Content playback apparatus method and program and key management apparatus and system
US7401232B2 · kind B2 · utility
22Cited by
12References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 18, 2003 |
| Grant date | Jul 15, 2008 |
| Priority date | — |
| Expiry date | May 29, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/63345
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A key management apparatus which can be used to encrypt/decrypt content data in a content playback device includes a storing unit for storing a secret key, a key information decrypting unit for decrypting encrypted key information and an updating unit operable to update the secret key with an algorithm stored therein, when the decrypted key information is key-updating information. Seed information can be received for use with the algorithm to provide a new secret key, and preliminary trigger information can be used to poll a group of appliances to request key information to determine any duplication of appliances.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.