Modelling and checking timed authentication of security protocols

Abstract. In this paper we offer a methodology for verifying correctness of (timed) security protocols whose actions are parametrized with time. To this aim the model of a protocol involves delays and timeouts on tran-sitions, and sets time constraints on actions to be executed. Our approach consists in specifying a security protocol, possibly with timestamps, in a higher-level language and translating automatically the specification to a timed automaton (or their networks). Moreover, we generalize the correspondence property so that attacks can be also discovered when some time constraints are not satisfied. Then, one can use each of the verification tools for timed automata for model checking generalized time authentication of security protocols. As a case study we verify general-ized (timed) authentication of KERBEROS, TMN, Neuman Stubblebine Protocol, and Andrew Secure Protocol.