Improved Neptune Witness Generation via Bellpepper

Cargo.toml

@@ -11,9 +11,6 @@ license-file = "LICENSE"
 keywords = ["zkSNARKs", "cryptography", "proofs"]
 
 [dependencies]
-# TODO: replace with the next version of bellperson
-# See : https://github.com/filecoin-project/bellperson/pull/314
-bellperson = { git="https://github.com/filecoin-project/bellperson", rev="8c5d202e", default-features = false }
 bellpepper-core = { version="0.2.0", default-features = false }
 bellpepper = { version="0.2.0", default-features = false }
 ff = { version = "0.13.0", features = ["derive"] }

src/bellperson/mod.rs

@@ -5,6 +5,7 @@
 pub mod r1cs;
 pub mod shape_cs;
 pub mod solver;
+pub mod test_shape_cs;
 
 #[cfg(test)]
 mod tests {

src/bellperson/r1cs.rs

@@ -2,7 +2,7 @@
 
 #![allow(non_snake_case)]
 
-use super::{shape_cs::ShapeCS, solver::SatisfyingAssignment};
+use super::{shape_cs::ShapeCS, solver::SatisfyingAssignment, test_shape_cs::TestShapeCS};
 use crate::{
   errors::NovaError,
   r1cs::{R1CSInstance, R1CSShape, R1CSWitness, R1CS},
@@ -45,43 +45,53 @@ impl<G: Group> NovaWitness<G> for SatisfyingAssignment<G> {
   }
 }
 
-impl<G: Group> NovaShape<G> for ShapeCS<G> {
-  fn r1cs_shape(&self) -> (R1CSShape<G>, CommitmentKey<G>) {
-    let mut A: Vec<(usize, usize, G::Scalar)> = Vec::new();
-    let mut B: Vec<(usize, usize, G::Scalar)> = Vec::new();
-    let mut C: Vec<(usize, usize, G::Scalar)> = Vec::new();
-
-    let mut num_cons_added = 0;
-    let mut X = (&mut A, &mut B, &mut C, &mut num_cons_added);
-
-    let num_inputs = self.num_inputs();
-    let num_constraints = self.num_constraints();
-    let num_vars = self.num_aux();
-
-    for constraint in self.constraints.iter() {
-      add_constraint(
-        &mut X,
-        num_vars,
-        &constraint.0,
-        &constraint.1,
-        &constraint.2,
-      );
+macro_rules! impl_nova_shape {
+  ( $name:ident) => {
+    impl<G: Group> NovaShape<G> for $name<G>
+    where
+      G::Scalar: PrimeField,
+    {
+      fn r1cs_shape(&self) -> (R1CSShape<G>, CommitmentKey<G>) {
+        let mut A: Vec<(usize, usize, G::Scalar)> = Vec::new();
+        let mut B: Vec<(usize, usize, G::Scalar)> = Vec::new();
+        let mut C: Vec<(usize, usize, G::Scalar)> = Vec::new();
+
+        let mut num_cons_added = 0;
+        let mut X = (&mut A, &mut B, &mut C, &mut num_cons_added);
+
+        let num_inputs = self.num_inputs();
+        let num_constraints = self.num_constraints();
+        let num_vars = self.num_aux();
+
+        for constraint in self.constraints.iter() {
+          add_constraint(
+            &mut X,
+            num_vars,
+            &constraint.0,
+            &constraint.1,
+            &constraint.2,
+          );
+        }
+
+        assert_eq!(num_cons_added, num_constraints);
+
+        let S: R1CSShape<G> = {
+          // Don't count One as an input for shape's purposes.
+          let res = R1CSShape::new(num_constraints, num_vars, num_inputs - 1, &A, &B, &C);
+          res.unwrap()
+        };
+
+        let ck = R1CS::<G>::commitment_key(&S);
+
+        (S, ck)
+      }
     }
-
-    assert_eq!(num_cons_added, num_constraints);
-
-    let S: R1CSShape<G> = {
-      // Don't count One as an input for shape's purposes.
-      let res = R1CSShape::new(num_constraints, num_vars, num_inputs - 1, &A, &B, &C);
-      res.unwrap()
-    };
-
-    let ck = R1CS::<G>::commitment_key(&S);
-
-    (S, ck)
-  }
+  };
 }
 
+impl_nova_shape!(ShapeCS);
+impl_nova_shape!(TestShapeCS);
+
 fn add_constraint<S: PrimeField>(
   X: &mut (
     &mut Vec<(usize, usize, S)>,