A. Hommersom, J.-J.Ch. Meyer and E.P. de Vink
Update Semantics of Security Protocols

We present a model-theoretic approach for reasoning about security protocols,
applying recent insights from dynamic epistemic logics. This enables us to
describe exactly the subsequent epistemic states of the agents participating in
the protocol, using Kripke models and transitions between these based on
updates of the agents' beliefs associated with steps in the protocol. As a case
study we will consider the SRA Three Pass protocol and discuss the Wide-Mouthed
Frog protocol.