Patent ID: 9425961
Filing Date: 2016-08-23
CPC Classification: H04L

Claim Text:
1. A method, comprising: protecting data stored in a hardware data media from attack using Advanced Encryption Standard (AES) cyphering circuitry, the protecting including: mapping polynomial representations in an AES finite field of bytes of a state matrix into respective fields of polynomials computed with respect to one of a plurality of irreducible polynomials, generating moved polynomials; applying Chinese-Remainder-Theorem (CRT) based mapping to the generated moved polynomials, generating a polynomial representing the state matrix in a polynomial ring; applying an AES process to the polynomial representing the state matrix in the polynomial ring, generating an AES-processed polynomial; and converting the AES-processed polynomial into the AES finite field, generating an AES-processed state matrix, wherein the method includes: obtaining the polynomial representation (b  of the input bytes (b providing the plurality of irreducible polynomials (f  computed with respect to one of said irreducible polynomials (f mapping said moved polynomials (α  obtained by applying an isomorphism (ω) between the direct product of said fields of polynomials  and said polynomial ring  based upon the Chinese remainder theorem (CRT), said polynomial (a(z)) representing the state matrix (B) in said polynomial ring applying the AES process to said polynomial (a(z)) that represents the state matrix (B) in said polynomial ring  and reconverting said polynomial (a(z)) that represents the state matrix (B) in said polynomial ring  into the AES finite field  to obtain an encrypted state matrix (CB).