http://www.bouncycastle.org/java.html: 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 1.5 to JDK 1.8.
  • The Legion of the Bouncy Castle Inc. 
package org.bouncycastle.math.ec.endo;

import java.math.BigInteger;

public interface GLVEndomorphism extends ECEndomorphism
{
    BigInteger[] decomposeScalar(BigInteger k);
}