Master digital data creation device and digital data reproduction device
US7076063B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 4, 2001 |
| Grant date | Jul 11, 2006 |
| Priority date | — |
| Expiry date | Mar 18, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/3281
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Data C generated by scrambling user-desired digital data P and a control word CWp corresponding to the number of reproductions p are recorded on recording media. When creating a master, a user has already been charged for the number of reproductions p. A decryption block decrypts the control word CWp, which is read from the recording media, to CW0. A de-scrambler uses the decryption control word CW0 to decrypt the digital data P for output to a reproduction unit. After confirming the end of reproduction, the decryption block writes a control word CW(p−1) back to the recording media. The recording media may be reproduced p times with no need for communication between a reproduction device and an accounting manager.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.