ABSTRACT The effectiveness of intelligent transportation systems (ITS) critically depends on vehicular ad‐hoc networks (VANETs) for vehicle‐to‐everything (V2X) communication. ITS relies on wireless technologies, particularly dedicated short‐range communication (DSRC), to facilitate vehicle‐to‐vehicle interactions through basic safety messages (BSMs). DSRC is a proven technology with established deployment models that do not depend on cellular network reliability. Despite its advantages, DSRC is vulnerable to various security threats, including hijacking, impersonation, and side‐channel attacks. Numerous authentication protocols for VANETs have been proposed; however, they have failed to address the challenges. Certification authority (CA)‐based protocols suffer from high latency, while decentralized protocols fall short in preserving vehicle identity and location privacy. Notably, existing solutions overlook the importance of localizing the V2X message sender, which allows adversaries to launch remote attacks from arbitrary locations. To address this gap, we propose LIMA (local and lightweight mutual authentication)—a protocol tailored for VANETs that ensures secure mutual authentication and message integrity by leveraging dual policy attribute‐based encryption (DP‐ABE). The protocol is designed to operate efficiently in real‐world conditions, including scenarios involving blind spots and obstructed vehicles. We validate LIMA through experimental evaluations on real‐world on‐board units (OBUs) and, using PlatoonSAFE OMNeT++ simulations, quantify LIMA's processing overhead and evaluate its effect during emergency events. Moreover, we conduct a formal security analysis using the AVISPA tool. The results demonstrate that LIMA is secure under AVISPA's backend on‐the‐fly model‐checker (OFMC) model and constraint‐logic‐based attack searcher (CLAtSe) model, confirming its resilience against known attacks.
Mukhandi et al. (Thu,) studied this question.