ATM: An Active-Detection Trust Mechanism for VANETs Based on Blockchain

Existing trust mechanisms in vehicular ad hoc networks (VANETs) suffer from a variety of vulnerabilities, such as trust inconsistency in different regions and fake trust values generated by a set of cooperating malicious nodes. In this paper, we propose a novel local trust management mechanism, ATM, to solve these problems. ATM employs active detection and blockchain techniques. Specifically, the active detection effectively filters the surrounding malicious nodes and prevents their active cooperation, while the blockchain ensures the consistency of trust data across different regions. We conduct numerical analysis to evaluate the performance of ATM. Our experiment results show that ATM performs the best among the three trust mechanisms under test. It can effectively identify malicious behaviors in terms of 95% detection accuracy and 90% deliver ratio, respectively.