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. 06, 2011
Filed:
May. 11, 2005
Nicolas Courtois, Meudon, FR;
Nicolas Courtois, Meudon, FR;
Gemalto SA, Meudon, FR;
Abstract
This invention relates to a method to protect an assembly implementing a cryptographic calculation process which uses a homographic function f of type:()=()/() when () is not equal to 0 and(−)=the function f operating on masked variables, wherein, for any k, if x is an input and y=f(x+k) is an output of the function f, to pass directly from a masked value x+m_i (additive masking of type XOR) to a masked value y+m_j, the method consists in comprises of performing this operation using a composition of several transformations operating on GF(2^k) with addition of the infinite, defined as (ax+b)/(cx+d), and of transformations which exchange two points.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile