Copy protection apparatus and information recording medium used in this copy protection apparatus
US6438692B1 · kind B1 · utility
24Cited by
7References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 23, 2001 |
| Grant date | Aug 20, 2002 |
| Priority date | — |
| Expiry date | Aug 23, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2201/0064
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
This invention protects the unauthorized copy of multimedia data, recorded on an information recording medium, by using electronic watermark information and key information. The electronic watermark information embedded in the multimedia data is extracted by an electronic watermark extraction unit on the decryption system side. A disk key is obtained using the electronic watermark information and a part master key. The multimedia data is decrypted using the resultant disk key.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.