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:
Jun. 08, 1993
Filed:
Jun. 11, 1991
Applicant:
Inventors:
Didier Angebaud, Chantepie, FR;
Jean-Luc Giachetti, Rennes, FR;
Louis Guillou, Rennes, FR;
Jean-Jacques Quisquater, Brussel, BE;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04K / ;
U.S. Cl.
CPC ...
380 23 ; 380 25 ;
Abstract
According to the invention, the chip card issues a first certificate comprising its letter of credentials (Crc), an exponential (X), an optional message (M), these quantities being signed. The security module verifies the signature and in return issues a second certificate containing its letter of credentials (Crm), an exponential (Y), an optional message (M'), a cryptogram (C), these quantities being signed. A common secret key is constituted between the card and the security module by the exponentials and allows the card to interpret the cryptogram addressed to it and to act in accordance therewith.