Automated Analysis of Security Protocols with Global State

Steve Kremer (1) , Robert Künnemann (2, 3)

1 CASSIS - Combination of approaches to the security of infinite states systems
2 PROSECCO - Programming securely with cryptography
3 TU Darmstadt - Technische Universität Darmstadt - Technical University of Darmstadt

Security APIs, key servers and protocols that need to keep the status of transactions, require to maintain a global, non-monotonic state, e.g., in the form of a database or register. However, most existing automated verification tools do not support the analysis of such stateful security protocols - sometimes because of fundamental reasons, such as the encoding of the protocol as Horn clauses, which are inherently monotonic. A notable exception is the recent tamarin prover which allows specifying protocols as multiset rewrite (MSR) rules, a formalism expressive enough to encode state. As multiset rewriting is a "low-level" specification language with no direct support for concurrent message passing, encoding protocols correctly is a difficult and error-prone process.We propose a process calculus which is a variant of the applied pi calculus with constructs for manipulation of a global state by processes running in parallel. We show that this language can be translated to MSR rules whilst preserving all security properties expressible in a dedicated first-order logic for security properties. The translation has been implemented in a prototype tool which uses the tamarin prover as a backend. We apply the tool to several case studies among which a simplified fragment of PKCS#11, the Yubikey security token, and an optimistic contract signing protocol.

Domaines: Cryptographie et sécurité [cs.CR]

Steve Kremer, Robert Künnemann. Automated Analysis of Security Protocols with Global State. 35th IEEE Symposium on Security and Privacy (S&P'14), May 2014, San Jose, United States. pp.163-178, ⟨10.1109/SP.2014.18⟩. ⟨hal-01091241⟩