Encoding / decoding strings

[Marc 'BlackJack' Rintsch]

In <1168018757.397170.216870 at 11g2000cwr.googlegroups.com>,
oliver at obeattie.com wrote:

> Basically, what I am trying to do is display all comments by a
> specified user on the website. As the only thing which has =always=
> been used to identify users which never changes is their e-mail
> addresses, this is the only thing which I can use. Obviously, I can't
> display this e-mail address though.

Associate a unique random number or string with each e-mail address and
use this outside the server to identify users.  An MD5 hash of the
mail address might be a good candidate for such a string but then it's
possible for attackers to verify if someone they know the address of, has
made specific comments.  So part of the anonymity is gone then.

Ciao,
	Marc 'BlackJack' Rintsch