org.bouncycastle.crypto.hash2curve.impl

Class BLS12_381G1MapToCurve

java.lang.Object

org.bouncycastle.crypto.hash2curve.impl.BLS12_381G1MapToCurve

All Implemented Interfaces:

MapToCurve

public class BLS12_381G1MapToCurve
extends java.lang.Object
implements MapToCurve

Map-to-curve implementation for the BLS12381G1_XMD:SHA-256_SSWU_RO_ suite (RFC 9380 sec. 8.8.1).

BLS12-381 G1 has A == 0, so the simplified SWU map cannot be applied to E directly. Instead the suite specifies an 11-isogenous curve E' (RFC 9380 App. E.2) with non-zero A' / B', SSWU is run on E', and the resulting point is mapped back to E by the iso_11 rational map.

Constructor Summary

Constructors

Constructor and Description
BLS12_381G1MapToCurve(ECCurve curveE)

Method Summary

Modifier and Type	Method and Description
ECPoint	process(java.math.BigInteger u) Processes the given BigInteger element and maps it to a point on the elliptic curve, as defined by the hash 2 curve specification

Methods inherited from class java.lang.Object

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

Constructor Detail

BLS12_381G1MapToCurve

public BLS12_381G1MapToCurve(ECCurve curveE)

Method Detail

process

public ECPoint process(java.math.BigInteger u)

Description copied from interface: MapToCurve

Processes the given BigInteger element and maps it to a point on the elliptic curve, as defined by the hash 2 curve specification

Specified by:

process in interface MapToCurve

Parameters:

u - the input BigInteger element to be mapped to a point on the curve

Returns:

the elliptic curve point corresponding to the input element