Misc nitpicks (#31)

Cargo.toml

@@ -50,7 +50,6 @@ secp256r1 = [
 ed25519 = [ "ark-ed25519" ]
 bandersnatch = [ "ark-ed-on-bls12-381-bandersnatch" ]
 ring = [
-  "bandersnatch",
   "ring-proof",
   "ark-bls12-381/curve",
 ]

src/pedersen.rs

@@ -2,6 +2,7 @@ use crate::ietf::IetfSuite;
 use crate::*;
 
 pub trait PedersenSuite: IetfSuite {
+    /// Blinding base.
     const BLINDING_BASE: AffinePoint<Self>;
 
     /// Pedersen blinding factor.

src/ring.rs

@@ -8,8 +8,11 @@ pub trait RingSuite: PedersenSuite {
     /// Pairing type.
     type Pairing: ark_ec::pairing::Pairing<ScalarField = BaseField<Self>>;
 
-    /// Complement point.
-    const COMPLEMENT_POINT: AffinePoint<Self>;
+    /// Accumulator base.
+    ///
+    /// In order for the ring-proof backend to work correctly, this is required to be
+    /// in the prime order subgroup.
+    const ACCUMULATOR_BASE: AffinePoint<Self>;
 }
 
 /// Polinomial Commitment Scheme (KZG)
@@ -189,7 +192,7 @@ where
         let piop_params = PiopParams::<S>::setup(
             ring_proof::Domain::new(domain_size, true),
             S::BLINDING_BASE.into_sw(),
-            S::COMPLEMENT_POINT.into_sw(),
+            S::ACCUMULATOR_BASE.into_sw(),
         );
 
         Ok(Self {
@@ -313,6 +316,7 @@ pub(crate) mod testing {
 
     pub const TEST_RING_SIZE: usize = 8;
 
+    #[allow(unused)]
     pub fn prove_verify<S: RingSuite>()
     where
         BaseField<S>: ark_ff::PrimeField,
@@ -343,34 +347,35 @@ pub(crate) mod testing {
         assert!(result.is_ok());
     }
 
-    pub fn check_complement_point<S: RingSuite>()
+    /// Check that complement point is not in the prime subgroup.
+    ///
+    /// This is a requirement for the correct working of ring-proof backend.
+    #[allow(unused)]
+    pub fn check_accumulator_base<S: RingSuite>()
     where
         BaseField<S>: ark_ff::PrimeField,
         CurveConfig<S>: ark_ec::short_weierstrass::SWCurveConfig + Clone,
         AffinePoint<S>: utils::te_sw_map::SWMapping<CurveConfig<S>>,
     {
         use utils::te_sw_map::SWMapping;
-        let pt = S::COMPLEMENT_POINT.into_sw();
+        let pt = S::ACCUMULATOR_BASE.into_sw();
         assert!(pt.is_on_curve());
         assert!(!pt.is_in_correct_subgroup_assuming_on_curve());
     }
 
     #[macro_export]
     macro_rules! ring_suite_tests {
-        ($suite:ident, true) => {
-            #[cfg(feature = "ring")]
+        ($suite:ident) => {
             #[test]
             fn ring_prove_verify() {
                 $crate::ring::testing::prove_verify::<$suite>()
             }
 
-            #[cfg(feature = "ring")]
             #[test]
-            fn check_complement_point() {
-                $crate::ring::testing::check_complement_point::<$suite>()
+            fn check_accumulator_base() {
+                $crate::ring::testing::check_accumulator_base::<$suite>()
             }
         };
-        ($suite:ident, false) => {};
     }
 
     pub trait RingSuiteExt: RingSuite

src/suites/bandersnatch.rs

@@ -101,7 +101,7 @@ pub mod weierstrass {
             /// A point on the curve not belonging to the prime order subgroup.
             ///
             /// Found using `ring_proof::find_complement_point::<Self::Config>()` function.
-            const COMPLEMENT_POINT: AffinePoint = {
+            const ACCUMULATOR_BASE: AffinePoint = {
                 const X: BaseField = MontFp!("0");
                 const Y: BaseField = MontFp!(
                     "11982629110561008531870698410380659621661946968466267969586599013782997959645"
@@ -113,8 +113,11 @@ pub mod weierstrass {
     #[cfg(feature = "ring")]
     pub use ring_defs::*;
 
+    #[cfg(all(test, feature = "ring"))]
+    ring_suite_tests!(BandersnatchSha512Tai);
+
     #[cfg(test)]
-    suite_tests!(BandersnatchSha512Tai, true);
+    suite_tests!(BandersnatchSha512Tai);
 }
 
 pub mod edwards {
@@ -143,7 +146,7 @@ pub mod edwards {
     }
 
     impl PedersenSuite for BandersnatchSha512Ell2 {
-        /// Found mapping the `BLINDING_BASE` of `weierstrass` module using the `utils::map_sw_to_te`
+        /// Found mapping `BLINDING_BASE` of `weierstrass` module using the `utils::map_sw_to_te`
         const BLINDING_BASE: AffinePoint = {
             const X: BaseField = MontFp!(
                 "14576224270591906826192118712803723445031237947873156025406837473427562701854"
@@ -190,7 +193,7 @@ pub mod edwards {
             /// A point on the curve not belonging to the prime order subgroup.
             ///
             /// Found mapping the `COMPLEMENT_POINT` of `weierstrass` module using the `utils::map_sw_to_te`
-            const COMPLEMENT_POINT: AffinePoint = {
+            const ACCUMULATOR_BASE: AffinePoint = {
                 const X: BaseField = MontFp!(
                     "3955725774225903122339172568337849452553276548604445833196164961773358506589"
                 );
@@ -204,8 +207,11 @@ pub mod edwards {
     #[cfg(feature = "ring")]
     pub use ring_defs::*;
 
+    #[cfg(all(test, feature = "ring"))]
+    ring_suite_tests!(BandersnatchSha512Ell2);
+
     #[cfg(test)]
-    suite_tests!(BandersnatchSha512Ell2, true);
+    suite_tests!(BandersnatchSha512Ell2);
 
     #[test]
     fn elligator2_hash_to_curve() {
@@ -242,6 +248,8 @@ mod tests {
 
         let sw_point = map_te_to_sw::<BandersnatchConfig>(&te_point).unwrap();
         assert!(sw_point.is_on_curve());
+
+        assert_eq!(org_point, sw_point);
     }
 }
 

src/testing.rs

@@ -29,7 +29,7 @@ pub fn random_val<T: UniformRand>(rng: Option<&mut dyn RngCore>) -> T {
 
 #[macro_export]
 macro_rules! suite_tests {
-    ($suite:ident, $build_ring:ident) => {
+    ($suite:ident, $build_ring:expr) => {
         suite_tests!($suite);
         ring_suite_tests!($suite, $build_ring);
     };