Content guard system for copy protection of recordable media
US6832319B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Jul 20, 1999 |
| Grant date | Dec 14, 2004 |
| Priority date | — |
| Expiry date | Jul 20, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/606
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system and method for enabling broadcast programs to be copied once only by consumer recorders includes writing a unique media identification on each blank disk to which content is to copied in a read-only area of the disk before it is initially recorded. Also, a one-way key management media key block is written to the disk. A content key is derived by combining a media key, derived from the media key block, with the media identification. Additionally, to facilitate copying the content one time only, an exchange key is established between the recorder and a sender such as a satellite receiver or a disk player that is associated with the recorder, and the exchange key is modified with special numbers representing control commands including copy once and copy no more. The exchange key is then encrypted using the content key and then hashed with a nonce to render a bus content key. The bus content key is then used to encrypt the data for copying the data to a disk.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.