Secure quantum aggregate signature scheme for vehicular ad-hoc networks

The rapid evolution of smart cities and intelligent transportation systems has led to the widespread deployment of Vehicular Ad Hoc Networks (VANETs), enabling real-time inter-vehicular communication and data sharing related to traffic congestion, vehicle location, and road safety. However, the open and dynamic nature of VANETs makes them vulnerable to various security threats, including identity tracing and message forgery. To address these concerns, this paper proposes a quantum aggregate signature scheme that leverages quantum teleportation and untraceable identity mechanisms for secure and privacy-preserving communication in VANETs. The proposed scheme enables the aggregation of multiple signatures into a single, compact signature while preserving the anonymity of vehicular nodes through pseudo-identities and quantum-enhanced privacy techniques. By incorporating quantum teleportation, our scheme ensures quantum-level security for message transmission without directly transferring the secret state. Furthermore, it supports efficient batch verification to authenticate messages from multiple vehicles with minimal computational and communication overhead. The protocol's correctness and security are validated using both Scyther tool-based formal verification and informal analysis, demonstrating strong resistance against existential forgery, impersonation, and traceability attacks. Compared to existing schemes, our approach reduces computational time by 0.053 ms and communication overhead by 778 bytes, making it scalable, efficient, and highly applicable for real-world VANET deployments.