Public key media key block
US7305711B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 2002 |
| Grant date | Dec 4, 2007 |
| Priority date | — |
| Expiry date | Aug 22, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/60
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Protected content distribution is accomplished by a first entity generating a set of asymmetric key pairs, creating a plurality of sets of private keys by selecting a combination of private keys from the set of asymmetric key pairs for each created set, and distributing the sets of private keys to playback devices. A second entity produces protected content including encrypted content and a public key media key block, encrypts a symmetric content key with each public key in the set of asymmetric key pairs to form the public key media key block and encrypts a content title with the symmetric content key to form the encrypted content. A playback device stores one set of private keys, receives the protected content, and decrypts and plays the content title stored in the protected content when a selected one of the set of private keys stored by the playback device successfully decrypts the encrypted symmetric content key stored in the public key media key block of the received protected content.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.