derive rho from random value and not secret key and change registration

Author: lovesh

.github/workflows/dart-bp-tests.yml

@@ -49,7 +49,7 @@ jobs:
       run: cargo test --release --package polymesh-dart-bp
 
     - name: Run tests with ignore_prover_input_sanitation feature
-      run: cargo test --release --package polymesh-dart-bp --features ignore_prover_input_sanitation input_sanitation_disabled
+      run: cargo test --package polymesh-dart-bp --features ignore_prover_input_sanitation input_sanitation_disabled
 
   test-wasm:
     name: Build dart-bp for WASM target
@@ -76,4 +76,4 @@ jobs:
           ${{ runner.os }}-cargo-
           
     - name: Build for WASM
-      run: cargo build --package polymesh-dart-bp --target wasm32-unknown-unknown --no-default-features
+      run: cargo build --package polymesh-dart-bp --target wasm32-unknown-unknown --no-default-features

dart-bp/benches/affirmation_proofs.rs

@@ -141,7 +141,7 @@ fn create_account_and_tree<
     let asset_id = 1;
     let id = PallasFr::rand(rng);
     let poseidon_config = get_poseidon2_params_for_2_1_hashing().unwrap();
-    let mut account =
+    let (mut account, _) =
         AccountState::new(rng, id, sk.0, sk_enc.0, asset_id, 0, poseidon_config).unwrap();
     account.balance = 200;
 

dart-bp/benches/fee_account_proofs.rs

@@ -110,9 +110,7 @@ fn bench_fee_account_topup_verification(c: &mut Criterion) {
     );
 
     let nonce = b"test-nonce";
-    let updated_account = account
-        .get_state_for_topup(&mut setup_rng, increase_bal_by)
-        .unwrap();
+    let updated_account = account.get_state_for_topup(increase_bal_by).unwrap();
     let updated_account_comm = updated_account.commit(account_comm_key.clone()).unwrap();
     let path = account_tree.get_path_to_leaf_for_proof(0, 0).unwrap();
     let root = account_tree.root_node();
@@ -176,9 +174,7 @@ fn bench_fee_account_topup_verification_with_rmc(c: &mut Criterion) {
     );
 
     let nonce = b"test-nonce";
-    let updated_account = account
-        .get_state_for_topup(&mut setup_rng, increase_bal_by)
-        .unwrap();
+    let updated_account = account.get_state_for_topup(increase_bal_by).unwrap();
     let updated_account_comm = updated_account.commit(account_comm_key.clone()).unwrap();
     let path = account_tree.get_path_to_leaf_for_proof(0, 0).unwrap();
     let root = account_tree.root_node();
@@ -247,9 +243,7 @@ fn bench_fee_payment_verification(c: &mut Criterion) {
 
     // Or could be hash(a_txn_id, a_payee_id)
     let nonce = b"a_txn_id,a_payee_id";
-    let updated_account = account
-        .get_state_for_payment(&mut setup_rng, fee_amount)
-        .unwrap();
+    let updated_account = account.get_state_for_payment(fee_amount).unwrap();
     let updated_account_comm = updated_account.commit(account_comm_key.clone()).unwrap();
     let path = account_tree.get_path_to_leaf_for_proof(0, 0).unwrap();
     let root = account_tree.root_node();
@@ -312,9 +306,7 @@ fn bench_fee_payment_verification_with_rmc(c: &mut Criterion) {
 
     // Or could be hash(a_txn_id, a_payee_id)
     let nonce = b"a_txn_id,a_payee_id";
-    let updated_account = account
-        .get_state_for_payment(&mut setup_rng, fee_amount)
-        .unwrap();
+    let updated_account = account.get_state_for_payment(fee_amount).unwrap();
     let updated_account_comm = updated_account.commit(account_comm_key.clone()).unwrap();
     let path = account_tree.get_path_to_leaf_for_proof(0, 0).unwrap();
     let root = account_tree.root_node();

dart-bp/benches/settlement_proofs.rs

@@ -45,7 +45,9 @@ fn new_account<R: CryptoRngCore>(
     id: PallasFr,
 ) -> AccountState<PallasA> {
     let poseidon_config = get_poseidon2_params_for_2_1_hashing().unwrap();
-    AccountState::new(rng, id, sk.0, sk_enc.0, asset_id, 0, poseidon_config).unwrap()
+    AccountState::new(rng, id, sk.0, sk_enc.0, asset_id, 0, poseidon_config)
+        .unwrap()
+        .0
 }
 
 /// Create shared setup params

dart-bp/src/account/mint.rs

@@ -650,7 +650,7 @@ mod tests {
         let (sk_enc, _) = keygen_enc(&mut rng, account_comm_key.sk_enc_gen());
 
         let id = PallasFr::rand(&mut rng);
-        let (account, _, _) = new_account(&mut rng, asset_id, sk_i, sk_enc, id.clone());
+        let (account, _, _, _) = new_account(&mut rng, asset_id, sk_i, sk_enc, id.clone());
 
         let account_tree = get_tree_with_account_comm::<L, _>(
             &account,

dart-bp/src/account/pob.rs

@@ -911,7 +911,7 @@ mod tests {
         let (sk_enc, _) = keygen_enc(&mut rng, enc_key_gen);
         // Account exists with some balance and pending txns
         let id = PallasFr::rand(&mut rng);
-        let (mut account, _, _) = new_account(&mut rng, asset_id, sk, sk_enc, id.clone());
+        let (mut account, _, _, _) = new_account(&mut rng, asset_id, sk, sk_enc, id.clone());
         account.balance = 1000;
         account.counter = 7;
         let account_comm = account.commit(account_comm_key.clone()).unwrap();
@@ -959,7 +959,7 @@ mod tests {
 
         // Account exists with some balance and pending txns
         let id = PallasFr::rand(&mut rng);
-        let (mut account, _, _) = new_account(&mut rng, asset_id, sk, sk_e, id.clone());
+        let (mut account, _, _, _) = new_account(&mut rng, asset_id, sk, sk_e, id.clone());
         account.balance = 1000000;
         account.counter = num_pending_txns;
         let account_comm = account.commit(account_comm_key.clone()).unwrap();
@@ -1082,7 +1082,7 @@ mod tests {
         let num_pending_txns = 20;
 
         let id = PallasFr::rand(&mut rng);
-        let (mut account, _, _) = new_account(&mut rng, asset_id, sk, sk_e, id.clone());
+        let (mut account, _, _, _) = new_account(&mut rng, asset_id, sk, sk_e, id.clone());
         account.balance = 1000000;
         account.counter = num_pending_txns;
         let account_comm = account.commit(account_comm_key.clone()).unwrap();
@@ -1213,7 +1213,7 @@ mod tests {
         let num_pending_txns = 10;
 
         let id = PallasFr::rand(&mut rng);
-        let (mut account, _, _) = new_account(&mut rng, asset_id, sk, sk_e, id);
+        let (mut account, _, _, _) = new_account(&mut rng, asset_id, sk, sk_e, id);
         account.balance = 1000000;
         account.counter = num_pending_txns;
         let account_comm = account.commit(account_comm_key.clone()).unwrap();
@@ -1322,7 +1322,7 @@ mod tests {
         let num_pending_txns = 12;
 
         let id = PallasFr::rand(&mut rng);
-        let (mut account, _, _) = new_account(&mut rng, asset_id, sk, sk_e, id);
+        let (mut account, _, _, _) = new_account(&mut rng, asset_id, sk, sk_e, id);
         account.balance = 1000000;
         account.counter = num_pending_txns;
         let account_comm = account.commit(account_comm_key.clone()).unwrap();
@@ -1455,7 +1455,7 @@ mod tests {
         let num_pending_txns = 6;
 
         let id = PallasFr::rand(&mut rng);
-        let (mut account, _, _) = new_account(&mut rng, asset_id, sk, sk_e, id);
+        let (mut account, _, _, _) = new_account(&mut rng, asset_id, sk, sk_e, id);
         account.balance = 1000000;
         account.counter = num_pending_txns;
         let account_comm = account.commit(account_comm_key.clone()).unwrap();

dart-bp/src/account/state.rs

@@ -315,6 +315,7 @@ where
 {
     /// `sk_aff` is the affirmation secret key
     /// `sk_enc` is the encryption secret key
+    /// Returns `(AccountState, rho_randomness)` where `rho_randomness` is needed for the registration proof.
     pub fn new<R: CryptoRngCore>(
         rng: &mut R,
         id: G::ScalarField, // User can hash its string ID onto the field
@@ -323,36 +324,43 @@ where
         asset_id: AssetId,
         counter: NullifierSkGenCounter,
         poseidon_config: Poseidon2Params<G::ScalarField>,
-    ) -> Result<Self> {
+    ) -> Result<(Self, G::ScalarField)> {
         let randomness = G::ScalarField::rand(rng);
-        Self::new_given_randomness(
+        let rho_randomness = G::ScalarField::rand(rng);
+        let account = Self::new_given_randomness(
             id,
             sk_aff,
             sk_enc,
             asset_id,
             counter,
             randomness,
+            rho_randomness,
             poseidon_config,
-        )
+        )?;
+        Ok((account, rho_randomness))
     }
 
+    /// `rho_randomness` is the random value used to derive `rho` via Poseidon hash. It is NOT
+    /// stored in `AccountState` and must be retained by the caller for creating the registration proof.
     pub fn new_given_randomness(
         id: G::ScalarField, // User can hash its string ID onto the field
         sk_aff: G::ScalarField,
         sk_enc: G::ScalarField,
         asset_id: AssetId,
         counter: NullifierSkGenCounter,
         randomness: G::ScalarField,
+        rho_randomness: G::ScalarField,
         poseidon_config: Poseidon2Params<G::ScalarField>,
     ) -> Result<Self> {
         if asset_id > MAX_ASSET_ID {
             return Err(Error::AssetIdTooLarge(asset_id));
         }
         let sk_enc_inv = sk_enc.inverse().ok_or(Error::InvertingZero)?;
         let combined = Self::concat_asset_id_counter(asset_id, counter);
-        let rho = Poseidon_hash_2_simple::<G::ScalarField>(sk_aff, combined, poseidon_config)?;
-        let current_rho = rho;
-        let current_randomness = randomness;
+        let rho =
+            Poseidon_hash_2_simple::<G::ScalarField>(rho_randomness, combined, poseidon_config)?;
+        let current_rho = rho.square();
+        let current_randomness = randomness.square();
 
         Ok(Self {
             id,
@@ -520,8 +528,8 @@ where
     /// Set rho and commitment randomness to new values. Used as each update to the account state
     /// needs these refreshed.
     pub fn refresh_randomness_for_state_change(&mut self) {
-        self.current_rho = self.current_rho * self.rho;
-        self.current_randomness = self.current_randomness * self.randomness;
+        self.current_rho *= self.rho;
+        self.current_randomness *= self.randomness;
     }
 
     pub fn nullifier(&self, comm_key: &impl AccountCommitmentKeyTrait<G>) -> G {

dart-bp/src/account/state_transition.rs

@@ -943,7 +943,7 @@ mod tests {
 
             // Create Carol's account
             let carol_id = PallasFr::rand(&mut rng);
-            let (mut carol_account, _, _) = new_account(
+            let (mut carol_account, _, _, _) = new_account(
                 &mut rng,
                 asset_id,
                 sk_carol.clone(),
@@ -1170,7 +1170,7 @@ mod tests {
 
         // Create Alice's account
         let alice_id = PallasFr::rand(&mut rng);
-        let (mut alice_account, _, _) =
+        let (mut alice_account, _, _, _) =
             new_account(&mut rng, asset_id, sk_alice, sk_alice_e, alice_id);
         alice_account.balance = 1000;
 
@@ -1387,7 +1387,7 @@ mod tests {
 
         // Create Alice's account
         let alice_id = PallasFr::rand(&mut rng);
-        let (mut alice_account, _, _) =
+        let (mut alice_account, _, _, _) =
             new_account(&mut rng, asset_id, sk_alice, sk_alice_e, alice_id);
         alice_account.balance = 1000;
 
@@ -1518,7 +1518,7 @@ mod tests {
 
         // Create Alice's account
         let alice_id = PallasFr::rand(&mut rng);
-        let (mut alice_account, _, _) =
+        let (mut alice_account, _, _, _) =
             new_account(&mut rng, asset_id, sk_alice, sk_alice_e, alice_id);
         alice_account.balance = 1000;
 
@@ -1677,7 +1677,7 @@ mod tests {
 
         // Create Alice's accounts for both assets
         let alice_id = PallasFr::rand(&mut rng);
-        let (mut alice_account_asset1, _, _) = new_account(
+        let (mut alice_account_asset1, _, _, _) = new_account(
             &mut rng,
             asset_id_1,
             sk_alice.clone(),
@@ -1686,7 +1686,7 @@ mod tests {
         );
         alice_account_asset1.balance = 1000;
 
-        let (mut alice_account_asset2, _, _) =
+        let (mut alice_account_asset2, _, _, _) =
             new_account(&mut rng, asset_id_2, sk_alice, sk_alice_e, alice_id);
         alice_account_asset2.balance = 2000;
 
@@ -2019,7 +2019,7 @@ mod tests {
             .unwrap();
 
         let alice_id = PallasFr::rand(&mut rng);
-        let (mut alice_account, _, _) =
+        let (mut alice_account, _, _, _) =
             new_account(&mut rng, asset_id, sk_alice, sk_alice_e, alice_id);
         alice_account.balance = 1000;