Partition vs. Comparison Side-Channel Distinguishers: An Empirical Evaluation of Statistical Tests for Univariate Side-Channel Attacks against Two Unprotected CMOS Devices

Given a cryptographic device leaking side-channel information, different distinguishers can be considered to turn this information into a successful key recovery. Such proposals include e.g . Kocher's original DPA, correlation and template attacks. A natural question is therefore to determine the most efficient approach. In the last years, various experiments have confirmed the effectiveness of side-channel attacks. Unfortunately, these attacks were generally conducted against different devices and using different distinguishers. Additionally, the public literature contains more proofs of concept (e.g . single experiments exhibiting a key recovery) than sound statistical evaluations using unified criteria. As a consequence, this paper proposes a fair experimental comparison of different statistical tests for side-channel attacks. This analysis allows us to revisit a number of known intuitions and to put forward new ones. It also provides a methodological contribution to the analysis of physically observable cryptography. Additionally, we suggest an informal classification of side-channel distinguishers that underlines the similarities between different attacks. We finally describe a new (but highly inspired from previous ones) statistical test to exploit side-channel leakages.