RSA

src/RSA/RSA.java

@@ -0,0 +1,63 @@
+public class RSA
+{
+  double q,alpha,Xa,Xb;
+
+  public static void main(String[] args)
+  {
+    RSA pair1 = new RSA(71, 7, 5, 12);
+    System.out.println(pair1.getYa());
+    System.out.println(pair1.getYb());
+    System.out.println(pair1.getKey());
+  }
+
+  RSA(double q , double alpha, double Xa, double Xb)
+  {
+    if(isPrime(q))
+    {
+    this.q = q;
+    this.alpha = alpha;
+    this.Xa = Xa;
+    this.Xb = Xb;
+    }
+    else
+    System.out.println("q must be prime!");
+  }
+
+  public double getYa()
+  {
+    return  Math.pow(alpha,Xa) % q; 
+  }
+
+  public double getYb()
+  {
+    return  Math.pow(alpha,Xb) % q; 
+  }
+  public double getKey()
+  {
+    double Kab,Kba;
+    Kab = Math.pow(getYb(),Xa) % (int) q;
+    System.out.println(Kab);
+    Kba = Math.pow(getYa(),Xb) % (int) q;
+    System.out.println(Kba);
+    if(Kab == Kba)
+      return  Kab;
+    else if(Math.abs(Kab - Kba) <= 1.9 && Kab > Kba)
+      return Kab;
+    else if(Math.abs(Kab - Kba) <= 1.9 && Kba > Kab)
+      return Kba;
+    else 
+      return 0;
+  }
+  //Check if number is prime
+  public static boolean isPrime(double n)
+  {
+    for(double i=2;i<n;i++)
+    {
+      if(n%i==0)
+      {
+        return false;
+      }
+    }
+    return true;
+  }
+}