org.bouncycastle.math.ec.endo.GLVTypeAEndomorphism Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of bcprov-ext-jdk14 Show documentation

The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for JDK 1.4. Note: this package includes the NTRU encryption algorithms.

There is a newer version: 1.78

Show newest version

package org.bouncycastle.math.ec.endo;

import java.math.BigInteger;

import org.bouncycastle.math.ec.ECCurve;
import org.bouncycastle.math.ec.ECPointMap;
import org.bouncycastle.math.ec.ScaleYNegateXPointMap;

public class GLVTypeAEndomorphism implements GLVEndomorphism
{
    protected final GLVTypeAParameters parameters;
    protected final ECPointMap pointMap;

    public GLVTypeAEndomorphism(ECCurve curve, GLVTypeAParameters parameters)
    {
        /*
         * NOTE: 'curve' MUST only be used to create a suitable ECFieldElement. Due to the way
         * ECCurve configuration works, 'curve' will not be the actual instance of ECCurve that the
         * endomorphism is being used with.
         */

        this.parameters = parameters;
        this.pointMap = new ScaleYNegateXPointMap(curve.fromBigInteger(parameters.getI()));
    }

    public BigInteger[] decomposeScalar(BigInteger k)
    {
        return EndoUtil.decomposeScalar(parameters.getSplitParams(), k);
    }

    public ECPointMap getPointMap()
    {
        return pointMap;
    }

    public boolean hasEfficientPointMap()
    {
        return true;
    }
}