Encrypt/Decrypt Querystring

 First Create Class as Encrypt.cs



using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Security.Cryptography;

using System.IO;

using System.Text;



/// <summary>

/// Summary description for Encrypt

/// </summary>

public class EncryptDecryptQueryString

{

    private byte[] key = { };

    private byte[] IV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xab, 0xcd, 0xef };

    public string Decrypt(string stringToDecrypt, string sEncryptionKey)

    {

        byte[] inputByteArray = new byte[stringToDecrypt.Length + 1];

        try

        {

            key = System.Text.Encoding.UTF8.GetBytes(sEncryptionKey);

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            inputByteArray = Convert.FromBase64String(stringToDecrypt);

            MemoryStream ms = new MemoryStream();

            CryptoStream cs = new CryptoStream(ms,

              des.CreateDecryptor(key, IV), CryptoStreamMode.Write);

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

            cs.FlushFinalBlock();

            System.Text.Encoding encoding = System.Text.Encoding.UTF8;

            return encoding.GetString(ms.ToArray());

        }

        catch (Exception e)

        {

            return e.Message;

        }

    }



    public string Encrypt(string stringToEncrypt, string SEncryptionKey)

    {

        try

        {

            key = System.Text.Encoding.UTF8.GetBytes(SEncryptionKey);

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            byte[] inputByteArray = Encoding.UTF8.GetBytes(stringToEncrypt);

            MemoryStream ms = new MemoryStream();

            CryptoStream cs = new CryptoStream(ms,

              des.CreateEncryptor(key, IV), CryptoStreamMode.Write);

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

            cs.FlushFinalBlock();

            return Convert.ToBase64String(ms.ToArray());

        }

        catch (Exception e)

        {

            return e.Message;

        }

    }

}

---------------------

Now For Encrypt...

FirstPage.aspx

 protected void Button1_Click(object sender, EventArgs e)

    {

        string strName = "", strAge = "", strPhone = "";

        strName = "Dhruval";

        string strURL = "Executive.aspx?";

        if (HttpContext.Current != null)

        {

            string strURLWithData = strURL +

              EncryptQueryString(string.Format("Name={0}",

              strName));

            HttpContext.Current.Response.Redirect(strURLWithData);

        }

        else

        { }

    }



public string EncryptQueryString(string strQueryString)

    {

        EncryptDecryptQueryString objEDQueryString = new EncryptDecryptQueryString();

        return objEDQueryString.Encrypt(strQueryString, "r0b1nr0y");

    }



-------------------

SecondPage.aspx

 if (!IsPostBack)

        {

            string strReq = "";

            strReq = Request.RawUrl;

            strReq = strReq.Substring(strReq.IndexOf('?') + 1);



            if (!strReq.Equals(""))

            {

                strReq = DecryptQueryString(strReq);



                //Parse the value... this is done is very raw format..

                //you can add loops or so to get the values out of the query string...

                string[] arrMsgs = strReq.Split('&');

                string[] arrIndMsg;

                string strName = "", strAge = "", strPhone = "";

                arrIndMsg = arrMsgs[0].Split('='); //Get the Name

                strName = arrIndMsg[1].ToString().Trim();

                //arrIndMsg = arrMsgs[1].Split('='); //Get the Age

                //strAge = arrIndMsg[1].ToString().Trim();

                //arrIndMsg = arrMsgs[2].Split('='); //Get the Phone

                //strPhone = arrIndMsg[1].ToString().Trim();



                lblName.Text = strName;



            }

            else

            {

                Response.Redirect("Page1.aspx");

            }

        }