<CITE>On the web, you might use MD5 to verify a time-limited login. When a user logs in, you make an md5 'hash' (digest) out of their login name, password, a timestamp, and some secret key only you know, and set that as a value of a browser cookie....</CITE>

Why to do this kind of terrible thing?
On my site, I just generate a random session ID and set that as a cookie. On server-side a make association of this session id with user's login name and a 'last access' timestamp. When the user returns, I just check the validity of session Id by following the association.

This has several advatages:

  1. I do not have to compute (slow) MD5 on every request.
  2. Cookie value (SessionId) is random, that means totaly secure. It is not based on user's password or username.
  3. This will accomodate any authentication scheme (e.g. X.509 certs) not just plain passwords.

In reply to Re: Re: Using MD5 and the theory behind it by gildir
in thread Using MD5 and the theory behind it by r.joseph

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