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:
Dec. 24, 2013
Filed:
Jan. 18, 2010
Jean-luc Danger, Antony, FR;
Sylvain Guilley, Paris, FR;
Jean-Luc Danger, Antony, FR;
Sylvain Guilley, Paris, FR;
Institut Telecom-Telecom Paristech, Paris, FR;
Abstract
A cryptography circuit protected against observation attacks comprises at least one register R providing a variable x masked by the mask m, the masked variable being encrypted by a first substitution box S -in a cyclic manner. The circuit also comprises a mask register M delivering at each cycle a mask m, the transformation of m, the mask m being extracted from mbefore being encrypted by a second substitution box S', the new mask m′ obtained on output from this box S′ is transformed into a mask m′before being stored in the mask register M. The transformation consists of a bijection or a composition law making it possible to reduce or indeed to cancel any high-order attack in accordance with a model of activity of the registers R and M. Cryptography circuits are protected against high-order observation attacks on installations based on masking.