MD5 test application

On my Default.aspx page i have taken following controls:

1.) Label lblMessage
2.) TextBox txtPalinStr
3.) Button btnEncrypt
4.) Label lblEnryptedString
5.) TextBox txtcheck
6.) Button btncheck onclick="btncheck_Click"
7.) Label lblcheck


This is my Default.aspx.cs page :

using System;
using System.Configuration;
using System.Data;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using MD5Encrypt;
public partial class _Default : System.Web.UI.Page
{
    private MD5 obj_MD5;

    protected void Page_Load(object sender, EventArgs e)
    {
        obj_MD5 = new MD5();
    }
    protected void btnEncrypt_Click(object sender, EventArgs e)
    {
        lblEnryptedString.Text = obj_MD5.Encrypt(txtPalinStr.Text);
    }
    protected void btncheck_Click(object sender, EventArgs e)
    {
        lblcheck.Text = obj_MD5.verify(txtcheck.Text);

        if (lblEnryptedString.Text == lblcheck.Text)
        {
            lblMessage.Text = "You Are Authenticated";
        }
        else
        {
            lblMessage.Text = "Authentication Failed";
        }
    }
}


And Finally My MD5 Class :


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;

namespace MD5Encrypt
{
    public class MD5
    {
        private Byte[] EncStringBytes;
        private UTF8Encoding Encoder = new UTF8Encoding();
        private MD5CryptoServiceProvider MD5Hasher = new MD5CryptoServiceProvider();
        private static string PasswordSalt;
        string MD5String;
      
        public MD5()
        { }

        public string Encrypt(string EncString)
        {
            Random RanGen = new Random();
            string RanString = "";           
            string RanSaltLoc;          

            while(RanString.Length<=3)
            {
                RanString = RanString + RanGen.Next(0, 9);
            }

            EncStringBytes = Encoder.GetBytes(EncString + RanString);

            EncStringBytes = MD5Hasher.ComputeHash(EncStringBytes);
            MD5String = BitConverter.ToString(EncStringBytes);
            MD5String = MD5String.Replace("-", String.Empty);


            RanSaltLoc = (RanGen.Next(4, MD5String.Length)).ToString();
            MD5String = MD5String.Insert(Convert.ToInt32(RanSaltLoc),RanString);
           
            if (Convert.ToInt32(RanSaltLoc) < 10)
            {
                RanSaltLoc = "0" + RanSaltLoc;
            }

            MD5String = MD5String.Insert(3, RanSaltLoc);
            PasswordSalt = RanSaltLoc + RanString;
            return MD5String;
        }

        public string verify(string chkString)
        {
            string SaltString = PasswordSalt.Substring(2,4);
            string SaltLoaction = PasswordSalt.Substring(0, 2);

            EncStringBytes = Encoder.GetBytes(chkString + SaltString);

            EncStringBytes = MD5Hasher.ComputeHash(EncStringBytes);
            MD5String = BitConverter.ToString(EncStringBytes);
            MD5String = MD5String.Replace("-", String.Empty);
            MD5String = MD5String.Insert(Convert.ToInt32(SaltLoaction), SaltString);
           
            MD5String = MD5String.Insert(3, SaltLoaction);

            return MD5String;
        }
    }
}