Tacan

Abstract

Nowadays, the interconnection of automotive systems with modern digital devices offers advanced user experiences to drivers. Electronic Control Units (ECUs) carry out a multitude of operations using the insecure Controller Area Network (CAN) bus in automotive Cyber-Physical Systems (CPSs). Therefore, dangerous attacks, such as disabling brakes, are possible and the safety of passengers is at risk. In this paper, we present TACAN (Transmitter Authentication in CAN), which provides secure authentication of ECUs by exploiting the covert channels without introducing CAN protocol modifications or traffic overheads (i.e., no extra bits or 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 trusted Monitor Node. TACAN consists of three different covert channels for ECU authentication: 1) Inter-Arrival Time (IAT)-based, leveraging the IATs of CAN messages; 2) offset-based, exploiting the clock offsets of CAN messages; 3) Least Significant Bit (LSB)-based, concealing authentication messages into the LSBs of normal CAN data. We implement the covert channels on the University of Washington (UW) EcoCAR testbed and evaluate their performance through extensive experiments. We demonstrate the feasibility of TACAN, highlighting no traffic overheads and attesting the regular functionality of ECUs. In particular, the bit error ratios are within 0.1% and 0.42% for the IAT-based and offset-based covert channels, respectively. Furthermore, the bit error ratio of the LSB-based covert channel is equal to that of a normal CAN bus, which is 3.1 × 10 −7 %. CCS CONCEPTS • Computer systems organization → Embedded and cyberphysical systems; • Security and privacy → Cryptography;

Cybersecurity protection on in‐vehicle networks for distributed automotive cyber‐physical systems: State‐of‐the‐art and future challenges

“…Most messages are sent periodically on the CAN bus, thus an IDS can be realized by monitoring the message intervals (message period) and the average message content changes. Ying et al 32 propose a covert‐channel based ECU identification method via a centralized monitor node, where the interarrival time based covert channel can be used for periodically transmitted messages, and the least significant bit based covert channel can be used for aperiodically transmitted messages. Taylor et al 33 give an IDS that measures intermessage timing over a sliding window, and the average times are compared with historical averages to yield an anomaly alert.…”

EASI: Edge-Based Sender Identification on Resource-Constrained Platforms for Automotive Networks

“…With TACAN [67] an approach to use covert channel-based transmitter authentication by exploiting physical characteristics of communication was introduced. Among others, the interarrival times are specifically adapted to transmit information for the authentication of ECUs.…”