In this new tutorial from DevShed, they continue the series looking at developing a simple web application with security being one of its primary goals.

In the last article we started to build our site and then continued to explore the login script. In this article we will continue to explore the script but will also discuss in detail the process of authentication and its security implications. We will eventually look at some of the common attacks that are perpetrated by malicious users.

This fourth part of the series adds the authentication piece to the puzzle - a simple system that does some form validation and checks the input against a MySQL table (users). Full code explanation and example usage is included.