Post-Quantum Secure Authenticated Key Agreement Scheme for Vehicular Digital Twin

The advent of digital twins, which leverage the server's robust data-processing and storage capacities to manage vehicular tasks, effectively addresses the limitations of traditional Internet of Vehicles (IoV). However, the communication link between a vehicle and its digital twin remains open and insecure, necessitating the development of an Authenticated Key Agreement (AKA) scheme to secure this channel. Existing AKA schemes for Vehicular Digital Twin (VDT) fail to achieve post-quantum security, and the progression of quantum computing has intensified the urgency to establish post-quantum secure solutions. To address these shortcomings, we propose a lightweight, quantum-resistant three-party AKA scheme for VDT networks based on the Ring Learning With Errors (RLWE) computational problem. Our scheme enables one-round interaction with privacy preservation while ensuring the efficiency of the AKA protocol through its RLWE-based design. Additionally, our approach mitigates the risk of temporary key reuse during Gaussian sampling, thereby resisting newly discovered key reuse attacks targeting lattice-based key agreement schemes. Security proofs and analyses prove that the proposed scheme meets the fundamental security and privacy requirements of IoV. Furthermore, performance evaluations indicate that our scheme achieves post-quantum security with low computational overhead and energy consumption, making it compatible with quantum-resistant VDT communications.