Laborator6 SSC

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package laborator6;

//import java.math.BigInteger;
import java.math.*;

/**
 *
 * @author student
 */
public class Laborator6 {

    /**
     * @param args the command line arguments
     */
    private BigInteger e;
    private BigInteger n;
    private BigInteger d;

    //recursively searches for the sqr root of a in interval [left, right]
private static BigInteger NaiveSquareRootSearch(BigInteger a, BigInteger left,
BigInteger right)
 {
 // fix root as the arithmetic mean of left and right
 BigInteger root = left.add(right).shiftRight(1);
 // if the root is not between [root, root+1],
 //is not an integer and root is our best integer approximation
if(!((root.pow(2).compareTo(a) == -
1)&&(root.add(BigInteger.ONE).pow(2).compareTo(a) == 1))){
 if (root.pow(2).compareTo(a) == -1) root = NaiveSquareRootSearch(a, root,
right);
 if (root.pow(2).compareTo(a) == 1) root = NaiveSquareRootSearch(a, left,
root);
 }
 return root;
 }

public static BigInteger SquareRoot(BigInteger a)
{
 return NaiveSquareRootSearch(a, BigInteger.ZERO, a);
}
  /*
    public BigInteger Power (){

BigInteger numar = new BigInteger("17");
BigInteger putere = new BigInteger("-1");
 return Math.pow(numar, putere));

}*/


    public Laborator6() {
        this.e = new BigInteger("7");
        this.n = new BigInteger("837210799");
        this.d = new BigInteger("478341751");
    }
    private BigInteger PrivateKey(BigInteger e1){
        BigInteger delta = new BigInteger("9360562500");
        BigInteger k = new BigInteger("0");
        BigInteger sum = new BigInteger("112736");
        BigInteger dcautat = new BigInteger("0");

        //se calculeaza k dupa formula (d*e-1)/n
        k = this.d.multiply(e).subtract(new BigInteger("1")).divide(this.n);
        if(this.d.multiply(e).subtract(new BigInteger("1")).mod(n).compareTo(new BigInteger("0"))!= 0)
            k  = k.add(new BigInteger("1"));

        System.out.println(k);
       sum=((new BigInteger("4").multiply((this.n).add(new BigInteger("1")))).add( new BigInteger("1").substract(new BigInteger("7").multiply(this.d) ) ));

        BigInteger root1 = new BigInteger("0");
        BigInteger root2 = new BigInteger("0");

      //  System.out.println("eu " + SquareRoot(new BigInteger("100")) );
        root1 = sum.add(SquareRoot(delta)).divide(new BigInteger("2"));
        root2 = sum.subtract(SquareRoot(delta)).divide(new BigInteger("2"));

        System.out.println("radacina 1 are valoaea: " + root1);
        System.out.println("radacina 2 are valoaea: " + root2);

        dcautat= (new BigInteger("17").pow(-1)).mod((this.d).multiply(this.e).subtract(new BigInteger("1").divide(k)));
        return dcautat;
    }
    public static void main(String[] args) {
        // TODO code application logic here
            Laborator6 m = new Laborator6();
            Laborator6 g = new Laborator6();
            BigInteger e1 =new BigInteger("19");
            BigInteger e2 = new BigInteger("17");
            BigInteger resultm = m.PrivateKey(e2);
            BigInteger resultg = g.PrivateKey(e1);
            System.out.println("The private key is: " + resultg);
            System.out.println("The private key is: " + resultm);
    }

}