A Complete, Secure User Login System

When I started seeing spam messages posted to the new column annotation system, I knew I would have to create some sort of user authentication system that helps weed out the losers. I'm the type that would rather write an entire library myself than try to learn something like PHPLib or other similar libraries.

The library needed to handle registration, confirmation emails, account updates (passwords, emails) among other things. It also needed to be secure while not creating a burden on my overloaded database.