org.bouncycastle.crypto.hash2curve.impl

Class Elligator2MapToCurve

java.lang.Object

org.bouncycastle.crypto.hash2curve.impl.Elligator2MapToCurve

All Implemented Interfaces:

MapToCurve

public class Elligator2MapToCurve
extends java.lang.Object
implements MapToCurve

Implements the Elligator 2 Map to curve according to section 6.7.1 of RFC 9380 This is the straight-line implementation optimized for Montgomery curves as defined in section F.3.

Constructor Summary

Constructors

Constructor and Description
Elligator2MapToCurve(ECCurve curve, java.math.BigInteger z, java.math.BigInteger J, java.math.BigInteger K) Constructs an Elligator2MapToCurve instance using the provided elliptic curve parameters and constants.

Method Summary

Modifier and Type	Method and Description
ECPoint	process(java.math.BigInteger u) Processes the given input value to map it to an elliptic curve point using the Elligator 2 algorithm, optimized for Montgomery curves.

Methods inherited from class java.lang.Object

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

Constructor Detail

Elligator2MapToCurve

public Elligator2MapToCurve(ECCurve curve,
                            java.math.BigInteger z,
                            java.math.BigInteger J,
                            java.math.BigInteger K)

Constructs an Elligator2MapToCurve instance using the provided elliptic curve parameters and constants.

Parameters:

curve - the elliptic curve (ECCurve) to which the input values will be mapped

z - a non-square element of the elliptic curve field

J - the Montgomery curve equation A value (Named J in RFC 9380)

K - the Montgomery curve equation B value (Named K in RFC 9380)

Method Detail

process

public ECPoint process(java.math.BigInteger u)

Processes the given input value to map it to an elliptic curve point using the Elligator 2 algorithm, optimized for Montgomery curves. This implementation adheres to the specifications outlined in RFC 9380, section 6.7.1, and section F.3 for efficient computation.

Specified by:

process in interface MapToCurve

Parameters:

u - the input value to be mapped to a point on the elliptic curve

Returns:

the computed point on the elliptic curve represented as an ECPoint