SENG2250_Assignment3/Q2Tools.java

import java.math.BigInteger;

public class Q2Tools {

    Q2Tools()
    {
        //Nothing to do here
    }
    
    public void generateRSA()
    {

        int e = 65537;

        //Generate p

        //Generate q



    }

    /**
     * A^B mod C
     * @param A
     * @param B
     * @param C
     */
    public BigInteger fastModularExpon(String base, String exponent, String modulus)
    {
        // BigInteger baseVal = new BigInteger(base);
        // BigInteger exponentVal = new BigInteger(exponent);
        // BigInteger modulusVal = new BigInteger(modulus);  
        
        //modulusVal.equals(BigInteger.valueOf(1));
        if(modulusVal == 1)
        {  
            return BigInteger.valueOf(0);
        }

        BigInteger temp = new BigInteger("1");

        while(exponentVal>0)
        {
            if((exponentVal & 1)==1)
            {
               // temp = (temp * baseVal) % modulusVal;
               temp = temp.multiply(BigInteger.valueOf(baseVal));
               temp = temp.mod(BigInteger.valueOf(modulusVal));

            }

            exponentVal = exponentVal >> 1;
            baseVal = (baseVal*baseVal) % modulusVal;
        }
        return temp;
    }
}