rsarsarsa

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package rsa;

import java.math.BigInteger;

/**
 *
 * @author Student
 */
public class Rsa {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        int n;
        n = gcd(12, 40);
        System.out.println(n);
        n = atobmodn(2, 3, 4);
        System.out.println(n);

        System.out.println();

        int mc = sign(35, 7, 13);
        System.out.println(mc);
    }

    static int gcd(int a, int b) {
        int r;
        r = a % b;
        if (r == 0) {
            return b;
        } else {
            return gcd(b, r);
        }
    }

    static int atobmodn(int a, int b, int n) {
        double pow = Math.pow(a, b);
        return (int) (pow % n);
    }

    static int sign(int m, int p, int q) {
        int S;
        int v = 5;
        int pq= p*q;
        int n = (p-1) * (q-1);
        BigInteger s = BigInteger.valueOf(v).modInverse(BigInteger.valueOf(n));
        int ss = s.intValue();
        System.out.println(s);
        S = atobmodn(m, ss, pq);
        return S;
    }

}