Analysis of Cryptographic Protocol by Dynamic Epistemic Logic

The security of the cryptographic protocols has always been important to ensure proper implementation of a protocol. To assure protocol security, a number of works for analysis and verification of cryptographic protocols have emerged in the literature. In this paper, with dynamic epistemic logic, we propose a model approach to analyze a cryptographic protocol. In order to capture the security properties of the protocol, we present the update of the epistemic states based on the epistemic actions. The epistemic actions lead to changes in the knowledge set of the agents participating in the protocol. We model this execution process of the specific example of the cryptographic protocol using the Kripke models and the transition between states. The result of analysis demonstrates that this cryptographic protocol conforms to the security requirements.