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. 05, 2009
Filed:
Jun. 20, 2001
Applicant:
Pascal Guterman, Roquevaire, FR;
Inventor:
Pascal Guterman, Roquevaire, FR;
Assignee:
Gemalto SA, Gemenos, FR;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04L 9/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
In a data processing device, a first key is produced based on a secret key so that the latter is never used in a clear form. In a preliminary step, the secret key and a random number are applied to a function producing a first key. The first key and the random number are pre-stored in the device. For each data processing, the first key and another random number are applied to another function to produce a second key, and the second key and the stored number are applied as inverse of the function to produce a third key used for processing the data. The device can be a smart card and the data the confidential code presented to the card.