My site is in asp.net 3.5 and C#. I am sending link to my user through mail, now I want to send each user a specific URL. So instead of sending the clear text I want to send link with encrypted string URL, which I will decrypt on my home page.
Like instead of `www.mysite.aspx\mypage?userId=12` I'll send `www.mysite.aspx\mypage?UserId=)@kasd12`
and the same I'll decrypt on my page so that I'll get the `userId = 12`.

Please let me know if my approach is correct and not and how can I encrypt & decrypt the string in simplest and easier manner.