Md5

MD5 is a cryptographic one-way hashing algorithm first described in RFC 1321 back in 1992.

MD5 is no longer recommended for use, following a presentation at the 2004 Crypto Conference that revealed hash collision problems with the algorithm. One replacement perhaps is SHA256.

This MD5 sum is infamous:

d41d8cd98f00b204e9800998ecf8427e

What is it? An empty file.

Salted MD5 passwords broken
With off the shelf hardware.. see here it's probably wise to use another cipher, perhaps bcrypt based on many rounds of blowfish.