Conditional access system
US5796829A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1996 |
| Grant date | Aug 18, 1998 |
| Priority date | — |
| Expiry date | Jun 24, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/4623
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An access control processor for a conditional access system in which encrypted information segments provided by a plurality of information service providers are encrypted for transmission in accordance with different conditional access processes respectively utilizing different algorithms for encrypting the information segments. The processor includes a decryptor in an information receiver by decrypting encrypted information segmets received by the information receiver by processing the received encrypted information segments with a session key used for encrypting the information segments in accordance with an algorithm utilized in one of said conditional access processes; and a conditional access controller in the information receiver for selectively enabling the decryptor to decrypt received information segments encrypted in accordance with any of said different conditional access processes by providing to the decryptor cryptographic information for defining the algorithm utilized in said one of said different conditional access processes for use by the decryptor to decrypt the received information segment encrypted in accordance with said algorithm. Algorithm-defining cryptograp…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.