Revocation information updating method, revocation informaton updating apparatus and storage medium
US6850914B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Nov 8, 1999 |
| Grant date | Feb 1, 2005 |
| Priority date | — |
| Expiry date | Nov 8, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/00086
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
At least one set of revocation information for identifying electronic appliances that should be revoked for content protection and master revocation information for identifying electronic appliances that have special permission to update the revocation information are recorded in advance into a special storage region on a storage medium. When the storage medium is loaded into an electronic appliance indicated by the master revocation information, the revocation information can be updated. However, when the storage medium is loaded into an electronic appliance indicated by the revocation information, the electronic appliance is revoked and so the protection of contents is improved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.