Paper 2012/084

Improved Algebraic Side-Channel Attack on AES

Mohamed Saied Emam Mohamed and Stanislav Bulygin and Michael Zohner and Annelie Heuser and Michael Walter

Abstract

In this paper we present improvements of the algebraic side- channel analysis of the Advanced Encryption Standard (AES) proposed in [9]. In particular, we optimize the algebraic representation of AES and the algebraic representation of the obtained side-channel information in order to speed up the attack and increase the success rate. We study the performance of our improvements in both known and unknown plain-text/ciphertext attack scenarios. Our experiments indicate that in both cases the amount of required side-channel information is less than the one required in the attacks introduced in [9]. Furthermore, we introduce a method for error handling, which allows our improved algebraic side-channel attack to escape the assumption of an error-free measurement and thus become applicable in practice. We demonstrate the practical use of our improved algebraic side-channel attack by inserting predictions from a single-trace template attack.