refactor(mutability): remove unnecessary mutable references in NISigmaProtocol

- refactor: eliminate unnecessary mutable character from NISigmaProtocol method parameters

Author: nougzarm

src/fiat_shamir.rs

@@ -90,7 +90,7 @@ where
     /// # Panics
     /// Panics if local verification fails.
     pub fn prove(
-        &mut self,
+        &self,
         witness: &P::Witness,
         rng: &mut (impl RngCore + CryptoRng),
     ) -> Result<Transcript<P>, ProofError> {
@@ -127,7 +127,7 @@ where
     ///   - The challenge doesn't match the recomputed one from the commitment.
     ///   - The response fails verification under the Sigma protocol.
     pub fn verify(
-        &mut self,
+        &self,
         commitment: &P::Commitment,
         challenge: &P::Challenge,
         response: &P::Response,
@@ -159,7 +159,7 @@ where
     /// # Panics
     /// Panics if serialization fails (should not happen under correct implementation).
     pub fn prove_batchable(
-        &mut self,
+        &self,
         witness: &P::Witness,
         rng: &mut (impl RngCore + CryptoRng),
     ) -> Result<Vec<u8>, ProofError> {
@@ -183,7 +183,7 @@ where
     /// - Returns `ProofError::VerificationFailure` if:
     ///   - The challenge doesn't match the recomputed one from the commitment.
     ///   - The response fails verification under the Sigma protocol.
-    pub fn verify_batchable(&mut self, proof: &[u8]) -> Result<(), ProofError> {
+    pub fn verify_batchable(&self, proof: &[u8]) -> Result<(), ProofError> {
         let (commitment, response) = self.sigmap.deserialize_batchable(proof).unwrap();
 
         let mut codec = self.hash_state.clone();
@@ -220,7 +220,7 @@ where
     /// # Panics
     /// Panics if serialization fails.
     pub fn prove_compact(
-        &mut self,
+        &self,
         witness: &P::Witness,
         rng: &mut (impl RngCore + CryptoRng),
     ) -> Result<Vec<u8>, ProofError> {
@@ -246,7 +246,7 @@ where
     /// - Returns `ProofError::VerificationFailure` if:
     ///   - Deserialization fails.
     ///   - The recomputed commitment or response is invalid under the Sigma protocol.
-    pub fn verify_compact(&mut self, proof: &[u8]) -> Result<(), ProofError> {
+    pub fn verify_compact(&self, proof: &[u8]) -> Result<(), ProofError> {
         let (challenge, response) = self.sigmap.deserialize_compact(proof).unwrap();
         // Compute the commitments
         let commitment = self.sigmap.get_commitment(&challenge, &response)?;

tests/morphism_preimage.rs

@@ -232,7 +232,7 @@ fn NI_discrete_logarithm() {
     let protocol = SchnorrProtocol::from_preimage(morphismp);
     // Fiat-Shamir wrapper
     let domain_sep = b"test-fiat-shamir-schnorr";
-    let mut nizk =
+    let nizk =
         NISigmaProtocol::<SchnorrProtocol<G>, ShakeCodec<G>, G>::new(domain_sep, protocol);
 
     // Batchable and compact proofs
@@ -261,7 +261,7 @@ fn NI_dleq() {
     let protocol = SchnorrProtocol::from_preimage(morphismp);
     // Fiat-Shamir wrapper
     let domain_sep = b"test-fiat-shamir-DLEQ";
-    let mut nizk =
+    let nizk =
         NISigmaProtocol::<SchnorrProtocol<G>, ShakeCodec<G>, G>::new(domain_sep, protocol);
 
     // Batchable and compact proofs
@@ -290,7 +290,7 @@ fn NI_pedersen_commitment() {
     let protocol = SchnorrProtocol::from_preimage(morphismp);
     // Fiat-Shamir wrapper
     let domain_sep = b"test-fiat-shamir-pedersen-commitment";
-    let mut nizk =
+    let nizk =
         NISigmaProtocol::<SchnorrProtocol<G>, ShakeCodec<G>, G>::new(domain_sep, protocol);
 
     // Batchable and compact proofs
@@ -319,7 +319,7 @@ fn NI_pedersen_commitment_dleq() {
     let protocol = SchnorrProtocol::from_preimage(morphismp);
     // Fiat-Shamir wrapper
     let domain_sep = b"test-fiat-shamir-pedersen-commitment-DLEQ";
-    let mut nizk =
+    let nizk =
         NISigmaProtocol::<SchnorrProtocol<G>, ShakeCodec<G>, G>::new(domain_sep, protocol);
 
     // Batchable and compact proofs
@@ -348,7 +348,7 @@ fn NI_bbs_blind_commitment_computation() {
     let protocol = SchnorrProtocol::from_preimage(morphismp);
     // Fiat-Shamir wrapper
     let domain_sep = b"test-fiat-shamir-bbs-blind-commitment-computation";
-    let mut nizk =
+    let nizk =
         NISigmaProtocol::<SchnorrProtocol<G>, ShakeCodec<G>, G>::new(domain_sep, protocol);
 
     // Batchable and compact proofs

tests/proof_composition.rs

@@ -76,7 +76,7 @@ fn and_proof_correct() {
     witness.extend(&x1);
     witness.extend(&x2);
 
-    let mut nizk = NISigmaProtocol::<AndProtocol<RistrettoPoint>, ShakeCodec<G>, G>::new(
+    let nizk = NISigmaProtocol::<AndProtocol<RistrettoPoint>, ShakeCodec<G>, G>::new(
         domain_sep,
         and_protocol,
     );
@@ -111,7 +111,7 @@ fn and_proof_incorrect() {
     witness.push(fake_x);
     witness.extend(x2);
 
-    let mut nizk = NISigmaProtocol::<AndProtocol<RistrettoPoint>, ShakeCodec<G>, G>::new(
+    let nizk = NISigmaProtocol::<AndProtocol<RistrettoPoint>, ShakeCodec<G>, G>::new(
         domain_sep,
         and_protocol,
     );
@@ -143,7 +143,7 @@ fn or_proof_correct() {
 
     let witness = (1, x1);
 
-    let mut nizk = NISigmaProtocol::<OrProtocol<RistrettoPoint>, ShakeCodec<G>, G>::new(
+    let nizk = NISigmaProtocol::<OrProtocol<RistrettoPoint>, ShakeCodec<G>, G>::new(
         domain_sep,
         or_protocol,
     );
@@ -177,7 +177,7 @@ fn or_proof_incorrect() {
 
     let witness = (0, vec![<G as Group>::Scalar::random(&mut rng)]);
 
-    let mut nizk = NISigmaProtocol::<OrProtocol<RistrettoPoint>, ShakeCodec<G>, G>::new(
+    let nizk = NISigmaProtocol::<OrProtocol<RistrettoPoint>, ShakeCodec<G>, G>::new(
         domain_sep,
         or_protocol,
     );

tests/spec/sage_test_vectors.rs

@@ -250,7 +250,7 @@ fn NI_discrete_logarithm(seed: &[u8], context: &[u8]) -> (Vec<Scalar>, Vec<u8>)
 
     let protocol = SchnorrProtocolCustom(morphismp);
     let domain_sep: Vec<u8> = context.to_vec();
-    let mut nizk = NISigmaP::new(&domain_sep, protocol);
+    let nizk = NISigmaP::new(&domain_sep, protocol);
 
     let proof_bytes = nizk.prove_batchable(&witness, &mut rng).unwrap();
     let verified = nizk.verify_batchable(&proof_bytes).is_ok();
@@ -265,7 +265,7 @@ fn NI_dleq(seed: &[u8], context: &[u8]) -> (Vec<Scalar>, Vec<u8>) {
 
     let protocol = SchnorrProtocolCustom(morphismp);
     let domain_sep: Vec<u8> = context.to_vec();
-    let mut nizk = NISigmaP::new(&domain_sep, protocol);
+    let nizk = NISigmaP::new(&domain_sep, protocol);
 
     let proof_bytes = nizk.prove_batchable(&witness, &mut rng).unwrap();
     let verified = nizk.verify_batchable(&proof_bytes).is_ok();
@@ -280,7 +280,7 @@ fn NI_pedersen_commitment(seed: &[u8], context: &[u8]) -> (Vec<Scalar>, Vec<u8>)
 
     let protocol = SchnorrProtocolCustom(morphismp);
     let domain_sep: Vec<u8> = context.to_vec();
-    let mut nizk = NISigmaP::new(&domain_sep, protocol);
+    let nizk = NISigmaP::new(&domain_sep, protocol);
 
     let proof_bytes = nizk.prove_batchable(&witness, &mut rng).unwrap();
     let verified = nizk.verify_batchable(&proof_bytes).is_ok();
@@ -295,7 +295,7 @@ fn NI_pedersen_commitment_dleq(seed: &[u8], context: &[u8]) -> (Vec<Scalar>, Vec
 
     let protocol = SchnorrProtocolCustom(morphismp);
     let domain_sep: Vec<u8> = context.to_vec();
-    let mut nizk = NISigmaP::new(&domain_sep, protocol);
+    let nizk = NISigmaP::new(&domain_sep, protocol);
 
     let proof_bytes = nizk.prove_batchable(&witness, &mut rng).unwrap();
     let verified = nizk.verify_batchable(&proof_bytes).is_ok();
@@ -310,7 +310,7 @@ fn NI_bbs_blind_commitment_computation(seed: &[u8], context: &[u8]) -> (Vec<Scal
 
     let protocol = SchnorrProtocolCustom(morphismp);
     let domain_sep: Vec<u8> = context.to_vec();
-    let mut nizk = NISigmaP::new(&domain_sep, protocol);
+    let nizk = NISigmaP::new(&domain_sep, protocol);
 
     let proof_bytes = nizk.prove_batchable(&witness, &mut rng).unwrap();
     let verified = nizk.verify_batchable(&proof_bytes).is_ok();