A semi-centralized key agreement protocol integrated multiple security communication techniques for LLM-based autonomous driving system

Integrating large language models (LLMs) into autonomous vehicles facilitates AI-driven interactions for vehicle operations, yet it also introduces vulnerabilities to cyberattacks. Existing session key agreement schemes encounter significant challenges, including key leakage, single points of failure, and resource constraints. To address these limitations, we propose a semi-centralized key agreement protocol tailored for LLM-based autonomous driving systems. The protocol incorporates physical unclonable functions (PUFs) for electronic control unit (ECU) authentication, certificateless public key cryptosystems (CL-PKC) for key pair generation, Shamir’s secret sharing for group session key negotiation, and interarrival time-based covert channels with hash key chains for secure communication. Security analysis conducted using the random oracle model and the AVISPA simulation tool verifies the protocol’s security and consistency properties. Experimental evaluations demonstrate that the proposed protocol achieves reduced communication and computational overhead while exhibiting strong resilience against in-vehicle cyberattacks. These findings establish the protocol as a lightweight and robust solution for securing LLM-based autonomous driving environments.