Method to manage members of at least one group of decoders having access to audio/video data

摘要

The present invention aims at proposing a method allowing a versatile management of a group of decoders, this group having conditional access to audio/video content.;Accordingly, it is proposed a method to manage members of at least one group of decoders having access to audio/video data, each group member having the status of non-revoked or revoked member, and sharing a common broadcast encryption scheme allowing to revoke at least one member of the group by sending a group addressed message, comprising the steps of:;In a stage for a decoder to become member of the group :- receiving and storing the keys pertaining to the position into the group according to the broadcast encryption scheme,- receiving and storing a current group access data (CGD) comprising at least a current group access key (CGK) common to said group,;In a stage of accessing audio/video data :- using the current group access data (CGD) to directly or indirectly access to the audio/video data,;In a stage of renewing the current group access key (CGK):- sending a first group message comprising at least a next group access data (NGAD) comprising at least a next group access key (NGAK) encrypted so that only the non-revoked decoders can access to it, said group message being further encrypted by the current group access key (CGK),- updating the current group access key with the next group access key.