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:
Jan. 23, 2018
Filed:
Mar. 18, 2015
Stmicroelectronics S.r.l., Agrate Brianza, IT;
Filippo Melzani, Burago di Molgora, IT;
STMICROELECTRONICS S.R.L., Agrate Brianza, IT;
Abstract
A device of the Substitution-Box (S-Box) type, which is suitable for operating in a symmetric-key encryption apparatus, in particular an AES (Advanced Encryption Standard) encryption apparatus, and includes at least one module configured for carrying out a non-linear operation in a finite field (GF(2)) of an encryption method implemented by the above encryption apparatus, the module including at least one reprogrammable look-up table to, for example, implement countermeasures against side-channel attacks. When no countermeasures are employed, the tables may be set to fixed values, instead of being reprogrammable. The above module includes a plurality of composite look-up tables that implement the non-linear operation in a composite field of finite subfields (GF(2); GF((2))) deriving from the finite field (GF(2)), each of the above composite look-up tables being smaller than a look-up table that is able to implement autonomously the non-linear operation in a finite field (GF(2)).