Edit: Note, this really barely scratches the surface for building secure software. AC says how to apply cryptographic primitives correctly. It won't teach you how to avoid vulnerabilities specific to particular application domains (like CSS, SQL injection, etc...).
That book is old, and though still basically correct, there's much better ways to learn about the practice of developing secure systems. I recommend "Cryptography Engineering" by Ferguson, Schneier, Kohno which is a more modern descendant of Schneier's AC.
Being a programmer means committing yourself to a life of continued education. Building a secure authentication system? Time to read up on the subject. You don't have to go far before you learn about the vulnerability of MD5 hashes for password storage.