Michael Southwell, Pro PHP Security

Pro PHP Security is one of the first books devoted solely to PHP security. It will serve as your complete guide for taking defensive and proactive security measures within your PHP applications. (And the methods discussed are compatible with PHP versions 3, 4, and 5.)

The knowledge you'll gain from this comprehensive guide will help you prevent attackers from potentially disrupting site operation or destroying data. And you'll learn about various security measures, for example, creating and deploying "captchas," validating e-mail, fending off SQL injection attacks, and preventing cross-site scripting attempts.