A Novel Security Model for Denial of Service Attacks on Multi-Party Key Exchange Protocol

Denial of Service (DoS) is an important factor to consider for multi-party key exchange protocols on a public network that is prone to attacks. There are various models that consider the security of multi-party key exchange protocols, but unfortunately DoS has been avoided. Many protocols, said to be secure against DoS attacks, turned out to be ineffective and were subsequently broken. In this paper, we propose a security model, modeling DoS attacks on multi-party key exchange protocol. We propose a formal definition of DoS-resistant protocol and also integrate the security with the DoS framework. The model achieves the objective of securing the protocol by making use of client puzzles. We present how to integrate the DoS countermeasures with the key exchange protocol to prevent attacks.