We present a model of adaptive attacks which we combine with information-theoretic metrics to quantify the information revealed to an adaptive adversary. This enables us to express an adversary’s remaining uncertainty about a secret as a function of the number of interactions with the system under attack. We present algorithms and approximation methods for computing this function. The main application area for our approach is the analysis of side-channels in cryptographic algorithms and we give examples of how it can be used to characterize the vulnerability of hardware implementations to timing and power attacks. We also show the generality of our approach by using it to quantify the information leaked by a security protocol.
Boris Köpf, David A. Basin