To describe website areas which require authentication, only a simple associative array is needed. array('{URL_PATTERN}' => array('{AUTHENTICATION_LISTENERS}'));.

In Symfony language this array is named $firewalls, I prefer the term $rules because a Firewall which has a collection of $firewalls it is weird. Moreover $rules is semantically closer to real firewall software (http://en.wikipedia.org/wiki/Firewall_(computing)).