HIPCAM: Data Stream-Driven Group Key Management for In-Vehicle Network With Seamless Key Updates

The vehicular network primarily relies on the Controller Area Network (CAN) because it meets the requirements of vehicular networks in terms of high reliability and real-time performance. However, the absence of robust security measures on the CAN bus exposes vulnerabilities, enabling attackers to potentially compromise vehicles remotely. Many cryptography based methods are proposed to enhance the security of CAN bus, but they rarely involve key management issues. In this paper, we propose a lightweight group key management scheme that innovatively utilizes the residual part of the Message Authentication Code (MAC) of data stream to maintain a synchronized fields between Electronic Control Units (ECUs), which is called hippocampus. Each ECU executes the refresh process by applying the XOR operation between hippocampus and old key. Moreover, we provide formal security proofs and informal analyses for the robustness of the proposed scheme. Afterwards, a series of evaluations on three typical hardware platforms are detailed. The results demonstrate that the additional time overhead introduced by our scheme remains within acceptable limits and validate its advantage, efficiency, and flexibility by comparing it with other methods.