Encrypt/Decrypt Key

    public static string Encrypt(string key, string originalString){
            byte[] bytes = Encoding.ASCII.GetBytes(key);
            if (String.IsNullOrEmpty(originalString)) return string.Empty; 
            DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider(); 
            MemoryStream memoryStream = new MemoryStream(); 
            CryptoStream cryptoStream = new CryptoStream(memoryStream, cryptoProvider.CreateEncryptor(bytes, bytes), CryptoStreamMode.Write); 
            StreamWriter writer = new StreamWriter(cryptoStream); 
            writer.Write(originalString); 
            writer.Flush(); 
            cryptoStream.FlushFinalBlock(); 
            writer.Flush(); 
            return Convert.ToBase64String(memoryStream.GetBuffer(), 0, (int)memoryStream.Length); 
        }

   public static string Decrypt(string key, string cryptedString){
            byte[] bytes = Encoding.ASCII.GetBytes(key);
            if (String.IsNullOrEmpty(cryptedString)) return string.Empty;
            DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
            MemoryStream memoryStream = new MemoryStream(Convert.FromBase64String(cryptedString));
            CryptoStream cryptoStream = new CryptoStream(memoryStream, cryptoProvider.CreateDecryptor(bytes, bytes), CryptoStreamMode.Read);
            StreamReader reader = new StreamReader(cryptoStream); 
            return reader.ReadToEnd();
        }