrade {
-            // drop the shared_key arc because we don't need it and we can't hold it for the purposes of upgrade
-            drop(auth_res);
-
-            let updated_key = gateway_client
-                .upgrade_key_authenticated()
-                .await
-                .map_err(gateway_failure)?;
-
-            details_store
-                .upgrade_stored_remote_gateway_key(gateway_client.gateway_identity(), &updated_key)
-                .await.map_err(|err| {
-                error!("failed to store upgraded gateway key! this connection might be forever broken now: {err}");
-                ClientCoreError::GatewaysDetailsStoreError { source: Box::new(err) }
-            })?
-        }
-
        gateway_client
            .claim_initial_bandwidth()
            .await
@@ -486,7 +481,6 @@ where
        config: &Config,
        initialisation_result: InitialisationResult,
        bandwidth_controller: Option<BandwidthController<C, S::CredentialStore>>,
-        details_store: &S::GatewaysDetailsStore,
        packet_router: PacketRouter,
        stats_reporter: ClientStatsSender,
        #[cfg(unix)] connection_fd_callback: Option<Arc<dyn Fn(RawFd) + Send + Sync>>,
@@ -495,7 +489,6 @@ where
    where
        <S::KeyStore as KeyStore>::StorageError: Send + Sync + 'static,
        <S::CredentialStore as CredentialStorage>::StorageError: Send + Sync + 'static,
-        <S::GatewaysDetailsStore as GatewaysDetailsStore>::StorageError: Sync + Send,
    {
        // if we have setup custom gateway sender and persisted details agree with it, return it
        if let Some(mut custom_gateway_transceiver) = custom_gateway_transceiver {
@@ -518,7 +511,6 @@ where
            config,
            initialisation_result,
            bandwidth_controller,
-            details_store,
            packet_router,
            stats_reporter,
            #[cfg(unix)]
@@ -560,15 +552,22 @@ where
        topology_accessor: TopologyAccessor,
        local_gateway: NodeIdentity,
        wait_for_gateway: bool,
-        mut shutdown: TaskClient,
+        mut task_client: TaskClient,
    ) -> Result<(), ClientCoreError> {
        let topology_refresher_config =
            TopologyRefresherConfig::new(topology_config.topology_refresh_rate);

+        if topology_config.disable_refreshing {
+            // if we're not spawning the refresher, don't cause shutdown immediately
+            info!("The background topology refesher is not going to be started");
+            task_client.disarm();
+        }
+
        let mut topology_refresher = TopologyRefresher::new(
            topology_refresher_config,
            topology_accessor,
            topology_provider,
+            task_client,
        );
        // before returning, block entire runtime to refresh the current network view so that any
        // components depending on topology would see a non-empty view
@@ -609,15 +608,11 @@ where
            }
        }

-        if topology_config.disable_refreshing {
-            // if we're not spawning the refresher, don't cause shutdown immediately
-            info!("The topology refesher is not going to be started");
-            shutdown.disarm();
-        } else {
+        if !topology_config.disable_refreshing {
            // don't spawn the refresher if we don't want to be refreshing the topology.
            // only use the initial values obtained
            info!("Starting topology refresher...");
-            topology_refresher.start_with_shutdown(shutdown);
+            topology_refresher.start();
        }

        Ok(())
@@ -628,30 +623,29 @@ where
        user_agent: Option<UserAgent>,
        client_stats_id: String,
        input_sender: Sender<InputMessage>,
-        shutdown: TaskClient,
+        task_client: TaskClient,
    ) -> ClientStatsSender {
        info!("Starting statistics control...");
-        StatisticsControl::create_and_start_with_shutdown(
+        StatisticsControl::create_and_start(
            config.debug.stats_reporting,
            user_agent
                .map(|u| u.application)
                .unwrap_or("unknown".to_string()),
            client_stats_id,
            input_sender.clone(),
-            shutdown.with_suffix("controller"),
+            task_client,
        )
    }

    fn start_mix_traffic_controller(
        gateway_transceiver: Box<dyn GatewayTransceiver + Send>,
        shutdown: TaskClient,
-        forget_me: ForgetMe,
-    ) -> BatchMixMessageSender {
+    ) -> (BatchMixMessageSender, ClientRequestSender) {
        info!("Starting mix traffic controller...");
-        let (mix_traffic_controller, mix_tx) =
-            MixTrafficController::new(gateway_transceiver, forget_me);
-        mix_traffic_controller.start_with_shutdown(shutdown);
-        mix_tx
+        let (mix_traffic_controller, mix_tx, client_tx) =
+            MixTrafficController::new(gateway_transceiver, shutdown);
+        mix_traffic_controller.start();
+        (mix_tx, client_tx)
    }

    // TODO: rename it as it implies the data is persistent whilst one can use InMemBackend
@@ -686,6 +680,7 @@ where
        setup_method: GatewaySetup,
        key_store: &S::KeyStore,
        details_store: &S::GatewaysDetailsStore,
+        derivation_material: Option<DerivationMaterial>,
    ) -> Result<InitialisationResult, ClientCoreError>
    where
        <S::KeyStore as KeyStore>::StorageError: Sync + Send,
@@ -695,7 +690,12 @@ where
        if key_store.load_keys().await.is_err() {
            info!("could not find valid client keys - a new set will be generated");
            let mut rng = OsRng;
-            let keys = ClientKeys::generate_new(&mut rng);
+            let keys = if let Some(derivation_material) = derivation_material {
+                ClientKeys::from_master_key(&mut rng, &derivation_material)
+                    .map_err(|_| ClientCoreError::HkdfDerivationError {})?
+            } else {
+                ClientKeys::generate_new(&mut rng)
+            };
            store_client_keys(keys, key_store).await?;
        }

@@ -717,11 +717,11 @@ where
            self.setup_method,
            self.client_store.key_store(),
            self.client_store.gateway_details_store(),
+            self.derivation_material,
        )
        .await?;

-        let (reply_storage_backend, credential_store, details_store) =
-            self.client_store.into_runtime_stores();
+        let (reply_storage_backend, credential_store, _) = self.client_store.into_runtime_stores();

        // channels for inter-component communication
        // TODO: make the channels be internally created by the relevant components
@@ -773,7 +773,7 @@ where
        );

        let stats_reporter = Self::start_statistics_control(
-            self.config,
+            &self.config,
            self.user_agent.clone(),
            generate_client_stats_id(*self_address.identity()),
            input_sender.clone(),
@@ -799,10 +799,9 @@ where

        let gateway_transceiver = Self::setup_gateway_transceiver(
            self.custom_gateway_transceiver,
-            self.config,
+            &self.config,
            init_res,
            bandwidth_controller,
-            &details_store,
            gateway_packet_router,
            stats_reporter.clone(),
            #[cfg(unix)]
@@ -833,10 +832,9 @@ where
        // traffic stream.
        // The MixTrafficController then sends the actual traffic

-        let message_sender = Self::start_mix_traffic_controller(
+        let (message_sender, client_request_sender) = Self::start_mix_traffic_controller(
            gateway_transceiver,
            shutdown.fork("mix_traffic_controller"),
-            self.forget_me,
        );

        // Channels that the websocket listener can use to signal downstream to the real traffic
@@ -911,6 +909,8 @@ where
            },
            stats_reporter,
            task_handle: shutdown,
+            client_request_sender,
+            forget_me: self.config.debug.forget_me,
        })
    }
 }
@@ -922,6 +922,7 @@ pub struct BaseClient {
    pub client_output: ClientOutputStatus,
    pub client_state: ClientState,
    pub stats_reporter: ClientStatsSender,
-
+    pub client_request_sender: ClientRequestSender,
    pub task_handle: TaskHandle,
+    pub forget_me: ForgetMe,
 }
@@ -2,24 +2,11 @@
 // SPDX-License-Identifier: Apache-2.0

 pub mod v1_1_33 {
-    use crate::client::base_client::{
-        non_wasm_helpers::setup_fs_gateways_storage,
-        storage::helpers::{set_active_gateway, store_gateway_details},
-    };
    use crate::config::disk_persistence::old_v1_1_33::CommonClientPathsV1_1_33;
    use crate::config::disk_persistence::CommonClientPaths;
    use crate::config::old_config_v1_1_33::OldGatewayEndpointConfigV1_1_33;
    use crate::error::ClientCoreError;
-    use nym_client_core_gateways_storage::{
-        CustomGatewayDetails, GatewayDetails, GatewayRegistration, RemoteGatewayDetails,
-    };
-    use nym_gateway_requests::shared_key::LegacySharedKeys;
    use serde::{Deserialize, Serialize};
-    use sha2::{digest::Digest, Sha256};
-    use std::ops::Deref;
-    use std::path::Path;
-    use std::sync::Arc;
-    use zeroize::Zeroizing;

    mod base64 {
        use base64::{engine::general_purpose::STANDARD, Engine as _};
@@ -57,155 +44,18 @@ pub mod v1_1_33 {
        details: OldGatewayEndpointConfigV1_1_33,
    }

-    impl PersistedGatewayConfig {
-        fn verify(&self, shared_key: &LegacySharedKeys) -> bool {
-            let key_bytes = Zeroizing::new(shared_key.to_bytes());
-
-            let mut key_hasher = Sha256::new();
-            key_hasher.update(&key_bytes);
-            let key_hash = key_hasher.finalize();
-
-            self.key_hash == key_hash.deref()
-        }
-    }
-
    #[derive(Debug, Clone, Serialize, Deserialize)]
    struct PersistedCustomGatewayDetails {
        gateway_id: String,
    }

-    fn load_shared_key<P: AsRef<Path>>(path: P) -> Result<LegacySharedKeys, ClientCoreError> {
-        // the shared key was a simple pem file
-        Ok(nym_pemstore::load_key(path)?)
-    }
-
-    fn gateway_details_from_raw(
-        gateway_id: String,
-        gateway_owner: String,
-        gateway_listener: String,
-        gateway_shared_key: LegacySharedKeys,
-    ) -> Result<GatewayDetails, ClientCoreError> {
-        Ok(GatewayDetails::Remote(RemoteGatewayDetails {
-            gateway_id: gateway_id
-                .parse()
-                .map_err(|err| ClientCoreError::UpgradeFailure {
-                    message: format!("the stored gateway id was malformed: {err}"),
-                })?,
-            shared_key: Arc::new(gateway_shared_key.into()),
-            gateway_owner_address: Some(gateway_owner.parse().map_err(|err| {
-                ClientCoreError::UpgradeFailure {
-                    message: format!("the stored gateway owner address was malformed: {err}"),
-                }
-            })?),
-            gateway_listener: gateway_listener.parse().map_err(|err| {
-                ClientCoreError::UpgradeFailure {
-                    message: format!("the stored gateway listener address was malformed: {err}"),
-                }
-            })?,
-        }))
-    }
-
-    // helper to extract shared key and gateway details into the new GatewayRegistration
-    fn extract_gateway_registration(
-        storage_paths: &CommonClientPathsV1_1_33,
-    ) -> Result<GatewayRegistration, ClientCoreError> {
-        let details_file = std::fs::File::open(&storage_paths.gateway_details).map_err(|err| {
-            ClientCoreError::UpgradeFailure {
-                message: format!(
-                    "failed to open gateway details file at {}: {err}",
-                    storage_paths.gateway_details.display()
-                ),
-            }
-        })?;
-
-        // in v1.1.33 of the clients, the gateway details struct was saved as json
-        let details: PersistedGatewayDetails =
-            serde_json::from_reader(details_file).map_err(|err| {
-                ClientCoreError::UpgradeFailure {
-                    message: format!(
-                        "failed to deserialize gateway details from {}: {err}",
-                        storage_paths.gateway_details.display()
-                    ),
-                }
-            })?;
-
-        let details = match details {
-            PersistedGatewayDetails::Default(config) => {
-                let gateway_shared_key =
-                    load_shared_key(&storage_paths.keys.gateway_shared_key_file)?;
-                if !config.verify(&gateway_shared_key) {
-                    return Err(ClientCoreError::UpgradeFailure {
-                        message: "failed to verify consistency of the existing gateway details"
-                            .to_string(),
-                    });
-                }
-                gateway_details_from_raw(
-                    config.details.gateway_id,
-                    config.details.gateway_owner,
-                    config.details.gateway_listener,
-                    gateway_shared_key,
-                )?
-            }
-            PersistedGatewayDetails::Custom(custom) => {
-                GatewayDetails::Custom(CustomGatewayDetails {
-                    gateway_id: custom.gateway_id.parse().map_err(|err| {
-                        ClientCoreError::UpgradeFailure {
-                            message: format!("the stored gateway id was malformed: {err}"),
-                        }
-                    })?,
-                    data: None,
-                })
-            }
-        };
-
-        Ok(details.into())
-    }
-
-    // it's responsibility of the caller to ensure this is called **after** new registration has already been saved
-    fn remove_old_gateway_details(storage_paths: &CommonClientPathsV1_1_33) -> std::io::Result<()> {
-        std::fs::remove_file(&storage_paths.gateway_details)?;
-
-        if storage_paths.keys.gateway_shared_key_file.exists() {
-            std::fs::remove_file(&storage_paths.keys.gateway_shared_key_file)?;
-        }
-        Ok(())
-    }
-
    pub async fn migrate_gateway_details(
-        old_storage_paths: &CommonClientPathsV1_1_33,
-        new_storage_paths: &CommonClientPaths,
-        preloaded_config: Option<OldGatewayEndpointConfigV1_1_33>,
+        _old_storage_paths: &CommonClientPathsV1_1_33,
+        _new_storage_paths: &CommonClientPaths,
+        _preloaded_config: Option<OldGatewayEndpointConfigV1_1_33>,
    ) -> Result<(), ClientCoreError> {
-        let gateway_registration = match preloaded_config {
-            Some(config) => {
-                let gateway_shared_key =
-                    load_shared_key(&old_storage_paths.keys.gateway_shared_key_file)?;
-                gateway_details_from_raw(
-                    config.gateway_id,
-                    config.gateway_owner,
-                    config.gateway_listener,
-                    gateway_shared_key,
-                )?
-                .into()
-            }
-            None => extract_gateway_registration(old_storage_paths)?,
-        };
-
-        // since we're migrating to a brand new store, the store should be empty
-        // and thus set the 'new' gateway as the active one
-        let details_store =
-            setup_fs_gateways_storage(&new_storage_paths.gateway_registrations).await?;
-        store_gateway_details(&details_store, &gateway_registration).await?;
-        set_active_gateway(
-            &details_store,
-            &gateway_registration.details.gateway_id().to_base58_string(),
-        )
-        .await?;
-
-        remove_old_gateway_details(old_storage_paths).map_err(|err| {
-            ClientCoreError::UpgradeFailure {
-                message: format!("failed to remove old data: {err}"),
-            }
-        })
+        Err(ClientCoreError::UnsupportedMigration(
+            "migration of legacy keys has been removed and is no longer supported".into(),
+        ))
    }
 }
@@ -4,6 +4,8 @@
 // TODO: combine those more closely. Perhaps into a single underlying store.
 // Like for persistent, on-disk, storage, what's the point of having 3 different databases?

+use rand::rngs::OsRng;
+
 use crate::client::key_manager::persistence::{InMemEphemeralKeys, KeyStore};
 use crate::client::replies::reply_storage;
 use crate::client::replies::reply_storage::ReplyStorageBackend;
@@ -63,7 +65,7 @@ pub trait MixnetClientStorage {
    fn gateway_details_store(&self) -> &Self::GatewaysDetailsStore;
 }

-#[derive(Clone, Default)]
+#[derive(Clone)]
 pub struct Ephemeral {
    key_store: InMemEphemeralKeys,
    reply_store: reply_storage::Empty,
@@ -71,9 +73,14 @@ pub struct Ephemeral {
    gateway_details_store: InMemGatewaysDetails,
 }

-impl Ephemeral {
-    pub fn new() -> Self {
-        Default::default()
+impl Default for Ephemeral {
+    fn default() -> Self {
+        Ephemeral {
+            key_store: InMemEphemeralKeys::new(&mut OsRng),
+            reply_store: Default::default(),
+            credential_store: Default::default(),
+            gateway_details_store: Default::default(),
+        }
    }
 }

@@ -13,6 +13,7 @@ use nym_sphinx::cover::generate_loop_cover_packet;
 use nym_sphinx::params::{PacketSize, PacketType};
 use nym_sphinx::utils::sample_poisson_duration;
 use nym_statistics_common::clients::{packet_statistics::PacketStatisticsEvent, ClientStatsSender};
+use nym_task::TaskClient;
 use rand::{rngs::OsRng, CryptoRng, Rng};
 use std::pin::Pin;
 use std::sync::Arc;
@@ -64,6 +65,8 @@ where
    packet_type: PacketType,

    stats_tx: ClientStatsSender,
+
+    task_client: TaskClient,
 }

 impl<R> Stream for LoopCoverTrafficStream<R>
@@ -110,6 +113,7 @@ impl LoopCoverTrafficStream<OsRng> {
        traffic_config: config::Traffic,
        cover_config: config::CoverTraffic,
        stats_tx: ClientStatsSender,
+        task_client: TaskClient,
    ) -> Self {
        let rng = OsRng;

@@ -128,6 +132,7 @@ impl LoopCoverTrafficStream<OsRng> {
            secondary_packet_size: traffic_config.secondary_packet_size,
            packet_type: traffic_config.packet_type,
            stats_tx,
+            task_client,
        }
    }

@@ -175,7 +180,7 @@ impl LoopCoverTrafficStream<OsRng> {
            }
        };

-        let cover_message = generate_loop_cover_packet(
+        let cover_message = match generate_loop_cover_packet(
            &mut self.rng,
            topology_ref,
            &self.ack_key,
@@ -184,8 +189,15 @@ impl LoopCoverTrafficStream<OsRng> {
            self.cover_traffic.loop_cover_traffic_average_delay,
            cover_traffic_packet_size,
            self.packet_type,
-        )
-        .expect("Somehow failed to generate a loop cover message with a valid topology");
+        ) {
+            Ok(cover_message) => cover_message,
+            Err(err) => {
+                warn!(
+                    "Somehow failed to generate a loop cover message with a valid topology: {err}"
+                );
+                return;
+            }
+        };

        if let Err(err) = self.mix_tx.try_send(vec![cover_message]) {
            match err {
@@ -217,7 +229,7 @@ impl LoopCoverTrafficStream<OsRng> {
        tokio::task::yield_now().await;
    }

-    pub fn start_with_shutdown(mut self, mut shutdown: nym_task::TaskClient) {
+    pub fn start(mut self) {
        if self.cover_traffic.disable_loop_cover_traffic_stream {
            // we should have never got here in the first place - the task should have never been created to begin with
            // so panic and review the code that lead to this branch
@@ -231,6 +243,8 @@ impl LoopCoverTrafficStream<OsRng> {
        );
        self.set_next_delay(sampled);

+        let mut shutdown = self.task_client.fork("select");
+
        spawn_future(async move {
            debug!("Started LoopCoverTrafficStream with graceful shutdown support");

@@ -2,14 +2,18 @@
 // SPDX-License-Identifier: Apache-2.0

 use crate::client::key_manager::persistence::KeyStore;
-use nym_crypto::asymmetric::{encryption, identity};
-use nym_gateway_requests::shared_key::{LegacySharedKeys, SharedGatewayKey, SharedSymmetricKey};
+use nym_crypto::{
+    asymmetric::{encryption, identity},
+    hkdf::{DerivationMaterial, InvalidLength},
+};
+use nym_gateway_requests::shared_key::SharedSymmetricKey;
 use nym_sphinx::acknowledgements::AckKey;
 use rand::{CryptoRng, RngCore};
 use std::sync::Arc;
 use zeroize::ZeroizeOnDrop;

 pub mod persistence;
+mod test;

 // Note: to support key rotation in the future, all keys will require adding an extra smart pointer,
 // most likely an AtomicCell, or if it doesn't work as I think it does, a Mutex. Although I think
@@ -43,6 +47,24 @@ impl ClientKeys {
        }
    }

+    pub fn from_master_key<R>(
+        rng: &mut R,
+        derivation_material: &DerivationMaterial,
+    ) -> Result<Self, InvalidLength>
+    where
+        R: RngCore + CryptoRng,
+    {
+        let secret = derivation_material.derive_secret()?;
+        Ok(ClientKeys {
+            identity_keypair: Arc::new(identity::KeyPair::from_secret(
+                secret,
+                derivation_material.index(),
+            )),
+            encryption_keypair: Arc::new(encryption::KeyPair::new(rng)),
+            ack_key: Arc::new(AckKey::new(rng)),
+        })
+    }
+
    pub fn from_keys(
        id_keypair: identity::KeyPair,
        enc_keypair: encryption::KeyPair,
@@ -84,7 +106,5 @@ fn _assert_keys_zeroize_on_drop() {
    _assert_zeroize_on_drop::<identity::KeyPair>();
    _assert_zeroize_on_drop::<encryption::KeyPair>();
    _assert_zeroize_on_drop::<AckKey>();
-    _assert_zeroize_on_drop::<LegacySharedKeys>();
    _assert_zeroize_on_drop::<SharedSymmetricKey>();
-    _assert_zeroize_on_drop::<SharedGatewayKey>();
 }
@@ -3,6 +3,7 @@

 use crate::client::key_manager::ClientKeys;
 use async_trait::async_trait;
+use rand::{CryptoRng, RngCore};
 use std::error::Error;
 use std::sync::Arc;
 use tokio::sync::Mutex;
@@ -195,9 +196,20 @@ impl KeyStore for OnDiskKeys {
    }
 }

-#[derive(Clone, Default)]
+#[derive(Clone)]
 pub struct InMemEphemeralKeys {
-    keys: Arc<Mutex<Option<ClientKeys>>>,
+    keys: Arc<Mutex<ClientKeys>>,
+}
+
+impl InMemEphemeralKeys {
+    pub fn new<R>(rng: &mut R) -> Self
+    where
+        R: RngCore + CryptoRng,
+    {
+        InMemEphemeralKeys {
+            keys: Arc::new(Mutex::new(ClientKeys::generate_new(rng))),
+        }
+    }
 }

 #[derive(Debug, thiserror::Error)]
@@ -210,11 +222,11 @@ impl KeyStore for InMemEphemeralKeys {
    type StorageError = EphemeralKeysError;

    async fn load_keys(&self) -> Result<ClientKeys, Self::StorageError> {
-        self.keys.lock().await.clone().ok_or(EphemeralKeysError)
+        Ok(self.keys.lock().await.clone())
    }

    async fn store_keys(&self, keys: &ClientKeys) -> Result<(), Self::StorageError> {
-        *self.keys.lock().await = Some(keys.clone());
+        *self.keys.lock().await = keys.clone();
        Ok(())
    }
 }
@@ -0,0 +1,89 @@
+#[cfg(test)]
+mod tests {
+    use crate::client::key_manager::ClientKeys;
+    use nym_crypto::hkdf::DerivationMaterial;
+    use rand::SeedableRng;
+    use rand_chacha::ChaCha20Rng;
+
+    #[test]
+    fn test_from_master_key_success() {
+        // Set up a deterministic RNG.
+        let seed = [33u8; 32];
+        let mut rng = ChaCha20Rng::from_seed(seed);
+
+        // Set up the derivation material.
+        let master_key = b"this is a secret master key";
+        let salt = b"unique-salt";
+        let derivation_material = DerivationMaterial::new(master_key, 0, salt);
+
+        // Generate ClientKeys from the master key.
+        let client_keys = ClientKeys::from_master_key(&mut rng, &derivation_material)
+            .expect("Failed to create client keys");
+
+        assert_eq!(
+            client_keys.identity_keypair().public_key().to_string(),
+            String::from("FX4Undr5LPPBA7zThWWpAKXKQTXSbW1C28PnxbCqUkU4")
+        );
+
+        assert_eq!(
+            client_keys.identity_keypair().private_key().to_string(),
+            String::from("6S3uMi2rU5SwyUUYCiMrF5qqdcYnEDMYLggBSvavVzEt")
+        );
+    }
+
+    #[test]
+    fn test_from_master_key_deterministic_identity() {
+        // Using identical derivation material should result in the exactly same identity keypair.
+        let seed = [1u8; 32];
+        let mut rng1 = ChaCha20Rng::from_seed(seed);
+        let mut rng2 = ChaCha20Rng::from_seed(seed);
+
+        let master_key = b"another secret master key";
+        let salt = b"deterministic-salt";
+        let index = 7u32;
+        let derivation_material = DerivationMaterial::new(master_key, index, salt);
+
+        let client_keys1 = ClientKeys::from_master_key(&mut rng1, &derivation_material)
+            .expect("Failed to create client keys (first instance)");
+        let client_keys2 = ClientKeys::from_master_key(&mut rng2, &derivation_material)
+            .expect("Failed to create client keys (second instance)");
+
+        assert_eq!(
+            client_keys1.identity_keypair().public_key().to_string(),
+            client_keys2.identity_keypair().public_key().to_string()
+        );
+
+        assert_eq!(
+            client_keys1.identity_keypair().private_key().to_string(),
+            client_keys2.identity_keypair().private_key().to_string()
+        );
+    }
+
+    #[test]
+    fn test_from_master_key_different_indices() {
+        // Changing the index should yield a different identity key.
+        let seed = [5u8; 32];
+        let mut rng = ChaCha20Rng::from_seed(seed);
+
+        let master_key = b"same secret key";
+        let salt = b"same-salt";
+
+        let derivation_material1 = DerivationMaterial::new(master_key, 1, salt);
+        let derivation_material2 = DerivationMaterial::new(master_key, 2, salt);
+
+        let client_keys1 = ClientKeys::from_master_key(&mut rng, &derivation_material1)
+            .expect("Failed to create client keys for index 1");
+        let client_keys2 = ClientKeys::from_master_key(&mut rng, &derivation_material2)
+            .expect("Failed to create client keys for index 2");
+
+        assert_ne!(
+            client_keys1.identity_keypair().public_key().to_string(),
+            client_keys2.identity_keypair().public_key().to_string()
+        );
+
+        assert_ne!(
+            client_keys1.identity_keypair().private_key().to_string(),
+            client_keys2.identity_keypair().private_key().to_string()
+        );
+    }
+}
@@ -2,13 +2,18 @@
 // SPDX-License-Identifier: Apache-2.0

 use crate::client::mix_traffic::transceiver::GatewayTransceiver;
-use crate::{spawn_future, ForgetMe};
+use crate::error::ClientCoreError;
+use crate::spawn_future;
 use log::*;
 use nym_gateway_requests::ClientRequest;
 use nym_sphinx::forwarding::packet::MixPacket;
+use nym_task::TaskClient;
+use transceiver::ErasedGatewayError;

 pub type BatchMixMessageSender = tokio::sync::mpsc::Sender<Vec<MixPacket>>;
 pub type BatchMixMessageReceiver = tokio::sync::mpsc::Receiver<Vec<MixPacket>>;
+pub type ClientRequestReceiver = tokio::sync::mpsc::Receiver<ClientRequest>;
+pub type ClientRequestSender = tokio::sync::mpsc::Sender<ClientRequest>;

 pub mod transceiver;

@@ -23,52 +28,73 @@ pub struct MixTrafficController {
    gateway_transceiver: Box<dyn GatewayTransceiver + Send>,

    mix_rx: BatchMixMessageReceiver,
+    client_rx: ClientRequestReceiver,

    // TODO: this is temporary work-around.
    // in long run `gateway_client` will be moved away from `MixTrafficController` anyway.
    consecutive_gateway_failure_count: usize,
-    forget_me: ForgetMe,
+
+    task_client: TaskClient,
 }

 impl MixTrafficController {
    pub fn new<T>(
        gateway_transceiver: T,
-        forget_me: ForgetMe,
-    ) -> (MixTrafficController, BatchMixMessageSender)
+        task_client: TaskClient,
+    ) -> (
+        MixTrafficController,
+        BatchMixMessageSender,
+        ClientRequestSender,
+    )
    where
        T: GatewayTransceiver + Send + 'static,
    {
        let (message_sender, message_receiver) =
            tokio::sync::mpsc::channel(MIX_MESSAGE_RECEIVER_BUFFER_SIZE);
+
+        let (client_sender, client_receiver) = tokio::sync::mpsc::channel(1);
+
        (
            MixTrafficController {
                gateway_transceiver: Box::new(gateway_transceiver),
                mix_rx: message_receiver,
+                client_rx: client_receiver,
                consecutive_gateway_failure_count: 0,
-                forget_me,
+                task_client,
            },
            message_sender,
+            client_sender,
        )
    }

    pub fn new_dynamic(
        gateway_transceiver: Box<dyn GatewayTransceiver + Send>,
-        forget_me: ForgetMe,
-    ) -> (MixTrafficController, BatchMixMessageSender) {
+        task_client: TaskClient,
+    ) -> (
+        MixTrafficController,
+        BatchMixMessageSender,
+        ClientRequestSender,
+    ) {
        let (message_sender, message_receiver) =
            tokio::sync::mpsc::channel(MIX_MESSAGE_RECEIVER_BUFFER_SIZE);
+        let (client_sender, client_receiver) = tokio::sync::mpsc::channel(1);
        (
            MixTrafficController {
                gateway_transceiver,
                mix_rx: message_receiver,
+                client_rx: client_receiver,
                consecutive_gateway_failure_count: 0,
-                forget_me,
+                task_client,
            },
            message_sender,
+            client_sender,
        )
    }

-    async fn on_messages(&mut self, mut mix_packets: Vec<MixPacket>) {
+    async fn on_messages(
+        &mut self,
+        mut mix_packets: Vec<MixPacket>,
+    ) -> Result<(), ErasedGatewayError> {
        debug_assert!(!mix_packets.is_empty());

        let result = if mix_packets.len() == 1 {
@@ -80,64 +106,60 @@ impl MixTrafficController {
                .await
        };

-        match result {
-            Err(err) => {
-                error!("Failed to send sphinx packet(s) to the gateway: {err}");
-                self.consecutive_gateway_failure_count += 1;
-                if self.consecutive_gateway_failure_count == MAX_FAILURE_COUNT {
-                    // todo: in the future this should initiate a 'graceful' shutdown or try
-                    // to reconnect?
-                    panic!("failed to send sphinx packet to the gateway {MAX_FAILURE_COUNT} times in a row - assuming the gateway is dead. Can't do anything about it yet :(")
-                }
-            }
-            Ok(_) => {
-                trace!("We *might* have managed to forward sphinx packet(s) to the gateway!");
-                self.consecutive_gateway_failure_count = 0;
-            }
+        if result.is_err() {
+            self.consecutive_gateway_failure_count += 1;
+        } else {
+            trace!("We *might* have managed to forward sphinx packet(s) to the gateway!");
+            self.consecutive_gateway_failure_count = 0;
        }
+
+        result
    }

-    pub fn start_with_shutdown(mut self, mut shutdown: nym_task::TaskClient) {
+    pub fn start(mut self) {
        spawn_future(async move {
            debug!("Started MixTrafficController with graceful shutdown support");

-            loop {
+            while !self.task_client.is_shutdown() {
                tokio::select! {
                    mix_packets = self.mix_rx.recv() => match mix_packets {
                        Some(mix_packets) => {
-                            self.on_messages(mix_packets).await;
+                            if let Err(err) = self.on_messages(mix_packets).await {
+                                error!("Failed to send sphinx packet(s) to the gateway: {err}");
+                                if self.consecutive_gateway_failure_count == MAX_FAILURE_COUNT {
+                                    // Disconnect from the gateway. If we should try to re-connect
+                                    // is handled at a higher layer.
+                                    error!("Failed to send sphinx packet to the gateway {MAX_FAILURE_COUNT} times in a row - assuming the gateway is dead");
+                                    // Do we need to handle the embedded mixnet client case
+                                    // separately?
+                                    self.task_client.send_we_stopped(Box::new(ClientCoreError::GatewayFailedToForwardMessages));
+                                    break;
+                                }
+                            }
                        },
                        None => {
                            log::trace!("MixTrafficController: Stopping since channel closed");
                            break;
                        }
                    },
-                    _ = shutdown.recv_with_delay() => {
+                    client_request = self.client_rx.recv() => match client_request {
+                        Some(client_request) => {
+                            match self.gateway_transceiver.send_client_request(client_request).await {
+                                Ok(_) => (),
+                                Err(e) => error!("Failed to send client request: {}", e),
+                            };
+                        },
+                        None => {
+                            log::trace!("MixTrafficController, client request channel closed");
+                        }
+                    },
+                    _ = self.task_client.recv() => {
                        log::trace!("MixTrafficController: Received shutdown");
                        break;
                    }
                }
            }
-            shutdown.recv_timeout().await;
-
-            if self.forget_me.any() {
-                log::info!("Sending forget me request to the gateway");
-                match self
-                    .gateway_transceiver
-                    .send_client_request(ClientRequest::ForgetMe {
-                        client: self.forget_me.client(),
-                        stats: self.forget_me.stats(),
-                    })
-                    .await
-                {
-                    Ok(_) => {
-                        log::info!("Successfully sent forget me request to the gateway");
-                    }
-                    Err(err) => {
-                        log::error!("Failed to send forget me request to the gateway: {err}");
-                    }
-                }
-            }
+            self.task_client.recv_timeout().await;

            log::debug!("MixTrafficController: Exiting");
        });
@@ -86,7 +86,9 @@ impl<G: GatewayTransceiver + ?Sized + Send> GatewayTransceiver for Box<G> {
        &mut self,
        message: ClientRequest,
    ) -> Result<(), GatewayClientError> {
-        (**self).send_client_request(message).await
+        let _ = (**self).send_client_request(message.clone()).await?;
+        log::debug!("Sent client request: {:?}", message);
+        Ok(())
    }
 }

@@ -143,14 +145,7 @@ where
        &mut self,
        message: ClientRequest,
    ) -> Result<(), GatewayClientError> {
-        if let Some(shared_key) = self.gateway_client.shared_key() {
-            self.gateway_client
-                .send_websocket_message(message.encrypt(&*shared_key)?)
-                .await?;
-            Ok(())
-        } else {
-            Err(GatewayClientError::ConnectionInInvalidState)
-        }
+        self.gateway_client.send_client_request(message).await
    }
 }

@@ -11,6 +11,7 @@ use nym_sphinx::{
    acknowledgements::{identifier::recover_identifier, AckKey},
    chunking::fragment::{FragmentIdentifier, COVER_FRAG_ID},
 };
+use nym_task::TaskClient;
 use std::sync::Arc;

 /// Module responsible for listening for any data resembling acknowledgements from the network
@@ -20,6 +21,7 @@ pub(super) struct AcknowledgementListener {
    ack_receiver: AcknowledgementReceiver,
    action_sender: AckActionSender,
    stats_tx: ClientStatsSender,
+    task_client: TaskClient,
 }

 impl AcknowledgementListener {
@@ -28,12 +30,14 @@ impl AcknowledgementListener {
        ack_receiver: AcknowledgementReceiver,
        action_sender: AckActionSender,
        stats_tx: ClientStatsSender,
+        task_client: TaskClient,
    ) -> Self {
        AcknowledgementListener {
            ack_key,
            ack_receiver,
            action_sender,
            stats_tx,
+            task_client,
        }
    }

@@ -64,9 +68,14 @@ impl AcknowledgementListener {
        trace!("Received {} from the mix network", frag_id);
        self.stats_tx
            .report(PacketStatisticsEvent::RealAckReceived(ack_content.len()).into());
-        self.action_sender
+        if let Err(err) = self
+            .action_sender
            .unbounded_send(Action::new_remove(frag_id))
-            .unwrap();
+        {
+            if !self.task_client.is_shutdown_poll() {
+                error!("Failed to send remove action to action controller: {err}");
+            }
+        }
    }

    async fn handle_ack_receiver_item(&mut self, item: Vec<Vec<u8>>) {
@@ -76,10 +85,10 @@ impl AcknowledgementListener {
        }
    }

-    pub(super) async fn run_with_shutdown(&mut self, mut shutdown: nym_task::TaskClient) {
+    pub(super) async fn run(&mut self) {
        debug!("Started AcknowledgementListener with graceful shutdown support");

-        while !shutdown.is_shutdown() {
+        while !self.task_client.is_shutdown() {
            tokio::select! {
                acks = self.ack_receiver.next() => match acks {
                    Some(acks) => self.handle_ack_receiver_item(acks).await,
@@ -88,12 +97,12 @@ impl AcknowledgementListener {
                        break;
                    }
                },
-                _ = shutdown.recv_with_delay() => {
+                _ = self.task_client.recv() => {
                    log::trace!("AcknowledgementListener: Received shutdown");
                }
            }
        }
-        shutdown.recv_timeout().await;
+        self.task_client.recv_timeout().await;
        log::debug!("AcknowledgementListener: Exiting");
    }
 }
@@ -9,6 +9,7 @@ use log::*;
 use nym_nonexhaustive_delayqueue::{Expired, NonExhaustiveDelayQueue, QueueKey};
 use nym_sphinx::chunking::fragment::FragmentIdentifier;
 use nym_sphinx::Delay as SphinxDelay;
+use nym_task::TaskClient;
 use std::collections::HashMap;
 use std::sync::Arc;
 use std::time::Duration;
@@ -101,6 +102,8 @@ pub(super) struct ActionController {

    /// Channel for notifying `RetransmissionRequestListener` about expired acknowledgements.
    retransmission_sender: RetransmissionRequestSender,
+
+    task_client: TaskClient,
 }

 impl ActionController {
@@ -108,6 +111,7 @@ impl ActionController {
        config: Config,
        retransmission_sender: RetransmissionRequestSender,
        incoming_actions: AckActionReceiver,
+        task_client: TaskClient,
    ) -> Self {
        ActionController {
            config,
@@ -115,6 +119,7 @@ impl ActionController {
            pending_acks_timers: NonExhaustiveDelayQueue::new(),
            incoming_actions,
            retransmission_sender,
+            task_client,
        }
    }

@@ -216,11 +221,7 @@ impl ActionController {
    }

    // note: when the entry expires it's automatically removed from pending_acks_timers
-    fn handle_expired_ack_timer(
-        &mut self,
-        expired_ack: Expired<FragmentIdentifier>,
-        task_client: &mut nym_task::TaskClient,
-    ) {
+    fn handle_expired_ack_timer(&mut self, expired_ack: Expired<FragmentIdentifier>) {
        // I'm honestly not sure how to handle it, because getting it means other things in our
        // system are already misbehaving. If we ever see this panic, then I guess we should worry
        // about it. Perhaps just reschedule it at later point?
@@ -238,15 +239,13 @@ impl ActionController {
            // downgrading an arc and then upgrading vs cloning is difference of 30ns vs 15ns
            // so it's literally a NO difference while it might prevent us from unnecessarily
            // resending data (in maybe 1 in 1 million cases, but it's something)
-            if self
+            if let Err(err) = self
                .retransmission_sender
                .unbounded_send(Arc::downgrade(pending_ack_data))
-                .is_err()
            {
-                assert!(
-                    task_client.is_shutdown_poll(),
-                    "Failed to send pending ack for retransmission"
-                );
+                if !self.task_client.is_shutdown_poll() {
+                    log::error!("Failed to send pending ack for retransmission: {err}");
+                }
            }
        } else {
            // this shouldn't cause any issues but shouldn't have happened to begin with!
@@ -265,10 +264,10 @@ impl ActionController {
        }
    }

-    pub(super) async fn run_with_shutdown(&mut self, mut shutdown: nym_task::TaskClient) {
+    pub(super) async fn run(&mut self) {
        debug!("Started ActionController with graceful shutdown support");

-        loop {
+        while !self.task_client.is_shutdown() {
            tokio::select! {
                action = self.incoming_actions.next() => match action {
                    Some(action) => self.process_action(action),
@@ -280,19 +279,19 @@ impl ActionController {
                    }
                },
                expired_ack = self.pending_acks_timers.next() => match expired_ack {
-                    Some(expired_ack) => self.handle_expired_ack_timer(expired_ack, &mut shutdown),
+                    Some(expired_ack) => self.handle_expired_ack_timer(expired_ack),
                    None => {
                        log::trace!("ActionController: Stopping since ack channel closed");
                        break;
                    }
                },
-                _ = shutdown.recv_with_delay() => {
+                _ = self.task_client.recv() => {
                    log::trace!("ActionController: Received shutdown");
                    break;
                }
            }
        }
-        shutdown.recv_timeout().await;
+        self.task_client.recv_timeout().await;
        log::debug!("ActionController: Exiting");
    }
 }
@@ -11,6 +11,7 @@ use nym_sphinx::anonymous_replies::requests::AnonymousSenderTag;
 use nym_sphinx::forwarding::packet::MixPacket;
 use nym_sphinx::params::PacketType;
 use nym_task::connections::TransmissionLane;
+use nym_task::TaskClient;
 use rand::{CryptoRng, Rng};

 /// Module responsible for dealing with the received messages: splitting them, creating acknowledgements,
@@ -23,6 +24,7 @@ where
    input_receiver: InputMessageReceiver,
    message_handler: MessageHandler<R>,
    reply_controller_sender: ReplyControllerSender,
+    task_client: TaskClient,
 }

 impl<R> InputMessageListener<R>
@@ -36,11 +38,13 @@ where
        input_receiver: InputMessageReceiver,
        message_handler: MessageHandler<R>,
        reply_controller_sender: ReplyControllerSender,
+        task_client: TaskClient,
    ) -> Self {
        InputMessageListener {
            input_receiver,
            message_handler,
            reply_controller_sender,
+            task_client,
        }
    }

@@ -63,8 +67,14 @@ where
        lane: TransmissionLane,
    ) {
        // offload reply handling to the dedicated task
-        self.reply_controller_sender
+        if let Err(err) = self
+            .reply_controller_sender
            .send_reply(recipient_tag, data, lane)
+        {
+            if !self.task_client.is_shutdown_poll() {
+                error!("failed to send a reply - {err}");
+            }
+        }
    }

    async fn handle_plain_message(
@@ -164,10 +174,10 @@ where
        };
    }

-    pub(super) async fn run_with_shutdown(&mut self, mut shutdown: nym_task::TaskClient) {
+    pub(super) async fn run(&mut self) {
        debug!("Started InputMessageListener with graceful shutdown support");

-        while !shutdown.is_shutdown() {
+        while !self.task_client.is_shutdown() {
            tokio::select! {
                input_msg = self.input_receiver.recv() => match input_msg {
                    Some(input_msg) => {
@@ -178,12 +188,12 @@ where
                        break;
                    }
                },
-                _ = shutdown.recv_with_delay() => {
+                _ = self.task_client.recv() => {
                    log::trace!("InputMessageListener: Received shutdown");
                }
            }
        }
-        shutdown.recv_timeout().await;
+        self.task_client.recv_timeout().await;
        log::debug!("InputMessageListener: Exiting");
    }
 }
@@ -24,6 +24,7 @@ use nym_sphinx::{
    Delay as SphinxDelay,
 };
 use nym_statistics_common::clients::ClientStatsSender;
+use nym_task::TaskClient;
 use rand::{CryptoRng, Rng};
 use std::{
    sync::{Arc, Weak},
@@ -66,7 +67,7 @@ pub(crate) enum PacketDestination {

 /// Structure representing a data `Fragment` that is on-route to the specified `Recipient`
 #[derive(Debug)]
-pub(crate) struct PendingAcknowledgement {
+pub struct PendingAcknowledgement {
    message_chunk: Fragment,
    delay: SphinxDelay,
    destination: PacketDestination,
@@ -216,6 +217,7 @@ where
        message_handler: MessageHandler<R>,
        reply_controller_sender: ReplyControllerSender,
        stats_tx: ClientStatsSender,
+        task_client: TaskClient,
    ) -> Self {
        let (retransmission_tx, retransmission_rx) = mpsc::unbounded();

@@ -225,6 +227,7 @@ where
            action_config,
            retransmission_tx,
            connectors.ack_action_receiver,
+            task_client.fork("action_controller"),
        );

        // will listen for any acks coming from the network
@@ -233,6 +236,7 @@ where
            connectors.ack_receiver,
            connectors.ack_action_sender.clone(),
            stats_tx,
+            task_client.fork("acknowledgement_listener"),
        );

        // will listen for any new messages from the client
@@ -240,6 +244,7 @@ where
            connectors.input_receiver,
            message_handler.clone(),
            reply_controller_sender.clone(),
+            task_client.fork("input_message_listener"),
        );

        // will listen for any ack timeouts and trigger retransmission
@@ -249,12 +254,16 @@ where
            message_handler,
            retransmission_rx,
            reply_controller_sender,
+            task_client.fork("retransmission_request_listener"),
        );

        // will listen for events indicating the packet was sent through the network so that
        // the retransmission timer should be started.
-        let sent_notification_listener =
-            SentNotificationListener::new(connectors.sent_notifier, connectors.ack_action_sender);
+        let sent_notification_listener = SentNotificationListener::new(
+            connectors.sent_notifier,
+            connectors.ack_action_sender,
+            task_client.with_suffix("sent_notification_listener"),
+        );

        AcknowledgementController {
            acknowledgement_listener,
@@ -265,53 +274,35 @@ where
        }
    }

-    pub(super) fn start_with_shutdown(
-        self,
-        shutdown: nym_task::TaskClient,
-        packet_type: PacketType,
-    ) {
+    pub(super) fn start(self, packet_type: PacketType) {
        let mut acknowledgement_listener = self.acknowledgement_listener;
        let mut input_message_listener = self.input_message_listener;
        let mut retransmission_request_listener = self.retransmission_request_listener;
        let mut sent_notification_listener = self.sent_notification_listener;
        let mut action_controller = self.action_controller;

-        let shutdown_handle = shutdown.fork("acknowledgement_listener");
        spawn_future(async move {
-            acknowledgement_listener
-                .run_with_shutdown(shutdown_handle)
-                .await;
+            acknowledgement_listener.run().await;
            debug!("The acknowledgement listener has finished execution!");
        });

-        let shutdown_handle = shutdown.fork("input_message_listener");
        spawn_future(async move {
-            input_message_listener
-                .run_with_shutdown(shutdown_handle)
-                .await;
+            input_message_listener.run().await;
            debug!("The input listener has finished execution!");
        });

-        let shutdown_handle = shutdown.fork("retransmission_request_listener");
        spawn_future(async move {
-            retransmission_request_listener
-                .run_with_shutdown(shutdown_handle, packet_type)
-                .await;
+            retransmission_request_listener.run(packet_type).await;
            debug!("The retransmission request listener has finished execution!");
        });

-        let shutdown_handle = shutdown.fork("sent_notification_listener");
        spawn_future(async move {
-            sent_notification_listener
-                .run_with_shutdown(shutdown_handle)
-                .await;
+            sent_notification_listener.run().await;
            debug!("The sent notification listener has finished execution!");
        });

        spawn_future(async move {
-            action_controller
-                .run_with_shutdown(shutdown.with_suffix("action_controller"))
-                .await;
+            action_controller.run().await;
            debug!("The controller has finished execution!");
        });
    }
@@ -14,7 +14,7 @@ use log::*;
 use nym_sphinx::chunking::fragment::Fragment;
 use nym_sphinx::preparer::PreparedFragment;
 use nym_sphinx::{addressing::clients::Recipient, params::PacketType};
-use nym_task::connections::TransmissionLane;
+use nym_task::{connections::TransmissionLane, TaskClient};
 use rand::{CryptoRng, Rng};
 use std::sync::{Arc, Weak};

@@ -25,6 +25,7 @@ pub(super) struct RetransmissionRequestListener<R> {
    message_handler: MessageHandler<R>,
    request_receiver: RetransmissionRequestReceiver,
    reply_controller_sender: ReplyControllerSender,
+    task_client: TaskClient,
 }

 impl<R> RetransmissionRequestListener<R>
@@ -37,6 +38,7 @@ where
        message_handler: MessageHandler<R>,
        request_receiver: RetransmissionRequestReceiver,
        reply_controller_sender: ReplyControllerSender,
+        task_client: TaskClient,
    ) -> Self {
        RetransmissionRequestListener {
            maximum_retransmissions,
@@ -44,6 +46,7 @@ where
            message_handler,
            request_receiver,
            reply_controller_sender,
+            task_client,
        }
    }

@@ -79,9 +82,12 @@ where
        if let Some(limit) = self.maximum_retransmissions {
            if timed_out_ack.retransmissions >= limit {
                warn!("reached maximum number of allowed retransmissions for the packet");
-                self.action_sender
+                if let Err(err) = self
+                    .action_sender
                    .unbounded_send(Action::new_remove(frag_id))
-                    .unwrap();
+                {
+                    error!("Failed to send remove action to the controller: {err}");
+                }
                return;
            }
        }
@@ -93,11 +99,16 @@ where
            } => {
                // if this is retransmission for reply, offload it to the dedicated task
                // that deals with all the surbs
-                return self.reply_controller_sender.send_retransmission_data(
+                if let Err(err) = self.reply_controller_sender.send_retransmission_data(
                    *recipient_tag,
                    weak_timed_out_ack,
                    *extra_surb_request,
-                );
+                ) {
+                    if !self.task_client.is_shutdown_poll() {
+                        error!("Failed to send retransmission data to the reply controller: {err}");
+                    }
+                }
+                return;
            }
            PacketDestination::KnownRecipient(recipient) => {
                self.prepare_normal_retransmission_chunk(
@@ -114,9 +125,12 @@ where
            Err(err) => {
                warn!("Could not retransmit the packet - {err}");
                // we NEED to start timer here otherwise we will have this guy permanently stuck in memory
-                self.action_sender
+                if let Err(err) = self
+                    .action_sender
                    .unbounded_send(Action::new_start_timer(frag_id))
-                    .unwrap();
+                {
+                    error!("Failed to send start timer action to the controller: {err}");
+                }
                return;
            }
        };
@@ -141,9 +155,14 @@ where
        // is sent to the `OutQueueControl` and has gone through its internal queue
        // with the additional poisson delay.
        // And since Actions are executed in order `UpdateTimer` will HAVE TO be executed before `StartTimer`
-        self.action_sender
+        if let Err(err) = self
+            .action_sender
            .unbounded_send(Action::new_update_pending_ack(frag_id, new_delay))
-            .unwrap();
+        {
+            if !self.task_client.is_shutdown_poll() {
+                error!("Failed to send update pending ack action to the controller: {err}");
+            }
+        }

        // send to `OutQueueControl` to eventually send to the mix network
        self.message_handler
@@ -157,14 +176,10 @@ where
            .await
    }

-    pub(super) async fn run_with_shutdown(
-        &mut self,
-        mut shutdown: nym_task::TaskClient,
-        packet_type: PacketType,
-    ) {
+    pub(super) async fn run(&mut self, packet_type: PacketType) {
        debug!("Started RetransmissionRequestListener with graceful shutdown support");

-        while !shutdown.is_shutdown() {
+        while !self.task_client.is_shutdown() {
            tokio::select! {
                timed_out_ack = self.request_receiver.next() => match timed_out_ack {
                    Some(timed_out_ack) => self.on_retransmission_request(timed_out_ack, packet_type).await,
@@ -173,12 +188,12 @@ where
                        break;
                    }
                },
-                _ = shutdown.recv() => {
+                _ = self.task_client.recv() => {
                    log::trace!("RetransmissionRequestListener: Received shutdown");
                }
            }
        }
-        shutdown.recv_timeout().await;
+        self.task_client.recv_timeout().await;
        log::debug!("RetransmissionRequestListener: Exiting");
    }
 }
@@ -6,6 +6,7 @@ use super::SentPacketNotificationReceiver;
 use futures::StreamExt;
 use log::*;
 use nym_sphinx::chunking::fragment::{FragmentIdentifier, COVER_FRAG_ID};
+use nym_task::TaskClient;

 /// Module responsible for starting up retransmission timers.
 /// It is required because when we send our packet to the `real traffic stream` controlled
@@ -14,16 +15,19 @@ use nym_sphinx::chunking::fragment::{FragmentIdentifier, COVER_FRAG_ID};
 pub(super) struct SentNotificationListener {
    sent_notifier: SentPacketNotificationReceiver,
    action_sender: AckActionSender,
+    task_client: TaskClient,
 }

 impl SentNotificationListener {
    pub(super) fn new(
        sent_notifier: SentPacketNotificationReceiver,
        action_sender: AckActionSender,
+        task_client: TaskClient,
    ) -> Self {
        SentNotificationListener {
            sent_notifier,
            action_sender,
+            task_client,
        }
    }

@@ -32,15 +36,20 @@ impl SentNotificationListener {
            trace!("sent off a cover message - no need to start retransmission timer!");
            return;
        }
-        self.action_sender
+        if let Err(err) = self
+            .action_sender
            .unbounded_send(Action::new_start_timer(frag_id))
-            .unwrap();
+        {
+            if !self.task_client.is_shutdown_poll() {
+                error!("Failed to send start timer action to action controller: {err}");
+            }
+        }
    }

-    pub(super) async fn run_with_shutdown(&mut self, mut shutdown: nym_task::TaskClient) {
+    pub(super) async fn run(&mut self) {
        debug!("Started SentNotificationListener with graceful shutdown support");

-        loop {
+        while !self.task_client.is_shutdown() {
            tokio::select! {
                frag_id = self.sent_notifier.next() => match frag_id {
                    Some(frag_id) => {
@@ -51,13 +60,13 @@ impl SentNotificationListener {
                        break;
                    }
                },
-                _ = shutdown.recv_with_delay() => {
+                _ = self.task_client.recv() => {
                    log::trace!("SentNotificationListener: Received shutdown");
                    break;
                }
            }
        }
-        assert!(shutdown.is_shutdown_poll());
+        assert!(self.task_client.is_shutdown_poll());
        log::debug!("SentNotificationListener: Exiting");
    }
 }
@@ -19,6 +19,7 @@ use nym_sphinx::params::{PacketSize, PacketType};
 use nym_sphinx::preparer::{MessagePreparer, PreparedFragment};
 use nym_sphinx::Delay;
 use nym_task::connections::TransmissionLane;
+use nym_task::TaskClient;
 use nym_topology::{NymRouteProvider, NymTopologyError};
 use rand::{CryptoRng, Rng};
 use std::collections::HashMap;
@@ -149,12 +150,14 @@ pub(crate) struct MessageHandler<R> {
    topology_access: TopologyAccessor,
    reply_key_storage: SentReplyKeys,
    tag_storage: UsedSenderTags,
+    task_client: TaskClient,
 }

 impl<R> MessageHandler<R>
 where
    R: CryptoRng + Rng,
 {
+    #[allow(clippy::too_many_arguments)]
    pub(crate) fn new(
        config: Config,
        rng: R,
@@ -163,6 +166,7 @@ where
        topology_access: TopologyAccessor,
        reply_key_storage: SentReplyKeys,
        tag_storage: UsedSenderTags,
+        task_client: TaskClient,
    ) -> Self
    where
        R: Copy,
@@ -183,6 +187,7 @@ where
            topology_access,
            reply_key_storage,
            tag_storage,
+            task_client,
        }
    }

@@ -609,15 +614,25 @@ where
    }

    pub(crate) fn update_ack_delay(&self, id: FragmentIdentifier, new_delay: Delay) {
-        self.action_sender
+        if let Err(err) = self
+            .action_sender
            .unbounded_send(Action::UpdatePendingAck(id, new_delay))
-            .expect("action control task has died")
+        {
+            if !self.task_client.is_shutdown_poll() {
+                error!("Failed to send update action to the controller: {err}");
+            }
+        }
    }

    pub(crate) fn insert_pending_acks(&self, pending_acks: Vec<PendingAcknowledgement>) {
-        self.action_sender
+        if let Err(err) = self
+            .action_sender
            .unbounded_send(Action::new_insert(pending_acks))
-            .expect("action control task has died")
+        {
+            if !self.task_client.is_shutdown_poll() {
+                error!("Failed to send insert action to the controller: {err}");
+            }
+        }
    }

    // tells real message sender (with the poisson timer) to send this to the mix network
@@ -626,9 +641,14 @@ where
        messages: Vec<RealMessage>,
        transmission_lane: TransmissionLane,
    ) {
-        self.real_message_sender
+        if let Err(err) = self
+            .real_message_sender
            .send((messages, transmission_lane))
            .await
-            .expect("real message receiver task (OutQueueControl) has died");
+        {
+            if !self.task_client.is_shutdown_poll() {
+                error!("Failed to forward messages to the real message sender: {err}");
+            }
+        }
    }
 }
@@ -31,6 +31,7 @@ use nym_sphinx::addressing::clients::Recipient;
 use nym_sphinx::params::PacketType;
 use nym_statistics_common::clients::ClientStatsSender;
 use nym_task::connections::{ConnectionCommandReceiver, LaneQueueLengths};
+use nym_task::TaskClient;
 use rand::{rngs::OsRng, CryptoRng, Rng};
 use std::sync::Arc;

@@ -147,6 +148,7 @@ impl RealMessagesController<OsRng> {
        lane_queue_lengths: LaneQueueLengths,
        client_connection_rx: ConnectionCommandReceiver,
        stats_tx: ClientStatsSender,
+        task_client: TaskClient,
    ) -> Self {
        let rng = OsRng;

@@ -177,6 +179,7 @@ impl RealMessagesController<OsRng> {
            topology_access.clone(),
            reply_storage.key_storage(),
            reply_storage.tags_storage(),
+            task_client.fork("message_handler"),
        );

        let ack_control = AcknowledgementController::new(
@@ -186,6 +189,7 @@ impl RealMessagesController<OsRng> {
            message_handler.clone(),
            reply_controller_sender,
            stats_tx.clone(),
+            task_client.fork("ack_control"),
        );

        let reply_control = ReplyController::new(
@@ -193,6 +197,7 @@ impl RealMessagesController<OsRng> {
            message_handler,
            reply_storage,
            reply_controller_receiver,
+            task_client.fork("reply_controller"),
        );

        let out_queue_control = OutQueueControl::new(
@@ -205,6 +210,7 @@ impl RealMessagesController<OsRng> {
            lane_queue_lengths,
            client_connection_rx,
            stats_tx,
+            task_client.with_suffix("out_queue_control"),
        );

        RealMessagesController {
@@ -214,22 +220,20 @@ impl RealMessagesController<OsRng> {
        }
    }

-    pub fn start_with_shutdown(self, shutdown: nym_task::TaskClient, packet_type: PacketType) {
+    pub fn start(self, packet_type: PacketType) {
        let mut out_queue_control = self.out_queue_control;
        let ack_control = self.ack_control;
        let mut reply_control = self.reply_control;

-        let shutdown_handle = shutdown.fork("out_queue_control");
        spawn_future(async move {
-            out_queue_control.run_with_shutdown(shutdown_handle).await;
+            out_queue_control.run().await;
            debug!("The out queue controller has finished execution!");
        });
-        let shutdown_handle = shutdown.fork("reply_control");
        spawn_future(async move {
-            reply_control.run_with_shutdown(shutdown_handle).await;
+            reply_control.run().await;
            debug!("The reply controller has finished execution!");
        });

-        ack_control.start_with_shutdown(shutdown.with_suffix("ack_control"), packet_type);
+        ack_control.start(packet_type);
    }
 }
@@ -22,6 +22,7 @@ use nym_statistics_common::clients::{packet_statistics::PacketStatisticsEvent, C
 use nym_task::connections::{
    ConnectionCommand, ConnectionCommandReceiver, ConnectionId, LaneQueueLengths, TransmissionLane,
 };
+use nym_task::TaskClient;
 use rand::{CryptoRng, Rng};
 use std::pin::Pin;
 use std::sync::Arc;
@@ -117,6 +118,8 @@ where

    /// Channel used for sending metrics events (specifically `PacketStatistics` events) to the metrics tracker.
    stats_tx: ClientStatsSender,
+
+    task_client: TaskClient,
 }

 #[derive(Debug)]
@@ -176,6 +179,7 @@ where
        lane_queue_lengths: LaneQueueLengths,
        client_connection_rx: ConnectionCommandReceiver,
        stats_tx: ClientStatsSender,
+        task_client: TaskClient,
    ) -> Self {
        OutQueueControl {
            config,
@@ -190,6 +194,7 @@ where
            client_connection_rx,
            lane_queue_lengths,
            stats_tx,
+            task_client,
        }
    }

@@ -198,7 +203,9 @@ where
        // queues and client load rather than the required delay. So realistically we can treat
        // whatever is about to happen as negligible additional delay.
        trace!("{} is about to get sent to the mixnet", frag_id);
-        self.sent_notifier.unbounded_send(frag_id).unwrap();
+        if let Err(err) = self.sent_notifier.unbounded_send(frag_id) {
+            error!("Failed to notify about sent message: {err}");
+        }
    }

    fn loop_cover_message_size(&mut self) -> PacketSize {
@@ -271,7 +278,9 @@ where
        };

        if let Err(err) = self.mix_tx.send(vec![next_message]).await {
-            log::error!("Failed to send: {err}");
+            if !self.task_client.is_shutdown_poll() {
+                log::error!("Failed to send: {err}");
+            }
        } else {
            let event = if fragment_id.is_some() {
                PacketStatisticsEvent::RealPacketSent(packet_size)
@@ -504,21 +513,29 @@ where
    }

    #[cfg(not(target_arch = "wasm32"))]
-    fn log_status(&self, shutdown: &mut nym_task::TaskClient) {
+    fn log_status(&self, shutdown: &mut TaskClient) {
        use crate::error::ClientCoreStatusMessage;

        let packets = self.transmission_buffer.total_size();
-        let backlog = self.transmission_buffer.total_size_in_bytes() as f64 / 1024.0;
-        let lanes = self.transmission_buffer.num_lanes();
+        let lanes = self.transmission_buffer.lanes();
        let mult = self.sending_delay_controller.current_multiplier();
        let delay = self.current_average_message_sending_delay().as_millis();
+
+        let lane_status = lanes
+            .iter()
+            .map(|lane_name| {
+                let lane_length = self.transmission_buffer.lane_length(lane_name).unwrap_or(0);
+                format!("{lane_name:?}: {lane_length}")
+            })
+            .collect::<Vec<String>>()
+            .join(", ");
+
        let status_str = if self.config.traffic.disable_main_poisson_packet_distribution {
-            format!("Packet backlog: {backlog:.2} kiB ({packets}), {lanes} lanes, no delay")
+            format!("Packet backlog: {lane_status}, no delay")
        } else {
-            format!(
-                "Packet backlog: {backlog:.2} kiB ({packets}), {lanes} lanes, avg delay: {delay}ms ({mult})"
-            )
+            format!("Packet backlog: {lane_status}, avg delay: {delay}ms ({mult})")
        };
+
        if packets > 1000 {
            log::warn!("{status_str}");
        } else if packets > 0 {
@@ -535,17 +552,19 @@ where
        }
    }

-    pub(super) async fn run_with_shutdown(&mut self, mut shutdown: nym_task::TaskClient) {
+    pub(super) async fn run(&mut self) {
        debug!("Started OutQueueControl with graceful shutdown support");

+        let mut shutdown = self.task_client.fork("select");
+
        #[cfg(not(target_arch = "wasm32"))]
        {
            let mut status_timer = tokio::time::interval(Duration::from_secs(5));

-            loop {
+            while !shutdown.is_shutdown() {
                tokio::select! {
                    biased;
-                    _ = shutdown.recv_with_delay() => {
+                    _ = shutdown.recv() => {
                        log::trace!("OutQueueControl: Received shutdown");
                        break;
                    }
@@ -20,6 +20,7 @@ use nym_sphinx::message::{NymMessage, PlainMessage};
 use nym_sphinx::params::ReplySurbKeyDigestAlgorithm;
 use nym_sphinx::receiver::{MessageReceiver, MessageRecoveryError, ReconstructedMessage};
 use nym_statistics_common::clients::{packet_statistics::PacketStatisticsEvent, ClientStatsSender};
+use nym_task::TaskClient;
 use std::collections::HashSet;
 use std::sync::Arc;

@@ -152,6 +153,7 @@ struct ReceivedMessagesBuffer<R: MessageReceiver> {
    inner: Arc<Mutex<ReceivedMessagesBufferInner<R>>>,
    reply_key_storage: SentReplyKeys,
    reply_controller_sender: ReplyControllerSender,
+    task_client: TaskClient,
 }

 impl<R: MessageReceiver> ReceivedMessagesBuffer<R> {
@@ -160,6 +162,7 @@ impl<R: MessageReceiver> ReceivedMessagesBuffer<R> {
        reply_key_storage: SentReplyKeys,
        reply_controller_sender: ReplyControllerSender,
        stats_tx: ClientStatsSender,
+        task_client: TaskClient,
    ) -> Self {
        ReceivedMessagesBuffer {
            inner: Arc::new(Mutex::new(ReceivedMessagesBufferInner {
@@ -172,6 +175,7 @@ impl<R: MessageReceiver> ReceivedMessagesBuffer<R> {
            })),
            reply_key_storage,
            reply_controller_sender,
+            task_client,
        }
    }

@@ -257,11 +261,15 @@ impl<R: MessageReceiver> ReceivedMessagesBuffer<R> {
                }
            };

-            self.reply_controller_sender.send_additional_surbs(
+            if let Err(err) = self.reply_controller_sender.send_additional_surbs(
                msg.sender_tag,
                reply_surbs,
                from_surb_request,
-            )
+            ) {
+                if !self.task_client.is_shutdown_poll() {
+                    error!("{err}");
+                }
+            }
        }
        reconstructed
    }
@@ -276,8 +284,14 @@ impl<R: MessageReceiver> ReceivedMessagesBuffer<R> {
                ReplyMessageContent::Data { message } => reconstructed.push(message.into()),
                ReplyMessageContent::SurbRequest { recipient, amount } => {
                    debug!("received request for {amount} additional reply SURBs from {recipient}");
-                    self.reply_controller_sender
-                        .send_additional_surbs_request(*recipient, amount);
+                    if let Err(err) = self
+                        .reply_controller_sender
+                        .send_additional_surbs_request(*recipient, amount)
+                    {
+                        if !self.task_client.is_shutdown_poll() {
+                            error!("{err}");
+                        }
+                    }
                }
            }
        }
@@ -399,16 +413,19 @@ pub enum ReceivedBufferMessage {
 struct RequestReceiver<R: MessageReceiver> {
    received_buffer: ReceivedMessagesBuffer<R>,
    query_receiver: ReceivedBufferRequestReceiver,
+    task_client: TaskClient,
 }

 impl<R: MessageReceiver> RequestReceiver<R> {
    fn new(
        received_buffer: ReceivedMessagesBuffer<R>,
        query_receiver: ReceivedBufferRequestReceiver,
+        task_client: TaskClient,
    ) -> Self {
        RequestReceiver {
            received_buffer,
            query_receiver,
+            task_client,
        }
    }

@@ -423,12 +440,12 @@ impl<R: MessageReceiver> RequestReceiver<R> {
        }
    }

-    async fn run_with_shutdown(&mut self, mut shutdown: nym_task::TaskClient) {
+    async fn run(&mut self) {
        debug!("Started RequestReceiver with graceful shutdown support");
-        while !shutdown.is_shutdown() {
+        while !self.task_client.is_shutdown() {
            tokio::select! {
                biased;
-                _ = shutdown.recv_with_delay() => {
+                _ = self.task_client.recv() => {
                    log::trace!("RequestReceiver: Received shutdown");
                }
                request = self.query_receiver.next() => {
@@ -441,7 +458,7 @@ impl<R: MessageReceiver> RequestReceiver<R> {
                },
            }
        }
-        shutdown.recv_timeout().await;
+        self.task_client.recv().await;
        log::debug!("RequestReceiver: Exiting");
    }
 }
@@ -449,25 +466,25 @@ impl<R: MessageReceiver> RequestReceiver<R> {
 struct FragmentedMessageReceiver<R: MessageReceiver> {
    received_buffer: ReceivedMessagesBuffer<R>,
    mixnet_packet_receiver: MixnetMessageReceiver,
+    task_client: TaskClient,
 }

 impl<R: MessageReceiver> FragmentedMessageReceiver<R> {
    fn new(
        received_buffer: ReceivedMessagesBuffer<R>,
        mixnet_packet_receiver: MixnetMessageReceiver,
+        task_client: TaskClient,
    ) -> Self {
        FragmentedMessageReceiver {
            received_buffer,
            mixnet_packet_receiver,
+            task_client,
        }
    }

-    async fn run_with_shutdown(
-        &mut self,
-        mut shutdown: nym_task::TaskClient,
-    ) -> Result<(), MessageRecoveryError> {
+    async fn run(&mut self) -> Result<(), MessageRecoveryError> {
        debug!("Started FragmentedMessageReceiver with graceful shutdown support");
-        while !shutdown.is_shutdown() {
+        while !self.task_client.is_shutdown() {
            tokio::select! {
                new_messages = self.mixnet_packet_receiver.next() => {
                    if let Some(new_messages) = new_messages {
@@ -477,12 +494,12 @@ impl<R: MessageReceiver> FragmentedMessageReceiver<R> {
                        break;
                    }
                },
-                _ = shutdown.recv_with_delay() => {
+                _ = self.task_client.recv_with_delay() => {
                    log::trace!("FragmentedMessageReceiver: Received shutdown");
                }
            }
        }
-        shutdown.recv_timeout().await;
+        self.task_client.recv_timeout().await;
        log::debug!("FragmentedMessageReceiver: Exiting");
        Ok(())
    }
@@ -501,41 +518,42 @@ impl<R: MessageReceiver + Clone + Send + 'static> ReceivedMessagesBufferControll
        reply_key_storage: SentReplyKeys,
        reply_controller_sender: ReplyControllerSender,
        metrics_reporter: ClientStatsSender,
+        task_client: TaskClient,
    ) -> Self {
        let received_buffer = ReceivedMessagesBuffer::new(
            local_encryption_keypair,
            reply_key_storage,
            reply_controller_sender,
            metrics_reporter,
+            task_client.fork("received_messages_buffer"),
        );

        ReceivedMessagesBufferController {
            fragmented_message_receiver: FragmentedMessageReceiver::new(
                received_buffer.clone(),
                mixnet_packet_receiver,
+                task_client.fork("fragmented_message_receiver"),
+            ),
+            request_receiver: RequestReceiver::new(
+                received_buffer,
+                query_receiver,
+                task_client.with_suffix("request_receiver"),
            ),
-            request_receiver: RequestReceiver::new(received_buffer, query_receiver),
        }
    }

-    pub fn start_with_shutdown(self, shutdown: nym_task::TaskClient) {
+    pub fn start(self) {
        let mut fragmented_message_receiver = self.fragmented_message_receiver;
        let mut request_receiver = self.request_receiver;

-        let shutdown_handle = shutdown.fork("fragmented_message_receiver");
        spawn_future(async move {
-            match fragmented_message_receiver
-                .run_with_shutdown(shutdown_handle)
-                .await
-            {
+            match fragmented_message_receiver.run().await {
                Ok(_) => {}
                Err(e) => error!("{e}"),
            }
        });
        spawn_future(async move {
-            request_receiver
-                .run_with_shutdown(shutdown.with_suffix("request_receiver"))
-                .await;
+            request_receiver.run().await;
        });
    }
 }
@@ -12,6 +12,7 @@ use nym_sphinx::anonymous_replies::requests::AnonymousSenderTag;
 use nym_sphinx::anonymous_replies::ReplySurb;
 use nym_sphinx::chunking::fragment::{Fragment, FragmentIdentifier};
 use nym_task::connections::{ConnectionId, TransmissionLane};
+use nym_task::TaskClient;
 use rand::{CryptoRng, Rng};
 use std::cmp::{max, min};
 use std::collections::btree_map::Entry;
@@ -68,6 +69,9 @@ pub struct ReplyController<R> {

    message_handler: MessageHandler<R>,
    full_reply_storage: CombinedReplyStorage,
+
+    // Listen for shutdown signals
+    task_client: TaskClient,
 }

 impl<R> ReplyController<R>
@@ -79,6 +83,7 @@ where
        message_handler: MessageHandler<R>,
        full_reply_storage: CombinedReplyStorage,
        request_receiver: ReplyControllerReceiver,
+        task_client: TaskClient,
    ) -> Self {
        ReplyController {
            config,
@@ -87,6 +92,7 @@ where
            pending_retransmissions: HashMap::new(),
            message_handler,
            full_reply_storage,
+            task_client,
        }
    }

@@ -96,6 +102,7 @@ where
        fragments: I,
        lane: TransmissionLane,
    ) {
+        trace!("buffering pending replies for {recipient}");
        self.pending_replies
            .entry(*recipient)
            .or_insert_with(TransmissionBuffer::new)
@@ -107,6 +114,7 @@ where
        recipient: &AnonymousSenderTag,
        fragments: Vec<(TransmissionLane, Fragment)>,
    ) {
+        trace!("re-inserting pending replies for {recipient}");
        // the buffer should ALWAYS exist at this point, if it doesn't, it's a bug...
        self.pending_replies
            .entry(*recipient)
@@ -119,6 +127,7 @@ where
        recipient: &AnonymousSenderTag,
        data: Vec<Arc<PendingAcknowledgement>>,
    ) {
+        trace!("re-inserting pending retransmissions for {recipient}");
        // the underlying entry MUST exist as we've just got data from there
        let map_entry = self
            .pending_retransmissions
@@ -136,7 +145,7 @@ where
    }

    fn should_request_more_surbs(&self, target: &AnonymousSenderTag) -> bool {
-        trace!("checking if we should request more surbs from {:?}", target);
+        trace!("checking if we should request more surbs from {target}");

        let pending_queue_size = self
            .pending_replies
@@ -152,11 +161,6 @@ where

        let total_queue = pending_queue_size + retransmission_queue;

-        // simple as that - there's absolutely nothing to retransmit
-        if total_queue == 0 {
-            return false;
-        }
-
        let available_surbs = self
            .full_reply_storage
            .surbs_storage_ref()
@@ -173,11 +177,27 @@ where
            .full_reply_storage
            .surbs_storage_ref()
            .max_surb_threshold();
+        let min_surbs_threshold_buffer =
+            self.config.reply_surbs.minimum_reply_surb_threshold_buffer;

-        debug!("total queue size: {total_queue} = pending data {pending_queue_size} + pending retransmission {retransmission_queue}, available surbs: {available_surbs} pending surbs: {pending_surbs} threshold range: {min_surbs_threshold}..{max_surbs_threshold}");
+        // After clearing the queue, we want to have at least `min_surbs_threshold` surbs available
+        // and reserved for requesting additional surbs, and in addition to that we also want to
+        // have `min_surbs_threshold_buffer` surbs available proactively.
+        let target_surbs_after_clearing_queue = min_surbs_threshold + min_surbs_threshold_buffer;

-        (pending_surbs + available_surbs) < max_surbs_threshold
-            && (pending_surbs + available_surbs) < (total_queue + min_surbs_threshold)
+        // Check if we have enough surbs to handle the total queue and maintain minimum thresholds
+        let total_required_surbs = total_queue + target_surbs_after_clearing_queue;
+        let total_available_surbs = pending_surbs + available_surbs;
+
+        debug!("total queue size: {total_queue} = pending data {pending_queue_size} + pending retransmission {retransmission_queue}, available surbs: {available_surbs} pending surbs: {pending_surbs} threshold range: {min_surbs_threshold}..+{min_surbs_threshold_buffer}..{max_surbs_threshold}");
+
+        // We should request more surbs if:
+        // 1. We haven't hit the maximum surb threshold, and
+        // 2. We don't have enough surbs to handle the queue plus minimum thresholds
+        let is_below_max_threshold = total_available_surbs < max_surbs_threshold;
+        let is_below_required_surbs = total_available_surbs < total_required_surbs;
+
+        is_below_max_threshold && is_below_required_surbs
    }

    async fn handle_send_reply(
@@ -238,6 +258,10 @@ where
                        &recipient_tag,
                    );
                    warn!("failed to send reply to {recipient_tag}: {err}");
+                    info!(
+                        "buffering {no_fragments} fragments for {recipient_tag}",
+                        no_fragments = to_send.len()
+                    );
                    self.insert_pending_replies(&recipient_tag, to_send, lane);
                }
            }
@@ -245,6 +269,13 @@ where

        // if there's leftover data we didn't send because we didn't have enough (or any) surbs - buffer it
        if !fragments.is_empty() {
+            // Ideally we should have enough surbs above the minimum threshold to handle sending
+            // new replies without having to first request more surbs. That's why I'd like to log
+            // these cases as they might indicate a problem with the surb management.
+            debug!(
+                "buffering {no_fragments} fragments for {recipient_tag}",
+                no_fragments = fragments.len()
+            );
            self.insert_pending_replies(&recipient_tag, fragments, lane);
        }

@@ -259,6 +290,7 @@ where
        target: AnonymousSenderTag,
        amount: u32,
    ) -> Result<(), PreparationError> {
+        debug!("requesting {amount} additional reply surbs for {target}");
        let reply_surb = self
            .full_reply_storage
            .surbs_storage_ref()
@@ -680,7 +712,7 @@ where
    // it should take into consideration the average latency, sending rate and queue size.
    // it should request as many surbs as it takes to saturate its sending rate before next batch arrives
    async fn request_reply_surbs_for_queue_clearing(&mut self, target: AnonymousSenderTag) {
-        trace!("requesting surbs for queues clearing");
+        trace!("requesting surbs for queue clearing");

        let pending_queue_size = self
            .pending_replies
@@ -694,17 +726,18 @@ where
            .map(|pending_queue| pending_queue.len())
            .unwrap_or_default();

+        let min_surbs_buffer = self.config.reply_surbs.minimum_reply_surb_threshold_buffer as u32;
+
        let total_queue = (pending_queue_size + retransmission_queue) as u32;

-        if total_queue == 0 {
-            trace!("the pending queues for {:?} are already empty", target);
-            return;
-        }
+        // To proactively request additional surbs, we aim to have a buffer of extra surbs in our
+        // storage.
+        let total_queue_with_buffer = total_queue + min_surbs_buffer;

        let request_size = min(
            self.config.reply_surbs.maximum_reply_surb_request_size,
            max(
-                total_queue,
+                total_queue_with_buffer,
                self.config.reply_surbs.minimum_reply_surb_request_size,
            ),
        );
@@ -846,9 +879,11 @@ where
    //     todo!()
    // }

-    pub(crate) async fn run_with_shutdown(&mut self, mut shutdown: nym_task::TaskClient) {
+    pub(crate) async fn run(&mut self) {
        debug!("Started ReplyController with graceful shutdown support");

+        let mut shutdown = self.task_client.fork("select");
+
        let polling_rate = Duration::from_secs(5);
        let mut stale_inspection = new_interval_stream(polling_rate);

@@ -860,7 +895,7 @@ where
        while !shutdown.is_shutdown() {
            tokio::select! {
                biased;
-                _ = shutdown.recv_with_delay() => {
+                _ = shutdown.recv() => {
                    log::trace!("ReplyController: Received shutdown");
                },
                req = self.request_receiver.next() => match req {
@@ -15,6 +15,27 @@ pub(crate) fn new_control_channels() -> (ReplyControllerSender, ReplyControllerR
    (tx.into(), rx)
 }

+#[derive(Debug, thiserror::Error)]
+pub enum ReplyControllerSenderError {
+    #[error("failed to send retransmission data to reply controller")]
+    SendRetransmissionData(#[source] mpsc::TrySendError<ReplyControllerMessage>),
+
+    #[error("failed to send reply to reply controller")]
+    SendReply(#[source] mpsc::TrySendError<ReplyControllerMessage>),
+
+    #[error("failed to send additional surbs to reply controller")]
+    AdditionalSurbs(#[source] mpsc::TrySendError<ReplyControllerMessage>),
+
+    #[error("failed to send additional surbs request to reply controller")]
+    AdditionalSurbsRequest(#[source] mpsc::TrySendError<ReplyControllerMessage>),
+
+    #[error("failed to request lane queue length from reply controller")]
+    LaneQueueLength(#[source] mpsc::TrySendError<ReplyControllerMessage>),
+
+    #[error("response channel was dropped before we could receive the response")]
+    ResponseChannelDropped(#[source] oneshot::Canceled),
+}
+
 #[derive(Debug, Clone)]
 pub struct ReplyControllerSender(mpsc::UnboundedSender<ReplyControllerMessage>);

@@ -30,14 +51,14 @@ impl ReplyControllerSender {
        recipient: AnonymousSenderTag,
        timed_out_ack: Weak<PendingAcknowledgement>,
        extra_surb_request: bool,
-    ) {
+    ) -> Result<(), ReplyControllerSenderError> {
        self.0
            .unbounded_send(ReplyControllerMessage::RetransmitReply {
                recipient,
                timed_out_ack,
                extra_surb_request,
            })
-            .expect("ReplyControllerReceiver has died!")
+            .map_err(ReplyControllerSenderError::SendRetransmissionData)
    }

    pub(crate) fn send_reply(
@@ -45,14 +66,14 @@ impl ReplyControllerSender {
        recipient: AnonymousSenderTag,
        message: Vec<u8>,
        lane: TransmissionLane,
-    ) {
+    ) -> Result<(), ReplyControllerSenderError> {
        self.0
            .unbounded_send(ReplyControllerMessage::SendReply {
                recipient,
                message,
                lane,
            })
-            .expect("ReplyControllerReceiver has died!")
+            .map_err(ReplyControllerSenderError::SendReply)
    }

    pub(crate) fn send_additional_surbs(
@@ -60,42 +81,47 @@ impl ReplyControllerSender {
        sender_tag: AnonymousSenderTag,
        reply_surbs: Vec<ReplySurb>,
        from_surb_request: bool,
-    ) {
+    ) -> Result<(), ReplyControllerSenderError> {
        self.0
            .unbounded_send(ReplyControllerMessage::AdditionalSurbs {
                sender_tag,
                reply_surbs,
                from_surb_request,
            })
-            .expect("ReplyControllerReceiver has died!")
+            .map_err(ReplyControllerSenderError::AdditionalSurbs)
    }

-    pub(crate) fn send_additional_surbs_request(&self, recipient: Recipient, amount: u32) {
+    pub(crate) fn send_additional_surbs_request(
+        &self,
+        recipient: Recipient,
+        amount: u32,
+    ) -> Result<(), ReplyControllerSenderError> {
        self.0
            .unbounded_send(ReplyControllerMessage::AdditionalSurbsRequest {
                recipient: Box::new(recipient),
                amount,
            })
-            .expect("ReplyControllerReceiver has died!")
+            .map_err(ReplyControllerSenderError::AdditionalSurbsRequest)
    }

-    pub async fn get_lane_queue_length(&self, connection_id: ConnectionId) -> usize {
+    pub async fn get_lane_queue_length(
+        &self,
+        connection_id: ConnectionId,
+    ) -> Result<usize, ReplyControllerSenderError> {
        let (response_tx, response_rx) = oneshot::channel();
-        self.0
+        if let Err(err) = self
+            .0
            .unbounded_send(ReplyControllerMessage::LaneQueueLength {
                connection_id,
                response_channel: response_tx,
            })
-            .expect("ReplyControllerReceiver has died!");
-
-        match response_rx.await {
-            Ok(length) => length,
-            Err(_) => {
-                error!("The reply controller has dropped our response channel!");
-                // TODO: should we panic here instead? this message implies something weird and unrecoverable has happened
-                0
-            }
+        {
+            return Err(ReplyControllerSenderError::LaneQueueLength(err));
        }
+
+        response_rx
+            .await
+            .map_err(ReplyControllerSenderError::ResponseChannelDropped)
    }
 }

@@ -110,7 +136,10 @@ impl ReplyQueueLengths {
        }
    }

-    pub async fn get_lane_queue_length(&self, connection_id: ConnectionId) -> usize {
+    pub async fn get_lane_queue_length(
+        &self,
+        connection_id: ConnectionId,
+    ) -> Result<usize, ReplyControllerSenderError> {
        self.reply_controller_sender
            .get_lane_queue_length(connection_id)
            .await
@@ -120,7 +149,7 @@ impl ReplyQueueLengths {
 pub(crate) type ReplyControllerReceiver = mpsc::UnboundedReceiver<ReplyControllerMessage>;

 #[derive(Debug)]
-pub(crate) enum ReplyControllerMessage {
+pub enum ReplyControllerMessage {
    RetransmitReply {
        recipient: AnonymousSenderTag,
        timed_out_ack: Weak<PendingAcknowledgement>,
@@ -22,7 +22,7 @@ use nym_sphinx::addressing::Recipient;
 use nym_statistics_common::clients::{
    ClientStatsController, ClientStatsReceiver, ClientStatsSender,
 };
-use nym_task::connections::TransmissionLane;
+use nym_task::{connections::TransmissionLane, TaskClient};
 use std::time::Duration;

 use crate::{
@@ -51,6 +51,9 @@ pub(crate) struct StatisticsControl {

    /// Config for stats reporting (enabled, address, interval)
    reporting_config: StatsReporting,
+
+    /// Task client for listening for shutdown
+    task_client: TaskClient,
 }

 impl StatisticsControl {
@@ -59,19 +62,24 @@ impl StatisticsControl {
        client_type: String,
        client_stats_id: String,
        report_tx: InputMessageSender,
+        task_client: TaskClient,
    ) -> (Self, ClientStatsSender) {
        let (stats_tx, stats_rx) = tokio::sync::mpsc::unbounded_channel();

        let stats = ClientStatsController::new(client_stats_id, client_type);

+        let mut task_client_stats_sender = task_client.fork("stats_sender");
+        task_client_stats_sender.disarm();
+
        (
            StatisticsControl {
                stats,
                stats_rx,
                report_tx,
                reporting_config,
+                task_client,
            },
-            ClientStatsSender::new(Some(stats_tx)),
+            ClientStatsSender::new(Some(stats_tx), task_client_stats_sender),
        )
    }

@@ -91,7 +99,7 @@ impl StatisticsControl {
        }
    }

-    async fn run_with_shutdown(&mut self, mut task_client: nym_task::TaskClient) {
+    async fn run(&mut self) {
        log::debug!("Started StatisticsControl with graceful shutdown support");

        #[cfg(not(target_arch = "wasm32"))]
@@ -121,8 +129,13 @@ impl StatisticsControl {
        let mut snapshot_interval =
            gloo_timers::future::IntervalStream::new(SNAPSHOT_INTERVAL.as_millis() as u32);

-        loop {
+        while !self.task_client.is_shutdown() {
            tokio::select! {
+                biased;
+                _ = self.task_client.recv() => {
+                    log::trace!("StatisticsControl: Received shutdown");
+                    break;
+                },
                stats_event = self.stats_rx.recv() => match stats_event {
                        Some(stats_event) => self.stats.handle_event(stats_event),
                        None => {
@@ -144,34 +157,34 @@ impl StatisticsControl {
                }

                _ = local_report_interval.next() => {
-                    self.stats.local_report(&mut task_client);
+                    self.stats.local_report(&mut self.task_client);
                }
-                _ = task_client.recv_with_delay() => {
-                    log::trace!("StatisticsControl: Received shutdown");
-                    break;
-                },
            }
        }
-        task_client.recv_timeout().await;
        log::debug!("StatisticsControl: Exiting");
    }

-    pub(crate) fn start_with_shutdown(mut self, task_client: nym_task::TaskClient) {
+    pub(crate) fn start(mut self) {
        spawn_future(async move {
-            self.run_with_shutdown(task_client).await;
+            self.run().await;
        })
    }

-    pub(crate) fn create_and_start_with_shutdown(
+    pub(crate) fn create_and_start(
        reporting_config: StatsReporting,
        client_type: String,
        client_stats_id: String,
        report_tx: InputMessageSender,
-        task_client: nym_task::TaskClient,
+        task_client: TaskClient,
    ) -> ClientStatsSender {
-        let (controller, sender) =
-            Self::create(reporting_config, client_type, client_stats_id, report_tx);
-        controller.start_with_shutdown(task_client);
+        let (controller, sender) = Self::create(
+            reporting_config,
+            client_type,
+            client_stats_id,
+            report_tx,
+            task_client,
+        );
+        controller.start();
        sender
    }
 }
@@ -6,6 +6,7 @@ pub(crate) use accessor::{TopologyAccessor, TopologyReadPermit};
 use futures::StreamExt;
 use log::*;
 use nym_sphinx::addressing::nodes::NodeIdentity;
+use nym_task::TaskClient;
 use nym_topology::NymTopologyError;
 use std::time::Duration;

@@ -43,6 +44,8 @@ pub struct TopologyRefresher {

    refresh_rate: Duration,
    consecutive_failure_count: usize,
+
+    task_client: TaskClient,
 }

 impl TopologyRefresher {
@@ -50,12 +53,14 @@ impl TopologyRefresher {
        cfg: TopologyRefresherConfig,
        topology_accessor: TopologyAccessor,
        topology_provider: Box<dyn TopologyProvider + Send + Sync>,
+        task_client: TaskClient,
    ) -> Self {
        TopologyRefresher {
            topology_provider,
            topology_accessor,
            refresh_rate: cfg.refresh_rate,
            consecutive_failure_count: 0,
+            task_client,
        }
    }

@@ -142,7 +147,7 @@ impl TopologyRefresher {
        }
    }

-    pub fn start_with_shutdown(mut self, mut shutdown: nym_task::TaskClient) {
+    pub fn start(mut self) {
        spawn_future(async move {
            debug!("Started TopologyRefresher with graceful shutdown support");

@@ -155,17 +160,17 @@ impl TopologyRefresher {
            let mut interval =
                gloo_timers::future::IntervalStream::new(self.refresh_rate.as_millis() as u32);

-            while !shutdown.is_shutdown() {
+            while !self.task_client.is_shutdown() {
                tokio::select! {
                    _ = interval.next() => {
                        self.try_refresh().await;
                    },
-                    _ = shutdown.recv() => {
+                    _ = self.task_client.recv() => {
                        log::trace!("TopologyRefresher: Received shutdown");
                    },
                }
            }
-            shutdown.recv_timeout().await;
+            self.task_client.recv_timeout().await;
            log::debug!("TopologyRefresher: Exiting");
        })
    }
@@ -58,8 +58,8 @@ impl<T> TransmissionBuffer<T> {
    }

    #[cfg(not(target_arch = "wasm32"))]
-    pub(crate) fn num_lanes(&self) -> usize {
-        self.buffer.keys().count()
+    pub(crate) fn lanes(&self) -> Vec<TransmissionLane> {
+        self.buffer.keys().cloned().collect()
    }

    pub(crate) fn lane_length(&self, lane: &TransmissionLane) -> Option<usize> {
@@ -83,6 +83,7 @@ impl<T> TransmissionBuffer<T> {
    }

    #[cfg(not(target_arch = "wasm32"))]
+    #[allow(unused)]
    pub(crate) fn total_size_in_bytes(&self) -> usize
    where
        T: SizedData,
@@ -12,6 +12,9 @@ use std::path::PathBuf;

 #[derive(thiserror::Error, Debug)]
 pub enum ClientCoreError {
+    #[error("could not perform the state migration: {0}")]
+    UnsupportedMigration(String),
+
    #[error("I/O error: {0}")]
    IoError(#[from] std::io::Error),

@@ -36,6 +39,13 @@ pub enum ClientCoreError {
    #[error("no gateway with id: {0}")]
    NoGatewayWithId(String),

+    #[error("Invalid URL: {0}")]
+    InvalidUrl(String),
+
+    #[cfg(not(target_arch = "wasm32"))]
+    #[error("resolution failed: {0}")]
+    ResolutionFailed(#[from] nym_http_api_client::HickoryDnsError),
+
    #[error("no gateways on network")]
    NoGatewaysOnNetwork,

@@ -96,6 +106,9 @@ pub enum ClientCoreError {
    #[error("timed out while trying to establish gateway connection")]
    GatewayConnectionTimeout,

+    #[error("failed to forward mix messages to gateway")]
+    GatewayFailedToForwardMessages,
+
    #[error("no ping measurements for the gateway ({identity}) performed")]
    NoGatewayMeasurements { identity: String },

@@ -212,6 +225,9 @@ pub enum ClientCoreError {
        "fresh registration with gateway {gateway_id} somehow requires an additional key upgrade!"
    )]
    UnexpectedKeyUpgrade { gateway_id: String },
+
+    #[error("failed to derive keys from master key")]
+    HkdfDerivationError {},
 }

 /// Set of messages that the client can send to listeners via the task manager
@@ -15,6 +15,9 @@ use std::{sync::Arc, time::Duration};
 use tungstenite::Message;
 use url::Url;

+#[cfg(not(target_arch = "wasm32"))]
+use crate::init::websockets::connect_async;
+
 use nym_topology::NodeId;
 #[cfg(not(target_arch = "wasm32"))]
 use tokio::net::TcpStream;
@@ -23,8 +26,6 @@ use tokio::time::sleep;
 #[cfg(not(target_arch = "wasm32"))]
 use tokio::time::Instant;
 #[cfg(not(target_arch = "wasm32"))]
-use tokio_tungstenite::connect_async;
-#[cfg(not(target_arch = "wasm32"))]
 use tokio_tungstenite::{MaybeTlsStream, WebSocketStream};
 #[cfg(target_arch = "wasm32")]
 use wasm_utils::websocket::JSWebsocket;
@@ -91,6 +92,7 @@ pub async fn gateways_for_init<R: Rng>(
    nym_apis: &[Url],
    user_agent: Option<UserAgent>,
    minimum_performance: u8,
+    ignore_epoch_roles: bool,
 ) -> Result<Vec<RoutingNode>, ClientCoreError> {
    let nym_api = nym_apis
        .choose(rng)
@@ -112,7 +114,7 @@ pub async fn gateways_for_init<R: Rng>(
    // (we don't want instability)
    let valid_gateways = gateways
        .iter()
-        .filter(|g| !g.supported_roles.mixnode)
+        .filter(|g| ignore_epoch_roles || !g.supported_roles.mixnode)
        .filter(|g| g.performance.round_to_integer() >= minimum_performance)
        .filter_map(|gateway| gateway.try_into().ok())
        .collect::<Vec<_>>();
@@ -131,7 +133,7 @@ pub async fn gateways_for_init<R: Rng>(
 async fn connect(endpoint: &str) -> Result<WsConn, ClientCoreError> {
    match tokio::time::timeout(CONN_TIMEOUT, connect_async(endpoint)).await {
        Err(_elapsed) => Err(ClientCoreError::GatewayConnectionTimeout),
-        Ok(Err(conn_failure)) => Err(conn_failure.into()),
+        Ok(Err(conn_failure)) => Err(conn_failure),
        Ok(Ok((stream, _))) => Ok(stream),
    }
 }
@@ -333,14 +335,6 @@ pub(super) async fn register_with_gateway(
            }
        })?;

-    // this should NEVER happen, if it did, it means the function was misused,
-    // because for any fresh **registration**, the derived key is always up to date
-    if auth_response.requires_key_upgrade {
-        return Err(ClientCoreError::UnexpectedKeyUpgrade {
-            gateway_id: gateway_id.to_base58_string(),
-        });
-    }
-
    Ok(RegistrationResult {
        shared_keys: auth_response.initial_shared_key,
        authenticated_ephemeral_client: gateway_client,
@@ -26,6 +26,8 @@ use serde::Serialize;

 pub mod helpers;
 pub mod types;
+#[cfg(not(target_arch = "wasm32"))]
+pub(crate) mod websockets;

 // helpers for error wrapping

@@ -11,7 +11,7 @@ use nym_client_core_gateways_storage::{
 };
 use nym_crypto::asymmetric::identity;
 use nym_gateway_client::client::InitGatewayClient;
-use nym_gateway_requests::shared_key::SharedGatewayKey;
+use nym_gateway_requests::shared_key::SharedSymmetricKey;
 use nym_sphinx::addressing::clients::Recipient;
 use nym_topology::node::RoutingNode;
 use nym_validator_client::client::IdentityKey;
@@ -96,7 +96,7 @@ impl SelectedGateway {
 /// - shared keys derived between ourselves and the node
 /// - an authenticated handle of an ephemeral handle created for the purposes of registration
 pub struct RegistrationResult {
-    pub shared_keys: Arc<SharedGatewayKey>,
+    pub shared_keys: Arc<SharedSymmetricKey>,
    pub authenticated_ephemeral_client: InitGatewayClient,
 }

@@ -0,0 +1,44 @@
+use crate::error::ClientCoreError;
+
+use nym_http_api_client::HickoryDnsResolver;
+use tokio::net::TcpStream;
+use tokio_tungstenite::{MaybeTlsStream, WebSocketStream};
+use tungstenite::handshake::client::Response;
+use url::{Host, Url};
+
+use std::net::SocketAddr;
+
+#[cfg(not(target_arch = "wasm32"))]
+pub(crate) async fn connect_async(
+    endpoint: &str,
+) -> Result<(WebSocketStream<MaybeTlsStream<TcpStream>>, Response), ClientCoreError> {
+    let resolver = HickoryDnsResolver::default();
+    let uri = Url::parse(endpoint).map_err(|_| ClientCoreError::InvalidUrl(endpoint.to_owned()))?;
+    let port: u16 = uri.port_or_known_default().unwrap_or(443);
+
+    let host = uri
+        .host()
+        .ok_or(ClientCoreError::InvalidUrl(endpoint.to_owned()))?;
+
+    // Get address for tcp connection, if a domain is provided use our preferred resolver rather than
+    // the default std resolve
+    let sock_addrs: Vec<SocketAddr> = match host {
+        Host::Ipv4(addr) => vec![SocketAddr::new(addr.into(), port)],
+        Host::Ipv6(addr) => vec![SocketAddr::new(addr.into(), port)],
+        Host::Domain(domain) => {
+            // Do a DNS lookup for the domain using our custom DNS resolver
+            resolver
+                .resolve_str(domain)
+                .await?
+                .into_iter()
+                .map(|a| SocketAddr::new(a, port))
+                .collect()
+        }
+    };
+
+    let stream = TcpStream::connect(&sock_addrs[..]).await?;
+
+    tokio_tungstenite::client_async_tls(endpoint, stream)
+        .await
+        .map_err(Into::into)
+}
@@ -33,48 +33,3 @@ where
 {
    tokio::spawn(future);
 }
-
-#[derive(Clone, Default, Debug)]
-pub struct ForgetMe {
-    client: bool,
-    stats: bool,
-}
-
-impl ForgetMe {
-    pub fn new_all() -> Self {
-        Self {
-            client: true,
-            stats: true,
-        }
-    }
-
-    pub fn new_client() -> Self {
-        Self {
-            client: true,
-            stats: false,
-        }
-    }
-
-    pub fn new_stats() -> Self {
-        Self {
-            client: false,
-            stats: true,
-        }
-    }
-
-    pub fn new(client: bool, stats: bool) -> Self {
-        Self { client, stats }
-    }
-
-    pub fn any(&self) -> bool {
-        self.client || self.stats
-    }
-
-    pub fn client(&self) -> bool {
-        self.client
-    }
-
-    pub fn stats(&self) -> bool {
-        self.stats
-    }
-}
@@ -27,6 +27,7 @@ nym-credential-storage = { path = "../../credential-storage" }
 nym-credentials-interface = { path = "../../credentials-interface" }
 nym-crypto = { path = "../../crypto" }
 nym-gateway-requests = { path = "../../gateway-requests" }
+nym-http-api-client = { path = "../../http-api-client" }
 nym-network-defaults = { path = "../../network-defaults" }
 nym-sphinx = { path = "../../nymsphinx" }
 nym-statistics-common = { path = "../../statistics" }
@@ -20,9 +20,8 @@ use nym_credentials_interface::TicketType;
 use nym_crypto::asymmetric::identity;
 use nym_gateway_requests::registration::handshake::client_handshake;
 use nym_gateway_requests::{
-    BinaryRequest, ClientControlRequest, ClientRequest, SensitiveServerResponse, ServerResponse,
-    SharedGatewayKey, SharedSymmetricKey, AES_GCM_SIV_PROTOCOL_VERSION,
-    CREDENTIAL_UPDATE_V2_PROTOCOL_VERSION, CURRENT_PROTOCOL_VERSION,
+    BinaryRequest, ClientControlRequest, ClientRequest, GatewayProtocolVersionExt, ServerResponse,
+    SharedSymmetricKey, CREDENTIAL_UPDATE_V2_PROTOCOL_VERSION, CURRENT_PROTOCOL_VERSION,
 };
 use nym_sphinx::forwarding::packet::MixPacket;
 use nym_statistics_common::clients::connection::ConnectionStatsEvent;
@@ -40,8 +39,6 @@ use url::Url;
 use std::os::fd::RawFd;
 #[cfg(not(target_arch = "wasm32"))]
 use tokio::time::sleep;
-#[cfg(not(target_arch = "wasm32"))]
-use tokio_tungstenite::connect_async;

 #[cfg(not(unix))]
 use std::os::raw::c_int as RawFd;
@@ -49,10 +46,14 @@ use std::os::raw::c_int as RawFd;
 use wasm_utils::websocket::JSWebsocket;
 #[cfg(target_arch = "wasm32")]
 use wasmtimer::tokio::sleep;
-use zeroize::Zeroizing;

 pub mod config;

+#[cfg(not(target_arch = "wasm32"))]
+pub(crate) mod websockets;
+#[cfg(not(target_arch = "wasm32"))]
+use websockets::connect_async;
+
 pub struct GatewayConfig {
    pub gateway_identity: identity::PublicKey,

@@ -79,8 +80,7 @@ impl GatewayConfig {
 #[must_use]
 #[derive(Debug)]
 pub struct AuthenticationResponse {
-    pub initial_shared_key: Arc<SharedGatewayKey>,
-    pub requires_key_upgrade: bool,
+    pub initial_shared_key: Arc<SharedSymmetricKey>,
 }

 // TODO: this should be refactored into a state machine that keeps track of its authentication state
@@ -92,7 +92,7 @@ pub struct GatewayClient<C, St = EphemeralCredentialStorage> {
    gateway_address: String,
    gateway_identity: identity::PublicKey,
    local_identity: Arc<identity::KeyPair>,
-    shared_key: Option<Arc<SharedGatewayKey>>,
+    shared_key: Option<Arc<SharedSymmetricKey>>,
    connection: SocketState,
    packet_router: PacketRouter,
    bandwidth_controller: Option<BandwidthController<C, St>>,
@@ -116,7 +116,7 @@ impl<C, St> GatewayClient<C, St> {
        gateway_config: GatewayConfig,
        local_identity: Arc<identity::KeyPair>,
        // TODO: make it mandatory. if you don't want to pass it, use `new_init`
-        shared_key: Option<Arc<SharedGatewayKey>>,
+        shared_key: Option<Arc<SharedSymmetricKey>>,
        packet_router: PacketRouter,
        bandwidth_controller: Option<BandwidthController<C, St>>,
        stats_reporter: ClientStatsSender,
@@ -146,7 +146,7 @@ impl<C, St> GatewayClient<C, St> {
        self.gateway_identity
    }

-    pub fn shared_key(&self) -> Option<Arc<SharedGatewayKey>> {
+    pub fn shared_key(&self) -> Option<Arc<SharedSymmetricKey>> {
        self.shared_key.clone()
    }

@@ -201,23 +201,15 @@ impl<C, St> GatewayClient<C, St> {
            "Attemting to establish connection to gateway at: {}",
            self.gateway_address
        );
-        let ws_stream = match connect_async(&self.gateway_address).await {
-            Ok((ws_stream, _)) => ws_stream,
-            Err(error) => {
-                return Err(GatewayClientError::NetworkConnectionFailed {
-                    address: self.gateway_address.clone(),
-                    source: error,
-                })
-            }
-        };
+        let (ws_stream, _) = connect_async(
+            &self.gateway_address,
+            #[cfg(unix)]
+            self.connection_fd_callback.clone(),
+        )
+        .await?;

        self.connection = SocketState::Available(Box::new(ws_stream));

-        #[cfg(unix)]
-        if let (Some(callback), Some(fd)) = (self.connection_fd_callback.as_ref(), self.ws_fd()) {
-            callback.as_ref()(fd);
-        }
-
        Ok(())
    }

@@ -271,6 +263,19 @@ impl<C, St> GatewayClient<C, St> {
        }
    }

+    pub async fn send_client_request(
+        &mut self,
+        message: ClientRequest,
+    ) -> Result<(), GatewayClientError> {
+        if let Some(shared_key) = self.shared_key() {
+            let encrypted = message.encrypt(&shared_key)?;
+            Box::pin(self.send_websocket_message(encrypted)).await?;
+            Ok(())
+        } else {
+            Err(GatewayClientError::ConnectionInInvalidState)
+        }
+    }
+
    async fn read_control_response(&mut self) -> Result<ServerResponse, GatewayClientError> {
        // we use the fact that all request responses are Message::Text and only pushed
        // sphinx packets are Message::Binary
@@ -402,49 +407,39 @@ impl<C, St> GatewayClient<C, St> {
        }
    }

-    fn check_gateway_protocol(
-        &self,
-        gateway_protocol: Option<u8>,
-    ) -> Result<(), GatewayClientError> {
+    fn check_gateway_protocol(&self, gateway_protocol: u8) -> Result<(), GatewayClientError> {
        debug!("gateway protocol: {gateway_protocol:?}, ours: {CURRENT_PROTOCOL_VERSION}");

-        // right now there are no failure cases here, but this might change in the future
-        match gateway_protocol {
-            None => {
-                warn!("the gateway we're connected to has not specified its protocol version. It's probably running version < 1.1.X, but that's still fine for now. It will become a hard error in 1.2.0");
-                // note: in +1.2.0 we will have to return a hard error here
-                Ok(())
-            }
-            Some(v) if v > CURRENT_PROTOCOL_VERSION => {
-                let err = GatewayClientError::IncompatibleProtocol {
-                    gateway: Some(v),
-                    current: CURRENT_PROTOCOL_VERSION,
-                };
-                error!("{err}");
-                Err(err)
-            }
+        // client should reject any gateways that do not indicate they support auth v2 or aes256gcm-siv
+        if !gateway_protocol.supports_authenticate_v2()
+            || !gateway_protocol.supports_aes256_gcm_siv()
+        {
+            return Err(GatewayClientError::IncompatibleProtocol {
+                gateway: gateway_protocol,
+                current: CURRENT_PROTOCOL_VERSION,
+            });
+        }

-            Some(_) => {
-                debug!("the gateway is using exactly the same (or older) protocol version as we are. We're good to continue!");
-                Ok(())
-            }
+        // we can't handle gateways with higher protocol than ours
+        if gateway_protocol <= CURRENT_PROTOCOL_VERSION {
+            debug!("the gateway is using exactly the same (or older) protocol version as we are. We're good to continue!");
+            Ok(())
+        } else {
+            let err = GatewayClientError::IncompatibleProtocol {
+                gateway: gateway_protocol,
+                current: CURRENT_PROTOCOL_VERSION,
+            };
+            error!("{err}");
+            Err(err)
        }
    }

-    async fn register(
-        &mut self,
-        derive_aes256_gcm_siv_key: bool,
-    ) -> Result<(), GatewayClientError> {
+    async fn register(&mut self) -> Result<(), GatewayClientError> {
        if !self.connection.is_established() {
            return Err(GatewayClientError::ConnectionNotEstablished);
        }

        debug_assert!(self.connection.is_available());
-        log::debug!(
-            "registering with gateway. using legacy key derivation: {}",
-            !derive_aes256_gcm_siv_key
-        );
-
        // it's fine to instantiate it here as it's only used once (during authentication or registration)
        // and putting it into the GatewayClient struct would be a hassle
        let mut rng = OsRng;
@@ -456,7 +451,6 @@ impl<C, St> GatewayClient<C, St> {
                self.local_identity.as_ref(),
                self.gateway_identity,
                self.cfg.bandwidth.require_tickets,
-                derive_aes256_gcm_siv_key,
                #[cfg(not(target_arch = "wasm32"))]
                self.task_client.clone(),
            )
@@ -484,99 +478,15 @@ impl<C, St> GatewayClient<C, St> {
        }

        // populate the negotiated protocol for future uses
-        self.negotiated_protocol = gateway_protocol;
+        self.negotiated_protocol = Some(gateway_protocol);

        Ok(())
    }

-    pub async fn upgrade_key_authenticated(
+    async fn send_authenticate_request_and_handle_response(
        &mut self,
-    ) -> Result<Zeroizing<SharedSymmetricKey>, GatewayClientError> {
-        info!("*** STARTING AES128CTR-HMAC KEY UPGRADE INTO AES256GCM-SIV***");
-
-        if !self.connection.is_established() {
-            return Err(GatewayClientError::ConnectionNotEstablished);
-        }
-
-        if !self.authenticated {
-            return Err(GatewayClientError::NotAuthenticated);
-        }
-
-        let Some(shared_key) = self.shared_key.as_ref() else {
-            return Err(GatewayClientError::NoSharedKeyAvailable);
-        };
-
-        if !shared_key.is_legacy() {
-            return Err(GatewayClientError::KeyAlreadyUpgraded);
-        }
-
-        // make sure we have the only reference, so we could safely swap it
-        if Arc::strong_count(shared_key) != 1 {
-            return Err(GatewayClientError::KeyAlreadyInUse);
-        }
-
-        assert!(shared_key.is_legacy());
-        let legacy_key = shared_key.unwrap_legacy();
-        let (updated_key, hkdf_salt) = legacy_key.upgrade();
-        let derived_key_digest = updated_key.digest();
-
-        let upgrade_request = ClientRequest::UpgradeKey {
-            hkdf_salt,
-            derived_key_digest,
-        }
-        .encrypt(legacy_key)?;
-
-        info!("sending upgrade request and awaiting the acknowledgement back");
-        let (ciphertext, nonce) = match self.send_websocket_message(upgrade_request).await? {
-            ServerResponse::EncryptedResponse { ciphertext, nonce } => (ciphertext, nonce),
-            ServerResponse::Error { message } => {
-                return Err(GatewayClientError::GatewayError(message))
-            }
-            other => return Err(GatewayClientError::UnexpectedResponse { name: other.name() }),
-        };
-
-        // attempt to decrypt it using NEW key
-        let Ok(response) = SensitiveServerResponse::decrypt(&ciphertext, &nonce, &updated_key)
-        else {
-            return Err(GatewayClientError::FatalKeyUpgradeFailure);
-        };
-
-        match response {
-            SensitiveServerResponse::KeyUpgradeAck { .. } => {
-                info!("received key upgrade acknowledgement")
-            }
-            _ => return Err(GatewayClientError::FatalKeyUpgradeFailure),
-        }
-
-        // perform in memory swap and make a copy for updating storage
-        let zeroizing_updated_key = updated_key.zeroizing_clone();
-        self.shared_key = Some(Arc::new(updated_key.into()));
-
-        Ok(zeroizing_updated_key)
-    }
-
-    async fn authenticate(&mut self) -> Result<(), GatewayClientError> {
-        let Some(shared_key) = self.shared_key.as_ref() else {
-            return Err(GatewayClientError::NoSharedKeyAvailable);
-        };
-
-        if !self.connection.is_established() {
-            return Err(GatewayClientError::ConnectionNotEstablished);
-        }
-        debug!("authenticating with gateway");
-
-        let self_address = self
-            .local_identity
-            .as_ref()
-            .public_key()
-            .derive_destination_address();
-
-        let msg = ClientControlRequest::new_authenticate(
-            self_address,
-            shared_key,
-            self.cfg.bandwidth.require_tickets,
-        )?;
-
+        msg: ClientControlRequest,
+    ) -> Result<(), GatewayClientError> {
        match self.send_websocket_message(msg).await? {
            ServerResponse::Authenticate {
                protocol_version,
@@ -587,7 +497,7 @@ impl<C, St> GatewayClient<C, St> {
                self.authenticated = status;
                self.bandwidth.update_and_maybe_log(bandwidth_remaining);

-                self.negotiated_protocol = protocol_version;
+                self.negotiated_protocol = Some(protocol_version);
                log::debug!("authenticated: {status}, bandwidth remaining: {bandwidth_remaining}");

                self.task_client.send_status_msg(Box::new(
@@ -600,6 +510,26 @@ impl<C, St> GatewayClient<C, St> {
        }
    }

+    async fn authenticate_v2(&mut self) -> Result<(), GatewayClientError> {
+        debug!("using v2 authentication");
+        let Some(shared_key) = self.shared_key.as_ref() else {
+            return Err(GatewayClientError::NoSharedKeyAvailable);
+        };
+
+        let msg = ClientControlRequest::new_authenticate_v2(shared_key, &self.local_identity)?;
+        self.send_authenticate_request_and_handle_response(msg)
+            .await
+    }
+
+    async fn authenticate(&mut self) -> Result<(), GatewayClientError> {
+        if !self.connection.is_established() {
+            return Err(GatewayClientError::ConnectionNotEstablished);
+        }
+        debug!("authenticating with gateway");
+
+        self.authenticate_v2().await
+    }
+
    /// Helper method to either call register or authenticate based on self.shared_key value
    #[instrument(skip_all,
        fields(
@@ -615,18 +545,26 @@ impl<C, St> GatewayClient<C, St> {
        }

        // 1. check gateway's protocol version
-        let supports_aes_gcm_siv = match self.get_gateway_protocol().await {
-            Ok(protocol) => protocol >= AES_GCM_SIV_PROTOCOL_VERSION,
-            Err(_) => {
-                // if we failed to send the request, it means the gateway is running the old binary,
-                // so it has reset our connection - we have to reconnect
-                self.establish_connection().await?;
-                false
-            }
-        };
+        // if we failed to get this request resolved, it means the gateway is on an old version
+        // that definitely does not support auth v2 or aes256gcm, so we bail
+        let gw_protocol = self.get_gateway_protocol().await?;
+
+        let supports_aes_gcm_siv = gw_protocol.supports_aes256_gcm_siv();
+        let supports_auth_v2 = gw_protocol.supports_authenticate_v2();

        if !supports_aes_gcm_siv {
-            warn!("this gateway is on an old version that doesn't support AES256-GCM-SIV");
+            error!("this gateway is on an old version that doesn't support AES256-GCM-SIV");
+        }
+        if !supports_aes_gcm_siv {
+            error!("this gateway is on an old version that doesn't support authentication v2");
+        }
+
+        if !supports_auth_v2 || !supports_aes_gcm_siv {
+            // we can't continue
+            return Err(GatewayClientError::IncompatibleProtocol {
+                gateway: gw_protocol,
+                current: CURRENT_PROTOCOL_VERSION,
+            });
        }

        if self.authenticated {
@@ -634,7 +572,6 @@ impl<C, St> GatewayClient<C, St> {
            return if let Some(shared_key) = &self.shared_key {
                Ok(AuthenticationResponse {
                    initial_shared_key: Arc::clone(shared_key),
-                    requires_key_upgrade: shared_key.is_legacy() && supports_aes_gcm_siv,
                })
            } else {
                Err(GatewayClientError::AuthenticationFailureWithPreexistingSharedKey)
@@ -648,17 +585,14 @@ impl<C, St> GatewayClient<C, St> {
                // if we are authenticated it means we MUST have an associated shared_key
                let shared_key = self.shared_key.as_ref().unwrap();

-                let requires_key_upgrade = shared_key.is_legacy() && supports_aes_gcm_siv;
-
                Ok(AuthenticationResponse {
                    initial_shared_key: Arc::clone(shared_key),
-                    requires_key_upgrade,
                })
            } else {
                Err(GatewayClientError::AuthenticationFailure)
            }
        } else {
-            self.register(supports_aes_gcm_siv).await?;
+            self.register().await?;

            // if registration didn't return an error, we MUST have an associated shared key
            let shared_key = self.shared_key.as_ref().unwrap();
@@ -667,7 +601,6 @@ impl<C, St> GatewayClient<C, St> {
            // so no upgrades are required
            Ok(AuthenticationResponse {
                initial_shared_key: Arc::clone(shared_key),
-                requires_key_upgrade: false,
            })
        }
    }
@@ -1045,7 +978,7 @@ impl GatewayClient<InitOnly, EphemeralCredentialStorage> {
            connection: SocketState::NotConnected,
            packet_router,
            bandwidth_controller: None,
-            stats_reporter: ClientStatsSender::new(None),
+            stats_reporter: ClientStatsSender::new(None, task_client.clone()),
            negotiated_protocol: None,
            #[cfg(unix)]
            connection_fd_callback: None,
@@ -0,0 +1,88 @@
+use crate::error::GatewayClientError;
+
+use nym_http_api_client::HickoryDnsResolver;
+#[cfg(unix)]
+use std::{
+    os::fd::{AsRawFd, RawFd},
+    sync::Arc,
+};
+use tokio::net::TcpStream;
+use tokio_tungstenite::{MaybeTlsStream, WebSocketStream};
+use tungstenite::handshake::client::Response;
+use url::{Host, Url};
+
+use std::net::SocketAddr;
+
+#[cfg(not(target_arch = "wasm32"))]
+pub(crate) async fn connect_async(
+    endpoint: &str,
+    #[cfg(unix)] connection_fd_callback: Option<Arc<dyn Fn(RawFd) + Send + Sync>>,
+) -> Result<(WebSocketStream<MaybeTlsStream<TcpStream>>, Response), GatewayClientError> {
+    use tokio::net::TcpSocket;
+
+    let resolver = HickoryDnsResolver::default();
+    let uri =
+        Url::parse(endpoint).map_err(|_| GatewayClientError::InvalidUrl(endpoint.to_owned()))?;
+    let port: u16 = uri.port_or_known_default().unwrap_or(443);
+
+    let host = uri
+        .host()
+        .ok_or(GatewayClientError::InvalidUrl(endpoint.to_owned()))?;
+
+    // Get address for tcp connection, if a domain is provided use our preferred resolver rather than
+    // the default std resolve
+    let sock_addrs: Vec<SocketAddr> = match host {
+        Host::Ipv4(addr) => vec![SocketAddr::new(addr.into(), port)],
+        Host::Ipv6(addr) => vec![SocketAddr::new(addr.into(), port)],
+        Host::Domain(domain) => {
+            // Do a DNS lookup for the domain using our custom DNS resolver
+            resolver
+                .resolve_str(domain)
+                .await?
+                .into_iter()
+                .map(|a| SocketAddr::new(a, port))
+                .collect()
+        }
+    };
+
+    let mut stream = Err(GatewayClientError::NoEndpointForConnection {
+        address: endpoint.to_owned(),
+    });
+    for sock_addr in sock_addrs {
+        let socket = if sock_addr.is_ipv4() {
+            TcpSocket::new_v4()
+        } else {
+            TcpSocket::new_v6()
+        }
+        .map_err(|err| GatewayClientError::NetworkConnectionFailed {
+            address: endpoint.to_owned(),
+            source: err.into(),
+        })?;
+
+        #[cfg(unix)]
+        if let Some(callback) = connection_fd_callback.as_ref() {
+            callback.as_ref()(socket.as_raw_fd());
+        }
+
+        match socket.connect(sock_addr).await {
+            Ok(s) => {
+                stream = Ok(s);
+                break;
+            }
+            Err(err) => {
+                stream = Err(GatewayClientError::NetworkConnectionFailed {
+                    address: endpoint.to_owned(),
+                    source: err.into(),
+                });
+                continue;
+            }
+        }
+    }
+
+    tokio_tungstenite::client_async_tls(endpoint, stream?)
+        .await
+        .map_err(|error| GatewayClientError::NetworkConnectionFailed {
+            address: endpoint.to_owned(),
+            source: error,
+        })
+}
@@ -43,8 +43,15 @@ pub enum GatewayClientError {
    #[error("connection failed: {address}: {source}")]
    NetworkConnectionFailed { address: String, source: WsError },

+    #[error("no socket address for endpoint: {address}")]
+    NoEndpointForConnection { address: String },
+
    #[error("Invalid URL: {0}")]
-    InvalidURL(String),
+    InvalidUrl(String),
+
+    #[cfg(not(target_arch = "wasm32"))]
+    #[error("resolution failed: {0}")]
+    ResolutionFailed(#[from] nym_http_api_client::HickoryDnsError),

    #[error("No shared key was provided or obtained")]
    NoSharedKeyAvailable,
@@ -107,7 +114,7 @@ pub enum GatewayClientError {
    MixnetMsgSenderFailedToSend,

    #[error("Attempted to negotiate connection with gateway using incompatible protocol version. Ours is {current} and the gateway reports {gateway:?}")]
-    IncompatibleProtocol { gateway: Option<u8>, current: u8 },
+    IncompatibleProtocol { gateway: u8, current: u8 },

    #[error(
        "The packet router hasn't been set - are you sure you started up the client correctly?"
@@ -7,9 +7,7 @@ use tracing::{error, warn};
 use tungstenite::{protocol::Message, Error as WsError};

 pub use client::{config::GatewayClientConfig, GatewayClient, GatewayConfig};
-pub use nym_gateway_requests::shared_key::{
-    LegacySharedKeys, SharedGatewayKey, SharedSymmetricKey,
-};
+pub use nym_gateway_requests::shared_key::SharedSymmetricKey;
 pub use packet_router::{
    AcknowledgementReceiver, AcknowledgementSender, MixnetMessageReceiver, MixnetMessageSender,
    PacketRouter,
@@ -47,7 +45,7 @@ pub(crate) fn cleanup_socket_messages(

 pub(crate) fn try_decrypt_binary_message(
    bin_msg: Vec<u8>,
-    shared_keys: &SharedGatewayKey,
+    shared_keys: &SharedSymmetricKey,
 ) -> Option<Vec<u8>> {
    match BinaryResponse::try_from_encrypted_tagged_bytes(bin_msg, shared_keys) {
        Ok(bin_response) => match bin_response {
@@ -9,7 +9,7 @@ use crate::{cleanup_socket_messages, try_decrypt_binary_message};
 use futures::channel::oneshot;
 use futures::stream::{SplitSink, SplitStream};
 use futures::{SinkExt, StreamExt};
-use nym_gateway_requests::shared_key::SharedGatewayKey;
+use nym_gateway_requests::shared_key::SharedSymmetricKey;
 use nym_gateway_requests::{ServerResponse, SimpleGatewayRequestsError};
 use nym_task::TaskClient;
 use si_scale::helpers::bibytes2;
@@ -63,7 +63,7 @@ pub(crate) struct PartiallyDelegatedHandle {

 struct PartiallyDelegatedRouter {
    packet_router: PacketRouter,
-    shared_key: Arc<SharedGatewayKey>,
+    shared_key: Arc<SharedSymmetricKey>,
    client_bandwidth: ClientBandwidth,

    stream_return: SplitStreamSender,
@@ -73,7 +73,7 @@ struct PartiallyDelegatedRouter {
 impl PartiallyDelegatedRouter {
    fn new(
        packet_router: PacketRouter,
-        shared_key: Arc<SharedGatewayKey>,
+        shared_key: Arc<SharedSymmetricKey>,
        client_bandwidth: ClientBandwidth,
        stream_return: SplitStreamSender,
        stream_return_requester: oneshot::Receiver<()>,
@@ -253,7 +253,7 @@ impl PartiallyDelegatedHandle {
    pub(crate) fn split_and_listen_for_mixnet_messages(
        conn: WsConn,
        packet_router: PacketRouter,
-        shared_key: Arc<SharedGatewayKey>,
+        shared_key: Arc<SharedSymmetricKey>,
        client_bandwidth: ClientBandwidth,
        shutdown: TaskClient,
    ) -> Self {
@@ -11,8 +11,7 @@ use crate::{
 use nym_api_requests::ecash::models::{
    AggregatedCoinIndicesSignatureResponse, AggregatedExpirationDateSignatureResponse,
    BatchRedeemTicketsBody, EcashBatchTicketRedemptionResponse, EcashTicketVerificationResponse,
-    IssuedTicketbooksChallengeResponse, IssuedTicketbooksForResponse, SpentCredentialsResponse,
-    VerifyEcashTicketBody,
+    IssuedTicketbooksChallengeResponse, IssuedTicketbooksForResponse, VerifyEcashTicketBody,
 };
 use nym_api_requests::ecash::{
    BlindSignRequestBody, BlindedSignatureResponse, PartialCoinIndicesSignatureResponse,
@@ -24,11 +23,12 @@ use nym_api_requests::models::{
    NymNodeDescription, RewardEstimationResponse, StakeSaturationResponse,
 };
 use nym_api_requests::models::{LegacyDescribedGateway, MixNodeBondAnnotated};
-use nym_api_requests::nym_nodes::SkimmedNode;
+use nym_api_requests::nym_nodes::{NodesByAddressesResponse, SkimmedNode};
 use nym_coconut_dkg_common::types::EpochId;
 use nym_ecash_contract_common::deposit::DepositId;
 use nym_http_api_client::UserAgent;
 use nym_network_defaults::NymNetworkDetails;
+use std::net::IpAddr;
 use time::Date;
 use url::Url;

@@ -647,13 +647,6 @@ impl NymApiClient {
            .await?)
    }

-    #[deprecated]
-    pub async fn spent_credentials_filter(
-        &self,
-    ) -> Result<SpentCredentialsResponse, ValidatorClientError> {
-        Ok(self.nym_api.double_spending_filter_v1().await?)
-    }
-
    pub async fn partial_expiration_date_signatures(
        &self,
        expiration_date: Option<Date>,
@@ -718,4 +711,11 @@ impl NymApiClient {
            .issued_ticketbooks_challenge(expiration_date, deposits)
            .await?)
    }
+
+    pub async fn nodes_by_addresses(
+        &self,
+        addresses: Vec<IpAddr>,
+    ) -> Result<NodesByAddressesResponse, ValidatorClientError> {
+        Ok(self.nym_api.nodes_by_addresses(addresses).await?)
+    }
 }
@@ -65,6 +65,12 @@ pub enum EcashApiError {
        #[from]
        source: cosmrs::ErrorReport,
    },
+
+    #[error("nym api error")]
+    NymApi {
+        #[from]
+        source: crate::ValidatorClientError,
+    },
 }

 impl TryFrom<ContractVKShare> for EcashApiClient {
@@ -15,7 +15,9 @@ use nym_api_requests::models::{
    AnnotationResponse, ApiHealthResponse, LegacyDescribedMixNode, NodePerformanceResponse,
    NodeRefreshBody, NymNodeDescription, PerformanceHistoryResponse, RewardedSetResponse,
 };
-use nym_api_requests::nym_nodes::PaginatedCachedNodesResponse;
+use nym_api_requests::nym_nodes::{
+    NodesByAddressesRequestBody, NodesByAddressesResponse, PaginatedCachedNodesResponse,
+};
 use nym_api_requests::pagination::PaginatedResponse;
 pub use nym_api_requests::{
    ecash::{
@@ -31,6 +33,7 @@ pub use nym_api_requests::{
        StakeSaturationResponse, UptimeResponse,
    },
    nym_nodes::{CachedNodesResponse, SkimmedNode},
+    NymNetworkDetailsResponse,
 };
 pub use nym_coconut_dkg_common::types::EpochId;
 use nym_contracts_common::IdentityKey;
@@ -39,6 +42,7 @@ pub use nym_http_api_client::Client;
 use nym_http_api_client::{ApiClient, NO_PARAMS};
 use nym_mixnet_contract_common::mixnode::MixNodeDetails;
 use nym_mixnet_contract_common::{GatewayBond, IdentityKeyRef, NodeId, NymNodeDetails};
+use std::net::IpAddr;
 use time::format_description::BorrowedFormatItem;
 use time::Date;
 use tracing::instrument;
@@ -849,20 +853,6 @@ pub trait NymApiClientExt: ApiClient {
        .await
    }

-    #[deprecated]
-    #[instrument(level = "debug", skip(self))]
-    async fn double_spending_filter_v1(&self) -> Result<SpentCredentialsResponse, NymAPIError> {
-        self.get_json(
-            &[
-                routes::API_VERSION,
-                routes::ECASH_ROUTES,
-                routes::DOUBLE_SPENDING_FILTER_V1,
-            ],
-            NO_PARAMS,
-        )
-        .await
-    }
-
    #[instrument(level = "debug", skip(self))]
    async fn partial_expiration_date_signatures(
        &self,
@@ -1027,6 +1017,32 @@ pub trait NymApiClientExt: ApiClient {
        )
        .await
    }
+
+    async fn nodes_by_addresses(
+        &self,
+        addresses: Vec<IpAddr>,
+    ) -> Result<NodesByAddressesResponse, NymAPIError> {
+        self.post_json(
+            &[
+                routes::API_VERSION,
+                "unstable",
+                routes::NYM_NODES_ROUTES,
+                routes::nym_nodes::BY_ADDRESSES,
+            ],
+            NO_PARAMS,
+            &NodesByAddressesRequestBody { addresses },
+        )
+        .await
+    }
+
+    #[instrument(level = "debug", skip(self))]
+    async fn get_network_details(&self) -> Result<NymNetworkDetailsResponse, NymAPIError> {
+        self.get_json(
+            &[routes::API_VERSION, routes::NETWORK, routes::DETAILS],
+            NO_PARAMS,
+        )
+        .await
+    }
 }

 #[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
@@ -13,8 +13,6 @@ pub const DETAILED: &str = "detailed";
 pub const DETAILED_UNFILTERED: &str = "detailed-unfiltered";
 pub const ACTIVE: &str = "active";
 pub const REWARDED: &str = "rewarded";
-pub const DOUBLE_SPENDING_FILTER_V1: &str = "double-spending-filter-v1";
-
 pub const ECASH_ROUTES: &str = "ecash";

 pub use ecash::*;
@@ -45,6 +43,7 @@ pub mod nym_nodes {
    pub const NYM_NODES_BONDED: &str = "bonded";
    pub const NYM_NODES_REWARDED_SET: &str = "rewarded-set";
    pub const NYM_NODES_REFRESH_DESCRIBED: &str = "refresh-described";
+    pub const BY_ADDRESSES: &str = "by-addresses";
 }

 pub const STATUS_ROUTES: &str = "status";
@@ -67,6 +66,8 @@ pub const STAKE_SATURATION: &str = "stake-saturation";
 pub const INCLUSION_CHANCE: &str = "inclusion-probability";
 pub const SUBMIT_GATEWAY: &str = "submit-gateway-monitoring-results";
 pub const SUBMIT_NODE: &str = "submit-node-monitoring-results";
-pub const PERFORMANCE: &str = "performance";

 pub const SERVICE_PROVIDERS: &str = "services";
+
+pub const DETAILS: &str = "details";
+pub const NETWORK: &str = "network";
@@ -28,7 +28,6 @@ use nym_network_defaults::{ChainDetails, NymNetworkDetails};
 use serde::{de::DeserializeOwned, Serialize};
 use std::fmt::Debug;
 use std::time::SystemTime;
-use tendermint_rpc::endpoint::block::Response as BlockResponse;
 use tendermint_rpc::endpoint::*;
 use tendermint_rpc::{Error as TendermintRpcError, Order};
 use url::Url;
@@ -63,6 +62,7 @@ pub use cw3;
 pub use cw4;
 pub use cw_controllers;
 pub use fee::{gas_price::GasPrice, GasAdjustable, GasAdjustment};
+pub use tendermint_rpc::endpoint::block::Response as BlockResponse;
 pub use tendermint_rpc::{
    endpoint::{tx::Response as TxResponse, validators::Response as ValidatorResponse},
    query::Query,
@@ -25,15 +25,6 @@ pub fn in6addr_any_init() -> IpAddr {
    IpAddr::V6(Ipv6Addr::UNSPECIFIED)
 }

-/// Helper for providing binding warnings if node tries to bind to any of those
-pub const SPECIAL_ADDRESSES: &[IpAddr] = &[
-    IpAddr::V4(Ipv4Addr::LOCALHOST),
-    IpAddr::V4(Ipv4Addr::UNSPECIFIED),
-    IpAddr::V4(Ipv4Addr::BROADCAST),
-    IpAddr::V6(Ipv6Addr::LOCALHOST),
-    IpAddr::V6(Ipv6Addr::UNSPECIFIED),
-];
-
 // TODO: is it really part of 'Config'?
 pub trait OptionalSet {
    /// If the value is available (i.e. `Some`), the provided closure is applied.
@@ -8,81 +8,81 @@ use thiserror::Error;

 #[derive(Error, Debug, PartialEq)]
 pub enum VestingContractError {
-    #[error("VESTING ({}): {0}", line!())]
+    #[error("VESTING ({l}): {0}", l = line!())]
    Std(#[from] StdError),

    #[error("VESTING: {0}")]
    OverflowError(#[from] OverflowError),

-    #[error("VESTING ({}): Account does not exist - {0}", line!())]
+    #[error("VESTING ({l}): Account does not exist - {0}", l = line!())]
    NoAccountForAddress(String),

-    #[error("VESTING ({}): Only admin can perform this action, {0} is not admin", line!())]
+    #[error("VESTING ({l}): Only admin can perform this action, {0} is not admin", l = line!())]
    NotAdmin(String),

-    #[error("VESTING ({}): Balance not found for existing account ({0}), this is a bug", line!())]
+    #[error("VESTING ({l}): Balance not found for existing account ({0}), this is a bug", l = line!())]
    NoBalanceForAddress(String),

-    #[error("VESTING ({}): Insufficient balance for address {0} -> {1}", line!())]
+    #[error("VESTING ({l}): Insufficient balance for address {0} -> {1}", l = line!())]
    InsufficientBalance(String, u128),

-    #[error("VESTING ({}): Insufficient spendable balance for address {0} -> {1}", line!())]
+    #[error("VESTING ({l}): Insufficient spendable balance for address {0} -> {1}", l = line!())]
    InsufficientSpendable(String, u128),

    #[error(
-    "VESTING ({}):Only delegation owner can perform delegation actions, {0} is not the delegation owner"
-    , line!())]
+    "VESTING ({l}):Only delegation owner can perform delegation actions, {0} is not the delegation owner"
+    , l = line!())]
    NotDelegate(String),

-    #[error("VESTING ({}): Total vesting amount is inprobably low -> {0}, this is likely an error", line!())]
+    #[error("VESTING ({l}): Total vesting amount is inprobably low -> {0}, this is likely an error", l = line!())]
    ImprobableVestingAmount(u128),

-    #[error("VESTING ({}): Address {0} has already bonded a node", line!())]
+    #[error("VESTING ({l}): Address {0} has already bonded a node", l = line!())]
    AlreadyBonded(String),

-    #[error("VESTING ({}): Received empty funds vector", line!())]
+    #[error("VESTING ({l}): Received empty funds vector", l = line!())]
    EmptyFunds,

-    #[error("VESTING ({}): Received wrong denom: {0}, expected {1}", line!())]
+    #[error("VESTING ({l}): Received wrong denom: {0}, expected {1}", l = line!())]
    WrongDenom(String, String),

-    #[error("VESTING ({}): Received multiple denoms, expected 1", line!())]
+    #[error("VESTING ({l}): Received multiple denoms, expected 1", l = line!())]
    MultipleDenoms,

-    #[error("VESTING ({}): No delegations found for account {0}, mix_identity {1}", line!())]
+    #[error("VESTING ({l}): No delegations found for account {0}, mix_identity {1}", l = line!())]
    NoSuchDelegation(Addr, NodeId),

-    #[error("VESTING ({}): Only mixnet contract can perform this operation, got {0}", line!())]
+    #[error("VESTING ({l}): Only mixnet contract can perform this operation, got {0}", l = line!())]
    NotMixnetContract(Addr),

-    #[error("VESTING ({}): Calculation underflowed", line!())]
+    #[error("VESTING ({l}): Calculation underflowed", l = line!())]
    Underflow,

-    #[error("VESTING ({}): No bond found for account {0}", line!())]
+    #[error("VESTING ({l}): No bond found for account {0}", l = line!())]
    NoBondFound(String),

    #[error("VESTING: Attempted to reduce mixnode bond pledge below zero! The current pledge is {current} and we attempted to reduce it by {decrease_by}.")]
    InvalidBondPledgeReduction { current: Coin, decrease_by: Coin },

-    #[error("VESTING ({}): Action can only be executed by account owner -> {0}", line!())]
+    #[error("VESTING ({l}): Action can only be executed by account owner -> {0}", l = line!())]
    NotOwner(String),

-    #[error("VESTING ({}): Invalid address: {0}", line!())]
+    #[error("VESTING ({l}): Invalid address: {0}", l = line!())]
    InvalidAddress(String),

-    #[error("VESTING ({}): Account already exists: {0}", line!())]
+    #[error("VESTING ({l}): Account already exists: {0}", l = line!())]
    AccountAlreadyExists(String),

-    #[error("VESTING ({}): Staking account already exists: {0}", line!())]
+    #[error("VESTING ({l}): Staking account already exists: {0}", l = line!())]
    StakingAccountAlreadyExists(String),

-    #[error("VESTING ({}): Too few coins sent for vesting account creation, sent {sent}, need at least {need}", line!())]
+    #[error("VESTING ({l}): Too few coins sent for vesting account creation, sent {sent}, need at least {need}", l = line!())]
    MinVestingFunds { sent: u128, need: u128 },

-    #[error("VESTING ({}): Maximum amount of locked coins has already been pledged: {current}, cap is {cap}", line!())]
+    #[error("VESTING ({l}): Maximum amount of locked coins has already been pledged: {current}, cap is {cap}", l = line!())]
    LockedPledgeCapReached { current: Uint128, cap: Uint128 },

-    #[error("VESTING: ({}: Account owned by {owner} has unpopulated vesting periods!", line!())]
+    #[error("VESTING: ({l}: Account owned by {owner} has unpopulated vesting periods!", l = line!())]
    UnpopulatedVestingPeriods { owner: Addr },

    #[error("VESTING: Vesting account associated with {0} already exists, only addresses with not existing vesting accounts can be added as staking addresses")]
@@ -26,7 +26,6 @@ nym-api-requests = { path = "../../nym-api/nym-api-requests" }
 nym-credentials = { path = "../credentials" }
 nym-credentials-interface = { path = "../credentials-interface" }
 nym-ecash-contract-common = { path = "../cosmwasm-smart-contracts/ecash-contract" }
-nym-ecash-double-spending = { path = "../ecash-double-spending" }
 nym-gateway-requests = { path = "../gateway-requests" }
 nym-gateway-storage = { path = "../gateway-storage" }
 nym-task = { path = "../task" }
@@ -13,6 +13,7 @@ use nym_api_requests::constants::MIN_BATCH_REDEMPTION_DELAY;
 use nym_api_requests::ecash::models::{BatchRedeemTicketsBody, VerifyEcashTicketBody};
 use nym_credentials_interface::Bandwidth;
 use nym_credentials_interface::{ClientTicket, TicketType};
+use nym_validator_client::coconut::EcashApiError;
 use nym_validator_client::nym_api::EpochId;
 use nym_validator_client::nyxd::contract_traits::{
    EcashSigningClient, MultisigQueryClient, MultisigSigningClient, PagedMultisigQueryClient,
@@ -352,7 +353,9 @@ impl CredentialHandler {
            }
            Err(err) => {
                error!("failed to send ticket {ticket_id} for verification to ecash signer '{client}': {err}. if we don't reach quorum, we'll retry later");
-                Ok(false)
+                Err(EcashTicketError::ApiFailure(EcashApiError::NymApi {
+                    source: err,
+                }))
            }
        }
    }
@@ -24,6 +24,7 @@ ed25519-dalek = { workspace = true, features = ["rand_core"], optional = true }
 rand = { workspace = true, optional = true }
 serde_bytes = { workspace = true, optional = true }
 serde = { workspace = true, features = ["derive"], optional = true }
+sha2 = { workspace = true, optional = true }
 subtle-encoding = { workspace = true, features = ["bech32-preview"] }
 thiserror = { workspace = true }
 zeroize = { workspace = true, optional = true, features = ["zeroize_derive"] }
@@ -36,11 +37,13 @@ nym-pemstore = { path = "../../common/pemstore", version = "0.3.0" }
 rand_chacha = { workspace = true }

 [features]
-default = ["sphinx"]
+default = []
 aead = ["dep:aead", "aead/std", "aes-gcm-siv", "generic-array"]
 serde = ["dep:serde", "serde_bytes", "ed25519-dalek/serde", "x25519-dalek/serde"]
 asymmetric = ["x25519-dalek", "ed25519-dalek", "zeroize"]
-hashing = ["blake3", "digest", "hkdf", "hmac", "generic-array"]
+hashing = ["blake3", "digest", "hkdf", "hmac", "generic-array", "sha2"]
 stream_cipher = ["aes", "ctr", "cipher", "generic-array"]
 sphinx = ["nym-sphinx-types/sphinx"]
-outfox = ["nym-sphinx-types/outfox"]
+
+[lints]
+workspace = true
@@ -202,6 +202,18 @@ impl PemStorableKey for PublicKey {
    }
 }

+impl From<x25519_dalek::PublicKey> for PublicKey {
+    fn from(public_key: x25519_dalek::PublicKey) -> Self {
+        PublicKey(public_key)
+    }
+}
+
+impl From<PublicKey> for x25519_dalek::PublicKey {
+    fn from(public_key: PublicKey) -> Self {
+        public_key.0
+    }
+}
+
 #[derive(Zeroize, ZeroizeOnDrop)]
 pub struct PrivateKey(x25519_dalek::StaticSecret);

@@ -308,109 +320,15 @@ impl PemStorableKey for PrivateKey {
    }
 }

-// compatibility with sphinx keys:
-#[cfg(feature = "sphinx")]
-impl From<PublicKey> for nym_sphinx_types::PublicKey {
-    fn from(key: PublicKey) -> Self {
-        nym_sphinx_types::PublicKey::from(key.to_bytes())
+impl From<x25519_dalek::StaticSecret> for PrivateKey {
+    fn from(secret: x25519_dalek::StaticSecret) -> Self {
+        PrivateKey(secret)
    }
 }

-#[cfg(feature = "sphinx")]
-impl<'a> From<&'a PublicKey> for nym_sphinx_types::PublicKey {
-    fn from(key: &'a PublicKey) -> Self {
-        nym_sphinx_types::PublicKey::from((*key).to_bytes())
-    }
-}
-
-#[cfg(feature = "sphinx")]
-impl From<nym_sphinx_types::PublicKey> for PublicKey {
-    fn from(pub_key: nym_sphinx_types::PublicKey) -> Self {
-        Self(x25519_dalek::PublicKey::from(*pub_key.as_bytes()))
-    }
-}
-
-#[cfg(feature = "sphinx")]
-impl From<PrivateKey> for nym_sphinx_types::PrivateKey {
-    fn from(key: PrivateKey) -> Self {
-        nym_sphinx_types::PrivateKey::from(key.to_bytes())
-    }
-}
-
-#[cfg(feature = "sphinx")]
-impl<'a> From<&'a PrivateKey> for nym_sphinx_types::PrivateKey {
-    fn from(key: &'a PrivateKey) -> Self {
-        nym_sphinx_types::PrivateKey::from(key.to_bytes())
-    }
-}
-
-#[cfg(feature = "sphinx")]
-impl From<nym_sphinx_types::PrivateKey> for PrivateKey {
-    fn from(private_key: nym_sphinx_types::PrivateKey) -> Self {
-        let private_key_bytes = private_key.to_bytes();
-        assert_eq!(private_key_bytes.len(), PRIVATE_KEY_SIZE);
-        Self::from_bytes(&private_key_bytes).unwrap()
-    }
-}
-
-#[cfg(test)]
-mod sphinx_key_conversion {
-    use super::*;
-    use rand_chacha::rand_core::SeedableRng;
-    use rand_chacha::ChaCha20Rng;
-
-    pub(super) fn test_rng() -> ChaCha20Rng {
-        let dummy_seed = [42u8; 32];
-        ChaCha20Rng::from_seed(dummy_seed)
-    }
-
-    const NUM_ITERATIONS: usize = 100;
-
-    #[test]
-    fn works_for_forward_conversion() {
-        let mut rng = test_rng();
-
-        for _ in 0..NUM_ITERATIONS {
-            let keys = KeyPair::new(&mut rng);
-            let private = &keys.private_key;
-            let public = &keys.public_key;
-
-            let dummy_remote = KeyPair::new(&mut rng);
-            let dh1 = private.diffie_hellman(&dummy_remote.public_key);
-
-            let public_bytes = public.to_bytes();
-
-            let sphinx_private: nym_sphinx_types::PrivateKey = private.into();
-            let recovered_private = PrivateKey::from(sphinx_private);
-
-            let dh2 = recovered_private.diffie_hellman(&dummy_remote.public_key);
-
-            let sphinx_public: nym_sphinx_types::PublicKey = public.into();
-            let recovered_public = PublicKey::from(sphinx_public);
-            assert_eq!(public_bytes, recovered_public.to_bytes());
-
-            // even though the byte representation of the private key changed, the resultant DH is the same
-            // which is what matters
-            assert_eq!(dh1, dh2);
-        }
-    }
-
-    #[test]
-    fn works_for_backward_conversion() {
-        for _ in 0..NUM_ITERATIONS {
-            let (sphinx_private, sphinx_public) = nym_sphinx_types::crypto::keygen();
-
-            let private_bytes = sphinx_private.to_bytes();
-            let public_bytes = sphinx_public.as_bytes();
-
-            let private: PrivateKey = sphinx_private.into();
-            let recovered_sphinx_private: nym_sphinx_types::PrivateKey = private.into();
-
-            let public: PublicKey = sphinx_public.into();
-            let recovered_sphinx_public: nym_sphinx_types::PublicKey = public.into();
-            assert_eq!(private_bytes, recovered_sphinx_private.to_bytes());
-            assert_eq!(public_bytes, recovered_sphinx_public.as_bytes());
-        }
+impl AsRef<x25519_dalek::StaticSecret> for PrivateKey {
+    fn as_ref(&self) -> &x25519_dalek::StaticSecret {
+        &self.0
    }
 }

@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0

 pub use ed25519_dalek::SignatureError;
-use ed25519_dalek::{Signer, SigningKey};
+use ed25519_dalek::{SecretKey, Signer, SigningKey};
 pub use ed25519_dalek::{Verifier, PUBLIC_KEY_LENGTH, SECRET_KEY_LENGTH, SIGNATURE_LENGTH};
 use nym_pemstore::traits::{PemStorableKey, PemStorableKeyPair};
 use std::fmt::{self, Debug, Display, Formatter};
@@ -18,7 +18,7 @@ pub mod serde_helpers;
 use nym_sphinx_types::{DestinationAddressBytes, DESTINATION_ADDRESS_LENGTH};

 #[cfg(feature = "rand")]
-use rand::{CryptoRng, RngCore};
+use rand::{CryptoRng, Rng, RngCore};
 #[cfg(feature = "serde")]
 use serde::de::Error as SerdeError;
 #[cfg(feature = "serde")]
@@ -62,16 +62,33 @@ pub struct KeyPair {
    // nothing secret about public key
    #[zeroize(skip)]
    public_key: PublicKey,
+
+    #[zeroize(skip)]
+    index: u32,
 }

+/// All keys will always have an index field populated this is to prevent anyone from figuring out if
+/// the keys are derived or random, and alter their behaviour based on that.
 impl KeyPair {
    #[cfg(feature = "rand")]
    pub fn new<R: RngCore + CryptoRng>(rng: &mut R) -> Self {
+        let index = rng.gen();
        let ed25519_signing_key = ed25519_dalek::SigningKey::generate(rng);

        KeyPair {
            private_key: PrivateKey(ed25519_signing_key.to_bytes()),
            public_key: PublicKey(ed25519_signing_key.verifying_key()),
+            index,
+        }
+    }
+
+    pub fn from_secret(secret: SecretKey, index: u32) -> Self {
+        let ed25519_signing_key = SigningKey::from(secret);
+
+        KeyPair {
+            private_key: PrivateKey(ed25519_signing_key.to_bytes()),
+            public_key: PublicKey(ed25519_signing_key.verifying_key()),
+            index,
        }
    }

@@ -87,15 +104,31 @@ impl KeyPair {
        Ok(KeyPair {
            private_key: PrivateKey::from_bytes(priv_bytes)?,
            public_key: PublicKey::from_bytes(pub_bytes)?,
+            index: fake_index(pub_bytes),
        })
    }
 }

+/// Reduces a byte slice into a u32 value by XOR-ing all its bytes into a 4-byte accumulator.
+/// The process iterates over every byte in the input slice, XOR-ing each one into a slot based on its index modulo 4.
+/// If the input slice contains fewer than 4 bytes, the remaining positions in the accumulator remain zero.
+/// Finally, the accumulator is interpreted in big-endian order to produce the resulting u32.
+/// Index is used to verify deterministic identity key, master key and salt are also requried for verification.
+fn fake_index(input: &[u8]) -> u32 {
+    let mut accumulator = [0u8; 4];
+    for (i, &byte) in input.iter().enumerate() {
+        accumulator[i % 4] ^= byte;
+    }
+    u32::from_be_bytes(accumulator)
+}
+
 impl From<PrivateKey> for KeyPair {
    fn from(private_key: PrivateKey) -> Self {
+        let public_key = (&private_key).into();
        KeyPair {
-            public_key: (&private_key).into(),
+            public_key,
            private_key,
+            index: fake_index(public_key.to_bytes().as_ref()),
        }
    }
 }
@@ -115,6 +148,7 @@ impl PemStorableKeyPair for KeyPair {
        KeyPair {
            private_key,
            public_key,
+            index: fake_index(public_key.to_bytes().as_ref()),
        }
    }
 }
@@ -8,6 +8,10 @@ use hkdf::{
    },
    Hkdf,
 };
+use sha2::{Sha256, Sha512};
+
+pub use hkdf::InvalidLength;
+use zeroize::ZeroizeOnDrop;

 /// Perform HKDF `extract` then `expand` as a single step.
 pub fn extract_then_expand<D>(
@@ -28,3 +32,80 @@ where

    Ok(okm)
 }
+
+/// `DerivationMaterial` encapsulates parameters for deterministic key derivation using
+/// HKDF (SHA-512).
+///
+/// It consists of:
+///   - A master key (`master_key`): the base secret.
+///   - An index (`index`): ensures unique derivations.
+///   - A salt (`salt`): adds additional uniqueness, should be application specific.
+///
+/// Use the `derive_secret()` method to generate a 32-byte secret. To prepare for a new derivation,
+/// call the `next()` method, which increments the index. **It is the caller's responsibility to
+/// track and persist the derivation index if keys need to be rederived.**
+///
+/// # Example
+///
+/// ```rust
+/// use nym_crypto::hkdf::DerivationMaterial;
+///
+/// let master_key = [0u8; 32]; // your secret master key
+/// let salt = b"unique-salt-value";
+/// let material = DerivationMaterial::new(master_key, 0, salt);
+///
+/// // Derive a secret
+/// let secret = material.derive_secret().expect("Failed to derive secret");
+///
+/// // Prepare for the next derivation
+/// let next_material = material.next();
+/// ```
+#[derive(ZeroizeOnDrop)]
+pub struct DerivationMaterial {
+    master_key: [u8; 32],
+    index: u32,
+    salt: Vec<u8>,
+}
+
+impl DerivationMaterial {
+    pub fn index(&self) -> u32 {
+        self.index
+    }
+
+    pub fn salt(&self) -> &[u8] {
+        &self.salt
+    }
+
+    /// Derives a 32-byte seed from a master seed and an index using HKDF (with SHA-512).
+    ///
+    /// The `salt` and the use of the index (as info) bind this derivation to an application/client.
+    pub fn derive_secret(&self) -> Result<[u8; 32], hkdf::InvalidLength> {
+        let salt = &self.salt;
+        let info = self.index.to_be_bytes(); // Use the index as info
+        let hk = Hkdf::<Sha512>::new(Some(salt), &self.master_key);
+        let mut okm = [0u8; 32];
+        hk.expand(&info, &mut okm)?;
+        Ok(okm)
+    }
+
+    pub fn new<T: AsRef<[u8]>>(master_key: T, index: u32, salt: &[u8]) -> Self {
+        // Coerce master_key to [u8; 32]
+        let mut hasher = Sha256::new();
+        hasher.update(master_key.as_ref());
+        let master_key = hasher.finalize().into();
+
+        Self {
+            master_key,
+            index,
+            salt: salt.to_vec(),
+        }
+    }
+
+    pub fn next(&self) -> Self {
+        Self {
+            master_key: self.master_key,
+            index: self.index + 1,
+            salt: self.salt.clone(),
+        }
+    }
+}
@@ -16,8 +16,11 @@ pub fn compute_keyed_hmac<D>(key: &[u8], data: &[u8]) -> HmacOutput<D>
 where
    D: Digest + BlockSizeUser,
 {
-    let mut hmac = SimpleHmac::<D>::new_from_slice(key)
-        .expect("HMAC was instantiated with a key of an invalid size!");
+    // SAFETY: hmac is fine with keys of any size; if they're smaller than the block size of the underlying
+    // digest, they're padded with 0. if they're larger they're hashed and padded
+    // the reason for `Result` return type is due to the trait definition
+    #[allow(clippy::unwrap_used)]
+    let mut hmac = SimpleHmac::<D>::new_from_slice(key).unwrap();
    hmac.update(data);
    hmac.finalize()
 }
@@ -27,8 +30,11 @@ pub fn recompute_keyed_hmac_and_verify_tag<D>(key: &[u8], data: &[u8], tag: &[u8
 where
    D: Digest + BlockSizeUser,
 {
-    let mut hmac = SimpleHmac::<D>::new_from_slice(key)
-        .expect("HMAC was instantiated with a key of an invalid size!");
+    // SAFETY: hmac is fine with keys of any size; if they're smaller than the block size of the underlying
+    // digest, they're padded with 0. if they're larger they're hashed and padded
+    // the reason for `Result` return type is due to the trait definition
+    #[allow(clippy::unwrap_used)]
+    let mut hmac = SimpleHmac::<D>::new_from_slice(key).unwrap();
    hmac.update(data);

    let tag_arr = Output::<D>::from_slice(tag);
@@ -27,12 +27,16 @@ where
    // after performing diffie-hellman we don't care about the private component anymore
    let dh_result = ephemeral_keypair.private_key().diffie_hellman(remote_key);

-    // there is no reason for this to fail as our okm is expected to be only C::KeySize bytes
+    // SAFETY: while this is a relatively weak assumption, it's unlikely that any stream cipher has `C::key_size()`
+    // larger than 255 * chunk_size of the digest (so for example keys larger than 8160 bytes if sh256 is used)
+    #[allow(clippy::expect_used)]
    let okm = hkdf::extract_then_expand::<D>(None, &dh_result, None, C::key_size())
        .expect("somehow too long okm was provided");

-    let derived_shared_key =
-        Key::<C>::from_exact_iter(okm).expect("okm was expanded to incorrect length!");
+    // SAFETY: the generated okm has exactly `C::key_size()` elements,
+    // so this call is safe
+    #[allow(clippy::unwrap_used)]
+    let derived_shared_key = Key::<C>::from_exact_iter(okm).unwrap();

    (ephemeral_keypair, derived_shared_key)
 }
@@ -48,9 +52,14 @@ where
 {
    let dh_result = local_key.diffie_hellman(remote_key);

-    // there is no reason for this to fail as our okm is expected to be only C::KeySize bytes
+    // SAFETY: while this is a relatively weak assumption, it's unlikely that any stream cipher has `C::key_size()`
+    // larger than 255 * chunk_size of the digest (so for example keys larger than 8160 bytes if sh256 is used)
+    #[allow(clippy::expect_used)]
    let okm = hkdf::extract_then_expand::<D>(None, &dh_result, None, C::key_size())
        .expect("somehow too long okm was provided");

-    Key::<C>::from_exact_iter(okm).expect("okm was expanded to incorrect length!")
+    // SAFETY: the generated okm has exactly `C::key_size()` elements,
+    // so this call is safe
+    #[allow(clippy::unwrap_used)]
+    Key::<C>::from_exact_iter(okm).unwrap()
 }
@@ -60,20 +60,15 @@ where
    Iv::<C>::default()
 }

-pub fn iv_from_slice<C>(b: &[u8]) -> &IV<C>
+pub fn try_iv_from_slice<C>(b: &[u8]) -> Option<&IV<C>>
 where
    C: IvSizeUser,
 {
    if b.len() != C::iv_size() {
-        // `from_slice` would have caused a panic about this issue anyway.
-        // Now we at least have slightly more information
-        panic!(
-            "Tried to convert {} bytes to IV. Expected {}",
-            b.len(),
-            C::iv_size()
-        )
+        None
+    } else {
+        Some(IV::<C>::from_slice(b))
    }
-    IV::<C>::from_slice(b)
 }

 // TODO: there's really no way to use more parts of the keystream if it was required at some point.
@@ -1,14 +0,0 @@
-[package]
-name = "nym-ecash-double-spending"
-version = "0.1.0"
-authors.workspace = true
-repository.workspace = true
-homepage.workspace = true
-documentation.workspace = true
-edition.workspace = true
-license.workspace = true
-
-[dependencies]
-bit-vec = { workspace = true }
-bloomfilter = { workspace = true }
-nym-network-defaults = { path = "../network-defaults" }
@@ -1,136 +0,0 @@
-// Copyright 2024 - Nym Technologies SA <contact@nymtech.net>
-// SPDX-License-Identifier: Apache-2.0
-
-use bit_vec::BitVec;
-use bloomfilter::Bloom;
-use nym_network_defaults::{BloomfilterParameters, ECASH_DS_BLOOMFILTER_PARAMS};
-
-pub struct DoubleSpendingFilter {
-    params: BloomfilterParameters,
-    inner: Bloom<Vec<u8>>,
-}
-
-impl Default for DoubleSpendingFilter {
-    fn default() -> Self {
-        DoubleSpendingFilter::new_empty_ecash()
-    }
-}
-
-pub fn bloom_from_params<T>(params: &BloomfilterParameters, bitvec: BitVec) -> Bloom<Vec<T>> {
-    assert_eq!(params.bitmap_size, bitvec.len() as u64);
-
-    Bloom::from_bit_vec(
-        bitvec,
-        params.bitmap_size,
-        params.num_hashes,
-        params.sip_keys,
-    )
-}
-
-impl DoubleSpendingFilter {
-    pub fn new_empty(params: BloomfilterParameters) -> Self {
-        let bitvec = BitVec::from_elem(params.bitmap_size as usize, false);
-        DoubleSpendingFilter {
-            inner: bloom_from_params(&params, bitvec),
-            params,
-        }
-    }
-
-    pub fn params(&self) -> BloomfilterParameters {
-        self.params
-    }
-
-    pub fn rebuild(&self) -> DoubleSpendingFilterBuilder {
-        DoubleSpendingFilterBuilder::new(self.params)
-    }
-
-    pub fn reset(&mut self) {
-        self.inner.clear()
-    }
-
-    pub fn new_empty_ecash() -> Self {
-        DoubleSpendingFilter::new_empty(ECASH_DS_BLOOMFILTER_PARAMS)
-    }
-
-    pub fn builder(params: BloomfilterParameters) -> DoubleSpendingFilterBuilder {
-        DoubleSpendingFilterBuilder::new(params)
-    }
-
-    pub fn from_bytes(params: BloomfilterParameters, bitmap: &[u8]) -> Self {
-        DoubleSpendingFilter {
-            inner: bloom_from_params(&params, BitVec::from_bytes(bitmap)),
-            params,
-        }
-    }
-
-    pub fn replace_bitvec(&mut self, new: BitVec) {
-        self.inner = bloom_from_params(&self.params, new)
-    }
-
-    pub fn dump_bitmap(&self) -> Vec<u8> {
-        self.inner.bitmap()
-    }
-
-    pub fn set(&mut self, b: &Vec<u8>) {
-        self.inner.set(b);
-    }
-
-    pub fn check(&self, b: &Vec<u8>) -> bool {
-        self.inner.check(b)
-    }
-}
-
-pub struct DoubleSpendingFilterBuilder {
-    params: BloomfilterParameters,
-    bit_vec_builder: Option<BitVecBuilder>,
-}
-
-impl DoubleSpendingFilterBuilder {
-    pub fn new(params: BloomfilterParameters) -> Self {
-        DoubleSpendingFilterBuilder {
-            params,
-            bit_vec_builder: None,
-        }
-    }
-
-    pub fn add_bytes(&mut self, b: &[u8]) -> bool {
-        match &mut self.bit_vec_builder {
-            None => {
-                self.bit_vec_builder = Some(BitVecBuilder::new(b));
-                true
-            }
-            Some(builder) => builder.add_bytes(b),
-        }
-    }
-
-    pub fn build(self) -> DoubleSpendingFilter {
-        match self.bit_vec_builder {
-            None => DoubleSpendingFilter::new_empty(self.params),
-            Some(builder) => DoubleSpendingFilter {
-                inner: bloom_from_params(&self.params, builder.finish()),
-                params: self.params,
-            },
-        }
-    }
-}
-
-pub struct BitVecBuilder(BitVec);
-
-impl BitVecBuilder {
-    pub fn new(initial_bitmap: &[u8]) -> Self {
-        BitVecBuilder(BitVec::from_bytes(initial_bitmap))
-    }
-
-    pub fn add_bytes(&mut self, b: &[u8]) -> bool {
-        let add = BitVec::from_bytes(b);
-        if self.0.len() != add.len() {
-            return false;
-        }
-        self.0.or(&add);
-        true
-    }
-
-    pub fn finish(self) -> BitVec {
-        self.0
-    }
-}
@@ -20,11 +20,14 @@ serde_json = { workspace = true }
 strum = { workspace = true }
 thiserror = { workspace = true }
 tracing = { workspace = true, features = ["log"] }
+time = { workspace = true }
+subtle = { workspace = true }
 zeroize = { workspace = true }

 nym-crypto = { path = "../crypto", features = ["aead", "hashing"] }
 nym-pemstore = { path = "../pemstore" }
 nym-sphinx = { path = "../nymsphinx" }
+nym-serde-helpers = { path = "../serde-helpers", features = ["base64"] }
 nym-task = { path = "../task" }

 nym-credentials = { path = "../credentials" }
@@ -1,67 +0,0 @@
-// Copyright 2020-2024 - Nym Technologies SA <contact@nymtech.net>
-// SPDX-License-Identifier: Apache-2.0
-
-use crate::shared_key::{SharedGatewayKey, SharedKeyUsageError};
-use nym_sphinx::DestinationAddressBytes;
-use thiserror::Error;
-
-/// Replacement for what used to be an `AuthToken`.
-///
-/// Replacement for what used to be an `AuthToken`. We used to be generating an `AuthToken` based on
-/// local secret and remote address in order to allow for authentication. Due to changes in registration
-/// and the fact we are deriving a shared key, we are encrypting remote's address with the previously
-/// derived shared key. If the value is as expected, then authentication is successful.
-#[derive(Debug, PartialEq, Eq, Hash, Clone)]
-// this is no longer constant size due to the differences in ciphertext between aes128ctr and aes256gcm-siv (inclusion of tag)
-pub struct EncryptedAddressBytes(Vec<u8>);
-
-#[derive(Debug, Error)]
-pub enum EncryptedAddressConversionError {
-    #[error("Failed to decode the encrypted address - {0}")]
-    DecodeError(#[from] bs58::decode::Error),
-}
-
-impl EncryptedAddressBytes {
-    pub fn new(
-        address: &DestinationAddressBytes,
-        key: &SharedGatewayKey,
-        nonce: &[u8],
-    ) -> Result<Self, SharedKeyUsageError> {
-        let ciphertext = key.encrypt_naive(address.as_bytes_ref(), Some(nonce))?;
-
-        Ok(EncryptedAddressBytes(ciphertext))
-    }
-
-    pub fn verify(
-        &self,
-        address: &DestinationAddressBytes,
-        key: &SharedGatewayKey,
-        nonce: &[u8],
-    ) -> bool {
-        let Ok(reconstructed) = Self::new(address, key, nonce) else {
-            return false;
-        };
-        self == &reconstructed
-    }
-
-    pub fn as_bytes(&self) -> &[u8] {
-        &self.0
-    }
-
-    pub fn try_from_base58_string<S: Into<String>>(
-        val: S,
-    ) -> Result<Self, EncryptedAddressConversionError> {
-        let decoded = bs58::decode(val.into()).into_vec()?;
-        Ok(EncryptedAddressBytes(decoded))
-    }
-
-    pub fn to_base58_string(self) -> String {
-        bs58::encode(self.0).into_string()
-    }
-}
-
-impl From<EncryptedAddressBytes> for String {
-    fn from(val: EncryptedAddressBytes) -> Self {
-        val.to_base58_string()
-    }
-}
@@ -1,4 +0,0 @@
-// Copyright 2020 - Nym Technologies SA <contact@nymtech.net>
-// SPDX-License-Identifier: Apache-2.0
-
-pub mod encrypted_address;
@@ -2,24 +2,17 @@
 // SPDX-License-Identifier: Apache-2.0

 pub use nym_crypto::generic_array;
-use nym_crypto::OutputSizeUser;
-use nym_sphinx::params::GatewayIntegrityHmacAlgorithm;

 pub use types::*;

-pub mod authentication;
 pub mod models;
 pub mod registration;
 pub mod shared_key;
 pub mod types;

-pub use shared_key::helpers::SymmetricKey;
-pub use shared_key::legacy::{LegacySharedKeySize, LegacySharedKeys};
-pub use shared_key::{
-    SharedGatewayKey, SharedKeyConversionError, SharedKeyUsageError, SharedSymmetricKey,
-};
+pub use shared_key::{SharedKeyConversionError, SharedKeyUsageError, SharedSymmetricKey};

-pub const CURRENT_PROTOCOL_VERSION: u8 = AES_GCM_SIV_PROTOCOL_VERSION;
+pub const CURRENT_PROTOCOL_VERSION: u8 = AUTHENTICATE_V2_PROTOCOL_VERSION;

 /// Defines the current version of the communication protocol between gateway and clients.
 /// It has to be incremented for any breaking change.
@@ -27,10 +20,23 @@ pub const CURRENT_PROTOCOL_VERSION: u8 = AES_GCM_SIV_PROTOCOL_VERSION;
 // 1 - initial release
 // 2 - changes to client credentials structure
 // 3 - change to AES-GCM-SIV and non-zero IVs
+// 4 - introduction of v2 authentication protocol to prevent reply attacks
 pub const INITIAL_PROTOCOL_VERSION: u8 = 1;
 pub const CREDENTIAL_UPDATE_V2_PROTOCOL_VERSION: u8 = 2;
 pub const AES_GCM_SIV_PROTOCOL_VERSION: u8 = 3;
+pub const AUTHENTICATE_V2_PROTOCOL_VERSION: u8 = 4;

-// TODO: could using `Mac` trait here for OutputSize backfire?
-// Should hmac itself be exposed, imported and used instead?
-pub type LegacyGatewayMacSize = <GatewayIntegrityHmacAlgorithm as OutputSizeUser>::OutputSize;
+pub trait GatewayProtocolVersionExt {
+    fn supports_aes256_gcm_siv(&self) -> bool;
+    fn supports_authenticate_v2(&self) -> bool;
+}
+
+impl GatewayProtocolVersionExt for u8 {
+    fn supports_aes256_gcm_siv(&self) -> bool {
+        *self >= AES_GCM_SIV_PROTOCOL_VERSION
+    }
+
+    fn supports_authenticate_v2(&self) -> bool {
+        *self >= AUTHENTICATE_V2_PROTOCOL_VERSION
+    }
+}
@@ -3,7 +3,7 @@

 use crate::registration::handshake::messages::{Finalization, GatewayMaterialExchange};
 use crate::registration::handshake::state::State;
-use crate::registration::handshake::SharedGatewayKey;
+use crate::registration::handshake::SharedSymmetricKey;
 use crate::registration::handshake::{error::HandshakeError, WsItem};
 use futures::{Sink, Stream};
 use rand::{CryptoRng, RngCore};
@@ -15,12 +15,12 @@ impl<S, R> State<'_, S, R> {
        S: Stream<Item = WsItem> + Sink<WsMessage> + Unpin,
        R: CryptoRng + RngCore,
    {
-        // 1. if we're using non-legacy, i.e. aes256gcm-siv derivation, generate initiator salt for kdf
-        let maybe_hkdf_salt = self.maybe_generate_initiator_salt();
+        // 1. generate initiator salt for kdf
+        let hkdf_salt = self.generate_initiator_salt();

-        // 1. send ed25519 pubkey alongside ephemeral x25519 pubkey and a hkdf salt if we're using non-legacy client
+        // 1. send ed25519 pubkey alongside ephemeral x25519 pubkey and a hkdf salt
        // LOCAL_ID_PUBKEY || EPHEMERAL_KEY || MAYBE_SALT
-        let init_message = self.init_message(maybe_hkdf_salt.clone());
+        let init_message = self.init_message(hkdf_salt.clone());
        self.send_handshake_data(init_message).await?;

        // 2. wait for response with remote x25519 pubkey as well as encrypted signature
@@ -31,7 +31,7 @@ impl<S, R> State<'_, S, R> {

        // 3. derive shared keys locally
        // hkdf::<blake3>::(g^xy)
-        self.derive_shared_key(&mid_res.ephemeral_dh, maybe_hkdf_salt.as_deref());
+        self.derive_shared_key(&mid_res.ephemeral_dh, &hkdf_salt);

        // 4. verify the received signature using the locally derived keys
        self.verify_remote_key_material(&mid_res.materials, &mid_res.ephemeral_dh)?;
@@ -49,7 +49,7 @@ impl<S, R> State<'_, S, R> {

    pub(crate) async fn perform_client_handshake(
        mut self,
-    ) -> Result<SharedGatewayKey, HandshakeError>
+    ) -> Result<SharedSymmetricKey, HandshakeError>
    where
        S: Stream<Item = WsItem> + Sink<WsMessage> + Unpin,
        R: CryptoRng + RngCore,
@@ -5,7 +5,7 @@ use crate::registration::handshake::messages::{
    HandshakeMessage, Initialisation, MaterialExchange,
 };
 use crate::registration::handshake::state::State;
-use crate::registration::handshake::SharedGatewayKey;
+use crate::registration::handshake::SharedSymmetricKey;
 use crate::registration::handshake::{error::HandshakeError, WsItem};
 use futures::{Sink, Stream};
 use tungstenite::Message as WsMessage;
@@ -18,18 +18,14 @@ impl<S, R> State<'_, S, R> {
    where
        S: Stream<Item = WsItem> + Sink<WsMessage> + Unpin,
    {
-        // 1. receive remote ed25519 pubkey alongside ephemeral x25519 pubkey and maybe a flag indicating non-legacy client
-        // LOCAL_ID_PUBKEY || EPHEMERAL_KEY || MAYBE_NON_LEGACY
+        // 1. receive remote ed25519 pubkey alongside ephemeral x25519 pubkey and initiator salt
+        // LOCAL_ID_PUBKEY || EPHEMERAL_KEY || INITIATOR_SALT
        let init_message = Initialisation::try_from_bytes(&raw_init_message)?;
        self.update_remote_identity(init_message.identity);
-        self.set_aes256_gcm_siv_key_derivation(!init_message.is_legacy());

        // 2. derive shared keys locally
        // hkdf::<blake3>::(g^xy)
-        self.derive_shared_key(
-            &init_message.ephemeral_dh,
-            init_message.initiator_salt.as_deref(),
-        );
+        self.derive_shared_key(&init_message.ephemeral_dh, &init_message.initiator_salt);

        // 3. send ephemeral x25519 pubkey alongside the encrypted signature
        // g^y || AES(k, sig(gate_priv, (g^y || g^x))
@@ -54,7 +50,7 @@ impl<S, R> State<'_, S, R> {
    pub(crate) async fn perform_gateway_handshake(
        mut self,
        raw_init_message: Vec<u8>,
-    ) -> Result<SharedGatewayKey, HandshakeError>
+    ) -> Result<SharedSymmetricKey, HandshakeError>
    where
        S: Stream<Item = WsItem> + Sink<WsMessage> + Unpin,
    {
@@ -4,7 +4,7 @@
 use crate::registration::handshake::error::HandshakeError;
 use crate::registration::handshake::KDF_SALT_LENGTH;
 use nym_crypto::asymmetric::{ed25519, x25519};
-use nym_crypto::symmetric::aead::{nonce_size, tag_size};
+use nym_crypto::symmetric::aead::{nonce_size, tag_size, Nonce};
 use nym_sphinx::params::GatewayEncryptionAlgorithm;

 // it is vital nobody changes the serialisation implementation unless you have an EXTREMELY good reason,
@@ -21,20 +21,13 @@ pub trait HandshakeMessage {
 pub struct Initialisation {
    pub identity: ed25519::PublicKey,
    pub ephemeral_dh: x25519::PublicKey,
-    pub initiator_salt: Option<Vec<u8>>,
-}
-
-impl Initialisation {
-    #[cfg(not(target_arch = "wasm32"))]
-    pub fn is_legacy(&self) -> bool {
-        self.initiator_salt.is_none()
-    }
+    pub initiator_salt: Vec<u8>,
 }

 #[derive(Debug)]
 pub struct MaterialExchange {
    pub signature_ciphertext: Vec<u8>,
-    pub nonce: Option<Vec<u8>>,
+    pub nonce: Nonce<GatewayEncryptionAlgorithm>,
 }

 impl MaterialExchange {
@@ -72,17 +65,12 @@ impl HandshakeMessage for Initialisation {
    // Eventually the ID_PUBKEY prefix will get removed and recipient will know
    // initializer's identity from another source.
    fn into_bytes(self) -> Vec<u8> {
-        let bytes = self
-            .identity
+        self.identity
            .to_bytes()
            .into_iter()
-            .chain(self.ephemeral_dh.to_bytes());
-
-        if let Some(salt) = self.initiator_salt {
-            bytes.chain(salt).collect()
-        } else {
-            bytes.collect()
-        }
+            .chain(self.ephemeral_dh.to_bytes())
+            .chain(self.initiator_salt)
+            .collect()
    }

    // this will need to be adjusted when REMOTE_ID_PUBKEY is removed
@@ -90,9 +78,8 @@ impl HandshakeMessage for Initialisation {
    where
        Self: Sized,
    {
-        let legacy_len = ed25519::PUBLIC_KEY_LENGTH + x25519::PUBLIC_KEY_SIZE;
-        let current_len = legacy_len + KDF_SALT_LENGTH;
-        if bytes.len() != legacy_len && bytes.len() != current_len {
+        let current_len = ed25519::PUBLIC_KEY_LENGTH + x25519::PUBLIC_KEY_SIZE + KDF_SALT_LENGTH;
+        if bytes.len() != current_len {
            return Err(HandshakeError::MalformedRequest);
        }

@@ -101,14 +88,13 @@ impl HandshakeMessage for Initialisation {

        // this can only fail if the provided bytes have len different from encryption::PUBLIC_KEY_SIZE
        // which is impossible
-        let ephemeral_dh =
-            x25519::PublicKey::from_bytes(&bytes[ed25519::PUBLIC_KEY_LENGTH..legacy_len]).unwrap();
+        let ephemeral_dh = x25519::PublicKey::from_bytes(
+            &bytes
+                [ed25519::PUBLIC_KEY_LENGTH..ed25519::PUBLIC_KEY_LENGTH + x25519::PUBLIC_KEY_SIZE],
+        )
+        .unwrap();

-        let initiator_salt = if bytes.len() == legacy_len {
-            None
-        } else {
-            Some(bytes[legacy_len..].to_vec())
-        };
+        let initiator_salt = bytes[ed25519::PUBLIC_KEY_LENGTH + x25519::PUBLIC_KEY_SIZE..].to_vec();

        Ok(Initialisation {
            identity,
@@ -121,43 +107,31 @@ impl HandshakeMessage for Initialisation {
 impl HandshakeMessage for MaterialExchange {
    // AES(k, SIG(PRIV_GATE, G^y || G^x))
    fn into_bytes(self) -> Vec<u8> {
-        if let Some(nonce) = self.nonce {
-            self.signature_ciphertext
-                .iter()
-                .cloned()
-                .chain(nonce)
-                .collect()
-        } else {
-            self.signature_ciphertext.to_vec()
-        }
+        self.signature_ciphertext
+            .iter()
+            .cloned()
+            .chain(self.nonce)
+            .collect()
    }

    fn try_from_bytes(bytes: &[u8]) -> Result<Self, HandshakeError>
    where
        Self: Sized,
    {
-        // we expect to receive either:
-        // LEGACY: ed25519 signature ciphertext (64 bytes)
        // CURRENT: ed25519 signature ciphertext (+ tag) + AES256-GCM-SIV nonce (76 bytes)
-        let legacy_len = ed25519::SIGNATURE_LENGTH;
-        let current_len = legacy_len
+        let current_len = ed25519::SIGNATURE_LENGTH
            + tag_size::<GatewayEncryptionAlgorithm>()
            + nonce_size::<GatewayEncryptionAlgorithm>();

-        if bytes.len() != legacy_len && bytes.len() != current_len {
+        if bytes.len() != current_len {
            return Err(HandshakeError::MalformedResponse);
        }

-        let (signature_ciphertext, nonce) = if bytes.len() == current_len {
-            let ciphertext_len =
-                ed25519::SIGNATURE_LENGTH + tag_size::<GatewayEncryptionAlgorithm>();
-            (
-                bytes[..ciphertext_len].to_vec(),
-                Some(bytes[ciphertext_len..].to_vec()),
-            )
-        } else {
-            (bytes.to_vec(), None)
-        };
+        let ciphertext_len = ed25519::SIGNATURE_LENGTH + tag_size::<GatewayEncryptionAlgorithm>();
+        let signature_ciphertext = bytes[..ciphertext_len].to_vec();
+
+        // SAFETY: we know the bytes have correct length
+        let nonce = Nonce::<GatewayEncryptionAlgorithm>::clone_from_slice(&bytes[ciphertext_len..]);

        Ok(MaterialExchange {
            signature_ciphertext,
--- a/Show More
+++ b/Show More