Lightweight hybrid key management framework towards centralized in-vehicle networks

The key management strategy assumes a pivotal role in safeguarding secure communication at the vehicle end. Nevertheless, existing methods exhibit high incompatibility with heterogeneous characteristics of the current centralized in-vehicle network architecture and fail to meet real-time requirements. To this end, a lightweight hybrid key management framework is proposed. Firstly, the in-vehicle network is hierarchically decoupled according to its network topologies, communication patterns and computational capabilities. Based on distinct characteristics across layers, lightweight pairwise and group key management schemes are applied to the first-layer star network topology and second-layer bus network topology, respectively. The hybrid framework demonstrates excellent compatibility with heterogeneous centralized in-vehicle network architectures while supporting comprehensive security features such as cross-domain isolation, dynamic session key updates, dynamic node joining and exiting. The favorable mathematical properties of adopted key management schemes and the incorporation of the authenticated encryption algorithm ensure high key negotiation efficiency. Performance evaluation demonstrates that the proposed strategy attains a 58.3% reduction in key update latency compared with existing methods. Security analysis demonstrates that the proposed strategy satisfies security objectives.