using System;

​

public class SubstitutionCipher

{

   public static void Main()

   {               

      string key = "1qazxsw23edcvfr45tgbnhy67ujm,ki89ol./;p0-[']=~`¥{}QAZXCDEW"; //You can change the Key,BUT always keep it 58 characters long AND each character is diffrent from the others.

      string plainText = "Im a student in Ness program";    //Please use only letters. no numbers or special characters.

      string cipherText = Encrypt(plainText, key);

      //string decryptedText = Decrypt(cipherText, key);

​

      Console.WriteLine("Plain     : {0}", plainText);

      Console.WriteLine("Encrypted : {0}", cipherText);

      //Console.WriteLine("Decrypted : {0}", decryptedText);

   }

​

   static string Encrypt(string plainText, string key)

   {

      char[] chars = new char[plainText.Length];

​

      for(int i = 0; i < plainText.Length; i++)

      {

         if (plainText[i] == ' ')

         {

            chars[i] = ' ';

         }   

         else

         {

            int j = plainText[i] - 65 ;

            chars[i] = key[j];

         }

      }

      return new string(chars);

   }

​

   //static string Decrypt(string cipherText, string key)

   //{

       //Write your code here!

   //} 

}