feat: add Grumpkin elliptic curve (native 2-cycle with BN254) (#1409)

Co-authored-by: Ivo Kubjas <[email protected]>

Author: yelhousni

std/algebra/defaults.go

@@ -11,6 +11,7 @@ import (
 	"github.com/consensys/gnark/std/algebra/emulated/sw_emulated"
 	"github.com/consensys/gnark/std/algebra/native/sw_bls12377"
 	"github.com/consensys/gnark/std/algebra/native/sw_bls24315"
+	"github.com/consensys/gnark/std/algebra/native/sw_grumpkin"
 	"github.com/consensys/gnark/std/math/emulated"
 	"github.com/consensys/gnark/std/math/emulated/emparams"
 )
@@ -58,6 +59,12 @@ func GetCurve[FR emulated.FieldParams, G1El G1ElementT](api frontend.API) (Curve
 			return ret, fmt.Errorf("new curve: %w", err)
 		}
 		*s = c
+	case *Curve[sw_grumpkin.ScalarField, sw_grumpkin.G1Affine]:
+		c, err := sw_grumpkin.NewCurve(api)
+		if err != nil {
+			return ret, fmt.Errorf("new curve: %w", err)
+		}
+		*s = c
 	default:
 		return ret, errors.New("unknown type parametrisation")
 	}

std/algebra/native/sw_grumpkin/doc.go

@@ -0,0 +1,9 @@
+// Package sw_grumpkin implements the the Grumpkin curve in-circuit.
+//
+// Grumpkin curve forms a 2-cycle over BN254 so the operations can use the
+// native field arithmetics. Grumpkin curve is not pairing friendly, so it is
+// not suitable for pairing based proof system recursion.
+//
+// References:
+// https://aztecprotocol.github.io/aztec-connect/primitives.html/
+package sw_grumpkin