CAN-MM: Multiplexed Message Authentication Code for Controller Area Network Message Authentication in Road Vehicles

As the automotive industry adopts more technology, the threat of cyberattacks on vehicles grows. Electronic Control Units (ECUs) operate in a hostile environment, raising safety concerns for drivers and passengers. Initiatives from both industry and government bodies aim to address these risks. The primary communication protocol used in the automotive industry, the standard Controller Area Networks (CANs) protocol, is a target for cybercriminals due to its limitations in ensuring communication integrity. This paper proposes CAN Multiplexed MAC (CAN-MM), using frequency modulation to multiplex Message Authentication Code (MAC) data with standard CAN communication. CAN-MM enables the transmission of MAC payloads at reduced time cost while maintaining backward compatibility with old CAN protocol versions. The solution is also compatible with modern evolutions of the CAN protocol and advanced algorithms resorting to MAC as part of the security infrastructure.