java实现Miller-Rabin算法

import java.security.SecureRandom;


public class MillerRabin {

public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("2047\t"+MillerRabin(2047, 1));
System.out.println("1203972837\t"+MillerRabin(1203972837, 1));
System.out.println("65535\t"+MillerRabin(65535, 1));
}
/**
*
* @param n The number should be tested whether it is a prime.
* @param t
* @return
* true means n is a prime with a probability of (1/4)^t.
* false means n is a composite number with a probability of 1.
*/
public static boolean MillerRabin(int n,int t)
{
for(int i=0;i if(!isPrime(n))
return false;
return true;
}
/**
*
* @param n The number should be tested whether it is a prime.
*/
public static boolean isPrime(int n)
{
int k,q;
SecureRandom random=new SecureRandom();
for(k=0;(((n-1)>>k)&1)==0;k++);
q=(n-1)>>k;
int a=random.nextInt(n);
if(squareMultiply(a, q, n)==1)
return true;
for(int j=0;j if(squareMultiply(a, (int)Math.pow(2, j)*q, n)==n-1)
return true;
return false;
}

public static int squareMultiply(int a,int b,int p)
{
int x=1,y=a;
int len=(int)Math.ceil((Math.log(b)/Math.log(2)));
for(int i=0;i {
if(((b>>i)&1)==1)
{
x=(x*y)%p;
}
y=(y*y)%p;
}
return x;
}

}