CAN FD Message Authentication Enhances Parallel in-vehicle Applications Security

Controller Area Network with Flexible Data-rate(CAN FD) has the advantages of high bandwidth and data field length to meet the higher communication requirements of parallel in-vehicle applications. If the CAN FD lacking the authentication security mechanism is used, it is easy to make it suffer from masquerade attack. Therefore, a two-stage method based on message authentication is proposed to enhance the security of it. In the first stage, an anti-exhaustive message exchange and comparison algorithm is proposed. After exchanging the message comparison sequence, the lower bound of the vehicle application and redundant message space is obtained. In the second stage, an enhanced round accumulation algorithm is proposed to enhance security, which adds Message Authentication Codes(MACs) to the redundant message space in a way of fewer accumulation rounds. Experimental examples show that the proposed two-stage approach enables both small-scale and large-scale parallel in-vehicle applications security to be enhanced. Among them, in the Adaptive Cruise Control Application(ACCA), when the laxity interval is 1300$\mu$s, the total increased MACs is as high as 388Bit, and the accumulation rounds is as low as 40 rounds.