Improved algebraic side-channel attack on AES

In this paper we present improvements of the algebraic side-channel analysis of the Advanced Encryption Standard (AES) proposed in [1]. 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 plaintext/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 [1]. Furthermore, we introduce a method for error handling, which allows our improved algebraic side-channel attack to escape the assumption of an error-free environment 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.