Decentralized authentication in VANETs using blockchain and edge computing

Vehicular Ad hoc Networks are highly dynamic wireless networks that enable communication between vehicles and roadside infrastructure. They enhance road safety by supporting driver-assistance services and advanced transportation applications, such as automated driving and intelligent transportation systems. These networks are characterized by dynamic topology, intermittent connectivity, and limited resources. Most existing blockchain-based authentication approaches rely on roadside units or continuous Internet connectivity, which increases deployment costs and limits vehicle autonomy in areas without network coverage. This article proposes an authentication mechanism that combines a consortium blockchain with integrated edge computing to enable vehicle-to-vehicle authentication without roadside units and without continuous Internet connectivity. Each vehicle is equipped with an Edge Box that performs local data processing, real-time inter-vehicle authentication, and secure communication. The system uses an elliptic-curve–based key exchange method and symmetric encryption to ensure communication confidentiality and integrity. Experiments conducted on two Raspberry Pi-based Edge Boxes over 10 trials show a communication cost of 64 bytes per authentication exchange, reducing communication overhead by 54%–97% compared to existing blockchain-based schemes, with an average mutual-authentication delay of 58.46 ms.