CONTENT PLAYBACK APPARATUS, CONTENT PLAYBACK METHOD, COMPUTER PROGRAM, KEY RELAY APPARATUS, AND RECORDING MEDIUM

摘要

A content playback apparatus reduces load concentration on a specific server apparatus that manages content keys of encrypted content, while protecting copyrights of the content. The content apparatus makes playback of content recorded in a recording medium soldposs ible after the speci f ic server breaks down. Akeyacquisition control unit (204) reads a playback control information table (211) from a recording medium (102) via a reading unit (201). The key acquisition unit (204) acquires a rights key via a key acquisition intermediation unit (223) from an apparatus specified by an acquisition-destination type and a request-destination type that are stored in the playback control information table (211) and that corresponding to the content to be played. The key acquisition unit (204) generates a content key using the acquired rights key and, when required, a medium key recorded in a medium. A decryption unit (203) decrypts encrypted content using the content key.