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. 31, 2013
Filed:
Apr. 27, 2010
Catherine Helen Gebotys, Baden, CA;
Catherine Helen Gebotys, Baden, CA;
Research In Motion Limited, Waterloo, Ontario, CA;
Abstract
For a defined cryptographic process including an original substitution table, split masked substitution tables are provided to resist cryptographic attacks. The split masked substitution tables are defined with reference to a set of random value data words and a mask value. An entry in the split masked substitution tables is defined by selecting bits from the corresponding entry in the original masked substitution table, as masked by the corresponding one of the set of random value data words and by selecting bits from the corresponding one of the set of random value data words as masked by the mask value. The split masked substitution tables are usable in a modified cryptographic process based on the defined cryptographic process to permit a masked output to be generated. The split masked substitution tables are refreshed by each entry in the tables being refreshed upon access during execution of the modified cryptographic process.