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:
Dec. 20, 2011
Filed:
Nov. 01, 2002
Corine Le Buhan, Les Paccots, CH;
Marco Sasselli, Chardonne, CH;
Patrick Bertholet, Lausanne, CH;
Nagravision S.A., Cheseaux-sur-Lausanne, CH;
Abstract
The objective of the present invention is a storage method in a decoder of an event encrypted by control words that guarantees the access to this event at whichever moment, even if certain keys of the system have changed for security reasons. This objective is achieved by a storage method of an event encrypted by control words in a reception and decryption unit connected to a security unit, said control words and the necessary rights being contained in management messages encrypted by system keys, comprising storing the encrypted event as well as the control messages in the storage unit, and storing in the storage unit the system keys encrypted by a predefined local key stored in the security unit.