Side Channel Leakage Alignment Based on Longest Common Subsequence
Anni Jia, Wei Yi Yang, Gongxuan Zhang · 2020
Side channel attacks (SCA) are powerful tools to recover the secret keys of cryptographic devices by employing physical leakages of the devices. In practice, numerous countermeasures (e.g.random process interrupts) and unintentional factors (e.g.imprecise triggering) are able to significantly degrade the performance of side channel attacks (SCA) by producing misaligning leakage measurements. The main solution to over-coming influences of misalignment is to align these traces before mounting an attack. According to this view, this paper proposes a novel leakage alignment method based on the longest common subsequence (LCS) algorithm. Initially, the misaligned traces are preprocessed by non-uniform quantification to remove part of the noise and retain the key-dependent information. Subsequently, the quantified traces are converted into symbols for sequence comparison. Finally, the aligned traces are obtained by inserting and deleting operations. Experiments for different cryptographic implementations with different levels of noise are carried out on several different devices. The experimental results show that the proposed method is effective for countering leakage misalignment and robust under high noise. Especially, it is still effective for multi-channel leakage alignment.