Concealment method, industrial equipment system, and computer program

Abstract

This concealment method for an industrial equipment system including a plurality of signal processing units and a plurality of signal paths for transmitting signals input to the plurality of signal processing units and signals output by the plurality of signal processing units includes a change step for changing the connection relationship of the plurality of signal paths to the plurality of signal processing units within the extent that the operation of the industrial equipment system does not change.

Description

Concealment method, industrial equipment system, and computer program

[0001] The present disclosure relates to a concealment method, an industrial equipment system, and a computer program.

[0002] There is a semiconductor manufacturing device that facilitates process management through virtual experiments based on a simulation model using digital twin technology (for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2022-185394

[0004] While the techniques for improving process efficiency through the integration of hardware and software in semiconductor manufacturing systems are a body of expertise, there is a risk that the mechanisms for the integration of the hardware and software may be revealed by analyzing the signals flowing through the signal paths. This problem of reverse engineering is not limited to semiconductor manufacturing systems, but is a problem that exists in other industrial equipment systems.

[0005] The present disclosure provides a concealment method, an industrial equipment system, and a computer program that can conceal the mechanism by which hardware and software in an industrial machinery system work together.

[0006] A concealment method according to one aspect of the present disclosure is a concealment method for an industrial equipment system including a plurality of signal processing units and a plurality of signal paths for transmitting signals input to the plurality of signal processing units and signals output by the plurality of signal processing units, and includes a change step of changing the connection relationship of the plurality of signal paths to the plurality of signal processing units within a range that does not change the operation of the industrial equipment system.

[0007] According to the present disclosure, it is possible to conceal the mechanism by which hardware and software in an industrial machinery system work together.

[0008] 1 is a block diagram showing an example of the configuration of a concealment system according to the present embodiment; FIG. 2 is a schematic diagram showing an example of a path changing circuit; FIG. 3 is a block diagram showing an example of the configuration of an information processing device according to the present embodiment; FIG. 4 is a schematic diagram showing a signal transmission path before a path change; FIG. 5 is a schematic diagram showing a signal transmission path after a path change; FIG. 6 is a conceptual diagram showing objects and morphisms when a network of signal transmission paths is considered as a category in category theory; FIG. 7 is a conceptual diagram showing a method of verifying a functor that changes a signal transmission path; FIG. 8 is a schematic diagram showing an image of concealment processing; FIG. 9 is a flowchart showing a processing procedure related to verification and distribution of change content information required for concealment; FIG. 10 is a flowchart showing a processing procedure related to changes in signal transmission paths and software functions.

[0009] A concealment method, an industrial equipment system, and a computer program according to embodiments of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. Furthermore, at least some of the embodiments described below may be combined in any manner.

[0010] <System Overview> Fig. 1 is a block diagram showing an example of the configuration of a concealment system according to this embodiment. The concealment system includes an information processing device 1 and an industrial equipment system 2 connected via a communication network N.

[0011] The industrial equipment system 2 is a system in which multiple pieces of hardware and software operate in functionally linked fashion. Each piece of functionally linked hardware inputs and outputs signals, but the signals input and output from the hardware can be intercepted from the outside and may be subject to reverse engineering. The industrial equipment system 2 has a function to dynamically change signal transmission paths in order to conceal the mechanism by which the hardware and software work together.

[0012] The information processing device 1 is a device that creates and verifies change information that indicates how to change the signal transmission paths and software functions in the industrial equipment system 2, and distributes the verified change information to the industrial equipment system 2. Distribution of inappropriate change information may cause abnormalities in the operation of the industrial equipment system 2, so the change information is verified before distribution. The industrial equipment system 2 receives the change information distributed from the information processing device 1 and changes the signal transmission paths and software functions based on the received change information. By changing the signal transmission paths and software functions of the industrial equipment system 2 periodically or when a specific event occurs, the mechanism for functional collaboration can be kept confidential.

[0013] <Industrial Equipment System 2> The industrial equipment system 2 includes, for example, a substrate processing apparatus, a cleaning apparatus, an inspection apparatus, a conveying apparatus, etc. that perform processes such as film formation, lithography, and etching on substrates such as semiconductor wafers, glass substrates, or flat panel substrates. The industrial equipment system 2 includes, as multiple pieces of hardware, a control unit 20, a memory unit 21, an operation panel 22, a communication unit 23, path change circuits 24 and 25, multiple signal processing circuits 26, multiple sensors 27, and multiple controllers 28.

[0014] The control unit 20 is a processor including one or more central processing units (CPUs), arithmetic circuits such as graphics processing units (GPUs), internal storage devices such as read-only memories (ROMs) and random access memories (RAMs), input / output terminals, timers, etc. The control unit 20 controls the operation of each unit of the industrial equipment system 2. The functions of the control unit 20 may be realized by software, or some or all of the functions may be realized by hardware using a field-programmable gate array (FPGA), an ASIC, etc.

[0015] The control unit 20 displays the names of setting values ​​of the industrial equipment system 2 on the display panel 22a of the operation panel 22 and accepts the setting values ​​at the operation panel 22. The control unit 20 controls the settings and operation of the industrial equipment system 2 by outputting a signal of the accepted setting value (hereinafter referred to as a setting value signal) to the signal processing circuit 26 via the path change circuit 24. The control unit 20 can also display the contents of the control signal and the detection value signal output from the signal processing circuit 26 and the sensor 27 during equipment operation on the display panel 22a of the operation panel 22.

[0016] Meanwhile, the control unit 20 executes a computer program P2 stored in the storage unit 21 to perform processing related to the concealment of the industrial equipment system 2. Specifically, the control unit 20 can change the names of set values ​​in accordance with the change content information. For example, the control unit 20 can change the name of a set voltage displayed when a set voltage value is received from "α" to "η." The names "α" and "η" are names unrelated to the content of the set value. Furthermore, by periodically changing the name of the set value, the input path of the set value signal can be concealed. Similarly, the control unit 20 can change the names of the control signal and the detection value signal displayed on the display panel 22a based on the change content information. By periodically changing the names, the control unit 20 can conceal the output path of the control signal and the sensor signal.

[0017] Furthermore, the control unit 20 can change the connection relationship of the signal path 2a connecting the control unit 20, the signal processing circuit 26, the sensor 27, and the controller 28, using the path change circuits 24 and 25. The control unit 20 changes the connection relationship in accordance with the change content information.

[0018] The storage unit 21 includes a nonvolatile memory such as a hard disk, a flash memory, etc. The storage unit 21 stores the computer program P2 executed by the control unit 20, the change content information distributed from the information processing device 1, and other data necessary for the concealment process of the industrial equipment system 2.

[0019] The computer program P2 may be provided by a non-transitory recording medium M2 on which the computer program is readably recorded. The storage unit 21 stores the computer program P2 read from the recording medium M2 by a reading device (not shown). The recording medium M2 may be, for example, a magnetic disk, an optical disk, or a semiconductor memory. The industrial equipment system 2 may also download the computer program P2 from an external server connected to the communication network N and store it in the storage unit 21. The computer program P2 may be a single computer program or may be composed of multiple computer programs, and may be executed on a single computer or multiple computers interconnected by the communication network N.

[0020] The operation panel 22 is an interface that accepts user operations. The operation panel 22 is, for example, a touch panel device with a built-in display panel 22a. The operation panel 22 outputs a control signal according to the operation content to the control unit 20. The display panel 22a displays images necessary for operating the industrial equipment system 2 and for performing concealment processing operations based on drawing data provided by the control unit 20. The operation panel 22 may be configured with a separate input device and display device. The input device is, for example, a keyboard and a mouse. The display device is, for example, a liquid crystal display, an organic EL (Electro Luminescence) display, or a CRT display.

[0021] The communication unit 23 includes a communication circuit connected to the information processing device 1 via the communication network N. The communication unit 23 transmits and receives various information in accordance with instructions from the control unit 20. For example, the control unit 20 receives, via the communication unit 23, change content information indicating a method for changing the signal transmission path and the content of the arithmetic processing in the signal processing circuit 26.

[0022] The signal processing circuit 26 is connected to the control unit 20, the sensor 27, and the controller 28 via the path changing unit and the signal path 2a. The signal processing circuit 26 can also be connected to other signal processing circuits 26 via the path changing circuits 24 and 25. The signal processing circuit 26 receives, via the path changing circuits 24 and 25 and the signal path 2a, a set value signal output from the control unit 20, a detected value signal output from the sensor 27, and signals output from other signal processing circuits 26. The signal processing circuit 26 also performs required arithmetic processing based on the input set value signal, detected value signal, and the like, and outputs a control signal obtained by the arithmetic processing to the controller 28. The signal processing circuit 26 may be configured to output the control signal to the control unit 20. The control unit 20 displays the content of the control signal output from the signal processing circuit 26 on the display panel 22a. The signal processing circuit 26 can also output the signal obtained by the arithmetic processing to other signal processing circuits 26 via the path changing circuits 24 and 25.

[0023] The content of the arithmetic processing executed by the signal processing circuit 26 can be changed by an instruction from the control unit 20 based on the change content information. For example, a state in which the first signal processing circuit 26 executes a first arithmetic processing and the second signal processing circuit 26 executes a second arithmetic processing can be changed to a state in which the first signal processing circuit 26 executes a second arithmetic processing and the second signal processing circuit 26 executes the first arithmetic processing. Furthermore, the signal processing circuit 26 can execute dummy signal processing by performing meaningless calculations and outputting dummy signals. The dummy signal is a signal with a meaningless value. The dummy signal may be a signal obtained by applying a predetermined function to a set value signal, a control signal, or a signal output from another signal processing circuit 26. Furthermore, the data of each signal may be encrypted and output as a dummy signal. By having the signal processing circuit 26 execute dummy signal processing and output a dummy signal, the arithmetic processing operation and output of the signal processing circuit 26 can be concealed.

[0024] The control unit 20 can also instruct the signal processing circuit 26 to change the terminals or communication protocols to which signals necessary for the signal processing circuit 26 to execute a specific arithmetic process are input. For example, the signal processing circuit 26 can change from a state in which the signal processing circuit 26 executes a specific arithmetic process using signals input to the first terminal and the second terminal to a state in which the signal processing circuit 26 executes the specific arithmetic process using signals input to the second terminal and the third terminal. For example, if signals input to the first and second terminals are now input to the second and third terminals by the path change circuits 24 and 25, the signal processing circuit 26 may change the signals used for the specific arithmetic process from the signals input to the first and second terminals to the signals input to the second and third terminals.

[0025] The sensor 27 detects physical quantities necessary for controlling the industrial equipment system 2, such as physical quantities indicating the state of the industrial equipment system 2, and outputs a detection value signal. The detection value signal output from the sensor 27 is output to the signal processing circuit 26 and the control unit 20 via the signal path 2a and the path change circuits 24 and 25. When the industrial equipment system 2 is a substrate processing apparatus that performs substrate processing using plasma, the sensor 27 may include, for example, a pressure sensor that detects the pressure in the chamber, a temperature sensor that detects the temperature in the chamber, and a voltage sensor and a current sensor that detect the voltage and current of the RF power supply. Physical quantities that are commonly detected by the industrial equipment system 2 include temperature, position, speed, acceleration, current, voltage, pressure, time, image data, torque, force, strain, power consumption, weight, etc. These physical quantities can be measured using a thermometer, position sensor, speed sensor, acceleration sensor, ammeter, voltmeter, pressure gauge, timer, camera, torque sensor, wattmeter, weight scale, etc.

[0026] The controller 28 is a controlled device that operates in accordance with a signal output from the signal processing circuit 26 via the path change circuit 25. When the industrial equipment system 2 is a substrate processing apparatus that performs substrate processing using plasma, the controller 28 includes, for example, an RF power supply, a flow control valve that controls the flow rate of a raw material gas, an electrostatic chuck, a heater provided in the electrostatic chuck, an impedance matching device that matches the impedance of the RF power supply and the plasma, etc. Note that examples of the controller 28 in a general industrial equipment system 2 include a power supply, an actuator, a heater, a pump, a valve, a light source, a heat source, a display device, a buzzer, a microphone, a signal transmitter, etc.

[0027] 2 is a schematic diagram showing an example of the path changing circuit 24. The path changing circuit 24 includes a plurality of terminals 24a to which set value signals are input, and a plurality of terminals 24b connected to a plurality of signal processing circuits 26 and a plurality of sensors 27 via a signal path 2a. The signal processing circuit 26 is a circuit that can arbitrarily change the connection relationship between the terminals 24a and 24b.

[0028] As shown in FIG. 2 , the path change circuit 24 can be configured, for example, by an FPGA (Field-Programmable Gate Array). It includes a plurality of logic blocks LB arranged in a grid pattern, wiring lines W arranged vertically and horizontally surrounding each logic block LB, switch blocks SB, connection blocks CB, and input / output blocks IOB for inputting and outputting data. The logic blocks LB include, for example, a lookup table (LUT) and are circuits that perform logical operations. The switch blocks SB are provided at intersections of the wiring lines W and include transistors that turn on and off the connection paths formed by the wiring lines W. The connection blocks CB are provided between the logic blocks LB and the wiring lines W and include transistors that turn on and off the connections between the logic blocks LB and the wiring lines W. Furthermore, the connection blocks CB are provided between the input / output blocks IOB and the wiring lines W and include transistors that turn on and off the connections between the input / output blocks IOB and the wiring lines W. The input / output blocks IOB are connected to terminals 24 a, 24 a..., 24 b, 24 b...

[0029] The FPGA can rewrite the circuit configuration by turning on and off the transistors that make up the LUT, switch block SB, and connection block CB of the logic block LB. The FPGA includes a nonvolatile circuit data memory that stores circuit data defining the circuit configuration. The FPGA can configure a specific circuit by reading the circuit data stored in the circuit data memory and controlling the transistors that make up the LUT, switch block SB, and connection block CB of the logic block LB. The FPGA of this embodiment can change the connection paths between the terminals 24a, 24a... and the terminals 24b, 24b... by rewriting the circuit data. More specifically, the control unit 20 changes the signal transmission path by writing circuit data that defines the connection relationships between the terminals 24a, 24a..., 24b, 24b... to the circuit data memory based on change content information. The control unit 20 can also write circuit data that defines the operation of the logic block LB to the circuit data memory so that the logic block LB performs signal processing such as encrypting or decrypting a signal. Although an FPGA has been given as an example of the path change circuit 24, the path change circuit 24 may be configured by a plurality of communication paths and relays or switches for switching between the communication paths.

[0030] The multiple signal paths 2a shown in Fig. 1 may be configured by multiple physical signal paths 2a or multiple logical signal paths 2a. The multiple physical signal paths 2a are configured by the same multiple communication lines. The multiple logical signal paths 2a are obtained by logically multiplexing the transmission path of a single communication line. There are no particular limitations on the method for logically multiplexing the transmission paths, but logical multiplexing can be achieved by techniques such as time multiplexing, frequency multiplexing, and code multiplexing.

[0031] Furthermore, the plurality of signal processing circuits 26 shown in FIG. 1 may be an arithmetic processing unit that executes one arithmetic processing, or may be configured as a plurality of signal processing units that execute a plurality of arithmetic processing.

[0032] The path changing circuit 25 has a plurality of terminals connected to a plurality of signal processing circuits 26 and a plurality of sensors 27 via the signal path 2a, and a plurality of terminals connected to a plurality of controllers 28 and the control unit 20. The signal processing circuit 26 is a circuit that can arbitrarily change the connection relationship between the terminals. The configuration of the path changing circuit 25 is similar to that of the path changing circuit 24, and therefore a detailed description thereof will be omitted.

[0033] The path change circuits 24 and 25 can dynamically change the connection relationship between the control unit 20, the signal processing circuit 26, the sensor 27, and the controller 28, thereby making it possible to conceal the signal transmission path.

[0034] 3 is a block diagram showing an example of the configuration of the information processing device 1 according to this embodiment. The information processing device 1 includes a processing unit 10, a storage unit 11, a display unit 12, an operation unit 13, and a communication unit 14. The information processing device 1 may be configured to perform distributed processing using multiple computers, may be realized by multiple virtual machines provided in a single server, or may be realized using a cloud server.

[0035] The processing unit 10 is a processor that includes one or more CPUs, arithmetic circuits such as GPUs (Graphics Processing Units), GPGPUs (General-purpose computing on graphics processing units), and TPUs (Tensor Processing Units), internal storage devices such as ROMs (Read Only Memory) and RAMs (Random Access Memory), input / output terminals, timers, etc.

[0036] The storage unit 11 includes a nonvolatile memory such as a hard disk, a flash memory, etc. The storage unit 11 stores the computer program P1 executed by the processing unit 10, the created change content information, and the like.

[0037] The computer program P1 may be provided by a non-transitory recording medium M1 on which the computer program is readably recorded. The storage unit 11 stores the computer program P1 read from the recording medium M1 by a reading device (not shown). The recording medium M1 may be, for example, a magnetic disk, an optical disk, or a semiconductor memory. The industrial equipment system 2 may also download the computer program P1 from an external server connected to the communication network N and store it in the storage unit 11. The computer program P1 may be a single computer program or may be composed of multiple computer programs, and may be executed on a single computer or multiple computers interconnected by the communication network N.

[0038] The display unit 12 is a display device such as a liquid crystal display, an organic EL display, a CRT display, etc. The display unit 12 displays a concealment dashboard screen (see FIG. 8 ) for creating, verifying, and distributing changes to the signal transmission path and the like in order to conceal the industrial equipment system 2, under the control of the processing unit 10.

[0039] The operation unit 13 is an interface that accepts operations such as data input. The operation unit 13 includes, for example, a keyboard, a mouse, a touch panel device, etc. The operation unit 13 accepts operations related to creating, verifying, and distributing changes to the signal transmission path, etc., and sends a control signal to the processing unit 10 according to the accepted operation.

[0040] The communication unit 14 includes a communication circuit connected to the industrial equipment system 2 via the communication network N. The communication unit 14 transmits and receives various information in accordance with instructions from the processing unit 10. For example, the control unit 20 transmits change content information indicating a method for changing a signal transmission path or the like to the industrial equipment system 2 via the communication unit 14.

[0041] <Method of Changing Signal Transmission Path, etc.> Fig. 4 is a schematic diagram showing the signal transmission path before the path is changed, and Fig. 5 is a schematic diagram showing the signal transmission path after the path is changed. Figs. 4 and 5 show an example in which the industrial equipment system 2 includes four signal processing circuits 26 and one sensor 27. Of the four signal processing circuits 26, the first signal processing circuit 26 is a circuit that performs signal processing related to control of the chamber surroundings and OES (Optical Emission Spectrometer) of the substrate processing apparatus. The second signal processing circuit 26 is a circuit that performs signal processing related to temperature control. The third and fourth signal processing circuits 26 are circuits that perform dummy processing. The sensor 27 is, for example, a temperature sensor.

[0042] In the figure, the vertically aligned squares on the right side indicate setpoint signals. Hatched squares indicate dummy setpoints. The Greek letters "α," "β," ... "λ" indicate the names given to the setpoint signals. In FIG. 4, setpoint signals named "α," "γ," and "δ" are input to the signal processing circuit 26 (chamber / OES), and setpoint signals named "β," "η," and "λ" are input to the signal processing circuit 26 (temperature control). In addition, a dummy signal named "θ" is input to the signal processing circuit 26 (dummy B).

[0043] The control unit 20 can change the names of the set values ​​and change the signal transmission path in accordance with the change content information as described above. In Fig. 5, set value signals named "η", "α", and "δ" are input to the signal processing circuit 26 (chamber / OES), and set value signals named "γ", "β", and "θ" are input to the signal processing circuit 26 (temperature control). In addition, a dummy set value named "γ" is input to the signal processing circuit 26 (dummy B).

[0044] The signal processing circuit 26 (temperature control) outputs a signal to the sensor 27 (temperature sensor) and the signal processing circuit 26 (dummy B). The signal processing circuit 26 (dummy B) outputs a signal to the signal processing circuit 26 (dummy A).

[0045] In the figure, the vertically arranged circles on the left side indicate the output paths of signals output from the signal processing circuit 26 and the sensor 27. The hatched circles are dummy output paths, and the signals output to these output paths are not used to control the industrial equipment system 2. The signal processing circuit 26 (chamber / OES) shown in Figure 4 outputs signals to "i" and "iii". The sensor 27 (temperature sensor) outputs detection signals to "iv" and "v", and outputs the detection signals to the dummy output path "vii". The signal processing circuit 26 (dummy A) outputs a dummy signal to "vi".

[0046] The control unit 20 can change the signal transmission path based on the change content information as described above. In Fig. 5, the signal processing circuit 26 (chamber / OES) outputs signals to "ii" and "vi". The sensor 27 (temperature sensor) outputs detection signals to "i" and "iv". The signal processing circuit 26 (dummy A) outputs dummy signals to "iii" and "vii".

[0047] In this way, the control unit 20 can change the names of the setting values ​​based on the change content information. The control unit 20 can also change the signal transmission paths of various signals. By changing the names of the setting values ​​and changing the signal transmission paths, the connection relationships of the signal paths 2a connecting the various pieces of hardware can be kept confidential. Although not shown in FIGS. 4 and 5 , the content of the signal processing executed by each signal processing circuit 26 may be replaced, changed, or added.

[0048] <Operation Guarantee Based on Category Theory> Although confidentiality can be achieved by changing the signal transmission path, it is necessary to strictly guarantee that the functionality of the industrial equipment system 2 is not impaired. If the signal path is interrupted midway or if a necessary or unnecessary signal is input to the signal processing circuit 26, serious malfunctions may occur, so mathematically rigorous guarantees are required. Therefore, we consider using mathematical category theory to guarantee that the signal transmission paths before and after the change are topologically equivalent.

[0049] Figure 6 is a conceptual diagram showing objects and arrows when a network of signal transmission paths is considered as a category in category theory. Hereinafter, for simplicity, unlike the usual notation in category theory, arrows are expressed using their starting and ending points, as in "starting point --> ending point." While there are generally multiple arrows with the same starting and ending points, multiple arrows with the same starting and ending points can also be considered in a similar manner. The signal transmission path connecting the control unit 20, signal processing circuit 26, sensor 27, and controller 28 via path change circuits 24 and 25 and signal path 2a can be considered as a network connecting multiple nodes with links corresponding to signal path 2a. More abstractly, this network can be considered as a category in mathematical category theory. In Figure 6, the circles represented by capital letters represent objects, and the arrows connecting two objects represent arrows. The method for setting the object is not particularly limited, but for example, the terminals of the control unit 20 that outputs the setting signal, the terminals of the path change circuits 24 and 25, the terminals of the signal processing circuit 26, and the terminals of the sensor 27 may be set as objects in the category. The morphism corresponds to the signal path 2a that connects the terminals. The morphism of the network of signal transmission paths satisfies the composition rule, satisfies the associative law, and can be thought of as an identity morphism. Since the definition of a category is satisfied, the network can be considered as a category.

[0050] 6, the area surrounded by a thick dashed line represents a regular signal transmission path related to the operation of the industrial equipment system 2. The objects and arrows outside the thick dashed line represent signal transmission paths where dummy processing and dummy signal transmission are performed.

[0051] The change of the signal transmission path and the change of the processing contents can be considered as a functor that corresponds the objects and arrows of the category of the network before the route change to the objects and arrows of the category of the network after the route change. The following operations can be considered as methods for changing the network or category of the signal transmission path. For example, as shown in FIG. 6 , the network or category of the signal transmission path can be changed by adding or deleting nodes and links that constitute a detour route. The network or category of the signal transmission path can also be changed by adding or deleting nodes and links that transmit dummy signals. The network or category of the signal transmission path can also be changed by adding or deleting nodes and links that parallelize the signal path. The network or category of the signal transmission path can also be changed by dividing one node into multiple nodes connected in series and merging the multiple nodes connected in series into one node. The network or category of the signal transmission path can also be changed by adding or deleting encryption nodes that encrypt signals and decryption nodes that decrypt encrypted signals.

[0052] (Labeling of Functors) Symbols (labels) that uniquely represent the nodes and links that make up the signal transmission path network are assigned to the nodes and links. The functor can be expressed as information that associates labels representing the nodes and links before the route change with labels representing the nodes and links after the route change (labeling). The change content information includes information on the labeled functor. For example, (1) a functor that does not change the signal transmission path can be expressed as {A=A}-{B=B}-...-{K=K}-{f=f}-{g=g}...{p=p}. (2) a functor that swaps links can be expressed as {A=A}-{B=B}-...-{K=K}-{f=q-A-l}-[g=g]-...-{p=p}. This expresses that link f is changed from link q to node A to link l. (3) The functor that swaps nodes can be expressed as {A = A} - [B = B - q - A] - ... - {K = K} - {f = l} - [g = g] - ... - {p = p}. Node B is changed to node B → link q → node A, and node f is changed to node l.

[0053] The correspondence between nodes and links before and after a route change can be expressed as {label before conversion = label after conversion}. The left label, associated with the "=" in the curly brackets, represents the node or link before the change, and the right label represents the node or link after the change.

[0054] (Guaranteeing network identity using category theory) If a functor can be created that does not change the connection relationships of multiple signal paths 2a, the control unit 20 can safely change the connection relationships of signal paths 2a by using the functor to map the category before the route change to the category after the route change.

[0055] For two different signal transmission path networks N1 and N2, a faithfully filled functor F that transforms N1 into N2 does not essentially damage the network structure if the functor F has a right adjoint functor and the adjoint units are naturally isomorphic. In other words, if a faithfully filled functor has a right adjoint functor such that the adjoint units are naturally isomorphic, even if the signal transmission path network is changed using the functor, the signal transmission path is equivalent and the operation of the industrial equipment system 2 does not change. The adjoint units being naturally isomorphic means that if an arbitrary object O1 or morphism A1 is moved by a functor (left adjoint functor) and the object O2 or morphism A2 moved by the functor is moved to an object O1' or A1' by a right adjoint functor, the object O1 or morphism A1 and the object O1' or A1' are naturally isomorphic. Faithfully filled means that the mapping by the functor is bijective.

[0056] Figure 7 is a conceptual diagram illustrating a method for verifying a functor for changing signal transmission paths. In the signal transmission path network of an industrial equipment system 2, setpoint signals "α" and "β" are input to signal processing circuits 26 "1" and 26 "2," and the processed control signals are securely transmitted to controllers 28 "I" and 28 "II." The square and circle nodes represent objects, and the arrows represent arrows. Since signal path 2a is physically susceptible to eavesdropping, we want to prevent an eavesdropper from obtaining enough information to perform reverse engineering. Therefore, the control unit 20 dynamically changes the signal transmission path. The upper diagram in Figure 7 shows the network before the path change, and the lower diagram in Figure 7 shows the network after the path change. As shown in Figure 7, the signal transmission path is changed using a functor. In the example shown in Figure 7, the signal flowing through signal path 2a "i" has stopped flowing due to the change in the signal transmission path, and the signal now flows through signal path 2a "k." Dynamically changing the signal transmission path network makes it possible to conceal the connection relationship of signal path 2a.

[0057] Next, we explain how to check whether changes to signal transmission lines will cause problems. By checking whether the functor that shifts the category of the signal transmission line network is a faithfully filled functor with a right adjoint functor, we can check whether the networks are equivalent.

[0058] The morphisms of category C, which is the network before the change, are as follows. To simplify the explanation, we will explain the morphisms with the set value signal as the starting point and the controller 28 as the end point. α → i → 1 → p → I β → i → 1 → p → I β → j → 2 → 1 → II

[0059] The morphisms of the category C', which is the network before the change, are as follows: α→j→1→p→I β→j→1→p→I β→k→2→1→II

[0060] The functor F that maps category C to category C' is as follows. Note that we will omit those that do not change objects or arrows. The functor for object A is F Ａ and the functor for morphism A → B is F Ａ→Ｂ The object or arrow acting on the functor is denoted by a subscript, e.g.

[0061] The functor E that maps category C' to category C is as follows:

[0062] The above-mentioned functor F is a faithfully full functor because it transfers objects and arrows one-to-one. Furthermore, the objects and arrows transferred by functor EF are naturally isomorphic to the objects and arrows in the original category, so there exists a right adjoint E for functor F. Therefore, it can be seen that the network of signal transmission lines transferred by functor F is equivalent to the signal transmission lines before the route change.

[0063] 9 is a flowchart showing the procedure for verifying and distributing the change information required for anonymization. The processing unit 10 of the information processing device 1 displays the device configuration encryption dashboard 3 on the display unit 12 (step S111).

[0064] The device configuration encryption dashboard 3 includes a masking target device display section 31, an encryption details display section 32, an encryption operation section 33, and an encryption status list 34.

[0065] The anonymization target device display unit 31 displays information such as the name and model number of the industrial equipment system 2 that is the anonymization target. The encryption details display unit 32 displays details of the anonymization process performed on the industrial equipment system 2 that is the anonymization target, such as an ID that identifies the change content information and the date of the most recent anonymization process. The encryption operation unit 33 displays an ID that identifies the change content information and the creation and distribution status of the change content information. The creation and distribution of change content information is broadly carried out in the following steps: "creation," "verification," "review," and "distribution." The encryption operation unit 33 has a "Create encryption rule" button 33a, a "Automatic encryption rule verification" button 33b, a "Request encryption rule review" button 33c, and a "Distribution" button 33d, which correspond to these steps. The "Create encryption rule" button 33a is a button for starting the creation of change content information. The "Automatic encryption rule verification" button 33b is a button for verifying whether the created change content information is problem-free based on knowledge of category theory. The "Request encryption rule review" button 33c is a button for requesting a final review of the change content information after creation and verification from a reviewer. The "Distribute" button 33d is a button for distributing the change content information that has been verified and reviewed to the industrial equipment system 2 that is to be kept confidential.

[0066] Next, the processing unit 10 creates a functor related to change information for changing the communication transmission path, etc., and labels it (step S112). For example, when the "Create Encryption Rule" button 33a is operated, the processing unit 10 creates change information for changing the signal transmission path. The timing of creating the change information in the information processing device 1 is not particularly limited, and the change information may be created periodically, or creation of the change information may be triggered by receiving a notification of an abnormality in the industrial equipment system 2. Examples of abnormalities in the industrial equipment system 2 include interception of a signal flowing through the signal path 2a or abnormal equipment operation. The industrial equipment system 2 can detect signal interception by monitoring, for example, the modulation pattern of the signal flowing through the signal line, the signal characteristics, and the characteristics of the electromagnetic waves emitted from the signal line. Furthermore, the industrial equipment system 2 can detect abnormal equipment operation by monitoring operation of the operation panel 22 at an unusual frequency or operation using an abnormal procedure. When an abnormality is detected, the industrial equipment system 2 transmits data notifying the abnormality to the information processing device 1, indicating that reverse engineering may be attempted. The information processing device 1 can recognize an abnormality in the industrial equipment system 2 based on the data transmitted from the industrial equipment system 2 .

[0067] The processing unit 10 creates data as a functor that associates symbols representing each object and arrow (node ​​and link) that make up the network of the signal transmission path before the change with symbols representing each object and arrow (node ​​and link) that make up the network of the signal transmission path after the change.

[0068] For example, the processing unit 10 creates a functor of changes such as swapping two randomly selected signal transmission paths, creating a detour path, or branching or parallelizing a signal path and creating one of the paths as an input path to a dummy signal processing circuit 26. The detour path is, for example, a path in which a certain set value signal is input as a dummy to the dummy signal processing circuit 26, the signal processing circuit 26 outputs the set value signal as is to the path change circuits 24, 25, and the set value signal returned from the dummy signal processing circuit 26 is input to the signal processing circuit 26 to which it should originally be input.

[0069] The processing unit 10 may also make a change to add nodes and links to which dummy signals are input. The processing unit 10 may also make a change to add dummy signal processing that executes meaningless dummy signal processing. The processing unit 10 may also make a change to add a functional unit that encrypts and decrypts signals along the signal transmission path. For example, a circuit that performs encryption or decryption may be configured inside the path change circuits 24 and 25, or the signal processing content may be changed so that encryption or decryption is performed in the signal processing circuit 26.

[0070] The processing unit 10 may convert the information relating to the category and functor of the labeled signal transmission line network into a representation of a processing system suitable for processing category theory, for example, a representation that can be run in Haskell.

[0071] The processing unit 10 may be configured to use a machine learning model to create a functor that changes the network of the signal transmission line. For example, training data including a plurality of data sets that associate data representing the network of the signal transmission line before the change with a functor that represents a functor that maps the network to the network of the signal transmission line after the change, with the equivalence guaranteed. Then, a machine learning model such as a large-scale language model or a deep neural network model is trained so that when data representing the network of the signal transmission line before the change is input, a functor that transfers the network to an equivalent network is output.

[0072] The processing unit 10 can input data representing the network of the signal transmission path before the change into the trained machine learning model and output a functor. Note that the machine learning model may be trained so that when data representing the network before the change is input, data representing the network after the change is output. In this case, the processing unit 10 creates a functor that associates the objects and morphisms that make up each network, in other words, the nodes and links, based on the data representing the networks before and after the change, i.e., pre-change information.

[0073] Furthermore, the functor representing the method of changing the communication transmission path, etc. may be created manually.

[0074] The functor created in step S112 does not guarantee the equivalence of the network before and after the change, so the processes in steps S113 to S115 confirm that no problems will arise due to the change in the signal transmission path.

[0075] When the "Automatic Encryption Rule Verification" button 33b is operated, the processing unit 10 executes the processes of steps S113 to S117 related to the verification of the functor. The processing unit 10 determines whether the created functor is a faithfully filled functor (step S113). That is, the processing unit 10 determines whether the nodes and links representing the signal transmission paths before the change and the nodes and links representing the signal transmission paths changed by the functor have a bijective relationship. If it is determined that the created functor is not a faithfully filled functor (step S113: NO), the processing unit 10 returns the process to step S112 and creates the functor again.

[0076] If it is determined that the functor is faithfully full (step S113: YES), the processing unit 10 creates a right adjoint functor of the created functor (step S114), and determines whether or not a right adjoint functor has been created such that the adjoint units are naturally isomorphic (step S115).

[0077] If it is determined that the creation of the right adjoint functor has failed (step S115: NO), the processing unit 10 returns the process to step S112 and starts the creation of the functor again. If it is determined that the creation of the right adjoint functor has been successful (step S115: YES), the processing unit 10 creates name change information indicating how to change the names of the setting values, sensor values, and control values ​​to be displayed on the display panel 22a of the industrial equipment system 2 (step S116). The name change information is information that associates various setting values ​​with the names of each setting value. The processing unit 10 may create the name change information by randomly associating setting values ​​with names. The method of changing the correspondence between setting values ​​and names is not particularly limited.

[0078] Then, the processing unit 10 stores the information on the created functor and the change content information including the name change information in the storage unit 11 (step S117).

[0079] After completing the verification of the change content information including the functor, if the "Request encryption rule review" button 33c is operated, the processing unit 10 notifies the reviewer of a request to review the created and verified change content information. If the reviewer responds that the review is complete, the processing unit 10 stores data indicating that the review of the change content information is complete.

[0080] Next, the processing unit 10 determines whether to distribute the change information (step S118). Specifically, the processing unit 10 determines whether the anonymization officer has operated the "Distribute" button 33d on the anonymization dashboard screen. If it is determined that the distribution operation has not been performed (step S118: NO), the processing unit 10 terminates the processing without performing distribution. The anonymization officer can distribute the change information stored in the memory unit 11 to the industrial equipment system 2 by operating the distribution button on the anonymization dashboard screen at any time. If it is determined that the distribution operation has been performed (step S118: YES), the processing unit 10 encrypts the change information and distributes the encrypted change information to the industrial equipment system 2 (step S119), and terminates the processing. Note that the processing of steps S113 to S115 can be modified as follows. For example, after completing the processing of step S112, the processing unit 10 may be configured to determine whether the created functor is invertible. That is, the processing unit 10 determines whether an inverse functor exists or whether an inverse functor can be created. If it is determined that the functor is not invertible, the processing unit 10 returns the process to step S112. If it is determined that the functor is invertible, the processing unit 10 executes the processes from step S116 onwards.

[0081] 10 is a flowchart showing a process for changing a signal transmission path and a software function. The control unit 20 of the industrial equipment system 2 receives the change content information distributed from the information processing device 1 (step S131), decodes the received change content information, and stores it in the storage unit 21 (step S132).

[0082] Next, the control unit 20 detects an abnormality or determines whether a predetermined change period has arrived (step S133). An abnormality may be a state in which a signal flowing through the signal path 2a is intercepted or an abnormal device operation is performed. Basically, the control unit 20 changes the signal transmission path when it receives change content information. However, when an unexpected abnormality is detected or if the signal transmission path has not been changed for a long period of time, it is desirable for the industrial equipment system 2 to start processing related to changing the signal transmission path. Step S133 is a process for this purpose, but is not a required process.

[0083] If it is determined that no abnormality exists and the predetermined change period has not arrived (step S133: NO), the control unit 20 ends the process. If an abnormality is detected or the predetermined change period has arrived (step S133: YES), the control unit 20 determines whether or not to change the signal transmission path (step S134). For example, the control unit 20 displays on the display of the operation panel 22 that the signal transmission path will be changed and accepts a change start operation by the user via the operation panel 22. If the change process for the signal transmission path, etc., is started at an inappropriate time, such as while the industrial equipment system 2 is operating, problems may occur. Therefore, it is desirable to start the change of the signal transmission path only after the user has made a final confirmation. Step S134 is a process for ensuring that the signal transmission path change is executed at the appropriate time.

[0084] If a change start operation is performed, the control unit 20 determines that it is OK to start changing the signal transmission path. If a change start operation for the signal transmission path is not performed (step S134: NO), the control unit 20 ends the process. If a change start operation for the signal transmission path is performed (step S134: YES), the control unit 20 changes the signal transmission path of the input signal based on the information of the functor included in the change content information (step S135). That is, the control unit 20 changes the signal transmission path of the path changing circuit 24.

[0085] Next, the control unit 20 changes the processing content to be executed by the signal processing circuits 26 as necessary based on the information on the functor included in the change content information (step S136). In other words, if the change content information describes a change in the signal processing content, the control unit 20 changes the processing content to be executed by each signal processing circuit 26. The change in the processing content also includes a change in the terminals to which signals used for processing are input.

[0086] Next, the control unit 20 changes the signal transmission path of the output signal based on the information of the functor included in the change content information (step S137).

[0087] Next, the processing unit 10 changes the name of the setting value, sensor value, or control value displayed on the operation panel 22 based on the name change information included in the change content information (step S138), and ends the process.

[0088] As described above, the concealment method, industrial machine system 2, and computer programs P1 and P2 according to this embodiment can conceal the mechanism for cooperation between hardware and software of an industrial machine system.

[0089] By dynamically changing the connection relationship of the signal paths 2a connecting the control unit 20, the plurality of signal processing circuits 26, the plurality of sensors 27, and the plurality of controllers 28, it is possible to conceal the functional cooperation within the industrial equipment system 2. For example, the signal paths can be changed by adding or deleting a detour to the signal transmission path, adding or deleting a signal path 2a through which a dummy signal is transmitted, parallelizing or merging the signal paths, or the like.

[0090] The control unit 20 can conceal the functional cooperation within the industrial equipment system 2 by changing the function of the signal processing circuit 26 .

[0091] The control unit 20 can conceal the functional cooperation within the industrial equipment system 2 by mixing in a dummy signal.

[0092] By providing the dummy signal processing circuit 26, the control unit 20 can conceal the functional cooperation within the industrial equipment system 2.

[0093] The control unit 20 can conceal the functional cooperation within the industrial equipment system 2 by changing the names of the signals displayed on the display panel 22 a of the industrial equipment system 2 .

[0094] By distributing change information to each industrial equipment system 2 from the information processing device 1 of the person who manages the manufacturing of multiple industrial equipment systems 2 and changing the connection relationship of the signal transmission paths in each industrial equipment system 2, the functional collaboration within the industrial equipment system 2 can be kept confidential.

[0095] The control unit 20 can change the signal transmission path so as not to cause abnormalities in the operation of the industrial equipment system 2 by verifying whether the signal transmission path network before and after the change is in an equivalence relationship in category theory.

[0096] The information processing device 1 and the industrial equipment system 2 can more reliably conceal the functional collaboration within the industrial equipment system 2 by changing the signal transmission path periodically or when an abnormality is detected.

[0097] In the present embodiment, the industrial equipment system 2 is described as a single device as shown in FIG. 1 . However, the industrial equipment system 2 may also be a system connecting multiple devices. That is, the technology according to the present embodiment can also be applied to concealing the connection relationship of the signal paths 2a connecting multiple devices. For example, in an industrial equipment system 2 in which multiple substrate processing apparatuses of the same type are connected via the signal paths 2a and each substrate processing apparatus performs optimization operations by transmitting and receiving signals, know-how related to the cooperation between the substrate processing apparatuses can be concealed by changing the connection relationship of the signal transmission paths connecting the substrate processing apparatuses. Furthermore, in an industrial equipment system 2 in which multiple heterogeneous devices are connected via the signal paths 2a and each apparatus performs optimization operations by transmitting and receiving signals, know-how related to the cooperation between the devices can be concealed by changing the connection relationship of the signal transmission paths connecting the devices.

[0098] The information processing device 1 may be configured to store a plurality of pieces of change information in the storage unit 11 in advance, and to transmit the change information stored in the storage unit 11 to the industrial equipment system 2 when an abnormality is detected in the industrial equipment system 2. The industrial equipment system 2 may be configured to store a plurality of pieces of change information in the storage unit 21 in advance, and to change the connection relationship of the signal transmission path based on the change information stored in the storage unit 11 when an abnormality is detected in the industrial equipment system 2. When an abnormality that could lead to the risk of reverse engineering is detected, such as interception of the signal path 2a or abnormal operation of the operation panel 22, the network of the signal transmission path can be changed to conceal the cooperation between the hardware and software of the industrial equipment system 2.

[0099] The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The technical features described in each embodiment can be combined with each other, and the scope of the present disclosure is intended to include all modifications within the scope of the claims and equivalents thereto. The sequence shown in each embodiment is not limited, and within the scope of no contradiction, each processing step may be executed in a different order, or multiple processes may be executed in parallel. The entity that performs each process is not limited, and within the scope of no contradiction, the process of each device may be executed by another device.

[0100] The matters described in each embodiment can be combined with each other. Furthermore, the independent claims and dependent claims described in the claims can be combined with each other in any and all combinations, regardless of the reference format. Furthermore, the claims use a format in which a claim references two or more other claims (multiple claim format), but this is not limited to this. A multiple claim (multi-multi claim) that references at least one other multiple claim may also be used.

[0101] Means for solving the problems of the present disclosure are appended below. (Supplementary Note 1) A concealment method for an industrial equipment system including a plurality of signal processing units and a plurality of signal paths for transmitting signals input to the plurality of signal processing units and signals output by the plurality of signal processing units, the concealment method comprising a changing step of changing a connection relationship of the plurality of signal paths to the plurality of signal processing units within a range where operation of the industrial equipment system does not change. (Supplementary Note 2) The concealment method according to Supplementary Note 1, in which functions of the plurality of signal processing units are changed. (Supplementary Note 3) The concealment method according to Supplementary Note 1 or Supplementary Note 2, in which the signals include sensor value signals output from sensors provided in the industrial equipment system and a plurality of setting value signals set in the industrial equipment system. (Supplementary Note 4) The concealment method according to any one of Supplementary Notes 1 to 3, in which the signals include dummy signals. (Supplementary Note 5) The concealment method according to any one of Supplementary Notes 1 to 4, in which the plurality of signal processing units include a dummy signal processing unit that performs dummy signal processing. (Supplementary Note 6) The concealment method according to any one of Supplementary Notes 1 to 5, comprising a step of changing names of signals displayed on a display panel of the industrial equipment system. (Supplementary Note 7) The concealment method according to any one of Supplementary Notes 1 to 6, wherein the changing step regards a connection relationship between the plurality of signal processing units and the plurality of signal paths as a category in category theory, and changes the connection relationship by mapping the connection relationship between the plurality of signal paths to a category different from the category using a functor that does not change the connection relationship. (Supplementary Note 8) The concealment method according to Supplementary Note 7, comprising a step of determining whether a functor is a faithfully full functor for which a right adjoint functor exists such that a unit of the adjoint is naturally isomorphic, thereby determining whether the functor does not change the operation of the industrial equipment system.(Supplementary Note 9) The concealment method according to any one of Supplementary Notes 1 to 8, wherein the changing step considers the connection relationship of the plurality of signal processing units and the plurality of signal paths as a network including a plurality of nodes and links connecting the nodes, and changes the connection relationship by adding or deleting nodes and links that configure detour paths, adding or deleting nodes and links that transmit dummy signals, adding or deleting nodes and links that parallelize signal paths, dividing one node into a plurality of nodes connected in series, merging a plurality of nodes connected in series into one node, and adding or deleting an encryption node that encrypts a signal and a decryption node that decrypts the encrypted signal. (Supplementary Note 10) The concealment method according to any one of Supplementary Notes 1 to 9, wherein the changing step considers the connection relationship of the plurality of signal processing units and the plurality of signal paths as a network including a plurality of nodes and links connecting the nodes, creates change content information that associates symbols representing each node and link before the change with symbols representing each node and link after the change, and changes the connection relationship based on the change content information. (Supplementary Note 11) The concealment method according to Supplementary Note 10, comprising: a step in which an information processing device external to the industrial equipment system creates the change content information and distributes it to the industrial equipment system; and a step in which the industrial equipment system receives the change content information distributed from the information processing device, wherein the changing step changes the connection relationship based on the received change content information. (Supplementary Note 12) The concealment method according to any one of Supplementary Notes 1 to 11, wherein the changing step changes the connection relationship of the plurality of signal paths to the plurality of signal processing units when it is detected that a signal transmitted through the signal path is being read from outside, when an abnormal operation on the industrial equipment system is detected, or when a predetermined change period has arrived. (Supplementary Note 13) An industrial equipment system comprising: a plurality of signal processing units; a plurality of signal paths for transmitting signals input to the plurality of signal processing units and signals output by the plurality of signal processing units; a path changing circuit that changes paths of the plurality of signal paths; and a control unit that causes the path changing circuit to change the connection relationship of the plurality of signal paths to the plurality of signal processing units within a range that does not change an operation related to signal processing.(Supplementary Note 14) A computer program that causes a computer to execute processing related to the concealment of an industrial equipment system that includes a plurality of signal processing units and a plurality of signal paths that transmit signals input to the plurality of signal processing units and signals output by the plurality of signal processing units, the computer program causing the computer to execute processing to change the connection relationships of the plurality of signal paths to the plurality of signal processing units within a range that does not change the operation of the industrial equipment system.

[0102] 1: Information processing device 2: Industrial equipment system 2a: Signal path 20: Control unit 24, 25: Path change circuit 26: Signal processing circuit P1, P2: Computer program

Claims

1. A method for concealing an industrial equipment system including a plurality of signal processing units and a plurality of signal paths for transmitting signals input to the plurality of signal processing units and signals output by the plurality of signal processing units, the method comprising a change step for changing the connection relationships of the plurality of signal paths to the plurality of signal processing units within a range that does not change the operation of the industrial equipment system.

2. The concealment method according to claim 1, wherein functions of the plurality of signal processing units are changed.

3. The concealment method according to claim 1, wherein the signals include a signal of a sensor value output from a sensor provided in the industrial equipment system and a signal of a plurality of setting values ​​set in the industrial equipment system.

4. The encryption method according to claim 1, wherein the signal includes a dummy signal.

5. The concealment method according to claim 1, wherein the plurality of signal processing units includes a dummy signal processing unit that performs dummy signal processing.

6. The concealment method according to claim 1, further comprising a step of changing the name of a signal displayed on a display panel of the industrial equipment system.

7. The concealment method according to claim 1, wherein the modifying step regards the connection relationships between the plurality of signal processing units and the plurality of signal paths as a category in category theory, and modifies the connection relationships by mapping the connection relationships to a category different from the category using a functor that does not change the connection relationships between the plurality of signal paths.

8. The concealment method according to claim 7, further comprising a step of determining whether the functor is a faithfully full functor for which there exists a right adjoint functor such that the units of the adjoint are naturally isomorphic, thereby determining whether the functor does not change the operation of the industrial equipment system.

9. The concealment method according to claim 1, wherein the modifying step modifies the connection relationships by regarding the connection relationships between the plurality of signal processing units and the plurality of signal paths as a network including a plurality of nodes and links connecting the nodes, and adding or deleting nodes and links that constitute detour routes, adding or deleting nodes and links that transmit dummy signals, adding or deleting nodes and links that parallelize signal paths, dividing one node into a plurality of nodes connected in series, merging a plurality of nodes connected in series into one node, and adding or deleting an encryption node that encrypts a signal and a decryption node that decrypts the encrypted signal.

10. The concealment method according to claim 1, wherein the change step considers the connection relationships between the plurality of signal processing units and the plurality of signal paths as a network including a plurality of nodes and links connecting the nodes, creates change content information that associates symbols representing each node and link before the change with symbols representing the nodes and links after the change, and changes the connection relationships based on the change content information.

11. A concealment method as described in claim 10, comprising: a step in which an information processing device external to the industrial equipment system creates the change content information and distributes it to the industrial equipment system; and a step in which the industrial equipment system receives the change content information distributed from the information processing device, wherein the change step changes the connection relationship based on the received change content information.

12. The concealment method according to claim 1, wherein the change step changes the connection relationship of the plurality of signal paths to the plurality of signal processing units when it is detected that a signal transmitted through the signal path is being read from outside, when an abnormal operation on the industrial equipment system is detected, or when a predetermined change period has arrived.

13. An industrial equipment system comprising: a plurality of signal processing units; a plurality of signal paths for transmitting signals input to the plurality of signal processing units and signals output by the plurality of signal processing units; a path change circuit for changing the paths of the plurality of signal paths; and a control unit for causing the path change circuit to change the connection relationship of the plurality of signal paths to the plurality of signal processing units within a range that does not change operation related to signal processing.

14. A computer program that causes a computer to execute processing related to the concealment of an industrial equipment system that includes a plurality of signal processing units and a plurality of signal paths that transmit signals input to the plurality of signal processing units and signals output by the plurality of signal processing units, the computer program causing the computer to execute processing to change the connection relationships of the plurality of signal paths to the plurality of signal processing units within a range that does not change the operation of the industrial equipment system.

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