sumcheck use transcript, reorganize some files

src/novacircuit.rs → src/circuits.rs

@@ -1,4 +1,5 @@
 use ark_crypto_primitives::snark::{FromFieldElementsGadget, SNARKGadget, SNARK};
+use ark_ec::AffineRepr;
 use ark_ec::CurveGroup;
 use ark_ff::{fields::Fp256, Field, PrimeField};
 use ark_r1cs_std::{
@@ -42,8 +43,6 @@ impl, Cfg: Co
 {
     fn generate_constraints(self, cs: ConstraintSystemRef<Fq>) -> Result<(), SynthesisError> {
         unimplemented!();
-        // nifscircuit::NIFSGadget::<Fq, C, GC<Fq, C>>::verify();
-        // hash
     }
 }
 

src/lib.rs

@@ -3,9 +3,9 @@
 #![allow(non_upper_case_globals)]
 #![allow(unused)] // TMP
 
+mod circuits;
 mod nifs;
-mod novacircuit;
 mod pedersen;
-mod r1cs;
+mod sumcheck;
 mod transcript;
 mod utils;

src/nifs.rs

@@ -1,15 +1,21 @@
 use ark_ec::AffineRepr;
+use ark_ff::fields::PrimeField;
+use ark_std::{
+    rand::{Rng, RngCore},
+    UniformRand,
+};
 use ark_std::{One, Zero};
 use std::marker::PhantomData;
 
 use crate::pedersen::{Commitment, Params as PedersenParams, Pedersen, Proof as PedersenProof};
-use crate::r1cs::*;
 use crate::transcript::Transcript;
 use crate::utils::*;
-use ark_std::{
-    rand::{Rng, RngCore},
-    UniformRand,
-};
+
+pub struct R1CS<F: PrimeField> {
+    pub A: Vec<Vec<F>>,
+    pub B: Vec<Vec<F>>,
+    pub C: Vec<Vec<F>>,
+}
 
 // Phi: φ in the paper (later 𝖴), a folded instance
 pub struct Phi<C: AffineRepr> {

src/pedersen.rs

@@ -22,7 +22,7 @@ pub struct Proof {
 pub struct Params<C: AffineRepr> {
     g: C,
     h: C,
-    pub r_vec: Vec<C>,
+    pub generators: Vec<C>,
 }
 
 pub struct Pedersen<C: AffineRepr> {
@@ -33,11 +33,11 @@ impl Pedersen {
     pub fn new_params<R: Rng>(rng: &mut R, max: usize) -> Params<C> {
         let h_scalar = C::ScalarField::rand(rng);
         let g: C = C::generator();
-        let r_vec: Vec<C> = vec![C::rand(rng); max];
+        let generators: Vec<C> = vec![C::rand(rng); max];
         let params: Params<C> = Params::<C> {
             g,
             h: g.mul(h_scalar).into(),
-            r_vec, // will need 2 r: rE, rW
+            generators,
         };
         params
     }
@@ -56,7 +56,7 @@ impl Pedersen {
         v: &Vec<C::ScalarField>,
         r: &C::ScalarField, // random value is provided, in order to be choosen by other parts of the protocol
     ) -> Commitment<C> {
-        let cm = params.h.mul(r) + naive_msm(v, &params.r_vec);
+        let cm = params.h.mul(r) + naive_msm(v, &params.generators);
         Commitment::<C>(cm.into())
     }
 
@@ -91,7 +91,7 @@ impl Pedersen {
         let r1 = transcript.get_challenge(b"r_1");
         let d = transcript.get_challenge_vec(b"d", v.len());
 
-        let R: C = (params.h.mul(r1) + naive_msm(&d, &params.r_vec)).into();
+        let R: C = (params.h.mul(r1) + naive_msm(&d, &params.generators)).into();
 
         transcript.add(b"cm", &cm.0);
         transcript.add(b"R", &R);
@@ -116,7 +116,7 @@ impl Pedersen {
         transcript.add(b"R", &proof.R);
         let e = transcript.get_challenge(b"e");
         let lhs = proof.R + cm.0.mul(e);
-        let rhs = params.h.mul(proof.ru_) + naive_msm(&proof.u_, &params.r_vec);
+        let rhs = params.h.mul(proof.ru_) + naive_msm(&proof.u_, &params.generators);
         if lhs != rhs {
             return false;
         }

src/r1cs.rs

@@ -1,34 +0,0 @@
-use crate::pedersen;
-
-use ark_ff::fields::PrimeField;
-use core::ops::Add;
-
-// this file contains an abstraction of R1CS struct, to later be plugged from arkworks
-// ConstraintSystem or something similar.
-
-pub struct R1CS<F: PrimeField> {
-    pub A: Vec<Vec<F>>,
-    pub B: Vec<Vec<F>>,
-    pub C: Vec<Vec<F>>,
-}
-
-pub struct RelaxedR1CS<F: PrimeField> {
-    pub ABC: R1CS<F>,
-    pub u: F,
-    pub E: F,
-}
-
-impl<F: PrimeField> R1CS<F> {
-    pub fn relax(self) -> RelaxedR1CS<F> {
-        RelaxedR1CS::<F> {
-            ABC: self,
-            u: F::one(),
-            E: F::zero(),
-        }
-    }
-}
-impl<F: PrimeField> RelaxedR1CS<F> {
-    pub fn fold(self, other: Self, r: F) -> Self {
-        unimplemented!();
-    }
-}

src/sumcheck.rs

@@ -1,5 +1,5 @@
 // Sum-check protocol initial implementation, not used by the rest of the repo but implemented as
-// an exercise and might be used in the future.
+// an exercise and it will probably be used in the future.
 
 use ark_ff::{BigInteger, PrimeField};
 use ark_poly::{
@@ -14,6 +14,8 @@ use ark_std::marker::PhantomData;
 use ark_std::ops::Mul;
 use ark_std::{rand::Rng, UniformRand};
 
+use crate::transcript::Transcript;
+
 pub struct SumCheck<
     F: PrimeField,
     UV: Polynomial<F> + DenseUVPolynomial<F>,
@@ -81,10 +83,8 @@ impl<
 
     fn point_complete(challenges: Vec<F>, n_elems: usize, iter_num: usize) -> Vec<F> {
         let p = Self::point(challenges, false, n_elems, iter_num);
-        // let mut r = Vec::new();
         let mut r = vec![F::zero(); n_elems];
         for i in 0..n_elems {
-            // r.push(p[i].unwrap());
             r[i] = p[i].unwrap();
         }
         r
@@ -96,7 +96,7 @@ impl<
         if none {
             // WIP
             if n_vars == 0 {
-                panic!("err");
+                panic!("err"); // or return directly challenges vector
             }
             n_vars -= 1;
         }
@@ -125,9 +125,10 @@ impl<
     where
         <MV as Polynomial<F>>::Point: From<Vec<F>>,
     {
-        let v = g.num_vars();
+        // init transcript
+        let mut transcript: Transcript<F> = Transcript::<F>::new();
 
-        let r = vec![F::from(2_u32), F::from(3_u32), F::from(6_u32)]; // TMP will come from transcript
+        let v = g.num_vars();
 
         // compute H
         let mut H = F::zero();
@@ -136,43 +137,56 @@ impl<
 
             H = H + g.evaluate(&p.into());
         }
+        transcript.add(b"H", &H);
 
         let mut ss: Vec<UV> = Vec::new();
+        let mut r: Vec<F> = vec![];
         for i in 0..v {
+            let r_i = transcript.get_challenge(b"r_i");
+            r.push(r_i);
+
             let var_slots = v - 1 - i;
             let n_points = 2_u64.pow(var_slots as u32) as usize;
+
             let mut s_i = UV::zero();
-            let r_round = r.as_slice()[..i].to_vec();
             for j in 0..n_points {
-                let point = Self::point(r_round.clone(), true, v, j);
+                let point = Self::point(r[..i].to_vec(), true, v, j);
                 s_i = s_i + Self::partial_evaluate(&g, &point);
             }
+            transcript.add(b"s_i", &s_i);
             ss.push(s_i);
         }
 
-        let point_last = r;
-        let last_g_eval = g.evaluate(&point_last.into());
+        let last_g_eval = g.evaluate(&r.into());
         (H, ss, last_g_eval)
     }
 
     pub fn verify(proof: (F, Vec<UV>, F)) -> bool {
-        // let c: F, ss: Vec<UV>;
-        let (c, ss, last_g_eval) = proof;
+        // init transcript
+        let mut transcript: Transcript<F> = Transcript::<F>::new();
+        transcript.add(b"H", &proof.0);
 
-        let r = vec![F::from(2_u32), F::from(3_u32), F::from(6_u32)]; // TMP will come from transcript
+        let (c, ss, last_g_eval) = proof;
 
+        let mut r: Vec<F> = vec![];
         for (i, s) in ss.iter().enumerate() {
             // TODO check degree
             if i == 0 {
                 if c != s.evaluate(&F::zero()) + s.evaluate(&F::one()) {
                     return false;
                 }
+                let r_i = transcript.get_challenge(b"r_i");
+                r.push(r_i);
+                transcript.add(b"s_i", s);
                 continue;
             }
 
+            let r_i = transcript.get_challenge(b"r_i");
+            r.push(r_i);
             if ss[i - 1].evaluate(&r[i - 1]) != s.evaluate(&F::zero()) + s.evaluate(&F::one()) {
                 return false;
             }
+            transcript.add(b"s_i", s);
         }
         // last round
         if ss[ss.len() - 1].evaluate(&r[r.len() - 1]) != last_g_eval {
@@ -264,9 +278,6 @@ mod tests {
     #[test]
     fn test_flow_hardcoded_values() {
         let mut rng = ark_std::test_rng();
-        // let p = SparsePolynomial::<Fr, SparseTerm>::rand(deg, 3, &mut rng);
-        // let p = rand_poly(3, 3, &mut rng);
-
         // g(X_0, X_1, X_2) = 2 X_0^3 + X_0 X_2 + X_1 X_2
         let terms = vec![
             (Fr::from(2u32), SparseTerm::new(vec![(0_usize, 3)])),
@@ -286,17 +297,43 @@ mod tests {
 
         let proof = SC::prove(p);
         assert_eq!(proof.0, Fr::from(12_u32));
-        println!("proof {:?}", proof);
+        // println!("proof {:?}", proof);
 
         let v = SC::verify(proof);
         assert!(v);
     }
 
+    fn rand_poly<R: Rng>(l: usize, d: usize, rng: &mut R) -> SparsePolynomial<Fr, SparseTerm> {
+        // This method is from the arkworks/algebra/poly/multivariate test:
+        // https://github.com/arkworks-rs/algebra/blob/bc991d44c5e579025b7ed56df3d30267a7b9acac/poly/src/polynomial/multivariate/sparse.rs#L303
+        let mut random_terms = Vec::new();
+        let num_terms = rng.gen_range(1..1000);
+        // For each term, randomly select up to `l` variables with degree
+        // in [1,d] and random coefficient
+        random_terms.push((Fr::rand(rng), SparseTerm::new(vec![])));
+        for _ in 1..num_terms {
+            let term = (0..l)
+                .map(|i| {
+                    if rng.gen_bool(0.5) {
+                        Some((i, rng.gen_range(1..(d + 1))))
+                    } else {
+                        None
+                    }
+                })
+                .flatten()
+                .collect();
+            let coeff = Fr::rand(rng);
+            random_terms.push((coeff, SparseTerm::new(term)));
+        }
+        SparsePolynomial::from_coefficients_slice(l, &random_terms)
+    }
+
     #[test]
     fn test_flow_rng() {
         let mut rng = ark_std::test_rng();
-        let p = SparsePolynomial::<Fr, SparseTerm>::rand(3, 3, &mut rng);
-        println!("p {:?}", p);
+        // let p = SparsePolynomial::<Fr, SparseTerm>::rand(3, 3, &mut rng);
+        let p = rand_poly(3, 3, &mut rng);
+        // println!("p {:?}", p);
 
         type SC = SumCheck<Fr, DensePolynomial<Fr>, SparsePolynomial<Fr, SparseTerm>>;
 

src/transcript.rs

@@ -3,6 +3,8 @@ use ark_serialize::CanonicalSerialize;
 use merlin::Transcript as MerlinTranscript;
 use std::marker::PhantomData;
 
+// TODO poseidon transcript (not keccak)
+
 // This Transcript approach is a modified version from https://github.com/arkworks-rs/gemini ,
 // using Merlin transcript (https://merlin.cool).
 pub struct Transcript<F: PrimeField> {