System for providing scrambled content, and system for descrambling scrambled content
US7116892B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 21, 2001 |
| Grant date | Oct 3, 2006 |
| Priority date | — |
| Expiry date | Oct 28, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2005/91364
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system for providing scrambled content, comprising a control word generator, each control word including a control word identifier, a scrambler for providing a stream of scrambled data packets, and an encryption device for providing entitlement control messages (ECM's). One or more consecutive packets are scrambled using the same control word (CW). Each packet includes a control word identifier identifying the control word used. The ECM encryption device provides ECM's including a previous control word (CWP), a current control word (CWC) and a next control word (CWN). A system for descrambling scrambled content comprises a descrambler for descrambling the scrambled content and a decryption device for decrypting ECM's to obtain control words. The ECM decryption device delivers control words to the descrambler and the descrambler descrambles the data packets of the scrambled content using a control word having a control word identifier corresponding with the control word identifier of the data packet to be descrambled. The system further comprises a storage device for storing scrambled content and means to control play back of the stored content, going fast forward and going backwa…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.