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:
Jul. 15, 2014
Filed:
Jun. 15, 2012
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 for verifying access conditions performed by two conditional access devices consecutively on a control message before releasing a control word to a descrambler. The control message includes a first part including first access conditions and a second part structured as a control message including at least second access conditions and a control word. A first conditional access device is configured for decrypting the control message with a common key specific to units having a first conditional access device and verifying the authenticity of said message. When the verification succeeds, the second part and a second right is transmitted to a second conditional access device, which decrypts the second part with a common key specific to units having a second conditional access device and verifies the authenticity of said second part and the second access conditions in relation to the second right encrypted by a personal key embedded therein.