| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital broadcast receiving apparatus capable of performing right protection for program content, regardless of whether an EMM (Entitlement Management Message) is used. SOLUTION: The digital broadcast receiving apparatus 2 includes a key storage 20, a multiplexing separator 21, an EMM decoder 22, a work key switcher 23, and an ECM (Entitlement Control Message) decoder 24. The key storage 20 stores in advance a previously embedded work key as a work key and a device key. The multiplexing separator 21 separates and extracts the encrypted program content, ECM, and EMM which are multiplexed for digital broadcasting. The EMM decoder 22 decodes the EMM with the device key to extract an update work key, which is a work key transmitted from a transmitting side. The work key switcher 23 performs switching so that either the previously embedded work key or the update work key is used as a work key according to work key switching information added to the ECM. The ECM decoder 24 decodes an encrypted area in the ECM with the work key to extract a scramble key. COPYRIGHT: (C)2011,JPO&INPIT |
