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. 07, 2009
Filed:
Oct. 29, 1999
Applicants:
Christophe Clavier, Gémenos, FR;
Jean-sébastien Coron, Paris, FR;
Inventors:
Christophe Clavier, Gémenos, FR;
Jean-Sébastien Coron, Paris, FR;
Assignee:
Gemalto SA, Meudon, FR;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04K 1/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
In an electronic component using a secret key cryptographic algorithm, one operation utilizes a first table for supplying output data from input data. The output data, and/or derived data, is manipulated by critical instructions. A countermeasure method involves the use of other tables such that the output data and the derived data are unpredictable. The other tables are obtained from the first table by an exclusive-OR operation with a random value, or a derived random value, on one and/or the other of the input and output data of the first table.