In his most recent post Edd Mann shows you how to secure your session in PHP applications via a custom SessionHandler class and a bit of encryption. For those interested in the full code right away, check out this gist over on Github.
Following on from my previous post on Self-signed SSL certificates, I would now like to address the second most common Web application vulnerability (Broken Authentication and Session Management). When delving into the subject I was unable to find a definitive resource for an PHP implementation. Due to this, I set out to combine all the best practice I could find into a single Session handler, to help protect against the common attack vectors. Since PHP 5.4, you are able to set the Session handler based on a class instance that extends the default 'SessionHandler' class.
He walks through the code talking about some of the functionality it offers, how it encrypts the data and integrates expiration and validation (fingerprinting). There's also an interesting set of methods (get and set) to access values in the current session. One thing to note, this example is only for PHP 5.4 and above as it makes use of the newer SessionHandler interface.