org.bouncycastle.crypto.bls

Class BLS12_381G2

java.lang.Object

org.bouncycastle.crypto.bls.BLS12_381G2

public class BLS12_381G2
extends java.lang.Object

Curve parameters for BLS12-381 G2, the prime-order subgroup of E(Fp^2) defined by y^2 = x^3 + 4 * (1 + I) over Fp^2.

Field Summary

Fields

Modifier and Type	Field and Description
static java.math.BigInteger	COFACTOR G2 cofactor.
static java.math.BigInteger	H_EFF Effective cofactor for hash-to-curve (RFC 9380 sec. 8.8.2).
static java.math.BigInteger	ORDER G2 prime-order subgroup order — identical to G1's, since pairing-friendly curves have G1 and G2 share the same scalar field.

Method Summary

Modifier and Type	Method and Description
static BLS12_381G2Point	getGenerator()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ORDER

public static final java.math.BigInteger ORDER

G2 prime-order subgroup order — identical to G1's, since pairing-friendly curves have G1 and G2 share the same scalar field.

COFACTOR

public static final java.math.BigInteger COFACTOR

G2 cofactor.

H_EFF

public static final java.math.BigInteger H_EFF

Effective cofactor for hash-to-curve (RFC 9380 sec. 8.8.2). Multiplying any point on E(Fp^2) by h_eff lands in the prime-order subgroup; the value is chosen for compatibility with the Budroni-Pintore optimised cofactor clearing.

Method Detail

getGenerator

public static BLS12_381G2Point getGenerator()

Returns:

the standard generator G2 of the prime-order subgroup, as a fresh affine point. The returned point is verified against the curve equation.