Implement polynomial commitment

nomos-da/kzgrs/src/common.rs

@@ -19,6 +19,8 @@ pub enum KzgRsError {
     },
     #[error("ChunkSize should be < 32 (bytes), got {0}")]
     ChunkSizeTooBig(usize),
+    #[error(transparent)]
+    PolyCommitError(#[from] ark_poly_commit::Error),
 }
 
 /// Transform chunks of bytes (of size `CHUNK_SIZE`) into `Fr` which are considered evaluations of a

nomos-da/kzgrs/src/kzg.rs

@@ -0,0 +1,44 @@
+use crate::common::KzgRsError;
+use ark_bls12_381::{Bls12_381, Fr};
+use ark_poly::univariate::DensePolynomial;
+use ark_poly_commit::kzg10::{Commitment, Powers, KZG10};
+
+pub fn commit_polynomial(
+    polynomial: &DensePolynomial<Fr>,
+    roots_of_unity: &Powers<Bls12_381>,
+) -> Result<Commitment<Bls12_381>, KzgRsError> {
+    KZG10::commit(roots_of_unity, polynomial, None, None)
+        .map_err(KzgRsError::PolyCommitError)
+        .map(|(commitment, _)| commitment)
+}
+
+#[cfg(test)]
+mod test {
+    use crate::kzg::commit_polynomial;
+    use ark_bls12_381::{Bls12_381, Fr};
+    use ark_poly::univariate::DensePolynomial;
+    use ark_poly::DenseUVPolynomial;
+    use ark_poly_commit::kzg10::{Powers, KZG10};
+    use std::borrow::Cow;
+
+    #[test]
+    fn test_poly_commit() {
+        const COEFFICIENTS_SIZE: usize = 10;
+        let mut rng = rand::thread_rng();
+        let trusted_setup =
+            KZG10::<Bls12_381, DensePolynomial<Fr>>::setup(COEFFICIENTS_SIZE - 1, true, &mut rng)
+                .unwrap();
+
+        let roots_of_unity = Powers {
+            powers_of_g: Cow::Borrowed(&trusted_setup.powers_of_g),
+            powers_of_gamma_g: Cow::Owned(
+                (0..COEFFICIENTS_SIZE)
+                    .map(|i| trusted_setup.powers_of_gamma_g[&i])
+                    .collect(),
+            ),
+        };
+
+        let poly = DensePolynomial::from_coefficients_vec((0..10).map(|i| Fr::from(i)).collect());
+        let _ = commit_polynomial(&poly, &roots_of_unity).unwrap();
+    }
+}