US Patent 6928427 Efficient computational techniques for authorization control

In an authorization system, access is defined by rules, roles and active rules. These definitions are preprocessed to form a bit array for each of a plurality of roles representing the rules that apply to that role. Once a bit array is calculated or generated for a given user based on that user's roles, the user bit array can be cached so that it need not be regenerated for each time the user requests access to resources. The rules used can either be role-based rules or active rules.