Add new aggregation function and struct for the aggregated wallet

common/nym-compact-ecash/src/scheme/aggregation.rs

@@ -1,5 +1,6 @@
 use core::iter::Sum;
 use core::ops::Mul;
+use std::cell::Cell;
 
 use bls12_381::{G2Prepared, G2Projective, Scalar};
 use group::Curve;
@@ -7,9 +8,10 @@ use itertools::Itertools;
 
 use crate::Attribute;
 use crate::error::{CompactEcashError, Result};
-use crate::scheme::{PartialSignature, Signature, SignatureShare, SignerIndex};
-use crate::scheme::keygen::VerificationKeyAuth;
+use crate::scheme::{PartialSignature, PartialWallet, Signature, SignatureShare, SignerIndex, Wallet};
+use crate::scheme::keygen::{SecretKeyUser, VerificationKeyAuth};
 use crate::scheme::setup::Parameters;
+use crate::scheme::withdrawal::RequestInfo;
 use crate::utils::{check_bilinear_pairing, perform_lagrangian_interpolation_at_origin};
 
 pub(crate) trait Aggregatable: Sized {
@@ -131,4 +133,25 @@ pub fn aggregate_signatures(
         ));
     }
     Ok(signature)
+}
+
+pub fn aggregate_wallets(params: &Parameters, verification_key: &VerificationKeyAuth, skUser: &SecretKeyUser, wallets: &[PartialWallet], reqInfo: &RequestInfo) -> Result<Wallet> {
+
+    // Aggregate partial wallets
+    let signature_shares: Vec<SignatureShare> = wallets
+        .iter()
+        .enumerate()
+        .map(|(idx, wallet)| SignatureShare::new(*wallet.signature(), (idx + 1) as u64))
+        .collect();
+
+    let attributes = vec![skUser.sk, reqInfo.get_v(), reqInfo.get_t()];
+    let aggregated_signature =
+        aggregate_signature_shares(&params, &verification_key, &attributes, &signature_shares)?;
+
+    Ok(Wallet {
+        sig: aggregated_signature,
+        v: reqInfo.get_v(),
+        t: reqInfo.get_t(),
+        l: Cell::new(0),
+    })
 }

common/nym-compact-ecash/src/scheme/mod.rs

@@ -1,3 +1,4 @@
+use std::cell::Cell;
 use std::convert::TryFrom;
 use std::convert::TryInto;
 
@@ -118,18 +119,32 @@ impl SignatureShare {
     // }
 }
 
-pub struct Wallet {
+pub struct PartialWallet {
     sig: Signature,
     v: Scalar,
     idx: Option<SignerIndex>,
 }
 
-impl Wallet {
+impl PartialWallet {
     pub fn signature(&self) -> &Signature { &self.sig }
-    pub fn v(&self) -> Scalar {
-        self.v
-    }
+    pub fn v(&self) -> Scalar { self.v }
     pub fn index(&self) -> Option<SignerIndex> {
         self.idx
     }
 }
+
+pub struct Wallet {
+    sig: Signature,
+    v: Scalar,
+    t: Scalar,
+    l: Cell<u64>,
+}
+
+impl Wallet {
+    pub fn signature(&self) -> &Signature { &self.sig }
+    pub fn v(&self) -> Scalar { self.v }
+    pub fn t(&self) -> Scalar { self.t }
+    fn up(&self) {
+        self.l.set(self.l.get() + 1);
+    }
+}

common/nym-compact-ecash/src/scheme/spend.rs

@@ -1 +1,10 @@
+use crate::scheme::keygen::{SecretKeyUser, VerificationKeyAuth};
+use crate::scheme::Wallet;
 
+pub struct PayInfo {}
+
+pub fn spend(wallet: &Wallet, verification_key: &VerificationKeyAuth, skUser: &SecretKeyUser, payInfo: &PayInfo) {
+    //
+}
+
+pub fn spend_verify() {}

common/nym-compact-ecash/src/scheme/withdrawal.rs

@@ -3,7 +3,7 @@ use group::{Curve, GroupEncoding};
 
 use crate::error::{CompactEcashError, Result};
 use crate::proofs::{WithdrawalReqInstance, WithdrawalReqProof, WithdrawalReqWitness};
-use crate::scheme::{BlindedSignature, Signature, Wallet};
+use crate::scheme::{BlindedSignature, PartialWallet, Signature};
 use crate::scheme::keygen::{PublicKeyUser, SecretKeyAuth, SecretKeyUser, VerificationKeyAuth};
 use crate::scheme::keygen::ttp_keygen;
 use crate::scheme::setup::Parameters;
@@ -140,7 +140,7 @@ pub fn issue_verify(
     sk_user: &SecretKeyUser,
     blind_signature: &BlindedSignature,
     req_info: &RequestInfo,
-) -> Result<Wallet> {
+) -> Result<PartialWallet> {
     // Parse the blinded signature
     let h = blind_signature.0;
     let c = blind_signature.1;
@@ -182,7 +182,7 @@ pub fn issue_verify(
         ));
     }
 
-    Ok(Wallet {
+    Ok(PartialWallet {
         sig: Signature(h, unblinded_c),
         v: req_info.v,
         idx: None,

common/nym-compact-ecash/src/tests/e2e.rs

@@ -1,8 +1,8 @@
 use itertools::izip;
 
 use crate::error::CompactEcashError;
-use crate::scheme::{SignatureShare, Wallet};
-use crate::scheme::aggregation::{aggregate_signature_shares, aggregate_verification_keys};
+use crate::scheme::{PartialWallet, SignatureShare};
+use crate::scheme::aggregation::{aggregate_signature_shares, aggregate_verification_keys, aggregate_wallets};
 use crate::scheme::keygen::{
     generate_keypair_user, PublicKeyUser, SecretKeyUser, ttp_keygen, VerificationKeyAuth,
 };
@@ -35,7 +35,7 @@ fn main() -> Result<(), CompactEcashError> {
         wallet_blinded_signatures.push(blind_signature.unwrap());
     }
 
-    let unblinded_wallet_shares: Vec<Wallet> = izip!(
+    let unblinded_wallet_shares: Vec<PartialWallet> = izip!(
         wallet_blinded_signatures.iter(),
         verification_keys_auth.iter()
     )
@@ -43,15 +43,7 @@ fn main() -> Result<(), CompactEcashError> {
         .collect();
 
     // Aggregate partial wallets
-    let signature_shares: Vec<SignatureShare> = unblinded_wallet_shares
-        .iter()
-        .enumerate()
-        .map(|(idx, wallet)| SignatureShare::new(*wallet.signature(), (idx + 1) as u64))
-        .collect();
-
-    let attributes = vec![user_keypair.secret_key().sk, req_info.get_v(), req_info.get_t()];
-    let aggregated_signature =
-        aggregate_signature_shares(&params, &verification_key, &attributes, &signature_shares)?;
+    let aggr_wallet = aggregate_wallets(&params, &verification_key, &user_keypair.secret_key(), &unblinded_wallet_shares, &req_info);
 
     Ok(())
 }