The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 22, 2016
Filed:
Nov. 20, 2012
Nagravision S.a., Cheseaux-sur-Lausanne, CH;
Bertrand Wendling, Divonne-les-Baines, FR;
Corinne Le Buhan, Les Paccots, CH;
NAGRAVISION S.A., Cheseaux-sur-Lausanne, CH;
Abstract
A method and cryptographic system for descrambling content packets, included within a digital transport stream, having conditional access messages and header data. The method and system require a deciphering algorithm, processed by a descrambler of a multimedia unit, using an initialization vector as a first input and a control word as a second input. The multimedia unit is connectable to a security module for processing the conditional access messages and extracting control words therefrom. The initialization vector, or intermediate data to determine the initialization vector, is the result of a cryptographic function based on at least one variable extracted from the digital transport stream and processed by the security module.