Using smartcards or other cryptographic modules for enabling connected devices to access encrypted audio and visual content
US7039816B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 2003 |
| Grant date | May 2, 2006 |
| Priority date | — |
| Expiry date | Oct 21, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/603
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
To prevent piracy, audiovisual content is encrypted prior to transmission to consumers. A low-cost, high-security cryptographic rights module (such as a smartcard) enables devices such as players/displays to decode such content. Security-critical functions may be performed by the cryptographic module in a manner that allows security compromises to be addressed by upgrading or replacing cryptographic modules, thereby avoiding the need to replace or modify other (typically much higher-cost) components. The security module contains cryptographic keys, which it uses to process rights enablement messages (REMs) and key derivation messages (KDMs). From a REM and KDM, the security module derives key data corresponding to content, uses public key and/or symmetric cryptography to re-encrypt the derived key data for another device, and provides the re-encrypted key data to the decoding device. The decoding device then uses cryptographic values derived from the re-encrypted key data to decrypt the content.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.