encrypting and decrypting cookies asp.net

public static void CreateCookie(string CookieName, string[] keys, string[] values, bool Expired, HttpResponse res)
{
    HttpCookie c = new HttpCookie(CookieName);
    if (keys != null)
    {
        for (int x = 0; x < keys.Length; x++)
            c.Values.Add(keys[x], values[x]);
        if (!Expired)

            c.Expires = DateTime.Now.AddDays(2);
    }
    else

        c.Expires = DateTime.Now.AddDays(-2);
    res.Cookies.Add(c);
}



public static string ReadFromCookie(string CookieName, string key, HttpRequest req)
{
    try
    {
        return req.Cookies[CookieName][key].ToString();
    }
    catch
    {

        return null;
    }

}



public static void RemoveCookie(string CookieName, HttpResponse res)
{
    CreateCookie(CookieName, null, null, false, res);
}

protected void btnLogin_Click(object sender, EventArgs e)
   {

       Member m = new Member();
       if (m.Login(Txtuser.Text, Txtpass.Text))
      {

          utility.CreateCookie("login", new string[] { "user", "pass" }, new string[] { Txtuser.Text, Txtpass.Text }, ChkReM.Checked, Response);
          Redirect(Txtuser.Text);
      }
      else
          lblmsg.Text = "Username/password incorrect";
      }



   private void Redirect(string user)
   {


       if (user == "Admin")
           Response.Redirect("Admin/Admin.aspx");

       else
       {
           Response.Redirect("Users/UserInfo.aspx");
       }
   }