A Trusted Multi-hop Broadcasting Protocol for Vehicular Ad Hoc Networks

The vehicular ad hoc networks (VANETs) are characterized by high mobility of nodes, which resulting in frequent and fast changes in the network topologies. To make sure the messages are received efficiently and reliably, particularly for safety applications, broadcasting is the most natural and promising approach. Besides the efficiency, security is another important issue for VANETs. Because the open nature of VANETs make it simple for malicious users to disrupt the system or lead to accidents. In this paper, we propose a PKI-based Multi-hop Broadcasting Protocol (PMBP), which aims at providing authenticated, integrated, non-repudiated vehicular communication. The authentication scheme is based on the Elliptic Curve Digital Signature Algorithm (ECDSA) method. To provide an efficient trusted broadcasting scheme, two strategies are adopted: only the message originator signs the message; one message only be rebroadcasted once by each vehicle. Experimental results prove that this protocol is efficient enough to support safety related vehicular applications.