org.dromara.hutool.crypto.asymmetric.paillier.PaillierKey Maven / Gradle / Ivy
/*
* Copyright (c) 2013-2024 Hutool Team and hutool.cn
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.dromara.hutool.crypto.asymmetric.paillier;
import java.math.BigInteger;
import java.security.Key;
import java.security.SecureRandom;
/**
* Paillier算法密钥
*
* @author peterstefanov
* @author looly
*/
public class PaillierKey implements Key {
private static final long serialVersionUID = 1L;
/**
* 算法名称：Paillier
*/
public static final String ALGORITHM_NAME = "Paillier";
private final BigInteger n;
protected PaillierKey(final BigInteger n) {
this.n = n;
}
/**
* 获取N值
*
* @return N值
*/
public BigInteger getN() {
return n;
}
@Override
public String getAlgorithm() {
return ALGORITHM_NAME;
}
@Override
public String getFormat() {
return "NONE";
}
@Override
public byte[] getEncoded() {
return null;
}
/**
* 获取N * N
*
* @return N * N
*/
public BigInteger getNSquare() {
return n.multiply(n);
}
/**
* This method generates a random {@code r} in {@code Z_{n}^*} for
* each separate encryption using the same modulus n Paillier cryptosystem
* allows the generated r to differ every time, such that the same plaintext
* encrypted several times will produce different ciphertext every time.
*
* @param random {@link SecureRandom}
* @return r
*/
public BigInteger generateRandomRinZn(final SecureRandom random) {
BigInteger r;
// use the same key size as initialised
final int length = n.bitLength();
// generate r random integer in Z*_n
do {
r = new BigInteger(length, 64, random);
} while (r.compareTo(n) >= 0 || r.gcd(n).intValue() != 1);
return r;
}
}