Visible to the public Biblio

Filters: Author is Hirschi, Lucca  [Clear All Filters]
2019-11-12
Dreier, Jannik, Hirschi, Lucca, Radomirovic, Sasa, Sasse, Ralf.  2018.  Automated Unbounded Verification of Stateful Cryptographic Protocols with Exclusive OR. 2018 IEEE 31st Computer Security Foundations Symposium (CSF). :359-373.

Exclusive-or (XOR) operations are common in cryptographic protocols, in particular in RFID protocols and electronic payment protocols. Although there are numerous applications, due to the inherent complexity of faithful models of XOR, there is only limited tool support for the verification of cryptographic protocols using XOR. The Tamarin prover is a state-of-the-art verification tool for cryptographic protocols in the symbolic model. In this paper, we improve the underlying theory and the tool to deal with an equational theory modeling XOR operations. The XOR theory can be freely combined with all equational theories previously supported, including user-defined equational theories. This makes Tamarin the first tool to support simultaneously this large set of equational theories, protocols with global mutable state, an unbounded number of sessions, and complex security properties including observational equivalence. We demonstrate the effectiveness of our approach by analyzing several protocols that rely on XOR, in particular multiple RFID-protocols, where we can identify attacks as well as provide proofs.

Basin, David, Dreier, Jannik, Hirschi, Lucca, Radomirovic, Sa\v sa, Sasse, Ralf, Stettler, Vincent.  2018.  A Formal Analysis of 5G Authentication. Proceedings of the 2018 ACM SIGSAC Conference on Computer and Communications Security. :1383-1396.

Mobile communication networks connect much of the world's population. The security of users' calls, SMSs, and mobile data depends on the guarantees provided by the Authenticated Key Exchange protocols used. For the next-generation network (5G), the 3GPP group has standardized the 5G AKA protocol for this purpose. We provide the first comprehensive formal model of a protocol from the AKA family: 5G AKA. We also extract precise requirements from the 3GPP standards defining 5G and we identify missing security goals. Using the security protocol verification tool Tamarin, we conduct a full, systematic, security evaluation of the model with respect to the 5G security goals. Our automated analysis identifies the minimal security assumptions required for each security goal and we find that some critical security goals are not met, except under additional assumptions missing from the standard. Finally, we make explicit recommendations with provably secure fixes for the attacks and weaknesses we found.