Countermeasure Uncooperative Behaviors with Dynamic Trust-Token in VANETs

As one special case of the mobile ad hoc networks (MANETs), vehicular ad hoc network (VANET) is featured for its extremely high mobility and constantly changing topology. As a fully distributed network, VANET can work properly only if all the participating vehicles cooperate well during communications. However, lacking centralized coordinators, individual vehicle might be uncooperative for its own benefits. To promote node cooperation and to protect VANET packets during propagation, this paper proposes a dynamic trust-token (DTT) based cooperation enhancement mechanism. DTT utilizes both symmetric and asymmetric cryptography mechanisms to protect packet integrity, and applies neighborhood WatchDog to generate trust token based on instant performance to verify packet correctness. As a result, cooperation among VANET nodes during packet disseminations could be achieved and packet delivery could be well-protected. Performance analysis shows that the latency degradation of the proposed DTT mechanism is negligible.