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:
May. 04, 1993
Filed:
Dec. 23, 1991
Applicant:
Inventors:
Michel Leduc, Boersch, FR;
Joel Hamon, Lipsheim, FR;
Jean-Claude Guillon, Gerstheim, FR;
Francis Renard, Ostwald, FR;
Eric Diehl, Neudorf, FR;
Assignee:
Laboratoire Europeen de Recherches Electroniques Avancees, Courvevoie, FR;
Primary Examiner:
Int. Cl.
CPC ...
H04N / ;
U.S. Cl.
CPC ...
380 14 ; 380 16 ; 380 17 ; 380 20 ;
Abstract
The method of the invention consists, during the transmission of composite video signals, in the inclusion therein of series of access messages (ECM1, ECM2) and, during the unscrambling, carried out using a chip card reader whose chip card comprises encoded digital data, in using an interactive method of identification of a digital signature.