Efficient and Security-Enhanced Certificateless Aggregate Signature-Based Authentication Scheme With Conditional Privacy Preservation for VANETs

Vehicular ad-hoc networks (VANETs) are integral to the evolution of intelligent transportation systems, offering substantial benefits in managing traffic flow, issuing warnings for potential accidents, and delivering information services to drivers. To ensure the authenticity and integrity of data exchanged within VANETs, numerous authentication schemes based on certificateless aggregate signature (CLAS) have been developed. However, state-of-the-art solutions often fail to be applicable in real-world VANETs due to security weaknesses and operational inefficiencies. Recently, Zhu et al. proposed an efficient CLAS-based authentication scheme with conditional privacy preservation (CPP) for VANETs (IEEE Transactions on Intelligent Transportation Systems, DOI: 10.1109/TITS.2023.3275077). Unfortunately, our analysis reveals that Zhu et al.’s scheme is incapable of withstanding coalition attacks from malicious RSUs and vehicles as well as public-key replacement attacks from dishonest vehicles. To facilitate secure communication in VANETs, we present a security-enhanced, pairing-free and energy-efficient CLAS-based authentication scheme with CPP for VANETs. This scheme has been rigorously proven to be secure against Type I, Type II and Type III attackers. Distinguished from other comparable schemes, our construction significantly reduces communication overhead and energy consumption while simultaneously fortifying security.

I. Introduction

Vehicula ad hoc networks (VANETs) are emerging mobile self-organizing networks that have the capacity to integrate a broad spectrum of sensor data from vehicles. Vehicles employ dedicated short-range communication protocols (e.g., IEEE 802.11p) for vehicle-to-roadside unit (RSU) communication and vehicle-to-vehicle communication [1]. Consequently, VANETs offer essential support for the advancement of intelligent transportation systems. In the conventional architecture of VANETs as illustrated in Fig. 1, on-board units (OBUs) are employed by vehicles to transmit pertinent traffic data (e.g., position, speed, traffic and weather conditions) to surrounding vehicles and neighboring RSUs at consistent intervals ranging from 100 to 300 milliseconds. Subsequently, the application server, which serves as the traffic control center, receives and evaluates the traffic data transmitted by the RSUs via the Internet. Based on its analysis, the application server promptly initiates appropriate traffic management actions, such as optimizing the timing of traffic signals. Additionally, a trusted authority is empowered to monitor and identify malevolent vehicles, afterward enforcing appropriate penalties. By facilitating the exchange of traffic information among vehicles, VANETs hold the potential to significantly reduce traffic congestion, minimize the incidence of accidents, and enhance intelligent driving capabilities in vehicles. Fig. 1.

The CLAS-based authentication architecture for VANETs.