关键词: 分布式访问控制，访问控制框架，quorum系统，可用性，访问控制容量

Abstract: By researching on generalized system for access control, the paper put forward an access control framework adopting quorum system, and presented a mutual quorum distributed access control system, with the high efficiency and the stability and security. Furthermore, the relation of system capability and system availability under the circumstance that the system nodes are not reliable was analyzed,and a result was given that the mode of the optimization of the entire system considers the capability and availability.

Key words: Distributed access control, Access control framework, Quorum system, Availability, Access control capability