Its not actually encryption btw

Its a hash
http://www.faqs.org/rfcs/rfc1321.html
Quote:
This document describes the MD5 message-digest algorithm. The algorithm takes as input a message of arbitrary length and produces as output a 128-bit "fingerprint" or "message digest" of the input.
It is conjectured that it is computationally infeasible to produce two messages having the same message digest, or to produce any message having a given prespecified target message digest
|