Java BigInteger is Prime hasSqrtModPrime(BigInteger r, BigInteger p)

Description

has Sqrt Mod Prime

License

Open Source License

Declaration

public static boolean hasSqrtModPrime(BigInteger r, BigInteger p) 

Method Source Code

//package com.java2s;
/*/* ww w . ja  v  a 2 s .c  o m*/
 * UniCrypt
 *
 *  UniCrypt(tm) : Cryptographical framework allowing the implementation of cryptographic protocols e.g. e-voting
 *  Copyright (C) 2014 Bern University of Applied Sciences (BFH), Research Institute for
 *  Security in the Information Society (RISIS), E-Voting Group (EVG)
 *  Quellgasse 21, CH-2501 Biel, Switzerland
 *
 *  Licensed under Dual License consisting of:
 *  1. GNU Affero General Public License (AGPL) v3
 *  and
 *  2. Commercial license
 *
 *
 *  1. This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU Affero General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU Affero General Public License for more details.
 *
 *   You should have received a copy of the GNU Affero General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 *  2. Licensees holding valid commercial licenses for UniCrypt may use this file in
 *   accordance with the commercial license agreement provided with the
 *   Software or, alternatively, in accordance with the terms contained in
 *   a written agreement between you and Bern University of Applied Sciences (BFH), Research Institute for
 *   Security in the Information Society (RISIS), E-Voting Group (EVG)
 *   Quellgasse 21, CH-2501 Biel, Switzerland.
 *
 *
 *   For further information contact <e-mail: unicrypt@bfh.ch>
 *
 *
 * Redistributions of files must retain the above copyright notice.
 */

import java.math.BigInteger;

public class Main {
    public static boolean hasSqrtModPrime(BigInteger r, BigInteger p) {
        BigInteger two = new BigInteger("2");
        return r.modPow(p.subtract(BigInteger.ONE).divide(two), p).equals(BigInteger.ONE);
    }
}

Related

1. calculateMPrime(BigInteger n, byte[] message)
2. fnvHash(final byte[] data, final BigInteger fnvOffs, final BigInteger fnvPrime, final BigInteger mod)
3. isBigPrime(BigInteger number)
4. isCoprime(BigInteger a, BigInteger b)
5. isFermatPrime(BigInteger f)
6. isPrime(BigInteger value)