Fix the definition of PairingFriendlyCycle (#217)

* Update lib.rs

* Update CHANGELOG.md

* Update CHANGELOG.md

* Update CHANGELOG.md

Co-authored-by: Pratyush Mishra <pratyushmishra@berkeley.edu>

Co-authored-by: Pratyush Mishra <pratyushmishra@berkeley.edu>

Author: weikengchen

CHANGELOG.md

@@ -96,5 +96,6 @@ The main features of this release are:
 - #165 (ark-ff) Enforce in the type system that an extension fields `BaseField` extends from the correct `BasePrimeField`.
 - #184 Compile with `panic='abort'` in release mode, for safety of the library across FFI boundaries.
 - #192 Fix a bug in the assembly backend for finite field arithmetic.
+- #217 (ark-ec) Fix the definition of `PairingFriendlyCycle` introduced in #190.
 
 ## v0.1.0 (Initial release of arkworks/algebra)

ec/src/lib.rs

@@ -347,8 +347,8 @@ pub trait PairingFriendlyCycle: CurveCycle {
     >;
 
     type Engine2: PairingEngine<
-        G2Affine = Self::E2,
-        G2Projective = <Self::E2 as AffineCurve>::Projective,
+        G1Affine = Self::E2,
+        G1Projective = <Self::E2 as AffineCurve>::Projective,
         Fq = <Self::E2 as AffineCurve>::BaseField,
         Fr = <Self::E2 as AffineCurve>::ScalarField,
     >;