/*
 * The MIT License
 *
 * Copyright 2016 Jack Tams.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package sh.jack.datastructures;

import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Random;

/**
 *
 * Simple factory that returns new CuckooHash functions. 
 * 
 * Currently not extensible in any way.
 * 
 * @author Jack Tams <dev@jack.sh>
 */
public class CuckooHashFactory 
{
 
    public static CuckooHash getHash(int size) throws NoSuchAlgorithmException
    {
        Random rand = SecureRandom.getInstanceStrong();
        return new CuckooHash(rand.nextInt(),rand.nextInt(),size);
    }
    
}

/*
 * The MIT License
 *
 * Copyright 2016 Jack Tams.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package sh.jack.datastructures;

import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Random;

/**
 *
 * Simple factory that returns new CuckooHash functions. 
 * 
 * Currently not extensible in any way.
 * 
 * @author Jack Tams <dev@jack.sh>
 */
public class CuckooHashFactory 
{
    private static Random rand = null;
    
    public static CuckooHash getHash(int size) throws NoSuchAlgorithmException
    {
        if ( rand == null )
            rand = SecureRandom.getInstance("SHA1PRNG");    
        
        return new CuckooHash(rand.nextInt(),rand.nextInt(),size);
    }
    
}

Improve random instance usage - Better handling for low entropy systems, dont keep creating new instances. - Use SHA1PRNG, its sufficient for the application, does not need to be "mathematically" random.