Implementing access policies with hidden credentials
用隐藏证书实现访问策略

To solve the efficiency problem of useing hidden credentials in trustmanagement system,a scheme using hidden credentials to efficiently implement complex polices with "polices expression" and "final prefix" was presented.The encryption and decipherment times were reduced by constructing and simplifying policy expression,the information restore was guaranteed by useing "final prefix".Example shows that the scheme is feasible and efficiency.