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:
Aug. 26, 2014
Filed:
Dec. 17, 2010
Fabien Gremaud, Chatel-St-Denis, CH;
Olivier Brique, Jongny, CH;
Fabien Gremaud, Chatel-St-Denis, CH;
Olivier Brique, Jongny, CH;
Nagravision S.A., Cheseaux-sur-Lausanne, CH;
Abstract
A method based on access conditions verification performed by two conditional access devices consecutively on a control message before releasing a control word to a descrambler. The control message encapsulates a second part including another control message. The processing unit for carrying out the method comprises a first conditional access device connected to a second conditional access device provided with a descrambler and a secured processor or secured hardware logic. The control message and the second part are each encrypted and accompanied by respectively first and second authentication data. The first conditional access device decrypts and verifies integrity of the control message, verifies the first access conditions and transmits the second part to the second access control device. The second conditional access device decrypts and verifies integrity of the second part and further verifies the second access conditions, and releases and loads the control word into the descrambler.