encryption!

[HSN]

Hello there,

What is the best way for encrypting (and decrypting) data in Php other than using mcrypt()? Specifically, I want to encrypt URL information.

Example:

http://www.vbulletin.com/forum/newthread.php?do=newthread&f=12

will be encrypted to:

http://www.vbulletin.com/forum/!%423524954

Thx... :)

[absolut]

Only crypt() that is one-way string encryption (hashing)
P.S. But what for? :)

[HSN]

Hashing is not useful!
What I'm planning to do is:
I have a registeration system. When a student enters, his/her ID appears in the URL to $_GET[] it and use it in different pages. I would like to encrypt this and other variables which appear in URL as a result of logging in. Using a hashing function, I need to develop a bruteforce algorithm which takes O(n) in order to manage this.
So, you suggest me any technique?! :)

[Lats]

I'd suggest using sessions, much better than using ugly url's.

http://www.php.net/manual/en/ref.session.php

[Icheb]

Just store those information in a cookie?

[HSN]

I don't like using sessions!! :D

I think cookies are also not very secure.

[Icheb]

If you want security you need SSL. If you don't use it, an attacker can intercept the login details when you login to your system just as well as he can intercept the data in a cookie.

[HSN]

How can I use the Secure Socket Layer?! I mean, how is it implemented?

[UK Jimbo]

How can I use the Secure Socket Layer?! I mean, how is it implemented?

Google for mod_ssl.

Cookie based sessions would do the trick for you.