Add simple curve cycle trait for curve cycles (#190)

Co-authored-by: Pratyush Mishra <[email protected]>

CHANGELOG.md

@@ -10,6 +10,7 @@ The main features of this release are:
 - Small speedups to MSMs
 - Big speedups to radix-2 FFTs
 - Fix in the assembly arithmetic backend
+- Adding new traits for basic curve cycles and pairing based curve cycles 
 
 ### Breaking changes
 - #20 (ark-poly) Move univariate DensePolynomial and SparsePolynomial into a 
@@ -80,6 +81,7 @@ The main features of this release are:
 - #169 (ark-poly) Improve radix-2 FFTs by moving to a faster algorithm by Riad S. Wahby.
 - #171, #173, #176 (ark-poly) Apply significant further speedups to the new radix-2 FFT.
 - #188 (ark-ec) Make Short Weierstrass random sampling result in an element with unknown discrete log
+- #190 (ark-ec) Add curve cycle trait and extended pairing cycle trait for all types of ec cycles.
 
 ### Bug fixes
 - #36 (ark-ec) In Short-Weierstrass curves, include an infinity bit in `ToConstraintField`.

ec/src/lib.rs

@@ -313,6 +313,7 @@ pub fn prepare_g2<E: PairingEngine>(g: impl Into<E::G2Affine>) -> E::G2Prepared
 }
 
 /// A cycle of pairing-friendly elliptic curves.
+#[deprecated(note = "Please use `PairingFriendlyCycle` instead")]
 pub trait CycleEngine: Sized + 'static + Copy + Debug + Sync + Send
 where
  <Self::E2 as PairingEngine>::G1Projective: MulAssign<<Self::E1 as PairingEngine>::Fq>,
@@ -324,3 +325,31 @@ where
  Fq = <Self::E1 as PairingEngine>::Fr,
  >;
 }
+
+pub trait CurveCycle
+where
+ <Self::E1 as AffineCurve>::Projective: MulAssign<<Self::E2 as AffineCurve>::BaseField>,
+ <Self::E2 as AffineCurve>::Projective: MulAssign<<Self::E1 as AffineCurve>::BaseField>,
+{
+ type E1: AffineCurve<
+ BaseField = <Self::E2 as AffineCurve>::ScalarField,
+ ScalarField = <Self::E2 as AffineCurve>::BaseField,
+ >;
+ type E2: AffineCurve;
+}
+
+pub trait PairingFriendlyCycle: CurveCycle {
+ type Engine1: PairingEngine<
+ G1Affine = Self::E1,
+ G1Projective = <Self::E1 as AffineCurve>::Projective,
+ Fq = <Self::E1 as AffineCurve>::BaseField,
+ Fr = <Self::E1 as AffineCurve>::ScalarField,
+ >;
+
+ type Engine2: PairingEngine<
+ G2Affine = Self::E2,
+ G2Projective = <Self::E2 as AffineCurve>::Projective,
+ Fq = <Self::E2 as AffineCurve>::BaseField,
+ Fr = <Self::E2 as AffineCurve>::ScalarField,
+ >;
+}