Method, device and system for evaluating the trustworthiness of edge device nodes

Abstract

The present invention provides a method, device and system for evaluating the trust of edge device nodes, and relates to the fields of power engineering technology and power system communication security technology. The method includes: obtaining data packet transmission information related to a first device node and a second device node among multiple edge device nodes, determining the tth retransmission data packet ratio according to the tth basic retransmission data packet number and the t-1th completed retransmission data packet number, the tth retransmission data packet ratio representing the change of the retransmission task between the first device node and the second device node; performing trust evaluation based on the tth retransmission data packet ratio to obtain the trust of the device node in the tth target period; and determining the risk device node that affects communication security from multiple edge device nodes based on the trust of the device node in at least one target period.

Description

Technical Field

[0001] The present invention relates to the fields of electric power engineering technology and electric power system communication security technology, and more specifically, to a method, device and system for performing trust evaluation on edge device nodes. Background Art

[0002] With the rapid development of smart grids, the number of edge devices in the distribution network is gradually increasing. An edge device system can be built by connecting multiple edge devices for communication, thereby realizing communication and interaction between multiple edge devices in the distribution network, and then realizing data collection, data transmission and data processing of power operation related data. However, the edge devices in the distribution network are vulnerable to attacks by untrusted malicious nodes, resulting in threats to the accuracy of data during data interaction and the overall security of the edge device system. The inventors found that the accuracy and timeliness of identifying malicious nodes that affect communication security are low, which will have a negative impact on the operational stability of the distribution network. Summary of the invention

[0003] In view of this, the present invention provides a method, apparatus and system for performing trust evaluation on edge device nodes.

[0004] One aspect of the present invention provides a method for trust evaluation of edge device nodes, which is applied to a substation edge device system, wherein the substation edge device system includes multiple edge device nodes that are communicatively coupled, and the method includes: obtaining data packet transmission information related to a first device node and a second device node among the multiple edge device nodes, wherein the data packet transmission information includes the tth basic retransmission data packet number and the t-1th completed retransmission data packet number, the tth basic retransmission data packet number represents the number of data packets that should be retransmitted between the first device node and the second device node in the tth target time period, and the t-1th completed retransmission data packet number Characterize the number of data packets that have been retransmitted between the first device node and the second device node in the t-1th target time period, where t is an integer greater than 1; determine the tth retransmission data packet ratio based on the tth basic retransmission data packet number and the t-1th completed retransmission data packet number, wherein the tth retransmission data packet ratio characterizes the change in the retransmission task between the first device node and the second device node; perform a trust evaluation based on the tth retransmission data packet ratio to obtain the trust of the device node in the tth target time period; and determine the risk device nodes that affect communication security from the multiple edge device nodes based on the trust of the device nodes in at least one target time period.

[0005] Another aspect of the present invention provides an apparatus for trust evaluation of edge device nodes, which is applied to a substation edge device system, wherein the substation edge device system includes a plurality of communicatively coupled edge device nodes, and the apparatus includes: an acquisition module, which is used to acquire data packet transmission information related to a first device node and a second device node among the plurality of the above-mentioned edge device nodes, wherein the above-mentioned data packet transmission information includes the tth basic retransmission data packet number and the t-1th completed retransmission data packet number, wherein the above-mentioned tth basic retransmission data packet number represents the number of data packets that should be retransmitted between the above-mentioned first device node and the above-mentioned second device node in the tth target time period, and the above-mentioned t-1th completed retransmission data packet number represents the t-1th target time period. The number of data packets that have been retransmitted between the first device node and the second device node, t is an integer greater than 1; a first determination module, used to determine the tth retransmission data packet ratio according to the tth basic retransmission data packet number and the t-1th completed retransmission data packet number, the tth retransmission data packet ratio characterizing the change of the retransmission task between the first device node and the second device node; a trust evaluation module, used to perform a trust evaluation based on the tth retransmission data packet ratio to obtain the trust of the device node in the tth target time period; and a second determination module, used to determine the risk device nodes that affect the communication security from the multiple edge device nodes based on the trust of the device nodes in at least one target time period.

[0006] Another aspect of the present invention provides a substation edge device system, which is arranged in a substation distribution network. The substation edge device system includes: a plurality of communicatively coupled edge device nodes; and a device for performing trust evaluation on the edge device nodes.

[0007] Another aspect of the present invention provides an electronic device, comprising:

[0008] one or more processors;

[0009] a memory for storing one or more programs,

[0010] When the one or more programs are executed by the one or more processors, the one or more processors implement the method provided according to the embodiment of the present invention.

[0011] Another aspect of the present invention provides a computer-readable storage medium storing computer-executable instructions, which are used to implement the method provided according to an embodiment of the present invention when executed.

[0012] Another aspect of the present invention provides a computer program product, which includes computer executable instructions. When the instructions are executed, they are used to implement the method provided by the embodiment of the present invention.

[0013] According to an embodiment of the present invention, by obtaining the tth basic retransmission data packet number and the t-1th completed retransmission data packet number generated between different device nodes in adjacent target time periods, and determining the tth retransmission data packet ratio to perform trust assessment, the number of data packets that need to be retransmitted in adjacent time periods can be used to more accurately discover device nodes in edge device nodes that are prone to data packet retransmission, and then more timely and accurately identify risky device nodes that affect communication security among multiple device nodes, so as to quickly isolate risky device nodes and improve the operating stability of the distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0015] Figure 1 A diagram showing an application scenario of the method and apparatus provided by the present invention for performing trust evaluation on edge device nodes.

[0016] Figure 2 A flow chart of a method for trust evaluation of edge device nodes according to an embodiment of the present invention is shown.

[0017] Figure 3 A flow chart of a method for trust evaluation of edge device nodes according to another embodiment of the present invention is shown.

[0018] Figure 4 A rendering of a method for trust evaluation of edge device nodes according to an embodiment of the present invention is shown.

[0019] Figure 5 A rendering of a method for trust evaluation of edge device nodes according to another embodiment of the present invention is shown.

[0020] Figure 6 A block diagram of an apparatus for performing trust evaluation on edge device nodes according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0021] Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

[0022] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0023] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0024] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0025] In the embodiments of the present invention, the collection, updating, analysis, processing, use, transmission, provision, disclosure, storage and other aspects of the data involved (for example, including but not limited to user personal information) are in compliance with the provisions of relevant laws and regulations, are used for legitimate purposes, and do not violate public order and good morals. In particular, necessary measures are taken for user personal information to prevent illegal access to user personal information data and maintain the security of user personal information, network security and national security.

[0026] In the embodiment of the present invention, before obtaining or collecting the user's personal information, the user's authorization or consent is obtained.

[0027] The inventors found that the frequency of data packet interaction between edge devices in the active distribution area distribution network built based on edge devices such as smart meter devices and smart fusion terminals is relatively high. In the presence of untrusted malicious device nodes, it will lead to information leakage and communication channel blockage between the edge device systems in the area, affecting the information security and operational stability of the distribution network.

[0028] Embodiments of the present invention provide a method, apparatus, and system for trust evaluation of edge device nodes. The method for trust evaluation of edge device nodes includes: being applied to an edge device system in a substation, the edge device system in a substation including a plurality of edge device nodes coupled in communication, the method of the embodiment including: obtaining data packet transmission information related to a first device node and a second device node among the plurality of edge device nodes, wherein the data packet transmission information includes the tth basic retransmission data packet number and the t-1th completed retransmission data packet number, the tth basic retransmission data packet number represents the number of data packets that should be retransmitted between the first device node and the second device node in the tth target time period, and the t-1th completed retransmission data packet number represents the number of data packets that have been retransmitted between the first device node and the second device node in the t-1th target time period, where t is an integer greater than 1; determining the tth retransmission data packet ratio based on the tth basic retransmission data packet number and the t-1th completed retransmission data packet number, the tth retransmission data packet ratio representing the change in the retransmission task between the first device node and the second device node; performing a trust evaluation based on the tth retransmission data packet ratio to obtain the trust of the device node in the tth target time period; and determining the risk device nodes that affect communication security from multiple edge device nodes based on the trust of the device nodes in at least one target time period.

[0029] According to an embodiment of the present invention, by obtaining the tth basic retransmission data packet number and the t-1th completed retransmission data packet number generated between different device nodes in adjacent target time periods, and determining the tth retransmission data packet ratio to perform trust assessment, the number of data packets that need to be retransmitted in adjacent time periods can be used to more accurately discover device nodes in edge device nodes that are prone to data packet retransmission, and then more timely and accurately identify risky device nodes that affect communication security among multiple device nodes, so as to quickly isolate risky device nodes and improve the operating stability of the distribution network.

[0030] Figure 1 A diagram showing an application scenario of the method and apparatus provided by the present invention for performing trust evaluation on edge device nodes.

[0031] like Figure 1 As shown, the application scenario 100 according to this embodiment may include a first edge device 101, a second edge device 102, a third edge device 103, and a network 104. The network 104 is used to provide a medium for a communication link between the first edge device 101, the second edge device 102, and the third edge device 103. The network 104 may include various connection types, such as wired, wireless communication links, or optical fiber cables, etc.

[0032] The first edge device 101, the second edge device 102, and the third edge device 103 may interact through the network 104 to receive or send messages, etc. The first edge device 101 may be equipped with a processor such as a CPU. The first edge device 101 and the third edge device 103 may be, for example, smart meter devices in a power system, which are used to record user-side power data such as user power consumption information and voltage change information.

[0033] The second edge device 102 may include a smart fusion terminal for the substation area, which may serve as a server to receive data packets sent by the first edge device 101, thereby obtaining user-side power data. The second edge device 102 may also receive data packets sent by the third edge device 103. The first edge device 101, the second edge device 102, and the third edge device 103 are connected in communication to form a substation area edge device system.

[0034] It should be noted that the method for trust evaluation of edge device nodes provided by the embodiment of the present invention can be executed by the second edge device 102. Accordingly, the device for trust evaluation of edge device nodes provided by the embodiment of the present invention can be arranged in the second edge device 102. The method for identity authentication of edge devices provided by the embodiment of the present invention can also be executed by an edge device that is different from the second edge device 102 and can communicate with the first edge device 101 and / or the third edge device 103. Correspondingly, the device for identity authentication of edge devices provided by the embodiment of the present invention can also be arranged in an edge device or edge device cluster that is different from the second edge device 102 and can communicate with the first edge device 101 and / or the third edge device 103. Alternatively, the method for trust evaluation of edge device nodes provided by the embodiment of the present invention can be executed by the first edge device 101 and / or the third edge device 103. Accordingly, the apparatus for performing trust evaluation on edge device nodes provided in the embodiment of the present invention may be disposed in the first edge device 101 and / or the third edge device 103 .

[0035] It should be understood that Figure 1 The number of edge devices and networks in the figure is only for illustration. Any number of edge devices and networks may be provided according to implementation requirements.

[0036] Figure 2 A flow chart of a method for trust evaluation of edge device nodes according to an embodiment of the present invention is shown.

[0037] like Figure 2As shown, the method for trust evaluation of edge device nodes in this embodiment is applied to a substation edge device system, and the substation edge device system includes multiple edge device nodes that are communicatively coupled. The method of this embodiment may include operations S210 to S240.

[0038] In operation S210, data packet transmission information related to a first device node and a second device node among a plurality of edge device nodes is obtained.

[0039] In operation S220, a tth retransmission packet ratio is determined according to the tth basic retransmission packet number and the t-1th completed retransmission packet number.

[0040] In operation S230, a trust evaluation is performed based on the tth retransmission data packet ratio to obtain the trust of the device node in the tth target period.

[0041] In operation S240 , based on the trust of the device nodes in at least one target period, risky device nodes that affect communication security are determined from a plurality of edge device nodes.

[0042] According to an embodiment of the present invention, the substation edge device system may be a system for collecting and analyzing power operation data in a distribution network, and the substation edge device system may include multiple edge devices such as smart meter devices and substation smart fusion terminal devices. Edge devices can be understood as edge devices and terminal devices. Edge devices may include devices such as smart gateways that provide access to communication networks, and terminal devices may include smart meter devices, etc. The embodiments of the present invention do not limit the specific device types of edge devices, and those skilled in the art may select them according to actual needs.

[0043] According to an embodiment of the present invention, the first device node and the second device node can be different edge devices in the substation edge device system. It can be understood that the edge devices in the substation edge device system can serve as device nodes, and different device nodes can interact with each other to receive data packets sent by other device nodes, or send data packets to other device nodes.

[0044] According to an embodiment of the present invention, the data packet transmission information includes the number of the tth basic retransmission data packets and the number of the t-1th completed retransmission data packets, and the tth basic retransmission data packet number represents the number of data packets that should be retransmitted between the first device node and the second device node in the tth target period. For example, the data packet that should be retransmitted may be: a data packet sent by the first device node i to the second device node j, but due to a communication link failure such as network delay, or the second device node j does not perform the relevant operation of receiving the data packet, the first device node i needs to retransmit the data packet.

[0045] In one example, in a substation edge device system, when the first device node is set as a data packet sending node and the second device node is set as a data packet receiving node or a data packet transfer node, the tth basic retransmission data packet number can represent the number of data packets that the first device node needs to retransmit to the second device node in the tth target time period.

[0046] According to an embodiment of the present invention, the number of retransmitted data packets completed at the t-1th time represents the number of data packets for which retransmission tasks have been performed between the first device node and the second device node in the t-1th target period, and t is any integer greater than 1. For example, the data packets for which retransmission tasks have been performed may be data packets that have been resent by the first device node to the second device node.

[0047] It should be understood that the t-1th target time period is earlier than the tth target time period, and the t-1th target time period and the tth target time period are adjacent time periods.

[0048] According to an embodiment of the present invention, the basic number of retransmitted data packets may include the number of data packets that the first device node needs to retransmit as a data packet sender, or may also include the number of data packets that the first device node needs to reforward as a data packet intermediate forwarder. Accordingly, the number of completed retransmitted data packets may include the number of data packets that the first device node has retransmitted as a data packet sender, or may also include the number of data packets that the first device node has reforwarded as a data packet intermediate forwarder.

[0049] According to an embodiment of the present invention, when the first device node acts as an intermediate forwarder of a data packet, the data packet successfully forwarded to the next device node by the device node as an intermediate forwarder cannot be directly monitored by the sender of the data packet. However, other device nodes tuned to the same channel and whose receivers are turned on can detect the data packet that needs to be forwarded, or the forwarding success status of the data packet that has been successfully forwarded, more timely and accurately. It can be understood that any device node within the preset communication range with the first device node can receive the data packet that needs to be forwarded. The number of basic data packet retransmissions and the number of completed data packet forwardings can be determined by monitoring the forwarding identifiers of the data packets of other device nodes within the communication distance range with the first device node, so as to improve the data monitoring accuracy and timeliness of the t-th basic retransmission data packet number and the t-1th completed retransmission data packet number, and improve the identification accuracy and timeliness of risky device nodes.

[0050] According to an embodiment of the present invention, the tth retransmission packet ratio characterizes the change of the retransmission task between the first device node and the second device node. The tth retransmission packet ratio can quantitatively characterize the change of the retransmission task between the first device node and the second device node from the t-1th target period to the tth target period. Through one or more retransmission packet ratios, it is possible to more accurately indicate the existence of packet loss, communication channel failure, etc. between different edge devices, or characterize the existence of failures in edge devices. The trust of the device nodes corresponding to the first device node and the second device node is determined by the tth retransmission packet ratio, and the risk device nodes that affect communication security can be more accurately and timely discovered through the changes in the packet retransmission tasks in different target periods.

[0051] According to an embodiment of the present invention, the tth retransmission data packet ratio can be determined based on the ratio between the tth basic retransmission data packet number and the t-1th completed retransmission data packet number, but is not limited to this. It can also be based on any type of algorithm such as a normalization algorithm, a long short-term memory network algorithm, etc. to process the tth basic retransmission data packet number and the t-1th completed retransmission data packet number to obtain the tth retransmission data packet ratio, as long as the obtained tth retransmission data packet ratio can characterize the change in the data packet retransmission task between the first device node and the second device node from the t-1th target time period to the tth target time period.

[0052] According to an embodiment of the present invention, trust evaluation is performed based on the tth retransmission data packet ratio, which may include evaluating whether there are changes that affect the quality of communication interaction and changes in data packet loss between the first edge device and the second edge device based on the tth retransmission data packet ratio, and quantifying the trust between different edge devices with communication interaction in the tth target time period based on the tth retransmission data packet ratio, so that the changes in retransmission tasks in multiple target time periods can be quantified by the tth retransmission data packet ratio, and by setting a comparative relationship between a preset trust threshold and the trust of the device node, it is possible to timely determine whether there are risky device nodes that affect communication security in the first edge device and the second edge device. In this way, the risky device nodes can be determined from multiple edge devices in a relatively timely and accurate manner through the quantified changes in the retransmission tasks, so as to timely isolate the risky device nodes to ensure the communication security of the substation substation substation network system and improve the communication stability and the operation stability of the substation substation power distribution network.

[0053] According to an embodiment of the present invention, determining the tth retransmission packet ratio based on the tth basic retransmission packet number and the t-1th completed retransmission packet number may also include: determining the tth target retransmission packet number associated with the tth target time period based on the sum of the tth basic retransmission packet number and the t-1th completed retransmission packet number; and determining the tth retransmission packet ratio based on the ratio between the tth basic retransmission packet number and the tth target retransmission packet number.

[0054] In an example, according to the tth basic retransmission packet number and the t-1th completed retransmission packet number, determining the tth retransmission packet ratio may include determining the tth retransmission packet ratio based on the following formula (1).

[0055] (1);

[0056] Among them, ps ij (t) represents the number of basic retransmission packets of the tth target period, which can be understood as the number of packets that the i-th node needs to transmit but needs to be retransmitted because the j-th node has not received them. ij (t-1) represents the number of retransmitted packets completed in the t-1 period, which can be understood as the number of packets retransmitted from the i-th node to the j-th node in the t-1 target period. The number of retransmitted packets for the t-th target can be expressed as ps ij (t) + ps ij (t-1).eva ij (t) represents the t-th retransmission data packet ratio, which may represent a normalized representation of the number of retransmission data packets between the i-th node and the j-th node from the t-1-th target period to the t-th target period.

[0057] It can be understood that the i-th node represents the first device node, and the j-th node represents the second device node.

[0058] According to an embodiment of the present invention, the first device node includes a smart meter device, and the second device node includes a substation fusion terminal device. The smart meter device can report voltage operation data, electricity fee balance, power consumption and other power operation data required by the substation distribution network by sending a data packet to the substation fusion terminal device.

[0059] According to an embodiment of the present invention, based on the trust of device nodes in at least one target period, determining risky device nodes that affect communication security from multiple edge device nodes may include: when the trust of device nodes in the tth target period meets the trust risk condition, the smart meter device corresponding to the trust of the device node in the tth target period is determined as a risky device node.

[0060] According to an embodiment of the present invention, the trust of the device node in the t target period meets the trust risk condition, which may include that the trust of the device node in the t target period is greater than or equal to a preset trust threshold. Since the substation fusion terminal device can be connected to multiple smart meter devices in communication, and the smart meter devices are prone to failures due to the deployment environment, and the settings are easily illegally configured or damaged, when the trust of the device node in the t target period meets the trust risk condition, it can be inferred that the data packet sending action behavior of the smart meter device corresponding to the trust of the device node has a security risk. By determining that the smart meter device is a risky device node, the smart meter device can be prevented from frequently experiencing communication anomalies such as data packet loss, thereby improving the operating stability of the substation edge device system and the substation power distribution network.

[0061] According to an embodiment of the present invention, trust evaluation is performed based on the tth retransmission data packet ratio to obtain the trust of the device node in the tth target time period, including: processing the tth retransmission data packet ratio and the tth received data packet ratio based on a weighted algorithm to obtain the trust of the device node in the tth target time period.

[0062] According to an embodiment of the present invention, the tth received data packet number represents the number of data packets received by the second device node from the first device node in the tth target period, and the tth received data packet ratio represents the packet loss change trend between the first device node and the second device node. The packet loss change trend can be understood as the change trend of the packet loss number or packet loss rate between the first device node and the second device node in multiple target periods.

[0063] According to an embodiment of the present invention, the tth received data packet ratio is determined according to the numbers of received data packets in each of a plurality of adjacent target time periods.

[0064] For example, the tth received packet ratio can be determined based on the ratio between the difference in number between the number of packets received by the second device node in the tth target time period and the number of packets received in the t-1th target time period and the preset number of packets. The preset number of packets may include a fixed number of reference packets, or the preset number of packets may also include a dynamic number of reference packets, for example, the number of packets received by the second device node in the current target time period may be used as the dynamic number of reference packets. It should be noted that the embodiment of the present invention does not limit the specific method for determining the tth received packet ratio, as long as it can characterize the packet loss change trend between the first device node and the second device node.

[0065] According to an embodiment of the present invention, risky device nodes in the substation edge device system may intentionally discard some or all data packets and engage in malicious attack behaviors. By characterizing the packet loss change trend between different edge devices in different target time periods through the tth received packet ratio, it is possible to more accurately and timely discover whether there are edge devices between the first device node and the second device node that interact with information, which cause a high packet loss rate or a rapid change in packet loss. Packet loss may occur due to the presence of untrusted malicious device nodes in the substation edge device system. According to the communication topology connection mode or communication distance between the first device node as the sending node and the second device node as the receiving node, there may be one or more malicious nodes between the first device node and the second device node, resulting in serious packet loss.

[0066] According to an embodiment of the present invention, processing the tth retransmission packet ratio and the tth reception packet ratio based on a weighted algorithm may include performing a weighted summation of the tth retransmission packet ratio and the tth reception packet ratio based on their respective weight parameters to obtain a quantized device node trust.

[0067] According to an embodiment of the present invention, the trust level of a device node is determined by processing the tth retransmission packet ratio and the tth reception packet ratio based on a weighted algorithm. The packet loss change trend and the packet retransmission task change trend in multiple target time periods can be comprehensively considered to more accurately assess whether there are risky device nodes between the first device node and the second device node that affect communication security and stability, so as to improve the identification accuracy and timeliness of untrusted malicious edge devices.

[0068] According to an embodiment of the present invention, the tth received data packet ratio is determined based on the following operations: performing a subtraction operation on the number of tth received data packets and the number of t-1th received data packets to obtain a difference number of tth received data packets; performing an addition operation on the number of tth received data packets and the number of t-1th received data packets to obtain a cumulative number of tth received data packets; and determining the tth received data packet ratio based on the ratio between the difference number of tth received data packets and the cumulative number of tth received data packets.

[0069] According to an embodiment of the present invention, a calculation operation may be performed based on the following formula (2) to obtain the tth received data packet ratio.

[0070] (2);

[0071] Among them, Pr ij(t) represents the number of data packets received from the data packet sender (first device node) to the data packet receiver (second device node) during the tth target period, which can be understood as the number of tth received data packets. ij (t-1) represents the number of data packets received from the data packet sender (first device node) to the data packet receiver (second device node) during the t-1 target period, which can be understood as the number of data packets received at the t-1th time. The difference in the number of data packets received at the tth time is Pr ij (t)- Pr ij (t-1), the cumulative number of received data packets for the tth time is Pr ij (t)+Pr ij (t-1). The accumulated number of received data packets at the tth time is used to normalize the number of received data packets in two adjacent target time periods, so as to accurately evaluate the packet loss change trend between the first device node and the second device node in the two adjacent target time periods.

[0072] According to an embodiment of the present invention, processing the tth retransmission data packet ratio and the tth reception data packet ratio based on a weighted algorithm to obtain the device node trust for the tth target time period may include: processing the tth retransmission data packet ratio and the tth reception data packet ratio based on a weighted algorithm to obtain the tth initial device node trust; updating the tth initial device node trust based on the tth data packet transmission quality parameter to obtain the device node trust for the tth target time period.

[0073] According to an embodiment of the present invention, a weighted average algorithm can be executed based on the weight parameters of the tth retransmission data packet ratio and the tth received data packet ratio to obtain the trust of the tth initial device node. The weight parameters can be designed based on actual needs, and the embodiment of the present invention does not limit this.

[0074] In one example, the trust degree of the tth initial device node may be determined based on the following formula (3).

[0075] (3);

[0076] Among them, ditr ij (t)' is the trust degree of the t-th initial device node, α is the weight parameter of the t-th received data packet ratio, and β is the weight parameter of the t-th retransmitted data packet ratio.

[0077] According to an embodiment of the present invention, the t-th data packet transmission quality parameter is determined based on the ratio between the t-th data packet transmission success rate in the t-th target period and the t-1-th data packet transmission success rate in the t-1-th target period. The t-th data packet transmission quality parameter characterizes the change in the data packet transmission success rate between the first device node and the second device node in multiple target periods.

[0078] According to an embodiment of the present invention, between a first device node and a second device node that are communicating and interacting, the number of data packets transmitted in target time periods of different lengths is different, and the transmission success rate of data packets in each target time period is also different. The change in the data packet transmission success rate in each target time period will also affect the data packet transmission success rate in the next target time period. By determining the data packet transmission quality parameter T, the trust of the t-th initial device node can be updated by considering the impact of the change in the data packet transmission success rate between the first device node and the second device node in different target time periods on the degree of trust of the device node. It can be achieved to evaluate the trust of the device node by integrating the change in the data packet transmission success rate, so as to improve the accuracy of identifying the degree of trust of risky device nodes.

[0079] In one example, the tth data packet transmission quality parameter may be determined based on the following formula (4).

[0080] (4);

[0081] Where R ij (t) is the number of data packets received by the first device node and the second device node in the tth target period, D ij (t) is the number of packets lost during the packet transmission between the first device node and the second device node in the tth target period, R ij (t) / D ij (t)+ R ij (t) can represent the transmission success rate of the tth data packet. ij (t-1) / D ij (t-1)+ R ij (t-1) can represent the transmission success rate of the t-1th data packet.

[0082] In one example, the trustworthiness of a device node may be determined based on the following formula (5).

[0083] (5);

[0084] Where PIT(t) represents the duration of the tth target period. T is the tth data packet transmission quality parameter. ij(t) is the trust of the device node in the tth target period. By introducing the trust of the device node in the t-1th target period in the process of updating the initial device node trust, the risk device nodes that generate internal attack behaviors such as denial of service and sending false reports in the edge device system of the substation can be identified based on the changes in the trust of each device node in multiple target periods. These risky device nodes can be isolated in time to avoid internal attack behaviors affecting reliable data packet transmission. In this way, the trust of device nodes that are communicating and interacting can be evaluated in a timely manner, so as to consider the changes in the trust of device nodes in multiple target periods, eliminate the impact of abnormal data in the trust evaluation process, and improve the accuracy of trust evaluation.

[0085] According to an embodiment of the present invention, processing the tth retransmission data packet ratio and the tth reception data packet ratio based on a weighted algorithm to obtain the tth initial device node trust includes: processing the tth retransmission data packet ratio, the tth reception data packet ratio, the tth forwarding data packet ratio and the device node trust of the t-1th target time period based on a weighted algorithm to obtain the tth initial device node trust.

[0086] According to an embodiment of the present invention, the tth forwarding packet ratio is determined based on the following operations: determining the tth forwarding packet difference number based on the difference between the tth forwarding packet number and the t-1th forwarding packet number; determining the tth forwarding packet cumulative number based on the sum of the tth forwarding packet number and the t-1th forwarding packet number; and determining the tth forwarding packet loss ratio based on the ratio between the tth forwarding packet difference number and the tth forwarding packet cumulative number.

[0087] According to an embodiment of the present invention, the data packet transmission information also includes the number of forwarded data packets for the tth time and the number of forwarded data packets for the tth time, wherein the number of forwarded data packets for the tth time represents the number of data packets forwarded by the second device node in the tth target period, and the forwarded data packets come from the first device node. Accordingly, the number of forwarded data packets for the tth time represents the number of data packets forwarded by the second device node from the first device node in the t-1 target period. The second device node can act as an intermediate forwarding device node to forward data packets sent by the first device node to other device nodes. Other device nodes can be other device nodes except the first device node and the second device node.

[0088] According to an embodiment of the present invention, when a first device node forwards a data packet that needs to be forwarded and needs to be sent to other device nodes through a second device node, it is possible to determine whether the second device node forwards the forwarded data packet to other device nodes by monitoring the data packet flow profile of the second device node receiving the first device node. In the tth target period, when the data packet flow profile indicates that the second device node has forwarded the forwarded data packet, the current number of t forwarded data packets in the data packet flow profile is increased by 1.

[0089] Alternatively, when the first device node i forwards a data packet that needs to be forwarded and needs to be sent to other device nodes k through the second device node j, it is possible to determine whether the second device node j forwards the forwarded data packet to other device nodes k by monitoring the data packet flow profile received by other device nodes k from the first device node i. In the tth target period, when the data packet flow profile indicates that the second device node j has forwarded the forwarded data packet, the current t forwarded data packet number of the data packet flow profile is increased by 1. Among them, the data packet that needs to be forwarded can be called a forwarded data packet.

[0090] In an example, the t-th forwarding packet loss ratio may be determined based on the operation of the following formula (6).

[0091] (6);

[0092] Among them, tp ij (t) represents the actual number of transmitted data packets that the second device node j forwards the forwarded data packets of the first device node i to other device nodes k in the t target period, tp ij (t) can be understood as the number of packets forwarded at the tth time. ij (t-1) represents the number of packets forwarded at the t-1th time. ij (t)-tp ij (t-1) is the difference in the number of packets forwarded at the tth time, tp ij (t)+tp ij (t-1) is the cumulative number of packets forwarded at the tth time, tpe ij (t) is the packet loss ratio of the tth forwarding.

[0093] In one example, based on a weighted algorithm, the tth retransmission packet ratio, the tth reception packet ratio, the tth forwarding packet ratio and the device node trust of the t-1th target period are processed to obtain the tth initial device node trust which can be expressed based on the operation of the following formula (7).

[0094] (7);

[0095] Wherein, PIT(t) represents the duration of the tth target period. T is the tth data packet transmission quality parameter. ij (t) is the trust of the device node in the tth target period, and γ represents the weight parameter of the tth forwarding packet ratio. By combining the tth retransmission packet ratio, the tth reception packet ratio, and the tth forwarding packet ratio, and using different weight parameters to characterize the contribution of the tth retransmission packet ratio, the tth reception packet ratio, and the tth forwarding packet ratio to the trust of the device node, the error rate of identifying risky device nodes can be further reduced, thereby improving the operating stability of the device system at the edge of the station.

[0096] In one example, α + β + γ = 1.

[0097] According to an embodiment of the present invention, the forwarding packet loss ratio is determined by the change in the number of forwarding data packets in one or more target time periods, and then it is evaluated whether the second device node as the intermediate forwarding node intentionally discards the forwarding data packets that need to be forwarded, or because the second device node has abnormal device configuration, device failure, network communication link abnormality, etc. In this way, the packet interaction behavior between the first device node and the second device node can be combined with the tth retransmission data packet ratio, the tth reception data packet ratio, the tth forwarding data packet ratio and the device node trust in the t-1th target time period to more accurately evaluate whether there are risky device nodes that affect communication security in the communication link between the first device node and the second device node, so as to improve the operating stability of the edge device system of the station area.

[0098] According to an embodiment of the present invention, based on the trust of the device nodes in at least one target period, determining the risky device nodes that affect communication security from multiple edge device nodes includes: when the trust of the device nodes in the tth target period meets the trust risk condition, the smart meter device corresponding to the trust of the device nodes in the tth target period is determined as a risky device node.

[0099] According to an embodiment of the present invention, based on the trust of device nodes in at least one target time period, determining risky device nodes that affect communication security from multiple edge device nodes may also include: when the trust of device nodes in the tth target time period satisfies the trust risk condition, determining the risky device nodes from device nodes that have a data packet transmission relationship with both the first device node and the second device node.

[0100] Figure 3 A flow chart of a method for trust evaluation of edge device nodes according to another embodiment of the present invention is shown.

[0101] like Figure 3As shown, the method of this embodiment includes operations S301 to S305.

[0102] After the start operation is performed, operation S301 retrieves the data packet flow profile of the device node to obtain data packet transmission information related to the first device node and the second device node. At the same time, the interactive behavior data of each target time period can be determined based on the data packet transmission information. The interactive behavior data may include a retransmission data packet ratio, a reception data packet ratio, and a forwarding data packet ratio.

[0103] In operation S302, the interactive behavior data is processed based on a weighted algorithm, which may include processing a retransmission packet ratio, a reception packet ratio, a forwarding packet ratio, and a device node trust in a previous target period based on a weighted algorithm to obtain an initial device node trust. The initial device node trust is updated based on a packet transmission quality parameter in a current target period to obtain a device node trust.

[0104] In operation S303, it is determined whether the trust of the device node meets the trust risk condition, for example, it is determined whether the trust of the device node in the current target period is greater than or equal to a preset trust threshold.

[0105] If the result of operation S303 is yes, operation S304 is performed to determine the trusted nodes, and the first device node and the second device node are determined as trusted nodes. If the result of operation S303 is no, operation S305 is performed to determine the device risk node. The device node having the target device type (e.g., smart meter device type) in the first device node and the second device node can be determined as the risky device node.

[0106] In one example, the method for trust evaluation of edge device nodes provided by the embodiment of the present invention can be performed based on the following embodiments.

[0107] First, establish a trust calculation model for edge devices in the edge device system of the active distribution station area.

[0108] The trust calculation model includes a traffic monitoring module, a trust evaluation module and a decision module. The traffic monitoring module obtains the data packet transmission information of each of the multiple device nodes representing the edge device by monitoring the exchange request and response data packets of the multiple edge devices and the traffic profile.

[0109] The trust evaluation module performs the method provided by the embodiment of the present invention based on the data packet transmission information obtained from the traffic monitoring module. The retransmission data packet ratio, the reception data packet ratio and the forwarding data packet ratio of the current target period are determined based on the data packet transmission information. The retransmission data packet ratio, the reception data packet ratio and the forwarding data packet ratio of the current target period are processed based on a weighted algorithm, and the device node trust of the previous target period is obtained to obtain the device node trust of the current target period.

[0110] The decision module compares the device node trust corresponding to each device node with the preset trust threshold. If the comparison result indicates that the device node trust is greater than or equal to the preset trust threshold, the device node is classified as a trusted node, or if the comparison result indicates that the device node trust is less than the preset trust threshold, the device node is determined as a risky device node, thereby isolating the risky device node. The trust evaluation module is responsible for evaluating the credibility value of each communication node through its packet forwarding, receiving and transmitting packet behaviors, and evaluating the probability of the device node being a risky device node or a trusted node.

[0111] Figure 4 A rendering of a method for trust evaluation of edge device nodes according to an embodiment of the present invention is shown.

[0112] Figure 5 A rendering of a method for trust evaluation of edge device nodes according to another embodiment of the present invention is shown.

[0113] like Figure 4As shown, the horizontal axis represents the time length, and the vertical axis represents the trust of the device node. The first evaluation mechanism, the second evaluation mechanism, and the third evaluation mechanism are respectively based on the AF-TNS (Trust-based neighbor selection using activation function for secure routing in wireless sensor networks) evaluation algorithm, TrustDoe (A novel trust model of dynamic optimization based on entropy methodin wireless sensor networks) and the method for trust evaluation of edge device nodes provided by the embodiment of the present invention, and the trust evaluation of the edge device system in the active substation area is performed to obtain three different trend lines of trust of the device nodes. By comparing the first evaluation mechanism, the second evaluation mechanism, and the third evaluation mechanism, it can be seen that the trust evaluation according to the method provided by the embodiment of the present invention can reach the point where the trust value of the device node gradually converges after a time length of about 800s, while the trust of the device node obtained based on the first evaluation mechanism and the second evaluation mechanism has not reached convergence when the time length is 1000s. This shows that the method provided by the embodiment of the present invention can quickly and accurately identify risky device nodes as time goes by, and improve the overall credibility of the substation edge device system. It can be seen from the changing trends of multiple broken lines that, as time goes by, the method provided by the embodiment of the present invention can more accurately identify risky device nodes within a time length of about 300 seconds to quickly improve the overall device node trust of the substation edge device system, while maintaining the overall device node trust stable, thereby better identifying malicious nodes.

[0114] like Figure 5 The multiple broken lines shown respectively represent the changes in the overall device node trust of the substation edge equipment system, when the proportion of risky device nodes in the substation edge equipment system identified from a time period of about 100s is 10% to 50%, respectively, and trust evaluation is performed based on the method provided in an embodiment of the present invention.

[0115] Figure 6 A block diagram of an apparatus for performing trust evaluation on edge device nodes according to an embodiment of the present invention is shown.

[0116] like Figure 6As shown, the device 600 for performing trust evaluation on edge device nodes is applied to a substation edge device system, and the substation edge device system includes multiple edge device nodes that are communicatively coupled. The device 600 for performing trust evaluation on edge device nodes includes: an acquisition module 610, a first determination module 620, a trust evaluation module 630 and a second determination module 640.

[0117] The acquisition module 610 is used to obtain data packet transmission information related to a first device node and a second device node among multiple edge device nodes, wherein the data packet transmission information includes the tth basic retransmission data packet number and the t-1th completed retransmission data packet number, the tth basic retransmission data packet number represents the number of data packets that should be retransmitted between the first device node and the second device node in the tth target time period, the t-1th completed retransmission data packet number represents the number of data packets that have been retransmitted between the first device node and the second device node in the t-1th target time period, and t is an integer greater than 1.

[0118] The first determination module 620 is used to determine the tth retransmission packet ratio according to the tth basic retransmission packet number and the t-1th completed retransmission packet number, wherein the tth retransmission packet ratio represents the change of the retransmission task between the first device node and the second device node.

[0119] The trust evaluation module 630 is used to perform a trust evaluation based on the t-th retransmission data packet ratio to obtain the trust of the device node in the t-th target time period.

[0120] The second determination module 640 is used to determine risky device nodes that affect communication security from multiple edge device nodes based on the trust of the device nodes in at least one target period.

[0121] According to an embodiment of the present invention, the trust evaluation module 630 includes a first device node trust obtaining unit.

[0122] The first device node trust acquisition unit is used to process the tth retransmission data packet ratio and the tth received data packet ratio based on a weighted algorithm to obtain the device node trust in the tth target time period, wherein the tth received data packet ratio is determined based on the number of received data packets in each of multiple adjacent target time periods, the tth received data packet number represents the number of data packets received by the second device node from the first device node in the tth target time period, and the tth received data packet ratio represents the packet loss change trend between the first device node and the second device node.

[0123] According to an embodiment of the present invention, the tth received data packet ratio is determined based on the following operations: performing a subtraction operation on the number of tth received data packets and the number of t-1th received data packets to obtain a difference number of tth received data packets; performing an addition operation on the number of tth received data packets and the number of t-1th received data packets to obtain a cumulative number of tth received data packets; and determining the tth received data packet ratio based on the ratio between the difference number of tth received data packets and the cumulative number of tth received data packets.

[0124] According to an embodiment of the present invention, the first device node trust degree obtaining unit includes: an initial device node trust degree obtaining subunit and a device node trust degree obtaining subunit.

[0125] The initial device node trust degree obtaining subunit is used to process the tth retransmission data packet ratio and the tth received data packet ratio based on a weighted algorithm to obtain the tth initial device node trust degree.

[0126] The device node trust acquisition subunit is used to update the tth initial device node trust based on the tth data packet transmission quality parameter to obtain the device node trust in the tth target period, wherein the tth data packet transmission quality parameter is determined based on the ratio between the tth data packet transmission success rate in the tth target period and the t-1th data packet transmission success rate in the t-1th target period.

[0127] According to an embodiment of the present invention, the initial device node trust acquisition subunit is further configured to: process the tth retransmission data packet ratio, the tth received data packet ratio, the tth forwarding data packet ratio and the device node trust of the t-1th target time period based on a weighted algorithm to obtain the tth initial device node trust, wherein the tth forwarding data packet ratio is determined based on the following operations: based on the difference between the tth forwarded data packet number and the t-1th forwarded data packet number, determine the tth forwarded data packet difference number, the data packet transmission information also includes the tth forwarded data packet number and the t-1th forwarded data packet number, the tth forwarded data packet number represents the number of data packets forwarded by the second device node in the t target time period, and the forwarded data packets come from the first device node; based on the sum of the tth forwarded data packet number and the t-1th forwarded data packet number, determine the tth forwarded data packet cumulative number; and based on the ratio between the tth forwarded data packet difference number and the tth forwarded data packet cumulative number, determine the tth forwarding packet loss ratio.

[0128] According to an embodiment of the present invention, the first determining module 620 includes: a first determining unit and a second determining unit.

[0129] The first determining unit is used to determine the tth target number of retransmission data packets associated with the tth target time period based on the sum of the tth basic number of retransmission data packets and the t-1th number of completed retransmission data packets.

[0130] The second determining unit is used to determine the tth retransmission data packet ratio based on the ratio between the tth basic retransmission data packet number and the tth target retransmission data packet number.

[0131] According to an embodiment of the present invention, the first device node includes a smart meter device, and the second device node includes a station area fusion terminal device.

[0132] According to an embodiment of the present invention, the second determining module 640 includes a third determining unit.

[0133] The third determining unit is configured to determine the smart meter device corresponding to the trust degree of the device node in the tth target period as a risky device node if the trust degree of the device node in the tth target period meets the trust risk condition.

[0134] Based on the apparatus for trust evaluation of edge device nodes provided in the above-mentioned embodiments, an embodiment of the present invention further provides an edge device system for a substation.

[0135] According to an embodiment of the present invention, a substation edge device system is arranged in a substation distribution network. The substation edge device system includes: a plurality of communicatively coupled edge device nodes and a device for performing trust evaluation on the edge device nodes provided in an embodiment of the present invention.

[0136] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present invention. In this regard, each box in the flowchart or block diagram may represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box may also occur in an order different from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions. It can be understood by those skilled in the art that the features recorded in the various embodiments of the present invention can be combined and / or combined in various ways, even if such a combination or combination is not explicitly recorded in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features recorded in the various embodiments of the present invention can be combined and / or combined in various ways. All these combinations and / or combinations fall within the scope of the present invention.

[0137] The embodiments of the present invention are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present invention. Although each embodiment is described above, it does not mean that the measures in each embodiment cannot be used in combination advantageously. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A method for evaluating the trustworthiness of an edge device node, characterized in that: Applied to a platform edge device system, the platform edge device system includes a plurality of edge device nodes coupled in communication, and the method includes: Obtaining data packet transmission information related to a first device node and a second device node among the plurality of edge device nodes, wherein the data packet transmission information includes a t-th basic retransmission data packet number and a t-1-th completed retransmission data packet number, wherein the t-th basic retransmission data packet number represents the number of data packets that should be retransmitted between the first device node and the second device node in the t-th target time period, and the t-1-th completed retransmission data packet number represents the number of data packets that have been retransmitted between the first device node and the second device node in the t-1-th target time period, and t is an integer greater than 1; Determine a tth retransmission data packet ratio according to the tth basic retransmission data packet number and the t-1th completed retransmission data packet number, wherein the tth retransmission data packet ratio represents a change in a retransmission task between the first device node and the second device node; The tth retransmission data packet ratio, the tth reception data packet ratio, the tth forwarding data packet ratio and the device node trust of the t-1th target period are processed based on a weighted algorithm to obtain the tth initial device node trust, wherein the tth reception data packet ratio is determined according to the number of reception data packets of each of the adjacent multiple target periods, and the tth reception data packet number represents the number of data packets received by the second device node from the first device node in the tth target period, Updating the tth initial device node trust based on the tth data packet transmission quality parameter to obtain the device node trust of the tth target period, wherein the tth data packet transmission quality parameter is determined based on the ratio between the tth data packet transmission success rate in the tth target period and the t-1th data packet transmission success rate in the t-1th target period; and Based on the trust of the device nodes in at least one target period, determining risky device nodes that affect communication security from the plurality of edge device nodes; The tth forwarding data packet ratio is determined based on the following operations: Determine the tth forwarded data packet difference number based on the difference between the tth forwarded data packet number and the t-1th forwarded data packet number, the data packet transmission information also includes the tth forwarded data packet number and the t-1th forwarded data packet number, the tth forwarded data packet number represents the number of data packets forwarded by the second device node in the tth target time period, and the forwarded data packets come from the first device node; Determine the cumulative number of t-th forwarded data packets based on the sum of the number of the t-th forwarded data packets and the number of the t-1-th forwarded data packets; The tth forwarding packet loss ratio is determined based on the ratio between the difference number of the tth forwarded data packets and the accumulated number of the tth forwarded data packets.

2. The method according to claim 1, characterized in that The tth received data packet ratio represents a packet loss variation trend between the first device node and the second device node.

3. The method according to claim 1, characterized in that The tth received data packet ratio is determined according to the following operation: Perform a subtraction operation on the number of received data packets of the tth time and the number of received data packets of the t-1th time to obtain the difference number of received data packets of the tth time; Performing an addition operation on the number of received data packets for the tth time and the number of received data packets for the t-1th time to obtain the accumulated number of received data packets for the tth time; as well as The tth received data packet ratio is determined based on a ratio between the tth received data packet difference quantity and the tth received data packet accumulation quantity.

4. The method according to any one of claims 1 to 3, characterized in that Determining the tth retransmission data packet ratio according to the tth basic retransmission data packet number and the t-1th completed retransmission data packet number includes: Determining a tth target number of retransmitted data packets associated with the tth target time period based on the sum of the tth basic number of retransmitted data packets and the t-1th number of completed retransmitted data packets; and The tth retransmission packet ratio is determined based on a ratio between the tth basic retransmission packet number and the tth target retransmission packet number.

5. The method according to claim 1, characterized in that The first device node includes a smart meter device, and the second device node includes an area fusion terminal device.

6. The method according to claim 5, characterized in that Based on the trust of the device nodes in at least one target period, determining the risk device nodes that affect the communication security from the plurality of edge device nodes includes: In a case where the trust degree of the device node in the t-th target period satisfies the trust risk condition, the smart meter device corresponding to the trust degree of the device node in the t-th target period is determined as the risky device node.

7. A device for evaluating the trustworthiness of an edge device node, characterized in that: Applied to a platform edge device system, the platform edge device system includes a plurality of edge device nodes coupled in communication, and the device includes: An acquisition module, used for acquiring data packet transmission information related to a first device node and a second device node among the plurality of edge device nodes, wherein the data packet transmission information includes a t-th basic retransmission data packet number and a t-1-th completed retransmission data packet number, wherein the t-th basic retransmission data packet number represents the number of data packets that should be retransmitted between the first device node and the second device node in the t-th target time period, and the t-1-th completed retransmission data packet number represents the number of data packets that have been retransmitted between the first device node and the second device node in the t-1-th target time period, and t is an integer greater than 1; A first determining module, configured to determine a tth retransmission data packet ratio according to the tth basic retransmission data packet number and the t-1th completed retransmission data packet number, wherein the tth retransmission data packet ratio represents a change in a retransmission task between the first device node and the second device node; a trust evaluation module, configured to perform a trust evaluation based on the t-th retransmission data packet ratio to obtain the trust of the device node in the t-th target time period; and A second determination module is used to determine risky device nodes that affect communication security from a plurality of edge device nodes based on the trust of the device nodes in at least one target period; Wherein, the first determination module is configured as follows: Processing the tth retransmission data packet ratio, the tth reception data packet ratio, the tth forwarding data packet ratio and the device node trust of the t-1th target period based on a weighted algorithm to obtain the tth initial device node trust, wherein the tth reception data packet ratio is determined according to the number of reception data packets of each of the adjacent multiple target periods, and the tth reception data packet number represents the number of data packets received by the second device node from the first device node in the tth target period; Updating the tth initial device node trust based on the tth data packet transmission quality parameter to obtain the device node trust of the tth target period, wherein the tth data packet transmission quality parameter is determined based on the ratio between the tth data packet transmission success rate in the tth target period and the t-1th data packet transmission success rate in the t-1th target period; The tth forwarding data packet ratio is determined based on the following operations: Determine the tth forwarded data packet difference number based on the difference between the tth forwarded data packet number and the t-1th forwarded data packet number, the data packet transmission information also includes the tth forwarded data packet number and the t-1th forwarded data packet number, the tth forwarded data packet number represents the number of data packets forwarded by the second device node in the tth target time period, and the forwarded data packets come from the first device node; Determine the cumulative number of t-th forwarded data packets based on the sum of the number of the t-th forwarded data packets and the number of the t-1-th forwarded data packets; The tth forwarding packet loss ratio is determined based on the ratio between the difference number of the tth forwarded data packets and the accumulated number of the tth forwarded data packets.

8. A station edge equipment system, characterized in that: Set up in the distribution network of the substation area, the substation edge equipment system includes: A plurality of edge device nodes that are communicatively coupled; and The device as claimed in claim 7.

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