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:
Aug. 17, 2010
Filed:
May. 13, 2005
Applicant:
Catherine Helen Gebotys, Waterloo, CA;
Inventor:
Catherine Helen Gebotys, Waterloo, CA;
Assignee:
Research In Motion Limited, Waterloo, CA;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04N 7/167 (2006.01);
U.S. Cl.
CPC ...
Abstract
Countermeasures for differential power or electromagnetic analysis attacks are provided with the definition and use of key encryption masks and masked substitution tables in a cryptographic process. Different key encryption masks and masked substitution tables are applied to different portions of masked keys used in the cryptographic process and are rotated as the cryptographic operations are carried out. The rotation of the key encryption masks and the masked substitution tables is non-uniform. Input and output masking for the substitution tables is provided.