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:
Jul. 11, 2023
Filed:
Jun. 23, 2020
Cryptography Research, Inc., San Jose, CA (US);
Michael Tunstall, Walnut Creek, CA (US);
Cryptography Research, Inc., San Jose, CA (US);
Abstract
Systems and methods for protecting block cipher computation operations from external monitoring attacks. An example apparatus for implementing a block cipher may comprise a memory device to store instructions for computing a block cipher; and a processing device coupled to the memory device. The processing device performs a Data Encryption Standard (DES) cryptographic operation with multiple rounds of a Feistel structure, each round including a substitution function and a transformation function that combines an expansion function and a permutation function into a single operation. The transformation function transforms a first input portion of an internal state of the respective round and a second input portion of the internal state into a first output portion and a second output portion of data. The second output portion is equal to the first input portion and the first output portion is dependent on a combined permutation output from the transformation function.