| 摘要 |
#CMT# #/CMT# The method involves scanning a service information table (SI) by a control access Kernel (CAK), and extracting an identifier of a right associated to a service from a descriptor. An index (In) corresponding to the right is searched in advance in a right table (Td). The index is transmitted to a security module (SM) when searching operation provides a positive result. A control message (ECM) is decrypted by the module. The identifier in the message is extracted. Rights in the module are verified by initiating verification of the rights in the right table using the right designated by the index. #CMT#USE : #/CMT# Method for evaluating user rights to access a flow transporting encrypted data of a broadcasted service or program e.g. football or rugby match, of a pay TV, in a security module e.g. chip card on a reader, integrated circuit on a motherboard or subscriber identity module, associated to a multimedia unit e.g. personal computer, decoder or mobile equipment. #CMT#ADVANTAGE : #/CMT# The index corresponding to the right is searched in advance in the right table by the security module, thus rapidly determining the access rights of the user. The utilization of the index avoids systematic search in all right tables by the security module. The method reduces time required for switching between reception channels. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The drawing shows a simplified block diagram of a multimedia unit with different modules intervened in a user right evaluating method. CAK : Control access Kernel ECM : Control message In : Index SI : Service information table SM : Security module Td : Right table. |
