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:
Jan. 20, 2026
Filed:
Dec. 06, 2023
Stmicroelectronics (Grand Ouest) Sas, Le Mans, FR;
Fabien Arrive, Chasné-sur-illet, FR;
Yves Magnaud, Chateaugiron, FR;
STMicroelectronics (Grand Ouest) SAS, Le Mans, FR;
Abstract
A device executes an authentication process protected by an authentication counter that is incremented in case of an authentication failure. The incrementation of the counter is protected against unexpected device power-off or power-off attacks. A non-volatile memory is divided into pairs of cells. The protecting includes writing a fixed value D into an active pair of two consecutive cells. As long as successful authentications occur, the content of the first cell is overwritten by a random value. When a failed authentication occurs, the content of the second cell is overwritten by a random value and the next two consecutive cells are written with the fixed value D. Those cells form the active pair and the protection process is repeated. This mechanism facilitates preventing the lack of incrementation of the authentication counter in case of unexpected device power-off during the processing of a failed authentication.