| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technology capable of avoiding the occurrence of a blackout even while a device key and a work key are updated (acquired) in a new RMP system. <P>SOLUTION: When a receiving means receives notification that invalidates a current device key to update the current device key to a new device key, an extracting means extracts related information, a generating means generates a new third device key, a new work encryption key encrypted by using the new device key is decrypted, and the receiver has a control means which controls: the generating means so as to decrypt a scramble key by using the current work key corresponding to the current device key until generating the scramble key by using the new work; and a decrypting means so as to decrypt an encrypted content included in a broadcast signal by using the scramble key. <P>COPYRIGHT: (C)2010,JPO&INPIT |
