A method and device for assessing the impact of network attacks on the CAN bus of a vehicle's network layer.

Abstract

This invention relates to the field of network security, and specifically to a method and apparatus for assessing the impact of network attacks on the CAN bus of a vehicle's network layer. The method includes: acquiring a system communication model of the vehicle's cyber-physical system; determining the actual transmission data when the vehicle exchanges information via the CAN bus under network attack conditions based on the system communication model; acquiring reference transmission data; processing the actual transmission data and reference transmission data based on a first evaluation rule to obtain information on the impact of the network attack on the availability of the CAN bus; processing the actual transmission data based on a second evaluation rule to obtain information on the impact of the network attack on the integrity of the CAN bus; and determining the assessment result of the attack impact on the vehicle's cyber-physical system based on the information on the impact of the network attack on the availability and integrity of the CAN bus. This invention can effectively quantify and assess the impact of network attacks on the CAN bus of a vehicle's cyber-physical system.

Description

Technical Field

[0001] This invention relates to the field of network security, and more particularly to a method and apparatus for assessing the impact of network attacks on the CAN bus of a vehicle network layer. Background Technology

[0002] The rapid development of radio frequency identification (RFID), sensing, and communication technologies in recent years has accelerated the intelligentization and informatization of automobiles and transportation, promoting the development of "intelligent transportation" (which focuses on the collection, processing, dissemination, exchange, analysis, and utilization of information to provide diverse services to traffic participants). Modern vehicles are equipped with more automated modules, making them autonomous and less driver-controlled. While vehicle safety is paramount in every aspect, computer malfunctions can lead to vehicle chaos. All submodules of the drivetrain, steering, and electrical systems are controlled by electronic control units (ECUs). Modern vehicles typically contain hundreds of ECUs, which communicate with each other via a common bus called CAN, enabling them to operate at high speeds to ensure driving safety and entertainment performance.

[0003] While in-vehicle networks offer benefits through connectivity, they also provide opportunities for cyberattacks. While connecting vehicles to the internet and intelligent services like big data analytics via external communication interfaces, connected vehicles also introduce potential network intrusion risks. The closed nature of traditional in-vehicle networks means that existing communication protocols, especially the widely deployed CAN bus protocol, lacked privacy and security protection mechanisms, including access control, authentication, and encryption, at the time of release. Due to the lack of access control mechanisms, attackers can directly intrude into the in-vehicle network by breaching external interfaces, leading to information leaks, theft, and even threats to personal safety. Summary of the Invention

[0004] This application aims to at least solve the technical problems existing in the prior art, and to provide a method and device for evaluating the impact of network attacks on the CAN bus of the vehicle network layer.

[0005] In a first aspect, the present invention provides a method for assessing the impact of network attacks on the CAN bus of a vehicle network layer, comprising:

[0006] Acquiring the system communication model of the vehicle information physical system;

[0007] The actual data transmitted when vehicles exchange information via the CAN bus under network attack conditions is determined based on the system communication model.

[0008] Acquire reference transmission data, which represents CAN bus message transmission information in the absence of network attacks;

[0009] Based on the first evaluation rule, the real transmission data and reference transmission data are processed to obtain the impact information of network attacks on CAN bus availability. CAN bus availability represents the proportion of CAN bus transmission of valid messages, and valid messages represent messages sent by nodes inside the vehicle.

[0010] Based on the second evaluation rule, the real transmission data is processed to obtain the impact information of network attacks on CAN bus integrity. CAN bus integrity represents the proportion of valid messages whose content has not been modified by the CAN bus.

[0011] Based on the impact information of network attacks on CAN bus availability and CAN bus integrity, a CAN bus attack impact model is constructed to obtain the attack impact assessment results of the vehicle cyber-physical system.

[0012] In a second aspect, the present invention provides an electronic device, the electronic device comprising:

[0013] At least one processor; and,

[0014] A memory communicatively connected to the at least one processor; wherein,

[0015] The memory stores a computer program that can be executed by the at least one processor, which enables the at least one processor to perform the aforementioned method for assessing the impact of network attacks on the vehicle network layer CAN bus.

[0016] In summary, this application includes the following beneficial technical effects:

[0017] This application considers the different impacts of attacks on the CAN bus. Starting from the two dimensions of CAN bus availability and CAN bus integrity, the impact of network attacks on the bus is divided into the impact on bus availability and the impact on bus integrity. The impact on CAN bus availability and the impact on CAN bus integrity are calculated using real transmission data and reference transmission data. The impact of network attacks on the CAN bus of the vehicle's cyber-physical system network layer is effectively quantified and evaluated, solving the problem of difficulty in quantifying the cross-impact of attacks.

[0018] The CAN bus attack impact model can reveal how the impact of an attack changes over a period of time, which helps predict future trends in the impact of attacks and allows for targeted preventative measures to improve the effectiveness of network attack defense. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating a method for evaluating the impact of network attacks on the CAN bus of a vehicle network layer, as provided in an embodiment of the present invention.

[0020] Figure 2 This is a system architecture diagram of a vehicle cyber-physical system provided in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of an electronic device that implements the method for evaluating the impact of network attacks on the CAN bus of a vehicle network layer, according to an embodiment of the present invention.

[0022] Reference numerals: 10, processor; 11, memory; 12, communication bus; 13, communication interface.

[0023] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0025] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0026] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0027] Reference Figure 1 The diagram shown is a flowchart illustrating a method for assessing the impact of network attacks on the CAN bus of a vehicle's network layer, according to an embodiment of the present invention. In this embodiment, the method for assessing the impact of network attacks on the CAN bus of a vehicle's network layer includes:

[0028] S1, System communication model for acquiring vehicle information physical system.

[0029] Reference Figure 2The architecture of a vehicle cyber-physical system includes an attacker and several internal vehicle nodes, which are connected via a CAN bus. The internal vehicle nodes include sensors, controllers, and actuators. The attacker could be a hacker, a car theft gang, or a terrorist. Different attackers can launch different types of attacks. DoS attacks can compromise availability, while spoofing attacks or replay attacks can compromise integrity.

[0030] The internal nodes of the vehicle communicate via the CAN bus. Specifically, the CAN network employs an arbitration mechanism for transmitted information. Messages from higher-priority internal nodes are sent first, and only one message is sent at a time. Only after the current message is sent will the arbitration process continue to select the next message to be sent from among the nodes waiting to send information. The CAN bus transmits messages in a broadcast manner, ensuring that all internal nodes of the vehicle are aware of the transmitted messages.

[0031] Attackers can exploit the characteristics of the CAN bus arbitration mechanism to create a high-priority fake internal node that sends a large number of useless messages (e.g., a DoS attack, where DoS stands for Denial of Service attack). This causes delays in message transmission by internal nodes on the CAN bus, and in severe cases, even prevents message transmission altogether. This prevents the vehicle's cyber-physical system from making timely decisions, compromising bus availability. Attackers can also use the characteristics of CAN bus broadcasting to obtain and modify the values ​​of transmitted messages. This can lead to modifications of messages sent by internal nodes, causing the vehicle's cyber-physical system to make incorrect decisions and compromising bus integrity.

[0032] Based on the vehicle cyber-physical system communication mechanism, a system communication model of the vehicle cyber-physical system is constructed. The CAN bus is then built according to its characteristics. The relationship between internal vehicle nodes and attackers is also established.

[0033] Specifically, when building the system communication model, the model is constructed based on information such as the number and priority of nodes inside the vehicle, the message sending cycle, the number and value of messages transmitted within the CAN bus, and the attacker's attack frequency and duration. This system communication model forms the basis for the method of assessing the impact of attacks on the CAN bus, the network layer of the vehicle's cyber-physical system. The model is used to calculate bus availability and integrity based on the messages transmitted on the bus and the attacker's attack methods and timing.

[0034] In this embodiment, the system communication model is defined as follows:

[0035] BS={Im,{B1,B2,…,B m ,…,B n}}

[0036] Where BS{.} represents the system communication model, Im is the set of messages from internal vehicle nodes that have been successfully transmitted via the CAN bus to date, and B m The CAN bus represents the messages sent by the vehicle's internal nodes, where m is the message index of the vehicle's internal nodes sent by the CAN bus, and n represents the total number of messages of the vehicle's internal nodes that have been successfully transmitted by the CAN bus so far. n is a positive integer greater than or equal to 1.

[0037] B m It can be defined as

[0038] B m ={Ns m Vm m}

[0039] Among them, Ns m Vm is the node number of the message m being sent. m The value passed in message m is the size of the value.

[0040] S2. Determine the actual data transmitted when vehicles exchange information via the CAN bus under network attack conditions based on the system communication model.

[0041] The actual transmitted data includes messages successfully sent by the CAN bus within a unit of time in the vehicle information physical system under network attack conditions.

[0042] S3. Obtain reference transmission data.

[0043] Reference transmission data is used to represent CAN bus message transmission information under no network attack conditions. The reference transmission data includes messages successfully sent by the CAN bus in the vehicle information physical system per unit time under no network attack conditions. The reference transmission data can be imported by staff through external devices or obtained through cloud systems. This application does not restrict the method of obtaining the reference transmission data. Network attacks will cause changes in the system communication model BS. The impact of network attacks on the CAN bus is obtained by calculating the normal and abnormal values ​​of the system communication model, and an attack impact model is constructed.

[0044] S4. Based on the first evaluation rule, process the real transmission data and the reference transmission data to obtain information on the impact of network attacks on the availability of the CAN bus.

[0045] CAN bus availability indicates the proportion of valid messages transmitted by the CAN bus, and valid messages are messages sent by nodes inside the vehicle.

[0046] Since different attack methods can have varying impacts, and calculating too many metrics would increase analytical complexity and affect assessment accuracy, only a select few metrics were chosen for evaluation. Most attacks can be categorized into interruption attacks affecting availability, target deception attacks affecting integrity, or a combination of both. Therefore, availability and integrity metrics for the CAN bus were selected for evaluation.

[0047] For availability, four metrics were selected for evaluation: the number of internal messages successfully transmitted per unit time in the vehicle's cyber-physical system under both network attack and non-network attack conditions, and the total number of messages successfully transmitted per unit time in both network attack and non-network attack conditions.

[0048] Specifically, based on the first evaluation rule, the actual transmitted data and reference transmitted data are processed to obtain information on the impact of network attacks on CAN bus availability, including:

[0049] S41. Filter out the valid messages successfully transmitted by the CAN bus within a unit of time under network attack conditions from the real transmission data.

[0050] S42. Determine the actual availability of the CAN bus based on the proportion of valid messages successfully sent per unit time in the actual transmitted data under network attack conditions.

[0051] S43. Filter out the valid messages successfully transmitted by the CAN bus per unit time under the condition of no network attack from the reference transmission data.

[0052] S44. Determine the expected availability of the CAN bus based on the proportion of valid messages successfully transmitted per unit time in the reference transmission data under no network attack conditions.

[0053] S45. Determine the impact of network attacks on CAN bus availability based on the actual availability and expected availability of the CAN bus.

[0054] The actual availability of the CAN bus is calculated by comparing the proportion of valid information transmitted within the vehicle's cyber-physical system per unit time under attack conditions to the total number of messages transmitted on the bus, and the proportion of valid information transmitted within the vehicle's cyber-physical system per unit time to the total number of messages transmitted on the bus under normal conditions; at time t a At that time, the formula for calculating the actual availability ABA of the CAN bus is:

[0055]

[0056] Among them, lra(t) a ) represents the state of a network attack. a-1Time to t a The proportion of the bus occupied by valid message transmissions within a given time period, lra(t) a )∈[0,1];

[0057] lre(t a ) represents the state without network attacks. a-1 to t a The proportion of the CAN bus occupied by valid messages in the actual transmitted data within a given time period, lre(t) a )∈[0,1];

[0058] Im(t a ) represents the actual situation up to t a The total number of vehicle information physical system (VPS) internal messages successfully transmitted by the time bus. VPS internal messages refer to valid messages sent by nodes inside the vehicle.

[0059] To t in the absence of network attacks a The total number of vehicle information messages successfully transmitted via the time bus within the physical system;

[0060] Im(t a-1 ) represents the actual situation up to t a-1 The total number of vehicle information messages successfully transmitted via the time bus within the physical system;

[0061] To t in the absence of network attacks a-1 The total number of vehicle information messages successfully transmitted by the time bus within the physical system.

[0062] It should be noted that t a It only represents a certain moment; moment t a-1 At time t a It is a unit of time, such as 1 second or 5 seconds. Different time intervals can be divided as needed to obtain the dynamic impact of network attacks under different time conditions.

[0063] The impact of network attacks on CAN bus availability is represented by the difference between the actual availability and the expected availability of the CAN bus.

[0064] At time t in a no-attack network attack state a Bus Expected Availability (EBA) is defined as:

[0065]

[0066]

[0067] Let IBA be the impact of a network attack on the availability of the CAN bus, and let time t be the time interval. a The impact of network attacks on CAN bus availability IBA(t) a The expression for ) is:

[0068]

[0069] The impact of a network attack on the availability of the CAN bus in an automotive cyber-physical system is determined based on the specific value of the Information on Impact of Network Attacks on CAN Bus Availability (IBA). In this embodiment, the proportion of effective information blocked within the automotive cyber-physical system can be determined based on the value of IBA. The specific determination method is shown in Table 1.

[0070] Table 1. Impact of cyberattacks on the bus availability of automotive cyber-physical systems.

[0071]

[0072] The impact of cyberattacks on CAN bus availability is categorized into multiple levels, determined by the difference between the actual and expected availability of the CAN bus (IBA).

[0073] The impact level can be set according to the actual progress requirements. In this embodiment, the impact level of CAN bus availability includes seven levels: no impact, slight impact, minor impact, moderate impact, high impact, severe impact, and complete impact. The impact level is determined according to the specific IBA value. The specific judgment rules can be found in Table 2.

[0074] Table 2. Impact of network attacks on bus availability

[0075]

[0076] The specific threshold range for each level of CAN bus availability impact can be set according to actual needs; this embodiment does not impose any restrictions.

[0077] S5. Process the real transmitted data based on the second evaluation rule to obtain information on the impact of network attacks on the integrity of the CAN bus.

[0078] CAN bus integrity refers to the proportion of valid messages that have not been modified during transmission by the CAN bus.

[0079] Regarding integrity, the number of valid, unmodified messages successfully transmitted per unit time in the automotive cyber-physical system under both non-network attack and real-world conditions is selected as the evaluation metric. This metric is based on four indicators: the number of valid messages successfully transmitted per unit time under non-network attack, real-world, and CAN bus conditions.

[0080] Specifically, based on the second evaluation rule, the actual transmitted data is processed to obtain information on the impact of network attacks on the integrity of the CAN bus, including:

[0081] S51. Filter out valid messages from the actual transmitted data whose content was successfully transmitted by the CAN bus within a unit of time under network attack conditions, and whose content has not been modified.

[0082] S52. Determine the actual integrity of the CAN bus based on the proportion of valid messages that have not been modified and are successfully transmitted by the CAN bus per unit time under network attack conditions in the actual transmitted data.

[0083] S53. Filter out valid messages from the reference transmission data whose content was successfully transmitted by the CAN bus within a unit of time under network attack conditions and whose content has not been modified.

[0084] S54. Determine the expected integrity of the CAN bus based on the proportion of valid messages whose content has not been modified and successfully transmitted per unit time under no network attack conditions in the reference transmission data.

[0085] S55. Determine the impact of network attacks on the integrity of the CAN bus based on the actual integrity of the CAN bus and the expected integrity of the CAN bus.

[0086] The actual integrity of the CAN bus is denoted as ABI, t a CAN bus actual integrity ABI(t) a The formula for calculating ) is:

[0087]

[0088] Among them, mt s (t a ) represents the CAN bus at t a-1 to t a The number of all messages transmitted in the vehicle's cyber-physical system at any given time;

[0089] mt m (t a ) represents the CAN bus at t a-1 to t a The number of unmodified messages among the valid messages transmitted at any given time;

[0090] Im s (t a ) until t a The number of valid messages successfully transmitted at any given time;

[0091] Im s (t a-1 ) until ta-1 The number of valid messages successfully transmitted at any given time;

[0092] Rv is the expected value of the message transmitted by the automotive cyber-physical system in a non-attack state;

[0093] Sv represents the actual value of the message transmitted by the automotive cyber-physical system in real-world conditions.

[0094] Let EBI be the expected integrity of the CAN bus in the absence of network attacks. a CAN bus expected integrity EBI(t) a The formula for calculating ) is:

[0095]

[0096] The impact of network attacks on CAN bus integrity is represented by the difference between the actual integrity of the CAN bus and the expected integrity of the CAN bus.

[0097] The impact of network attacks on the integrity of the CAN bus is denoted as IBI, and at time t... a The impact of network attacks on bus integrity (IBI(t)) a The formula for calculating ) is:

[0098]

[0099] The impact of a network attack on the integrity of the CAN bus of the automotive cyber-physical system is determined based on the specific value of the EBI (Effect Information on the Integrity of the CAN Bus). In this embodiment, the proportion of valid information within the automotive cyber-physical system that has been modified can be determined based on the value of the EBI. The specific determination method is shown in Table 3.

[0100] Table 3. Impact of cyberattacks on the bus integrity of automotive cyber-physical systems.

[0101]

[0102] The impact of a cyberattack on the integrity of the CAN bus is classified into several levels, which are determined by the difference between the actual integrity of the CAN bus and the expected integrity of the CAN bus.

[0103] The impact level of CAN bus integrity can be set according to the actual progress requirements. In this embodiment, the impact level of CAN bus integrity includes seven levels: no impact, slight impact, minor impact, moderate impact, high impact, severe impact, and complete impact. The impact level is determined according to the specific value of IBI, and the specific judgment rules can be found in Table 4.

[0104] Table 4. Impact of network attacks on bus integrity

[0105]

[0106]

[0107] The specific threshold range for each level of the CAN bus integrity impact can be set according to actual needs; this embodiment does not impose any restrictions.

[0108] S6. Construct a CAN bus attack impact model based on the impact information of network attacks on CAN bus availability and CAN bus integrity, so as to obtain the attack impact assessment results of the vehicle cyber-physical system.

[0109] The CAN bus attack impact model is represented in matrix form. Specifically, the expression for the CAN bus impact change matrix IAS corresponding to the CAN bus attack impact model is:

[0110]

[0111] IAS is the impact matrix of a network attack on the CAN bus of an automotive cyber-physical system. IAS can be represented as the change matrix from t0 to t0. n The impact of time-based cyberattacks on the availability of the CAN bus in automotive cyber-physical systems (IBA), and the impact on t0-t n The impact of time-of-flight networks on the integrity of the CAN bus in automotive cyber-physical systems (IBI) can be observed through the IAS matrix, revealing changes in the impact of attacks over a period of time.

[0112] Analyzing the changes in the impact of different attacks at different times helps personnel better understand the impact of cyberattacks on the CAN bus, and helps to develop targeted and optimized protection strategies to improve vehicle security.

[0113] This application addresses the issue of quantifying the cross-effects of attacks by dividing the impact of network attacks on the CAN bus into two dimensions: the impact on bus availability and the impact on bus integrity. It also uses evaluation metrics for calculation, thus resolving the problem of quantifying the cross-effects of attacks.

[0114] Furthermore, the technical solution of this application can obtain the changes in the attack impact over a period of time based on the impact change matrix of the CAN bus of the automotive cyber-physical system, and construct a CAN bus attack assessment model based on dynamic coupling analysis, which helps to predict the future trend of attack impact and thus take targeted preventive measures.

[0115] Reference Figure 3 Based on the same inventive concept, this application also discloses an electronic device, such as... Figure 3The diagram shown is a schematic representation of an electronic device used in an embodiment of the present invention to assess the impact of network attacks on the CAN bus of a vehicle network layer. The electronic device may include at least one processor 10, a memory 11 communicatively connected to the at least one processor, a communication bus 12, and a communication interface 13. It may also include a computer program stored in the memory 11 and executable on the processor 10, such as a program for assessing the impact of network attacks on the CAN bus of a vehicle network layer.

[0116] In some embodiments, the processor 10 may be composed of integrated circuits, such as a single packaged integrated circuit or multiple integrated circuits with the same or different functions, including combinations of one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and various control chips. The processor 10 is the control unit of the electronic device, connecting various components of the entire electronic device through various interfaces and lines. It executes programs or modules stored in the memory 11 (e.g., methods for evaluating the impact of network attacks on the vehicle's CAN bus), and calls data stored in the memory 11 to perform various functions of the electronic device and process data.

[0117] The memory 11 includes at least one type of readable storage medium, including flash memory, portable hard drive, multimedia card, card-type memory (e.g., SD or DX memory), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the memory 11 can be an internal storage unit of an electronic device, such as a portable hard drive. In other embodiments, the memory 11 can be an external storage device of the electronic device, such as a plug-in portable hard drive, smart media card (SMC), secure digital (SD) card, flash card, etc. Furthermore, the memory 11 can include both internal and external storage units of the electronic device. The memory 11 can be used not only to store application software and various types of data installed in the electronic device, such as the code of a method program for evaluating the impact of network attacks on the CAN bus of a vehicle network layer, but also to temporarily store data that has been output or will be output.

[0118] The communication bus 12 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This bus can be divided into an address bus, a data bus, a control bus, etc. The bus is configured to enable communication between the memory 11 and at least one processor 10, etc.

[0119] Communication interface 13 is used for communication between the aforementioned electronic device and other devices, including a network interface and a user interface. Optionally, the network interface may include a wired interface and / or a wireless interface (such as a Wi-Fi interface, Bluetooth interface, etc.), typically used to establish communication connections between the electronic device and other electronic devices. The user interface may be a display, an input unit (such as a keyboard), or, optionally, a standard wired or wireless interface. Optionally, in some embodiments, the display may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen, etc. The display may also be appropriately referred to as a screen or display unit, used to display information processed in the electronic device and to display a visual user interface.

[0120] Figure 3 Only electronic devices with components are shown; it will be understood by those skilled in the art that... Figure 3 The structure shown does not constitute a limitation on the electronic device and may include fewer or more components than shown, or combine certain components, or have different component arrangements. For example, although not shown, the electronic device may also include a power supply (such as a battery) to power the various components. Preferably, the power supply can be logically connected to at least one processor 10 through a power management device, thereby enabling functions such as charging management, discharging management, and power consumption management. The power supply may also include one or more DC or AC power supplies, recharging devices, power fault detection circuits, power converters or inverters, power status indicators, and other arbitrary components. The electronic device may also include various sensors, Bluetooth modules, Wi-Fi modules, etc., which will not be described in detail here.

[0121] It should be understood that the embodiments are for illustrative purposes only and are not limited to this structure in the scope of the patent application.

[0122] Furthermore, if the modules / units integrated into the electronic device are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. The computer-readable storage medium can be volatile or non-volatile.

[0123] In the description of this specification, the references to terms such as "an embodiment," "some embodiments," "example," "specific example," "a implementation," "a preferred implementation," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0124] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for assessing the impact of network attacks on the CAN bus of a vehicle network layer, characterized in that, The method includes: Acquiring the system communication model of the vehicle information physical system; The actual data transmitted when vehicles exchange information via the CAN bus under network attack conditions is determined based on the system communication model. Acquire reference transmission data, which represents CAN bus message transmission information in the absence of network attacks; Based on the first evaluation rule, the real transmission data and reference transmission data are processed to obtain the impact information of network attacks on CAN bus availability. CAN bus availability represents the proportion of CAN bus transmission of valid messages, and valid messages represent messages sent by nodes inside the vehicle. Based on the second evaluation rule, the real transmission data is processed to obtain the impact information of network attacks on CAN bus integrity. CAN bus integrity represents the proportion of valid messages whose content has not been modified by the CAN bus. Based on the impact information of network attacks on CAN bus availability and CAN bus integrity, a CAN bus attack impact model is constructed to obtain the attack impact assessment results of the vehicle cyber-physical system. The actual transmitted data includes messages successfully transmitted by the CAN bus within a unit of time under network attack conditions; the reference transmitted data includes messages successfully transmitted by the CAN bus within a unit of time under non-network attack conditions. The process of processing real and reference transmission data based on the first evaluation rule to obtain information on the impact of network attacks on CAN bus availability includes: Filter out valid messages successfully transmitted by the CAN bus per unit time under network attack conditions from real transmission data; The actual availability of the CAN bus is determined by the proportion of valid messages successfully sent per unit time in the actual transmitted data under network attack conditions. Filter out valid messages successfully transmitted by the CAN bus per unit time under network attack-free conditions from the reference transmission data; The expected availability of the CAN bus is determined by the proportion of valid messages successfully transmitted by the CAN bus per unit time in the reference transmission data under no network attack conditions. The impact of network attacks on CAN bus availability is determined based on the actual availability and expected availability of the CAN bus. The process of processing real transmitted data based on the second evaluation rule to obtain information on the impact of network attacks on the integrity of the CAN bus includes: Filter out valid messages from the actual transmitted data whose content was successfully transmitted by the CAN bus within a unit of time under network attack conditions, and whose content was not modified. The actual integrity of the CAN bus is determined by the proportion of valid messages that have not been modified and are successfully transmitted by the CAN bus per unit time under network attack conditions in the actual transmitted data. Filter out valid messages from the reference transmission data whose content was successfully transmitted by the CAN bus within a unit of time under network attack conditions and whose content was not modified. The expected integrity of the CAN bus is determined by the proportion of valid messages that have not been modified and are successfully transmitted by the CAN bus per unit time under no network attack conditions in the reference transmission data. The impact of network attacks on the integrity of the CAN bus is determined based on the actual integrity and expected integrity of the CAN bus.

2. The method for assessing the impact of network attacks on the vehicle network layer CAN bus as described in claim 1, characterized in that, The impact of network attacks on CAN bus availability is represented by the difference between the actual availability and the expected availability of the CAN bus.

3. The method for assessing the impact of network attacks on the vehicle network layer CAN bus as described in claim 2, characterized in that, The impact of cyberattacks on CAN bus availability can be categorized into several levels. The method further includes: determining the level of impact of network attacks on CAN bus availability based on the difference between the actual availability of the CAN bus and the expected availability of the CAN bus.

4. The method for assessing the impact of network attacks on the vehicle network layer CAN bus as described in claim 1, characterized in that, The impact of network attacks on CAN bus integrity is represented by the difference between the actual integrity of the CAN bus and the expected integrity of the CAN bus.

5. The method for assessing the impact of network attacks on the vehicle network layer CAN bus as described in claim 4, characterized in that, The impact of cyberattacks on the integrity of the CAN bus can be categorized into several levels. The method further includes determining the level of impact of a network attack on the integrity of the CAN bus by the difference between the actual integrity of the CAN bus and the expected integrity of the CAN bus.

6. The method for evaluating the impact of network attacks on the vehicle network layer CAN bus as described in any one of claims 1 to 5, characterized in that, The CAN bus attack impact model includes information on the impact of network attacks on CAN bus availability and CAN bus integrity at different times.

7. An electronic device, characterized in that, The electronic device includes: At least one processor (10); and, A memory (11) communicatively connected to the at least one processor (10); The memory (11) stores a computer program that can be executed by the at least one processor (10) to enable the at least one processor (10) to perform the method for evaluating the impact of network attacks on the vehicle network layer CAN bus as described in any one of claims 1 to 6.

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