Computationally sound implementations of equational theories against passive adversaries
In this paper we study the link between formal and cryptographic models for security protocols in the presence of a passive adversary. In contrast to other works, we do not consider a fixed set of primitives but aim at results for an arbitrary equational theory. We define a framework for comparing a cryptographic implementation and its idealization w.r.t. various security notions. In particular, we concentrate on the computational soundness of static equivalence, a standard tool in cryptographic pi calculi. We present a soundness criterion, which for many theories is not only sufficient but also necessary. Finally, we establish new soundness results for the Exclusive Or, as well as a theory of ciphers and lists.