Basics of Web Application Security: Hash and Salt Your Users' Passwords

If you need to store your users' passwords, it's essential that you never store
them plainly. Instead you must store a cryptographic hash of them, so that people
who get access to your database don't get the passwords. Cade and Daniel explain
how to do this properly: salting the hash to avoid lookup table attacks, and using
an appropriate hashing algorithm to defend against well-equipped attackers.