Information recording medium, information recording apparatus and information reproduction apparatus for the same
US7196994B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 2003 |
| Grant date | Mar 27, 2007 |
| Priority date | — |
| Expiry date | Sep 5, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/1403
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disk is provided that disables reproduction of sub-information even if the sub-information as a contents encryption key is recorded entirely onto another optical disk. Sub-information is recorded on the optical disk by deforming a recording mark slightly in accordance with a pseudo random number sequence that is obtained using as an initial value medium ID that is read out medium inherent information. This allows sub-information inherent in a medium to be recorded, and even if the sub-information is duplicated entirely to another optical disk, the illegally duplicated sub-information cannot be reproduced because of a difference in initial value of a pseudo random number sequence between media.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.