Dynamic consensus for secured vehicular ad hoc networks

Vehicular ad hoc networks provide vehicle-to-vehicle communications and safety-related applications to enhance the road safety. However, safety-related applications, like Local Danger Warning, need a high trust level in received messages. Indeed, decisions are made depending on these messages. To increase the trustworthiness, a consensus mechanism is used. With consensus, vehicles need to receive at least X times the same warning before making a decision. Because the consensus should meet real-time constraints of safety applications, a main issue is to set parameter X. In this paper, we investigate the problem of consensus and propose a generic model to define decision method involved in consensus. Then, we propose to dynamically set the consensus parameter according to the neighborhood density and the warning criticalness. The proposed mechanism enhances the “majority of freshest X with threshold” decision method [1] and is analytically modeled. This context-aware and data-centric security mechanism ensures a quick and correct decision. We present some simulation results that validate our model.