I'm doing a simple shopping cart for a small site.

I plan to store cart items as well as logged in user_id in session variables.

to make things a little more secure, I thought I'd do this:

1. sha1() the user_id before storing it in the session.

2. Also sha1() and store the http_user_agent var with some salt, and check this along with the user_id.

I know there is more one can do, but I thought this at least helps quite a bit right? and is easy for me to implement.