Use group crate for curve traits and wNAF

Cargo.toml

@@ -14,13 +14,14 @@ bit-vec = "0.4.4"
 ff = "0.4"
 futures = "0.1"
 futures-cpupool = "0.1"
+group = "0.1"
 num_cpus = "1"
 crossbeam = "0.3"
 byteorder = "1"
 
 [dependencies.pairing]
-git = "https://github.com/ebfull/pairing"
-rev = "183a64b08e9dc7067f78624ec161371f1829623e"
+git = "https://github.com/str4d/pairing"
+rev = "3d41ee5abaa4888ff3607689aba007be8856816d"
 
 [features]
 default = []

src/domain.rs

@@ -10,11 +10,9 @@
 //! This allows us to perform polynomial operations in O(n)
 //! by performing an O(n log n) FFT over such a domain.
 
-use ff::{Field, PrimeField};
-use pairing::{
-    Engine,
-    CurveProjective
-};
+use ff::{Field, PrimeField, ScalarEngine};
+use group::CurveProjective;
+use pairing::Engine;
 
 use super::{
     SynthesisError
@@ -188,7 +186,7 @@ impl<E: Engine, G: Group<E>> EvaluationDomain<E, G> {
     }
 }
 
-pub trait Group<E: Engine>: Sized + Copy + Clone + Send + Sync {
+pub trait Group<E: ScalarEngine>: Sized + Copy + Clone + Send + Sync {
     fn group_zero() -> Self;
     fn group_mul_assign(&mut self, by: &E::Fr);
     fn group_add_assign(&mut self, other: &Self);

src/groth16/generator.rs

@@ -3,12 +3,8 @@ use rand::Rng;
 use std::sync::Arc;
 
 use ff::{Field, PrimeField};
-use pairing::{
-    Engine,
-    Wnaf,
-    CurveProjective,
-    CurveAffine
-};
+use group::{CurveAffine, CurveProjective, Wnaf};
+use pairing::Engine;
 
 use super::{
     Parameters,

src/groth16/mod.rs

@@ -1,7 +1,7 @@
+use group::{CurveAffine, EncodedPoint};
 use pairing::{
     Engine,
-    CurveAffine,
-    EncodedPoint
+    PairingCurveAffine,
 };
 
 use ::{
@@ -385,9 +385,9 @@ pub struct PreparedVerifyingKey<E: Engine> {
     /// Pairing result of alpha*beta
     alpha_g1_beta_g2: E::Fqk,
     /// -gamma in G2
-    neg_gamma_g2: <E::G2Affine as CurveAffine>::Prepared,
+    neg_gamma_g2: <E::G2Affine as PairingCurveAffine>::Prepared,
     /// -delta in G2
-    neg_delta_g2: <E::G2Affine as CurveAffine>::Prepared,
+    neg_delta_g2: <E::G2Affine as PairingCurveAffine>::Prepared,
     /// Copy of IC from `VerifiyingKey`.
     ic: Vec<E::G1Affine>
 }

src/groth16/prover.rs

@@ -5,11 +5,8 @@ use std::sync::Arc;
 use futures::Future;
 
 use ff::{Field, PrimeField};
-use pairing::{
-    Engine,
-    CurveProjective,
-    CurveAffine
-};
+use group::{CurveAffine, CurveProjective};
+use pairing::Engine;
 
 use super::{
     ParameterSource,

src/groth16/tests/dummy_engine.rs

@@ -1,13 +1,8 @@
 use ff::{
     Field, LegendreSymbol, PrimeField, PrimeFieldDecodingError,
     PrimeFieldRepr, ScalarEngine, SqrtField};
-use pairing::{
-    Engine,
-    CurveProjective,
-    CurveAffine,
-    GroupDecodingError,
-    EncodedPoint
-};
+use group::{CurveAffine, CurveProjective, EncodedPoint, GroupDecodingError};
+use pairing::{Engine, PairingCurveAffine};
 
 use std::cmp::Ordering;
 use std::fmt;
@@ -277,8 +272,8 @@ impl Engine for DummyEngine {
 
     fn miller_loop<'a, I>(i: I) -> Self::Fqk
         where I: IntoIterator<Item=&'a (
-                                    &'a <Self::G1Affine as CurveAffine>::Prepared,
-                                    &'a <Self::G2Affine as CurveAffine>::Prepared
+                                    &'a <Self::G1Affine as PairingCurveAffine>::Prepared,
+                                    &'a <Self::G2Affine as PairingCurveAffine>::Prepared
                                )>
     {
         let mut acc = <Fr as Field>::zero();
@@ -401,11 +396,8 @@ impl EncodedPoint for FakePoint {
 }
 
 impl CurveAffine for Fr {
-    type Pair = Fr;
-    type PairingResult = Fr;
     type Compressed = FakePoint;
     type Uncompressed = FakePoint;
-    type Prepared = Fr;
     type Projective = Fr;
     type Base = Fr;
     type Scalar = Fr;
@@ -437,6 +429,16 @@ impl CurveAffine for Fr {
         res
     }
 
+    fn into_projective(&self) -> Self::Projective {
+        *self
+    }
+}
+
+impl PairingCurveAffine for Fr {
+    type Prepared = Fr;
+    type Pair = Fr;
+    type PairingResult = Fr;
+
     fn prepare(&self) -> Self::Prepared {
         *self
     }
@@ -444,8 +446,4 @@ impl CurveAffine for Fr {
     fn pairing_with(&self, other: &Self::Pair) -> Self::PairingResult {
         self.mul(*other)
     }
-
-    fn into_projective(&self) -> Self::Projective {
-        *self
-    }
 }

src/groth16/verifier.rs

@@ -1,9 +1,6 @@
 use ff::PrimeField;
-use pairing::{
-    Engine,
-    CurveProjective,
-    CurveAffine,
-};
+use group::{CurveAffine, CurveProjective};
+use pairing::{Engine, PairingCurveAffine};
 
 use super::{
     Proof,

src/lib.rs

@@ -1,4 +1,5 @@
 extern crate ff;
+extern crate group;
 extern crate pairing;
 extern crate rand;
 extern crate num_cpus;

src/multiexp.rs

@@ -1,8 +1,5 @@
 use ff::{Field, PrimeField, PrimeFieldRepr, ScalarEngine};
-use pairing::{
-    CurveAffine,
-    CurveProjective,
-};
+use group::{CurveAffine, CurveProjective};
 use std::sync::Arc;
 use std::io;
 use bit_vec::{self, BitVec};