Vehicle-mounted CAN bus anomaly detection method based on a relative entropy

Abstract

The invention discloses a vehicle-mounted CAN bus anomaly detection method based on a relative entropy. The method comprises the following steps: after a vehicle is powered on in an interrupt processing program, starting fixed-time interrupt and fixed-time triggering of a detection node to realize the calculation of the relative entropy of a message, triggering an alarm if the calculated result ofthe relative entropy exceeds a set threshold, otherwise, executing the operations of counting data clearing and window switching; and during calculation of the relative entropy of the message, usingtwo variable-length time windows alternately, which are recorded as a window 1 and a window 2 respectively, performing growth, and performing counting with two independent counters. An anomaly detection algorithm based on the relative entropy is adopted and improved, thereby improving the detection accuracy and the detection granularity. Through combination of anomaly detection based on a white list and a time interval, a better detection effect is achieved.

Description

technical field [0001] The invention relates to a CAN bus abnormality detection method, in particular to a vehicle-mounted CAN bus abnormality detection method based on relative entropy. Background technique [0002] Today's automobiles have very complex functions, and the interior of the vehicle is equipped with a large number of ECUs (Electronic Control Units, electronic control units). . CAN (Controller Area Network, Controller Area Network) bus is the most widely used vehicle communication bus. [0003] However, the CAN bus has not considered the information security issue at the beginning of its design, and is vulnerable to attacks by hackers. In the current stage of rapid development of vehicle networking and intelligent networked vehicle technology, it is particularly important to study how to improve the security of vehicle networks. This is not only an important part of realizing the security of the Internet of Vehicles, but also an important prerequisite and gua...

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Problems solved by technology

[0006] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a vehicle-mounted CAN bus anomaly detection method based on relative entropy, which solves the problems of low intrusion detection accuracy and granularity and poor detection effect of the vehicle-mounted CAN bus network

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