CCS from R1CS ( https://eprint.iacr.org/2023/552 )

src/hypernova/ccs.rs

@@ -0,0 +1,69 @@
+use ark_ff::fields::PrimeField;
+
+use crate::nifs::R1CS;
+use crate::utils::{hadamard_product, matrix_vector_product, vec_add, vector_elem_product};
+
+pub struct CCS<F: PrimeField> {
+    m: usize,
+    n: usize,
+    t: usize,
+    q: usize,
+    d: usize,
+    S: Vec<Vec<usize>>,
+    c: Vec<F>,
+    M: Vec<Vec<Vec<F>>>,
+}
+
+impl<F: PrimeField> R1CS<F> {
+    pub fn to_ccs(self) -> CCS<F> {
+        CCS::<F> {
+            m: self.A.len(),
+            n: self.A[0].len(),
+            t: 3,
+            q: 2,
+            d: 2,
+            S: vec![vec![0, 1], vec![2]],
+            c: vec![F::one(), F::one().neg()],
+            M: vec![self.A, self.B, self.C],
+        }
+    }
+}
+
+impl<F: PrimeField> CCS<F> {
+    pub fn check_relation(self, z: Vec<F>) -> bool {
+        let mut r: Vec<F> = vec![F::zero(); self.m];
+        for i in 0..self.q {
+            let mut hadamard_output = vec![F::one(); self.m];
+            for j in self.S[i].clone() {
+                hadamard_output =
+                    hadamard_product(hadamard_output, matrix_vector_product(&self.M[j], &z));
+            }
+            r = vec_add(&r, &vector_elem_product(&hadamard_output, &self.c[i]));
+        }
+
+        let zero: Vec<F> = vec![F::zero(); self.m];
+
+        r == zero
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::transcript::poseidon_test_config;
+    use ark_mnt4_298::{Fr, G1Projective};
+    use ark_std::One;
+    use ark_std::UniformRand;
+
+    use crate::nifs::gen_test_values;
+
+    #[test]
+    fn test_r1cs_to_ccs() {
+        let (r1cs, ws, _) = gen_test_values(2);
+        let w: Vec<Fr> = ws[0].clone();
+
+        let ccs = r1cs.to_ccs();
+
+        assert!(ccs.check_relation(w));
+    }
+}

src/hypernova/mod.rs

@@ -0,0 +1 @@
+pub mod ccs;

src/lib.rs

@@ -12,3 +12,6 @@ mod pedersen;
 mod sumcheck;
 mod transcript;
 mod utils;
+
+// hypernova related:
+mod hypernova;