Content playback apparatus, content playback method, computer program, key relay apparatus, and recording medium
US7940935B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2005 |
| Grant date | May 10, 2011 |
| Priority date | — |
| Expiry date | Dec 2, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2541
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
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 sold possible after the specific server breaks down. A key acquisition 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.