An Economical Model for the Risk Evaluation of DoS Vulnerabilities in Cryptography Protocols

Denial of Service (DoS) attacks are a virulent type of attack on the availability of networks’ intended services and resources. Defense against DoS attacks has been built into the cryptography protocols intended for authentication and establishment of communications. However the cryptography protocols have their own vulnerability to DoS. Consequently it is desirable to provide a methodology to evaluate the cryptography protocols’ resistance to DoS attacks. In this paper, we propose an economical model for the risk evaluation of Denial of Service vulnerabilities in cryptographical protocols. By characterizing the intruder capability with a probability model, our risk evaluation model specifies the Value at Risk (VaR) for the cryptography protocols. The Value at Risk does the very job answering the question that how much computing resources are expected to lose with a given level of confidence. The proposed model can help the common users to have a better knowledge of the protocols they are using, and in the meantime help designers to examine their designs and get clues to improve them. We validate the applicability and effectiveness of our risk evaluation model by applying it to analyze two related protocols.