Computationally Sound Implementations of Equational Theories against Passive Adversaries

Mathieu Baudet , Véronique Cortier (1) , Steve Kremer (2)

1 CASSIS - Combination of approaches to the security of infinite states systems
2 LSV - Laboratoire Spécification et Vérification [Cachan]

In this paper we study the link between formal and cryptographic models for security protocols in the presence of passive adversaries. In contrast to other works, we do not consider a fixed set of primitives but aim at results for arbitrary equational theories. We define a framework forcomparing a cryptographicimplementation and its idealization with respect to 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, to illustrate our framework, we establish the soundness of static equivalence for the exclusive OR and a theory of ciphers and lists.

Domaines: Cryptographie et sécurité [cs.CR]

Mathieu Baudet, Véronique Cortier, Steve Kremer. Computationally Sound Implementations of Equational Theories against Passive Adversaries. Information and Computation, 2009, 207 (4), pp.496-520. ⟨10.1016/j.ic.2008.12.005⟩. ⟨inria-00426620⟩