Statistics and secret leakage

Abstract

In addition to its usual complexity assumptions, cryptography silently assumes that information can be physically protected in a single location. As one can easily imagine, real-life devices are not ideal and information may leak through different physical channels. This paper gives a rigorous definition of leakage immunity and presents several leakage detection tests. In these tests, failure confirms the probable existence of secret-correlated emanations and indicates how likely the leakage is. Success does not refute the existence of emanations but indicates that significant emanations were not detected on the strength of the evidence presented, which of course, leaves the door open to reconsider the situation if further evidence comes to hand at, a later date.