Patent ID: 10123091

Abstract:
A playback management device (3) is provided for use with a receiver (2) for receiving a content signal encoded by a key (Ks) updated in a specified update period and first control information (ECM) obtained by encoding information about the key (Ks) and a playable time (Tpre) for the encoded content signal. The playback management device (3) includes: an interface (31) for collecting the first control information (ECM) from the receiver; a first decoding portion (34) for decoding the first control information (ECM) and thereby restoring the key (Ks) and the playable time (Tpre) for the encoded content signal; and a control portion (35) for determining, according to the playable time (Tpre) for the encoded content signal and the update period (Tud) for the key (Ks), whether to output the key (Ks) to the receiver (2), and outputting the restored key (Ks) to the receiver (2) when determining to output.