Computer Assisted Proof of Resistance of Denial of Service Attacks in Security Protocols Based on Events with CryptoVerif in Computational Model

Owning to the huge damage and difficulty of prevention of denial of service attacks in security protocols, people pay serious attentions on analysis, verification and prevention of denial of service attacks. Formal method in computational model is a powerful tool used to analyze and prove securities in security protocols, network and distributed system. But until now in computational model there does not exist an automatic method of proof of resistance of denial of service attacks. In this paper from the view of protocol state we initially present an automatic method of proof of resistance of denial of service attacks with CryptoVerif in computational model. Therefore Blanchet calculus is extended from adversary context, output process and the model of private channel, and then from the view of protocol state, the first automatic method of proof of resistance of denial of service attacks based on events in extended Blanchet calculus is proposed. Finally resistance of denial of service attacks in IEEE 802.11 i four-way handshake protocol is analyzed with CryptoVerif. The results we obtained are that it is not resistance of denial of service attacks. At the same time a new denial of service attack is found by us. Then the methods against denial of service attacks in IEEE 802.11 i four-way handshake protocol are proposed.