Use the A and B precomputation tables wherever possible

src/ggm.rs

@@ -107,6 +107,7 @@ pub struct Credential5 {
 // are blinded to the issuer.
 pub mod issue_nonblind_5 {
     use curve25519_dalek::ristretto::RistrettoPoint;
+    use curve25519_dalek::ristretto::RistrettoBasepointTable;
     use curve25519_dalek::scalar::Scalar;
     use curve25519_dalek::traits::IsIdentity;
 
@@ -114,7 +115,7 @@ pub mod issue_nonblind_5 {
     use zkp::ProofError;
     use zkp::Transcript;
 
-    use super::{CMZ_A,CMZ_B,Issuer,IssuerPubKey,Credential5};
+    use super::{CMZ_A,CMZ_B,CMZ_B_TABLE,Issuer,IssuerPubKey,Credential5};
 
     #[derive(Debug)]
     pub struct CredentialRequest {
@@ -184,10 +185,11 @@ pub mod issue_nonblind_5 {
                 -> CredentialResponse {
             let A : &RistrettoPoint = &CMZ_A;
             let B : &RistrettoPoint = &CMZ_B;
+            let Btable : &RistrettoBasepointTable = &CMZ_B_TABLE;
 
             let mut rng: rand::rngs::ThreadRng = rand::thread_rng();
             let b: Scalar = Scalar::random(&mut rng);
-            let P: RistrettoPoint = b * B;
+            let P: RistrettoPoint = &b * Btable;
             // There is a typo in the Hyphae paper: in Section 4.1, Q should
             // also have an x0*P term (also in Q').  (You can see that term
             // in Section 4.2.)
@@ -293,7 +295,8 @@ pub mod issue_blind124_5 {
     use zkp::ProofError;
     use zkp::Transcript;
 
-    use super::{CMZ_A,CMZ_B,CMZ_B_TABLE,Issuer,IssuerPubKey,Credential5};
+    use super::{CMZ_A,CMZ_B,CMZ_A_TABLE,CMZ_B_TABLE};
+    use super::{Issuer,IssuerPubKey,Credential5};
 
     // Example of a 5-attribute credential where the issuer sees attributes
     // 3 and 5, but attributes 1, 2, and 4 are blinded.
@@ -439,6 +442,8 @@ pub mod issue_blind124_5 {
                 -> Result<CredentialResponse, ProofError> {
             let A : &RistrettoPoint = &CMZ_A;
             let B : &RistrettoPoint = &CMZ_B;
+            let Atable : &RistrettoBasepointTable = &CMZ_A_TABLE;
+            let Btable : &RistrettoBasepointTable = &CMZ_B_TABLE;
 
             // First check the proof in the request
             let mut transcript = Transcript::new(b"Blind124 5 userblind proof");
@@ -460,25 +465,25 @@ pub mod issue_blind124_5 {
             // Compute the MAC on the visible attributes
             let mut rng: rand::rngs::ThreadRng = rand::thread_rng();
             let b: Scalar = Scalar::random(&mut rng);
-            let P: RistrettoPoint = b * B;
+            let P: RistrettoPoint = &b * Btable;
             let QHc: RistrettoPoint = (self.privkey.x[0] + (
                 self.privkey.x[3] * req.m3 +
                 self.privkey.x[5] * req.m5)) * P;
 
             // El Gamal encrypt it to the public key req.D
             let s: Scalar = Scalar::random(&mut rng);
-            let EncQHc = (s*B, QHc + s*req.D);
+            let EncQHc = (&s*Btable, QHc + s*req.D);
 
             // Homomorphically compute the part of the MAC corresponding to
             // the blinded attributes
             let t1 = self.privkey.x[1] * b;
-            let T1 = t1 * A;
+            let T1 = &t1 * Atable;
             let EncQ1 = ( t1 * req.Encm1B.0, t1 * req.Encm1B.1 );
             let t2 = self.privkey.x[2] * b;
-            let T2 = t2 * A;
+            let T2 = &t2 * Atable;
             let EncQ2 = ( t2 * req.Encm2B.0, t2 * req.Encm2B.1 );
             let t4 = self.privkey.x[4] * b;
-            let T4 = t4 * A;
+            let T4 = &t4 * Atable;
             let EncQ4 = ( t4 * req.Encm4B.0, t4 * req.Encm4B.1 );
 
             let EncQ = ( EncQHc.0 + EncQ1.0 + EncQ2.0 + EncQ4.0,