In recent years, the security of automotive Cyber-Physical Systems (CPSs) is facing urgent threats due to the widespread use of legacy in-vehicle communication systems. As a representative legacy bus system, the Controller Area Network (CAN) hosts Electronic Control Units (ECUs) that are crucial for the vehicles functioning. In this scenario, malicious actors can exploit the CAN vulnerabilities, such as the lack of built-in authentication and encryption schemes, to launch CAN bus attacks (e.g., suspension, injection, and masquerade attacks) with life-threatening consequences (e.g., disabling brakes). In this article, we present TACAN (Transmitter Authentication in CAN), which provides secure authentication of ECUs on the legacy CAN bus by exploiting the covert channels, without introducing CAN protocol modifications or traffic overheads (no extra bits or CAN messages are used). TACAN turns upside-down the originally malicious concept of covert channels and exploits it to build an effective defensive technique that facilitates transmitter authentication via a centralized, trusted Monitor Node. TACAN consists of three different covert channels for ECU authentication: 1) the Inter-Arrival Time (IAT)-based, leveraging the IATs of CAN messages; 2) the Least Significant Bit (LSB)-based, concealing authentication messages into the LSBs of normal CAN data; and 3) a hybrid covert channel, exploiting the combination of the first two. In order to validate TACAN, we implement the covert channels on the University of Washington (UW) EcoCAR (Chevrolet Camaro 2016) testbed. We further evaluate the bit error, throughput, and detection performance of TACAN through extensive experiments using the EcoCAR testbed and a publicly available dataset collected from Toyota Camry 2010. We demonstrate the feasibility of TACAN and the effectiveness of detecting CAN bus attacks, highlighting no traffic overheads and attesting the regular functionality of ECUs.

Trucks form a platoon, where they align in a lane on freeways, in order to save fuel. The trucks positioned behind the first truck in the platoon can save fuel because their air drag reduces. In a truck platoon, various technologies such as Adaptive Cruise Control (ACC) system and Vehicle-to-Vehicle (V2V) communication protocol are exploited to control the trucks in the platoon effectively. The camera sensors measure distance between contiguous trucks in the platoon and these sensor measurements are provided to the ACC system. By using these sensor measurement, the ACC system controls the truck speed via in-vehicle network protocols such as the controller area network, which does not encrypt data or authenticate messages. Also, the V2V communication protocol is vulnerable to cyber attacks that disable the wireless channels among the trucks in the platoon. As a result, the ACC system and V2V communication protocol may introduce attack surfaces in a truck platoon. In this survey, we analyze the attack surfaces of a truck platoon under different perspectives. Then, we summarize the defense systems corresponding to the discussed attacks in terms of detection mechanisms, response countermeasures, and proactive defenses. Finally, we provide the research issues that need to be addressed in future.