VTrust: A Robust Trust Framework for Relay Selection in Hybrid Vehicular Communications

As one of the essential components of Intelligent Transport Systems (ITS), Vehicular Ad Hoc Network (VANET) plays a significant role in enabling various on-road applications, most of which primarily rely on two-top Vehicle-To-Vehicle communications. To make such communications reliable and secure, it is significant to ensure that the trustworthy vehicles are selected as relays. To tackle this challenge, this paper proposes a robust trust framework, called VTrust, which systematically integrates a set of unique features of VANET, e.g., hybrid architecture, high dynamics, social attributes, into the traditional reputation system, with an objective to effectively differentiate the trust levels of the vehicles meanwhile preserve high scalability and robustness. The digital signature and multisignature techniques are also applied to enhance the security of VTrust. To validate the performance of the framework, an in-depth security analysis is conducted, which shows that it is secure and robust against several sophisticated attacks in VANETs. Also, a set of extensive simulations is carried out, demonstrating its effectiveness, accuracy, and scalability.