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. 05, 2006
Filed:
Jul. 12, 2000
Jean-sebastien Coron, Paris, FR;
David Naccache, Paris, FR;
Jean-Sebastien Coron, Paris, FR;
David Naccache, Paris, FR;
Gemplus, Gemenos Cedex, FR;
Abstract
Two methods for random number generation are modified to make them more resistant to attacks by current measurements. The methods are particularly designed to be implemented in electronic devices such as smart cards, PCMCIA, badges, contactless cards or any other portable device. The DES algorithm is encrypted using a key K having a value D representing date information, to generate an integer variable I. For j ranging from 1 to m, the following steps are carried out: substituting s with s XOR I; introducing in the integer variable y the result of the encryption of s with the DES algorithm using the key K; introducing in xthe result of y or s; substituting s with y XOR I; and introducing in s the result of the encryption of s with the DES algorithm using the key K. The sequence (x, x, x) is then restored in the output.