Encrupt Decrupt

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.Security;
using System.Security.Cryptography;

namespace testinglistview
{
    public partial class EncruptsDecrupt : System.Web.UI.Page
    {

     

        public static string Encrypt(string text)
        {
            TripleDESCryptoServiceProvider cryptDES3 = new TripleDESCryptoServiceProvider();
            MD5CryptoServiceProvider cryptMD5Hash = new MD5CryptoServiceProvider();
            string key = "5";


            cryptDES3.Key = cryptMD5Hash.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(key));
            cryptDES3.Mode = CipherMode.ECB;
            ICryptoTransform desdencrypt = cryptDES3.CreateEncryptor();
            byte[] buff = System.Text.ASCIIEncoding.ASCII.GetBytes(text);
            string Encrypt = Convert.ToBase64String(desdencrypt.TransformFinalBlock(buff, 0, buff.Length));
            Encrypt = Encrypt.Replace("+", "!");
            return Encrypt;
        }
        public static string Decypt(string text)
        {
            TripleDESCryptoServiceProvider cryptDES3 = new TripleDESCryptoServiceProvider();
            MD5CryptoServiceProvider cryptMD5Hash = new MD5CryptoServiceProvider();
            string key = "5";


            text = text.Replace("!", "+");
            byte[] buf = new byte[text.Length];
            cryptDES3.Key = cryptMD5Hash.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(key));
            cryptDES3.Mode = CipherMode.ECB;
            ICryptoTransform desdencrypt = cryptDES3.CreateDecryptor();
            buf = Convert.FromBase64String(text);
            string Decrypt = System.Text.ASCIIEncoding.ASCII.GetString(desdencrypt.TransformFinalBlock(buf, 0, buf.Length));
            return Decrypt;
        }
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            string data = Encrypt(TextBox1.Text);
            TextBox2.Text = data;
        }

        protected void Button2_Click(object sender, EventArgs e)
        {
            string dd = Decypt(TextBox2.Text);
            txtdcrpt.Text = dd;
        }
    }
}