using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Web;
 
///<summary>
/// Summary description for Security
///</summary>
publicclassSecurity
{
    privateconstint keysize = 256;
    privateconststring initVector = "tu89geji340t89u2";
 
       public Security()
       {
                  }
 
    //encrypt method
    publicstaticstring Encrypt(string plainText, string passPhrase)
    {
        byte[] initVectorBytes = Encoding.UTF8.GetBytes(initVector);
        byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
        PasswordDeriveBytes password = newPasswordDeriveBytes(passPhrase, null);
        byte[] keyBytes = password.GetBytes(keysize / 8);
        RijndaelManaged symmetricKey = newRijndaelManaged();
        symmetricKey.Mode = CipherMode.CBC;
        ICryptoTransform encryptor = symmetricKey.CreateEncryptor(keyBytes, initVectorBytes);
        MemoryStream memoryStream = newMemoryStream();
        CryptoStream cryptoStream = newCryptoStream(memoryStream, encryptor, CryptoStreamMode.Write);
        cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
        cryptoStream.FlushFinalBlock();
        byte[] cipherTextBytes = memoryStream.ToArray();
        memoryStream.Close();
        cryptoStream.Close();
        returnConvert.ToBase64String(cipherTextBytes);
    }
 
    //decrypt method
    publicstaticstring Decrypt(string cipherText)
    {
        byte[] initVectorBytes = Encoding.ASCII.GetBytes(initVector);
        byte[] cipherTextBytes = Convert.FromBase64String(cipherText);
        PasswordDeriveBytes password = newPasswordDeriveBytes(initVector, null);
        byte[] keyBytes = password.GetBytes(keysize / 8);
        RijndaelManaged symmetricKey = newRijndaelManaged();
        symmetricKey.Mode = CipherMode.CBC;
        ICryptoTransform decryptor = symmetricKey.CreateDecryptor(keyBytes, initVectorBytes);
        MemoryStream memoryStream = newMemoryStream(cipherTextBytes);
        CryptoStream cryptoStream = newCryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);
        byte[] plainTextBytes = newbyte[cipherTextBytes.Length];
        int decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
        memoryStream.Close();
        cryptoStream.Close();
        returnEncoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
    }
}