A Model to Evaluate Reliability of Authentication Protocols in C-ITS Safety-Critical Applications

In the near future, Vehicle-to-Vehicle (V2V) transmission will enable wireless broadcast communication among nearby vehicles. Benefits for users include improved driver safety and potentially optimized traffic. However, this communication is vulnerable to cyber attacks involving message manipulation. Research aimed at tackling this problem has resulted in the proposal of multiple authentication protocols. The security, privacy, and other desirable features of authentication in vehicular networks have been widely studied. However, the efficiency of such authentication schemes has not been suitably addressed. There is no model to evaluate the efficiency of the proposals in a practical context, where the delay introduced by V2V authentication may impact on driver safety. In this paper, we provide such a model for evaluation. We explicitly present the key factors involved to evaluate the computational delay in the V2V authentication protocols. Our model has clearly defined metrics for computing the delay and evaluating the impact. Developing this model enables future research in the design of secure and efficient V2V authentication protocols suitable for practical application. Applying the model to assess proposed authentication protocols permits categorization based on safety service they can support. We demonstrate the applicability of our model through case studies. Our model can effectively analyze the delay introduced by an authentication protocol, and determine whether this would result in a crash, in the real world vehicular environments.