Design And Implementation Of Anomaly Detection Algorithm For CAN Bus Of Intelligent Connected Vehicle

Driven by technologies such as 5G communications,autonomous driving,and the Internet of Things,the automotive industry has entered a period of rapid development.On-board equipment connects to the network through wireless technology,which can provide users with richer and more powerful functions,but at the same time it also poses a threat to vehicle security.An intelligent connected car may be equipped with dozens or even hundreds of single control units,and has various interfaces such as Bluetooth,WiFi,and Android operating systems.This causes the vehicle network to be exposed to a more open and complex environment,making CAN bus more vulnerable to attack.Since the CAN bus protocol did not consider information security issues at the beginning of its design,the CAN bus is very fragile in the face of malicious attacks,so it is particularly necessary to establish an intrusion detection capability for the CAN bus.In response to the above problems,this paper proposes two message feature anomaly detection technologies based on GMM-HMM and based on dynamic programming by analyzing CAN bus and message characteristics.Main contributions of this paper are as follows:(1)CAN bus penetration test The CAN bus penetration test tool is developed and its functions are introduced.The tool can connect the CAN bus through PCAN.After simple configuration,it can semi automatically carry out replay test,fuzzy test,DOS test and UDS protocol test on the bus to test the safety and compliance of the on-board can bus network.Then the tool is used to test the CAN bus of the real vehicle bench.The test process and results can prove that the tool provides a method of CAN bus safety detection.(2)Analysis of CAN Bus and Message Characteristics The network structure of the CAN bus protocol,the specific definition of the protocol frame and the communication mechanism of the bus are introduced,the characteristics of the CAN bus protocol and the attack methods against the protocol are summarized,and the classification and current status of intrusion detection technology are briefly described.The definition of CAN bus communication matrix is introduced,and the cycle characteristics,data characteristics and status characteristics of CAN messages on the bus are analyzed,and the method of CAN bus message abnormality detection is obtained.(3)CAN bus anomaly detection algorithm According to the characteristics of CAN messages,two anomaly detection algorithms based on GMM-HMM and dynamic programming are proposed and implemented,and combined to realize anomaly detection for CAN bus messages.The intelligent connected vehicle is still in the development stage.This article has made some explorations in the security test and abnormal detection of its on-board CAN bus network.The results provide a reference for further research and protection of the information security of the intelligent connected vehicle.