Controller Area Network Frame Research Articles

Single-Frame-Based Data Compression for CAN Security

To authenticate a controller area network (CAN) data frame, a message authentication code (MAC) must be sent along with the CAN frame, but there is no space reserved for the MAC in the CAN frame. Recently, difference-based compression (DBC) algorithms have been used to create a space inside the frame. DBC has the advantage of being very efficient, but its drawback is that, if an error occurs in one frame, the effects of that error propagate to subsequent frames. In this paper, a CAN data compression algorithm is proposed that compresses the current frame without relying on previous frames. Therefore, an error generated in one frame cannot be propagated to subsequent frames. In addition, a CAN signal grouping technique is proposed based on entropy analysis. To efficiently authenticate CAN frames, the length of the compressed data must be 4 bytes or less (4BL). Simulation shows that the 4BL-compression ratio of a Kia Sorento vehicle is 99.36% in the DBC method, but 100% in the proposed method. In an LS Mtron tractor, the 4BL-compression ratio is 98.58% in the DBC method, but 100% in the proposed method. In addition, the execution time of the proposed compression algorithm is only 27.39% of that of the DBC algorithm. The results show that the proposed algorithm has better compression characteristics for CAN security than the DBC algorithms.

A Model-Based Method for Enabling Source Mapping and Intrusion Detection on Proprietary Can Bus

With the deep integration of the Internet of Things (IoT) technology and the increase of computational power and memory, vehicles can also serve as the infrastructures for Intelligent Transportation System (ITS), e.g., as fog nodes. However, when connecting vehicles to the internet, alongside with the benefits it brings, it also opens many new challenges such as security attacks. Controller Area Network (CAN) is one of the main in-vehicle communication protocols in modern cars. Its lack of sender verification mechanism makes CAN particularly vulnerable to cyber-attacks including masquerade attack. Fingerprinting Electronic Control Units (ECUs) based on hardware characteristics has been proved feasible and effective on defending CAN buses. However, most state-of-the-art works exploited the supervised learning algorithm to identify the transmitter based on the signal characteristics. This makes the decision process hard to understand, and it also limits the deployment on proprietary CAN bus without prior knowledge. To solve this, we design a novel clock-skew-based approach capable of pinpointing the sender and detecting intrusion on proprietary CAN bus. We take a single CAN frame as the object for measurement, and adjust the measuring process such that our approach can be independent of the transmission time of frames. Based on the statistical analysis of data from real vehicles, we propose a novel box-plot algorithm based on score mechanism to filter the raw data. Finally, the clock skews are estimated and accumulated to build a linear model for representing the transmitter ECU. The evaluation results on one CAN prototype and two production vehicles show that our approach is able to well identify and differentiate ECUs on the bus without prior knowledge. The data processed by the proposed box-plot algorithm can describe the hardware characteristics of ECUs precisely. We also show the ability of our approach to protecting the CAN bus against the masquerade attack.

CANASTA: Controller Area Network Authentication Schedulability Timing Analysis

The Controller Area Network (CAN) dominates in-vehicle networking systems in modern vehicles. CAN was designed with low-latency and reliability as key features. Authenticity of a CAN frame was not considered in the design, thus, most in-vehicle network nodes inherently trust received messages as coming from a legitimate source. As a result, it is trivial to program (or hack) a network node to spoof traffic. Authentication is challenging for CAN and related protocols, such as SAE J1939, due to limited frame sizes and high bus utilization. Adding a message authentication code (MAC) as a separate message can unduly stress the real-time delivery of safety-critical messages. Although this stressor is well-known, the impact of authentication protocols on real-time message delivery in CAN has not yet been thoroughly examined. In this paper, we provide the first comprehensive analysis of realtime schedulability analysis applied to authentication schemes for CAN, CAN Flexible Data-rate (CAN FD), and CAN extra long payload (CAN XL). We formulate the response time analysis for addition of MACs and periodic transmission of MACs, and we examine their impact on two case studies and through evaluation with randomized schedulability experiments over a wide range of message sets.

Managing Concurrent Queues for Efficient In- Vehicle Gateways

In modern vehicles, electrical control units communicate over multiple in-vehicle networks via domainor zone-oriented gateway architectures. This work examines efficient frame transfer across incoming and outgoing Controller Area Network (CAN) interfaces at a gateway. In our embedded platform prototype, each CAN interface of a CAN-to-CAN gateway is controlled independently by a corresponding Portable Operating System Interface (POSIX) thread. Inter-thread communication and synchronization are implemented using shared data structures, either lock-free concurrent queues or traditional lock-based circular queues that embody single-producer single-consumer (SPSC) principles. Our experimental framework provides a realistic open automotive platform that integrates multiple CAN interfaces. An Odroid XU3 device acts as a gateway, providing two Universal Asynchronous Receiver- Transmitter (UART) to CAN interfaces that lead to Raspberry Pi 3B nodes (connected to CAN via Serial Peripheral Interface (SPI)). To increase communication reliability and performance by minimizing frame loss and improving the egress CAN frame rate, low-level parameters at the gateway are optimized, especially the inter-character delay of the UART-to-CAN interfaces. Our experiments show that the frame waiting time in the queue is shorter for the concurrent queue, while relaying messages is equally fast, reaching a maximum output rate of ~380 frames/s for large enqueue rates near saturation. Power consumption is almost four times higher for the concurrent queue implementation.

MAC-Based Compression Ratio Improvement for CAN Security

Information security in a controller area network (CAN) is becoming more important as the connections between a vehicle’s internal and external networks increase. Encryption and authentication techniques can be applied to CAN data frames to enhance security. To authenticate a data frame, a message authentication code (MAC) needs to be transmitted with the CAN data frame. Therefore, space for transmitting the MAC is required within the CAN frame. Recently, the Triple ID algorithm has been proposed to create additional space in the data field of the CAN frame. The Triple ID algorithm ensures every CAN frame is authenticated by at least 4 bytes of MAC without changing the original CAN protocol. However, since the Triple ID algorithm uses six header bits, there is a problem associated with low data compression efficiency. In this paper, we propose an algorithm that can remove up to 15 bits from frames compressed with the Triple ID algorithm. Through simulation using CAN signals of a Kia Sorento vehicle and an LS Mtron tractor, we show that the generation of frames containing compressed messages of 4 bytes or more is reduced by up to 99.57% compared to the Triple ID method.

V-SOC4AS: A Vehicle-SOC for Improving Automotive Security

Integrating embedded systems into next-generation vehicles is proliferating as they increase safety, efficiency, and driving comfort. These functionalities are provided by hundreds of electronic control units (ECUs) that communicate with each other using various protocols that, if not properly designed, may be vulnerable to local or remote attacks. The paper presents a vehicle-security operation center for improving automotive security (V-SOC4AS) to enhance the detection, response, and prevention of cyber-attacks in the automotive context. The goal is to monitor in real-time each subsystem of intra-vehicle communication, that is controller area network (CAN), local interconnect network (LIN), FlexRay, media oriented systems transport (MOST), and Ethernet. Therefore, to achieve this goal, security information and event management (SIEM) was used to monitor and detect malicious attacks in intra-vehicle and inter-vehicle communications: messages transmitted between vehicle ECUs; infotainment and telematics systems, which provide passengers with entertainment capabilities and information about the vehicle system; and vehicular ports, which allow vehicles to connect to diagnostic devices, upload content of various types. As a result, this allows the automation and improvement of threat detection and incident response processes. Furthermore, the V-SOC4AS allows the classification of the received message as malicious and non-malicious and acquisition of additional information about the type of attack. Thus, this reduces the detection time and provides more support for response activities. Experimental evaluation was conducted on two state-of-the-art attacks: denial of service (DoS) and fuzzing. An open-source dataset was used to simulate the vehicles. V-SOC4AS exploits security information and event management to analyze the packets sent by a vehicle using a rule-based mechanism. If the payload contains a CAN frame attack, it is notified to the SOC analysts.

Rec-CNN: In-vehicle networks intrusion detection using convolutional neural networks trained on recurrence plots

A controller area network (CAN) is a communication protocol for in-vehicle networks. Communication between electronic control units (ECUs) is facilitated by the CAN bus. This communication protocol provides no authentication or encryption to prevent the consequences of cyberattacks. As a security measure for this protocol, we have proposed an intrusion detection system (IDS) using a convolutional neural network (CNN). The CNN is trained on recurrence images generated from the encoded labels of CAN frame arbitration IDs, thus Rec-CNN. Using recurrence plots helps us capture the temporal dependency in the sequence of arbitration IDs unlike the state-of-art method, which does not capture this information. We have tested the proposed method on a publicly available dataset with denial of service (DoS), fuzzy, spoofing-gear, and spoofing-RPM attacks, resulting in an accuracy of 0.999. Furthermore, we have experimented with the method on our target vehicle. The proposed method can classify our simulated attacks with an accuracy of 0.999 in an attack frequency of 10 ms.

Fortifying Vehicular Security through Low Overhead Physically Unclonable Functions

Within vehicles, the Controller Area Network (CAN) allows efficient communication between the electronic control units (ECUs) responsible for controlling the various subsystems. The CAN protocol was not designed to include much support for secure communication. The fact that so many critical systems can be accessed through an insecure communication network presents a major security concern. Adding security features to CAN is difficult due to the limited resources available to the individual ECUs and the costs that would be associated with adding the necessary hardware to support any additional security operations without overly degrading the performance of standard communication. Replacing the protocol is another option, but it is subject to many of the same problems. The lack of security becomes even more concerning as vehicles continue to adopt smart features. Smart vehicles have a multitude of communication interfaces an attacker could exploit to gain access to the networks. In this work, we propose a security framework that is based on physically unclonable functions (PUFs) and lightweight cryptography (LWC). The framework does not require any modification to the standard CAN protocol while also minimizing the amount of additional message overhead required for its operation. The improvements in our proposed framework result in major reduction in the number of CAN frames that must be sent during operation. For a system with 20 ECUs, for example, our proposed framework only requires 6.5% of the number of CAN frames that is required by the existing approach to successfully authenticate every ECU.

A study of securing in-vehicle communication using IPSEC protocol

Abstract Current vehicles are increasingly dependent on Electronic Control Units (ECUs) that control virtually every system of the vehicle. To enable advanced features automotive embedded systems are opening to external world, which raises security concerns. At the same time these innovative systems require more complex software and higher bandwidth for information exchange. Thanks to its bandwidth, payload size, and openness, Ethernet is a candidate technology for future in-vehicle architectures. This paper deals with design of a novel approach to secure In-vehicle Systems by taking advantage of Ethernet/IP technology and proven security mechanisms from TCP/IP model. Main goal is to design an efficient solution that meets requirements for latency without requiring high amounts of processing power and provides secure exchange of control messages. The work is mainly focused on the widespread Controller Area Network (CAN). The presented solution is based on encapsulation of CAN frames into UDP datagrams with added authenticity, integrity, and (if required) confidentiality of communication using IPsec protocol in transport mode. This creates a “secure tunnel across backbone Ethernet network in a vehicle. Next part of the paper presents extensive tests in simulation that are based on our previous experiments on hardware, in order to evaluate the characteristics of the designed security extension. The results indicate that using IPsec is a viable solution for securing in-vehicle communications.

Triple ID Flexible MAC for Can Security Improvement

The development of automotive-information & communication technology (ICT) convergence has resulted in various vehicle-based electrical/electronic (E/E) systems. An automotive E/E system consists of one or more electronic control units (ECUs), sensors and actuators. With the commercialization of connected/autonomous cars, vehicle-based wireless communication systems have appeared, and are expected to grow in popularity. This increases the number of attack surfaces that can potentially threaten in-vehicle controller area network (CAN). To combat the vulnerabilities of the CAN protocol, the CAN data field should be encrypted and transmitted with authentication codes. Recently, a method of transmitting authentication codes by modifying the CAN protocol was proposed. However, changing the original CAN protocol can cause serious problems in CAN systems. In this paper, to enhance CAN security, a data compression algorithm is used to reduce the data frame length so that there is space for a message authentication code (MAC) to be contained inside the data field. The proposed algorithm guarantees that all CAN frames are authenticated by a MAC of at least four bytes without any change of the original CAN protocol. Simulations using CAN data from Kia Sorento, Kia Soul, and LS Mtron vehicles show that the proposed algorithm works successfully with only a slight increase in the peak load.

Clock-Based Sender Identification and Attack Detection for Automotive CAN Network

Building the security mechanism for Controller Area Network (CAN) to defend against attack has drawn substantial attention recently. Fingerprinting ECUs to provide the ability of authentication based on the physical characteristics can protect the CAN network effectively. The clock skew which is unique and stable can be exploited to pinpoint the attacker and detect intrusion. However, a common downside of existing clock-skew-based approaches is that the estimation process can be affected by the message scheduling or arbitration. In our work, a novel intrusion detection system (IDS) that exploits the inherent difference in the clock of devices for automotive CAN network is designed. The estimation process of clock skew in our approach relies only on the time measurement of a single CAN frame. Thus, the disturbance from the data-link layer can be avoided. Since the performance of our IDS depends heavily on the accuracy of estimated clock skew, our approach is evaluated on CAN networks with different settings to simulate cases in which the sampling rate is sufficient or not. The feasibility as well as the limitation of our approach are presented in our work. The evaluation shows that our IDS can identify the sender and detect attacks with an average identification rate of more than 99.7% when the sampling rate is sufficient. Besides, the performance degradation as low sampling accuracy is shown and feasible measures for improvement are also discussed.

Sensor-Based Extraction Approaches of In-Vehicle Information for Driver Behavior Analysis.

Advances in vehicle technology have resulted in the development of vehicles equipped with sensors to acquire standardized information such as engine speed and vehicle speed from the in-vehicle controller area network (CAN) system. However, there are challenges in acquiring proprietary information from CAN frames, such as the brake pedal and steering wheel operation, which are essential for driver behavior analysis. Such information extraction requires electronic control unit identifier analysis and accompanying data interpretation. In this paper, we present a system for the automatic extraction of proprietary in-vehicle information using sensor data correlated with the desired information. First, the proposed system estimates the vehicle’s driving status through threshold-, random forest-, and long short-term memory-based techniques using inertial measurement unit and global positioning system values. Then, the system segments in-vehicle CAN frames using the estimation and evaluates each segment with our scoring method to select suitable candidates by examining the similarity between each candidate and its estimation through the suggested distance matching technique. We conduct comprehensive experiments of the proposed system using real vehicles in an urban environment. Performance evaluation shows that the estimation accuracy of the driving condition is 84.20%, and the extraction accuracy of the in-vehicle information is 82.31%, which implies that the presented approaches are quite feasible for automatic extraction of proprietary in-vehicle information.

Integration of ZigBee based GPS receiver to CAN network for precision farming applications

Precision farming applications are often data centric and aim collecting data from a set of sensor modules to be delivered to the central computer. For this aim, the ISO 11783 protocol which uses the Controller Area Network (CAN) as a data link protocol to perform the data communication are used to standardize and provide the serial data communication as wired between the various sensor modules and the central computer a plug/play approach. Many different types of sensors may use to collect temporal and spatial variability in precision farming applications. Especially GPS receivers are the most important sensor in a precision farming application. And also, different data bus protocols can be used for collected data transmission to the central computer. In this context, wireless sensor protocols, especially ZigBee, is gaining popularity for managing precision farming through real-time monitoring of agricultural variability. Various parameters in the precision farming can be monitored and controlled using ZigBee communication integrated with the CAN bus. In this paper, integration of the wired CAN Bus and ZigBee communication was designed, developed and implemented. In this system, the data regarding the geographical coordinate is extracted from the GPS receiver with the help of the ZigBee communication and send it to a central computer with the help of wired CAN Bus. This method has been implemented in order to adapt the ZigBee messages to the CAN Bus and reduce wire using. Finally, the data flow within designed system between CAN and ZigBee data frames was described. In this study, multiple CAN frames usage and handshaking mechanism are explained for sending sensor data longer than 64 bits. This system’s advantage is not only reduce cabling cost and increase the communication speed but also provide dynamic, flexible and applicable communication in precision farming applications.

BTMonitor

With the rapid growth of connectivity and autonomy for today’s automobiles, their security vulnerabilities are becoming one of the most urgent concerns in the automotive industry. The lack of message authentication in Controller Area Network (CAN), which is the most popular in-vehicle communication protocol, makes it susceptible to cyber attack. It has been demonstrated that the remote attackers can take over the maneuver of vehicles after getting access to CAN, which poses serious safety threats to the public. To mitigate this issue, we propose a novel intrusion detection system (IDS), called BTMonitor (Bit-time-based CAN Bus Monitor). It utilizes the small but measurable discrepancy of bit time in CAN frames to fingerprint their sender Electronic Control Units (ECUs). To reduce the requirement for high sampling rate, we calculate the bit time of recessive bits and dominant bits, respectively, and extract their statistical features as fingerprint. The generated fingerprint is then used to detect intrusion and pinpoint the attacker. BTMonitor can detect new types of masquerade attack that the state-of-the-art clock-skew-based IDS is unable to identify. We implement a prototype system for BTMonitor using Xilinx Spartan 6 FPGA for data collection. We evaluate our method on both a CAN bus prototype and a real vehicle. The results show that BTMonitor can correctly identify the sender with an average probability of 99.76% on the real vehicle.

Unique Message Authentication Security Approach based Controller Area Network (CAN) for Anti-lock Braking System (ABS) in Vehicle Network

Controller Area Network (CAN) is one of the standard communication bus protocols used for intercommunication between electronics control units (ECUs) in vehicle network. However, due to its various security vulnerabilities, safety critical system connected to the network are most susceptible to malicious internal or external attacks. This paper proposes a new method to introduce a Message Authentication System to improve security features of CAN. The proposed method is implemented in a CAN based in-vehicle network (IVN) model with anti-lock braking system (ABS) designed in MATLAB and Simulink. The model employs message authentication security feature for detection of any third-party intrusion by incorporating each transmitted CAN frame with additional security characteristic information unique to the frame. The result analysis from the proposed method demonstrated that the additional security feature has proved to be effective by successfully detecting and preventing third party intrusions interfering with the ABS via CAN bus, therefore, maintaining the integrity of the connected ECUs.

Impact of Reducing Bit Stuffing Jitter on the Control Performance of a CAN-Based Distributed Furnace System

The Controller Area Network (CAN) protocol is widely used in distributed real-time, resource-constrained embedded systems. CAN uses “Non Return to Zero” (NRZ) coding and employs a bit-stuffing mechanism for clock synchronization. Such a mechanism causes a variation in the CAN frame length which may have a detrimental impact on the control behaviour of safety-critical systems employing this protocol. To address this issue, two techniques known as “byte-based XOR masking” and “software bit stuffing” were developed and achieved a jitter reduction of up to 20% and 40%, respectively, when employed in practical designs. This paper investigates the effectiveness of such techniques in a real-time control application; that is a simple furnace system case study based on a “hardware-in-the-loop” (HIL) testbed facility. The results show that reducing bit stuffing jitter has the potential to improve the control performance of distributed real-time systems employing CAN protocol.

Internet Protocol Based Satellite On-Board System

The reliability of satellite data communication can be enhanced by designing two subsystems involving data communication among subsystem and data communication between satellie and Ground Station (GS). In this paper, Error Control Coding (ECC) is applied in satellite data communication with Automatic Repeat Request (ARQ) method. Further, bit error checking uses the calculation of 15 bit Cyclic Redundancy Check (CRC) Controller Area Network (CAN) standard. The calculation of CRC is attached in CAN frame over IP communication protocol between primary OBC and secondary OBC. OBC is designed by implementing Triple Modular Redundant system on a Linux-based operating system. The CAN frame over IP simulation with manual input is found to correct all corrupted data. When the simulation uses NetEM, the system corrects 100 % data with 0-10 % value of corruption with maximum time transfer of 84.472 seconds. ION DTN is also found to correct all corrupted data with values from 0 to 2 % and maximum delay at an altitude of 50,000 kilometer orbit using NetEm for TMTC mission. The testing results show that the system will keep carrying out its mission as long as a fault does not occur on all three OBC at the same time.

English

A In spite of wide usage of controller area network (CAN) in the embedded networked control system, nondeterministic response time have restricted the wider use of CAN in safety-critical real time systems, since the CAN uses Non Return to Zero (NRZ) coding and includes a bit-stuffing mechanism, which causes the CAN frame length to become a complex function of the data contents. To minimize CAN response-time jitter and make the transmission time fixed value according to the number of bytes in the data field, many techniques have been suggested as XOR masking , Software Bit Stuffing (SBS), inversion bit stuffing mechanism (IBSM) and Eight-to-Eleven Modulation (EEM), in this paper a novel alternative method known as Third Bit Complement (TCB) is used for “bit stuffing” to prevent hard-ware bit stuffing in the data field part completely, the new technique was compared with previous available techniques showing that six data bytes can be inserted in the data part compared with five bytes in SBS and EEM techniques.

DLC와 전송 데이터 압축영역 설정을 이용한 CAN 데이터 압축

Controller Area Network (CAN)의 개발 목적은 차량 내 Electronic Control Units (ECUs)간의 다중 통신을 통해 자동차에서 큰 부피와 무게를 차지하는 와이어 하네스를 저비용의 네트워크 케이블로 대체하기 위한 것이었다. 차량에 탑재되는 ECU들의 증가로 인해 CAN 데이터 전송량이 많아짐에 따라 CAN 버스로드와 오류 확률도 증가하고 있다. CAN 데이터 전송 시간은 CAN 프레임의 길이에 비례하기 때문에 프레임의 길이를 줄이게 되면 효율적으로 CAN 버스로드와 오류확률을 감소시킬 수 있다. 본 논문에서는 CAN 메시지 길이를 감소시키기 위해 Data Length Code(DLC)와 전송 데이터 압축영역 설정 절차를 사용한 CAN 메시지 압축 알고리즘을 제안한다. 제안한 방법에서는 기존의 알고리즘과 달리 변화량을 저장하기 위한 최대 변화량의 범위를 설정하지 않아도 되기 때문에 부정확한 설정에서 발생하는 오류나 지나친 설정에서 발생하는 압축효율 저하를 피할 수 있다. 또한, DLC 크기에 의해 압축 유무를 판단함으로써 기존 방법에서 제안된 두 개의 ID로 압축 여부를 판단하는 비효율적인 문제점을 해결할 수 있다. 실제차량 주행 후 얻은 데이터로 시뮬레이션 해본 결과, 기존의 방법에 비해 최대 52%까지 더 압축된 것을 확인하였다. 또한, 임베디드 테스트 보드를 이용하여 테스트 했을 때 한 개의 64비트 EMS CAN 데이터를 압축하는데 0.16ms가 소요되어 차량용 CAN 통신에 사용가능함을 보인다.

Reducing message-length variations in resource-constrained embedded systems implemented using the Controller Area Network (CAN) protocol

The Controller Area Network (CAN) protocol is widely used in low-cost embedded systems. CAN uses “Non Return to Zero” (NRZ) coding and includes a bit-stuffing mechanism. Whilst providing an effective mechanism for clock synchronization, the bit-stuffing mechanism causes the CAN frame length to become (in part) a complex function of the data contents: variations in frame length can have a detrimental impact on the real-time behaviour of systems employing this protocol. In this paper, two software-based mechanisms for reducing the impact of CAN bit stuffing are considered and compared. The first approach considered is a modified version of a technique described elsewhere (e.g. Nolte et al. [T. Nolte, H.A. Hansson, C. Norström, Minimizing CAN response-time jitter by message manipulation, in: Proceedings of the Eighth IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2002), San Jose, California, 2002]). The second approach considered is a form of software bit stuffing (SBS). In both cases, not only the impact on message-length variations is addressed but also the implementation costs (including CPU and memory requirements) involved in creating practical implementation of each technique on a range of appropriate hardware platforms. It is concluded that the SBS technique is more effective in the reduction of message-length variations, but at the cost of an increase in CPU time and memory overheads and a reduction in the available data bandwidth. The choice of the most appropriate technique will, therefore, depend on the application requirements and the available resources.