MixCAN: Mixed and Backward-Compatible Data Authentication Scheme for Controller Area Networks

22 June 2020

The massive proliferation of state of the art interfaces into the automotive sector has triggered a revolution in terms of the technological ecosystem that is found in today's modern car. Accordingly, on the one hand, we find dozens of Electronic Control Units (ECUs) running several hundred MB of code, and more and more sophisticated dashboards with integrated wireless communications. On the other hand, in the same vehicle we find the underlying communication infrastructure struggling to keep up with the pace of these radical changes. This paper presents MixCAN (MIXed data authentication for Control Area Networks), an approach for mixing different message signatures (i.e., authentication tags) in order to reduce the overhead of Controller Area Network (CAN) communications. MixCAN leverages the attributes of Bloom Filters in order to ensure that an ECU can sign messages with different CAN identifiers (i.e., mix different message signatures), and that other ECUs can verify the signature for a subset of monitored CAN identifiers. Extensive experimental results based on Vectors Informatik's CANoe/CANalyzer simulation environment and the data set provided by Hacking and Countermeasure Research Lab (HCRL) confirm the validity and applicability of the developed approach. Subsequent experiments including a test bed consisting of Raspberry Pi 3 Model B+ systems equipped with CAN communication modules demonstrate the practical integration of MixCAN in real automotive systems.