Perfect Authentication Class: Authenticate users restrict access to site areas

This class is meant to authenticate users and store authentication session identifiers in cookies.

The class is also capable of managing the list of authorized users in a file stored in the server.

The authentication identifier contains an hash value that is stored in user computer by the means of cookies. The hash value is also stored on a temporary file on the server to verify that the authenticity of the user. This is meant to prevent that unauthorized users forge authentication cookies, thus making the system more secure.