Towards a Privacy Preserving and Flexible Scheme for Assessing the Credibility and the Accuracy of Safety Messages Exchanged in VANETs

In Vehicular Ad hoc NETworks (VANETs), vehicles exchange safety related messages in order to improve the driving experience. However, it is not realistic to presume the absence of attackers intending to subvert the proper operation of the network. While message authentication enables the receiver to make sure of the received message's integrity and to verify its originator, it does not permit the verification of the message's credibility and accuracy. The main contribution of this paper is then the proposition of a scheme to assess the credibility and the accuracy of safety related messages exchanged in VANETs. Three modules constitute our proposal: a reputation module to evaluate the respective reputations of vehicles, a time and location closeness estimation module to judge the accuracy of a reported event and a majority module to decide the trueness of a received traffic information. These modules can be used in a separated or a combined way enabling a more flexibility in front of different circumstances confronted in VANETs. An in-depth security analysis is performed to demonstrate the efficiency of our proposal. Case studies that illustrate the different modules are also presented.