With a trust store consisting of a single trusted ca and nothing more, the CRL approaches an equivalent per-DN revocation capability in which revocation of the certificate effectively revokes access.

Then, this paper describes the process of communication and revocation, analyses the security and capability of the system.

Proposed a pay-TV scheme with user revocation, but it is a private-key scheme, also it does not provide multiple-service capability and meantime can not resist collusion attack.