System and method for securely updating copy-protected media
US6609116B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 23, 1999 |
| Grant date | Aug 19, 2003 |
| Priority date | — |
| Expiry date | Aug 23, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/606
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system and method for updating old blank media onto which newer content is sought to be copied, to reduce the risk of unauthorized copying of new content onto old unupdated media. A computer system executes a method in which one or more calculate media key commands (CMKC) are written onto a blank recording medium, with the CMKCs defining an old media key. One or more CMKCs defining a new media key is associated with broadcast content, with the new CMKCs effectively revoking one or more device keys of a suspected pirate device. A legitimate player/recorder can decrypt the media keys from both the medium and the content, and then encrypt the content using the new media key and encrypt the first unconditional CMKC in the new CMKCs with the old media key. The encrypted content and the (now conditional) CMKC are recorded on the medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.