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:
Nov. 18, 2008
Filed:
Mar. 22, 2002
Jean-luc Dauvois, Paris, FR;
Michel Maillard, Rambouillet, FR;
Jean-Luc Dauvois, Paris, FR;
Michel Maillard, Rambouillet, FR;
Nagra Thomson Licensing, Boulogne-Billancourt, FR;
Abstract
A method for transmitting information between a transmitter station and a plurality of receiving stations in which encrypted information is transmitted from the transmitter station to the receiver station with a first key and at least a control message bearing a second key. The first key used for decryption is restored in each receiving station from the second key and from at least one datum selected from a set of data available in the receiving stations, according to a selection command periodically transmitted between the transmitting station and the receiving station. Such a system may find particular application to pay television.