public class PubKey1
{
   public static long[] prime =
		{ 3, 5, 7, 11, 13, 17, 19, 23, 29, 31,
		  919, 929, 937, 941, 947, 953, 967, 971, 977, 983,
		  433494437L, 2971215073L };

   public static long p, q;

   public static long n, m;
   public static long enc, dec;

   public static long encrypt( long x )
   {
      long out = 1;

      System.out.println("input >> " + x);

      for (int i=0; i < enc; i++ )
      {
         out = (out*x)%n;
         System.out.println("enc>> " + out);
      }

      return out;
   }

   public static long decrypt( long x )
   {
      long out = 1;

      System.out.println("input >> " + x);

      for (int i=0; i < dec; i++ )
      {
         out = (out*x)%n;
         System.out.println("dec>> " + out);
      }

      return out;
   }


   public static void main( String[] args )
   {
      p = prime[5];
      q = prime[3];

      n = p*q;
      m = (p-1)*(q-1);

      for ( enc = 7; enc < n; enc++ )
      {
          if ( m % enc != 0 )
             break;
      }

      for ( dec = 1; dec < n; dec++ )
      {
         if ( (dec*enc)%m == 1 )
	    break;
      }

      System.out.println("prime 1 p = " + p);
      System.out.println("prime 2 q = " + q);
      System.out.println("n (p*q) = " + n);
      System.out.println("m ((p-1)*(q-1)) = " + m);
      System.out.println("enc (m not div by enc) = " + enc);
      System.out.println("dec (=  not div by enc) = " + dec);

      long m, x, y;

      m = 131;

      x = encrypt(m);
      System.out.println();

      y = decrypt(x);

      System.out.println("m = " + m 
                          + "  Encrypted = " + x 
                          + "  Decrypted = " + y ); 
   }
}