import org.spongycastle.math.ec.FixedPointCombMultiplier; //导入依赖的package包/类
/**
 * 根据私匙计算公匙
 *
 * @param privKey
 * @return ECKey
 */
public static ECPoint publicPointFromPrivate(BigInteger privKey) {
    if (privKey.bitLength() > CURVE.getN().bitLength()) {
        privKey = privKey.mod(CURVE.getN());
    }
    return new FixedPointCombMultiplier().multiply(CURVE.getG(), privKey);
}
 

import org.spongycastle.math.ec.FixedPointCombMultiplier; //导入依赖的package包/类
/**
 * Returns public key point from the given private key. To convert a byte array into a BigInteger, use <tt>
 * new BigInteger(1, bytes);</tt>
 */
public static ECPoint publicPointFromPrivate(BigInteger privKey) {
    /*
     * TODO: FixedPointCombMultiplier currently doesn't support scalars longer than the group order,
     * but that could change in future versions.
     */
    if (privKey.bitLength() > CURVE.getN().bitLength()) {
        privKey = privKey.mod(CURVE.getN());
    }
    return new FixedPointCombMultiplier().multiply(CURVE.getG(), privKey);
}
 

import org.spongycastle.math.ec.FixedPointCombMultiplier; //导入依赖的package包/类
/**
 * Returns public key point from the given private key. To convert a byte
 * array into a BigInteger, use <tt>
 * new BigInteger(1, bytes);</tt>
 */
public static ECPoint publicPointFromPrivate(BigInteger privKey) {
    /*
     * TODO: FixedPointCombMultiplier currently doesn't support scalars
     * longer than the group order, but that could change in future
     * versions.
     */
    if (privKey.bitLength() > CURVE.getN().bitLength()) {
        privKey = privKey.mod(CURVE.getN());
    }
    return new FixedPointCombMultiplier().multiply(CURVE.getG(), privKey);
}