Towards Sound and Optimal Leakage Detection Procedure

Evaluation of side channel leakage for the embedded crypto systems requires sound leakage detection procedures. We relate the test vector leakage assessment (TVLA) procedure to the statistical minimum p-value (mini-p) procedure, and propose a sound method of deciding leakage existence in the statistical hypothesis setting. To improve detection, an advanced statistical procedure Higher Criticism (HC) is applied. The detection of leakage existence and the identification of exploitable leakage are separated when there are multiple leakage points. For leakage detection, the HC-based procedure is shown to be optimal in that, for a given number of traces with given length, it detects existence of leakage at the signal level as low as possibly detectable by any statistical procedure. We provide theoretical proof of the optimality of the HC procedure. Numerical studies show that the HC-based procedure perform as well as the mini-p based procedure when leakage signals are very sparse, and can improve the leakage detection significantly when there are multiple leakages.