Where a follow-up playback is realized for content data that is recorded by changing an encryption key at predetermined intervals for copyright protection, fast feed and playback operations are provided that can get close to a video scene of a present point of time. There are two areas on the memory in which to manage key information. The key information and seed information being written into a hard disk drive are held in memory in order to allow access to the key information and seed information even as they are written.