Enhancing Security in Automotive Unified Diagnostic Services: A Lightweight Certificate Validation Verification Approach

The surge in the frequency of automotive diagnostics, coupled with the exponential growth in data volume, underscores the pressing need for robust security measures. While unified diagnostic services (UDS) incorporate authentication services, we found that resource-constrained edge devices face challenges in verifying the status of certificates and validity period due to limited connectivity in application, posing serious risks to diagnostic security. To address this issue, we establish an attack model and propose a tailored lightweight certificate validation approach specifically designed for automotive scenarios. This approach employs diagnostic equipment as proxies, introducing the lightweight time query protocol (LTQP) and the Lightweight Online Certificate Status Protocol (LOCSP) to acquire precise real-time data and certificate status information. Furthermore, we integrate the protocols with authentication services while ensuring UDS protocol consistency, and standardizing the certificate verification flow. We constructed a certificate management platform based on public key infrastructure and simulated a vehicular environment to validate the security and feasibility of the approach. Through Proverif formal verification and experimental analysis, it is proved that our proposed approach significantly advances automotive cybersecurity by complementing authentication services, enhancing diagnostic communication security, and ensuring efficiency.