using System;

using System.Security.Cryptography;

using System.IO;

using System.Text;

public class Program

{

    public static void Main()

    {

        Func<int, int> sq = s => s*=s;

        Action<string> ac = a => Console.WriteLine(a);

        //ac(sq(22).ToString());

        //ac("the end");

        string EncryptionKey = GenerateEncryptionKey();

        ac(EncryptionKey);

        string Encrypted = Encrypt("PasswordHere", EncryptionKey);

        ac(Encrypted);

        string Decrypted = Decrypt(Encrypted, EncryptionKey);

        ac(Decrypted);

​

        //    string Encrypted = Encrypt("PasswordHere", EncryptionKey);

          //  string Decrypted = Decrypt(Encrypted, EncryptionKey);

    }

    public static string GenerateEncryptionKey()

        {

            string EncryptionKey = string.Empty;

​

            Random Robj = new Random();

            int Rnumber = Robj.Next();

            EncryptionKey = "XYZ" + Convert.ToString(Rnumber);

            return EncryptionKey;

        }

    public static string Encrypt(string clearText, string EncryptionKey)

        {

            byte[]  clearBytes = Encoding.Unicode.GetBytes(clearText);

            using  (Aes encryptor = Aes.Create())

            {

                Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[]  { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });

                encryptor.Key = pdb.GetBytes (32);

                encryptor.IV = pdb.GetBytes(16);

                using (MemoryStream ms = new MemoryStream())

                {

                    using (CryptoStream cs = new CryptoStream (ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))

                    {

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

                        cs.Close();

                    }

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

                }

            }

            return clearText;

        }

​

​

​

public static string Decrypt(string cipherText, string EncryptionKey)

        {            

            byte[]  cipherBytes = Convert.FromBase64String(cipherText);

            using  (Aes encryptor = Aes.Create())

            {

                Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[]  { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });

                encryptor.Key = pdb.GetBytes (32);

                encryptor.IV = pdb.GetBytes(16);

                using (MemoryStream ms = new MemoryStream())

                {

                    using (CryptoStream cs = new CryptoStream (ms, encryptor.CreateDecryptor(), CryptoStreamMode.Write))

                    {

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

                        cs.Close();

                    }

                    cipherText = Encoding.Unicode.GetString (ms.ToArray());

                }

            }

            return cipherText;

        }

​

}