Patent ID: 7891013
Filing Date: 2011-02-15
Classification: G06F,G11B,H04N

Abstract:
1. A contents playback apparatus that plays back sub-content relating to main content, wherein a storage medium pre-stores the main content that is a digital work, a main title ID, and a bind key in correspondence with each other, the main title ID being for uniquely identifying the main content, the bind key being used as an encryption key for encrypting the sub-content to generate an encrypted sub-content, the contents playback apparatus comprising: a first acquisition unit operable to acquire a sub-title ID that identifies the sub-content; a control unit operable to generate the main title ID based on the acquired sub-title ID; a reading unit operable to read from the storage medium the bind key corresponding to the generated main title ID; a second acquisition unit operable to acquire the encrypted sub-content identified by the sub-title ID acquired by the first acquisition unit; a decryption unit operable to decrypt the acquired encrypted sub-content using the read bind key as a decryption key to generate playback sub-content; and a playback unit operable to play back the generated playback sub-content.