Use XOR to encode and decode a message

   

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Use XOR to encode and decode a message. 
 
using System; 
 
public class Encode {  
  public static void Main() { 
    char ch1 = 'H'; 
    char ch2 = 'i'; 
    char ch3 = '!'; 
 
    int key = 88; 
 
    Console.WriteLine("Original message: " + 
                      ch1 + ch2 + ch3); 
 
    // encode the message 
    ch1 = (char) (ch1 ^ key); 
    ch2 = (char) (ch2 ^ key); 
    ch3 = (char) (ch3 ^ key); 
 
    Console.WriteLine("Encoded message: " +  
                      ch1 + ch2 + ch3); 
 
    // decode the message 
    ch1 = (char) (ch1 ^ key); 
    ch2 = (char) (ch2 ^ key); 
    ch3 = (char) (ch3 ^ key); 
    
    Console.WriteLine("Decoded message: " + 
                      ch1 + ch2 + ch3); 
  } 
}