using System;

using System.IO;

using System.Security.Cryptography;

using System.Text;

using System.Web;

​

public class SimpleSecurity

    {

       public static string Encrypt(string textToEncrypt)

       {

           try

           {

               string ToReturn = "";

               string _key = "EnfMDh7unVa%M8wU8?7aY*7Mr!";

               string _iv = "m%kRZjYaZ#QcVPe!fKr?K9gr^$";

               byte[] _ivByte = { };

               _ivByte = System.Text.Encoding.UTF8.GetBytes(_iv.Substring(0, 8));

               byte[] _keybyte = { };

               _keybyte = System.Text.Encoding.UTF8.GetBytes(_key.Substring(0, 8));

               MemoryStream ms = null; CryptoStream cs = null;

               byte[] inputbyteArray = System.Text.Encoding.UTF8.GetBytes(textToEncrypt);

               using (DESCryptoServiceProvider des = new DESCryptoServiceProvider())

               {

                   ms = new MemoryStream();

                   cs = new CryptoStream(ms, des.CreateEncryptor(_keybyte, _ivByte), CryptoStreamMode.Write);

                   cs.Write(inputbyteArray, 0, inputbyteArray.Length);

                   cs.FlushFinalBlock();

                   ToReturn = Convert.ToBase64String(ms.ToArray());

               }

               return ToReturn;

           }

           catch(Exception ae)

           {

               throw new Exception(ae.Message, ae.InnerException);

           }

       }

       public static string Decrypt(string textToDecrypt)

       {

           try

           {

               string ToReturn = "";

               string _key = "EnfMDh7unVa%M8wU8?7aY*7Mr!";

               string _iv = "m%kRZjYaZ#QcVPe!fKr?K9gr^$";

               byte[] _ivByte = { };

               _ivByte = System.Text.Encoding.UTF8.GetBytes(_iv.Substring(0, 8));

               byte[] _keybyte = { };

               _keybyte = System.Text.Encoding.UTF8.GetBytes(_key.Substring(0, 8));

               MemoryStream ms = null; CryptoStream cs = null;

               byte[] inputbyteArray = new byte[textToDecrypt.Replace(" ", "+").Length];

               inputbyteArray = Convert.FromBase64String(textToDecrypt.Replace(" ", "+"));

               using (DESCryptoServiceProvider des = new DESCryptoServiceProvider())

               {

                   ms = new MemoryStream();

                   cs = new CryptoStream(ms, des.CreateDecryptor(_keybyte, _ivByte), CryptoStreamMode.Write);

                   cs.Write(inputbyteArray, 0, inputbyteArray.Length);

                   cs.FlushFinalBlock();

                   Encoding encoding = Encoding.UTF8;

                   ToReturn = encoding.GetString(ms.ToArray());

               }

               return ToReturn;

           }

           catch(Exception ae)

           {

               throw new Exception(ae.Message, ae.InnerException);

           }

       }

        public static void Main()

        {

            string code = "A00-11182019287";

            string eCode = Encrypt(code);

            string dCode = Decrypt(eCode);

            Console.WriteLine("Encrypted cs: " + eCode);

            Console.WriteLine("Sample querystring used: cs=" + HttpUtility.UrlEncode(eCode));

            Console.WriteLine("Decrypted cs: " + dCode);

        }

    }

​

​