Vehicular ad hoc networks allow vehicles to share their information for the safety and efficiency of traffic purposes. However, information sharing can threaten the driver’s privacy as it includes spatiotemporal information, and the messages are unencrypted and broadcasted periodically. Therefore, they cannot estimate their privacy level because it also depends on their surroundings. This article proposes a centralized adaptive pseudonym change scheme that permits the certificate’s authority to adjust the pseudonyms assignment for each requesting vehicle. This scheme adapts dynamically depending on the density of the traffic environment and the user’s privacy level, and it aims to solve the trade-off problem between wasting pseudonyms and Sybil attack. We employ a Knapsack problem-based algorithm for target tracking and an entropy-based method to measure each vehicle’s privacy. In order to demonstrate the applicability of our framework, we use real-life data captured during the interoperability tests of the European project InterCor. According to the experimental results, the proposed scheme could easily estimate the level of confidentiality and, therefore, may best respond to the adaptation of the pseudonyms.

Vehicular communications have become essential for functional and road safety purposes due to the development of vehicle fleets. However, these communications have made vehicles more vulnerable to cyber-attacks. The security of data exchanges in vehicular networks currently relies on a centralized architecture that is responsible for managing various security services such as authentication, confidentiality, non-repudiation, real-time misbehavior detection, certificate management and revocation. However, this centralized approach can be challenging and costly for authorities, and it may even weaken the network's overall security. In this paper, we propose a complementary solution that uses a decentralized security framework to help authorities better manage their network security by involving each vehicle in the overall security management. Our framework, TileChain, is blockchain based solution that use road information to manage the network's security dynamically. The architecture is designed to optimize any security service efficiently. To demonstrate the feasibility and performance of our proposed solution, we selected certificate revocation as a critical service and performed simulations using real vehicle traffic data provided by The French road operator DIR Nord. Our Smart Contract achieved an accuracy of 81.3% in misbehavior detection, leading to certificate revocation. Furthermore, the computation load for security management by authorities potentially reduced by a factor of 96.8%. In summary, our proposed solution, TileChain, offers a promising decentralized approach for managing vehicular network security that can potentially improve the overall security of the network while reducing the computational burden on authorities.

Despite the decisive contribution of intelligent transport systems in road safety, they also open new vulnerabilities to cyber-attacks, particularly vehicle position-linked attacks. For that reason, centralized systems are becoming increasingly vulnerable to the growth of the connected-vehicle fleets as it becomes more challenging to revoke certificates in real-time. We have proposed a new method that integrates a decentralized, collaborative system to meet these challenges. This method efficiently allows Blockchain integration for vehicular network’s cyber security by dynamically creating communities to revoke malicious vehicles in real-time. This article presents analytical models of the system of real-time revoking certificates and examines our solution’s impact on two important types of attacks in V2X communications, Sybil and the faking position attacks. Our experiments using real V2X hardware demonstrated the feasibility and benefits of real-time revocation via vehicle communities. The results were obtained from consensus implementation in a vehicular network comprising three communicating vehicles and a single roadside unit. In parallel, simulations showed feasibility in large-scale communications. As a result, the exposure and detection times of our solution meet real-time requirements.