DevShed is continuing their series on PHP security with this new tutorial focusing on the security surrounding user authentication.

So far we have covered security vulnerabilities that involve form data, databases and file systems. In this article we are going to look at authentication and the security issues around it. We will also look at some of the most common attacks in this field.

They start things off by describing two of the usual authentication methods - via a login form and through HTTP authentication. They start poking a few holes by looking at some of the common attacks for these approaches including two popular ones - brute force attacks and password sniffing.