Control device and control method

Abstract

To provide a control device and a control method capable of performing inter-device authentication processing more reliably to improve security.SOLUTION: A control device comprises a controller that controls authentication processing of performing processing related to device authentication with at least one communication device on the basis of information included in a signal received by performing wireless communication with the communication device. The controller performs control to change authentication information used for the authentication processing for each processing group in which the authentication processing is to be repeated a plurality of times.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a control device and a control method. [Background technology]

[0002] In recent years, technology has been developed for authenticating devices based on the results of transmitting and receiving signals between devices. For example, in the following Patent Document 1, a first communication unit is used by an in-vehicle device to transmit and receive signals between the in-vehicle device and a portable device to authenticate the portable device. The portable device is a remote controller for locking and unlocking the vehicle, and is also called a smart key. The portable device is carried by the driver. Furthermore, the following Patent Document 1 discloses a smart key system in which, in addition to authentication by the first communication unit, a second communication unit is used by the in-vehicle device to measure the distance to the portable device to determine whether or not to permit vehicle operation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-31871 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in order to perform more reliable authentication, it is desirable to perform authentication processing multiple times, but at the same time, ensuring security is also important.

[0005] Therefore, the present invention has been made in consideration of the above problems, and an object of the present invention is to provide a new and improved control device and control method that can more reliably perform authentication processing between devices and improve security. [Means for solving the problem]

[0006] In order to solve the above problem, according to one aspect of the present invention, a control device is provided that includes a control unit that controls an authentication process that performs processing related to authentication of at least one communication device based on information contained in a signal received through wireless communication with the communication device, and the control unit controls changing authentication information, which is information used in the authentication process, for each processing group in which the authentication process is repeated multiple times.

[0007] In addition, in order to solve the above problem, according to another aspect of the present invention, a control method is provided, which includes a processor controlling an authentication process that performs processing related to authentication of at least one communication device with the communication device based on information contained in a signal received through wireless communication with the communication device, and changing authentication information, which is information used in the authentication process, for each processing group in which the authentication process is repeated multiple times. Effect of the Invention

[0008] As described above, according to the present invention, it is possible to perform authentication processing between devices more reliably and improve security. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of a configuration of a system according to an embodiment of the present invention. [Diagram 2] FIG. 11 is a sequence diagram showing an example of a basic flow of authentication processing according to the present embodiment. [Diagram 3] 11A and 11B are diagrams illustrating a case where a deviation occurs in signal recognition during a distance measurement process that is repeated multiple times, resulting in authentication failure. [Figure 4] FIG. 11 is a sequence diagram showing an example of the flow of a distance-based authentication process according to the embodiment. [Diagram 5] 11 is a sequence diagram showing an example of a process flow for changing authentication information when starting a processing group L according to this embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals, and duplicated explanations will be omitted.

[0011] <1. Configuration example> Fig. 1 is a diagram showing an example of the configuration of a system 1 according to an embodiment of the present invention. As shown in Fig. 1, the system 1 according to the present embodiment includes a portable device 100 and a control device 200. The control device 200 in the present embodiment is mounted on a vehicle 20, as an example. The vehicle 20 is an example of a moving object that is one of the objects of use by a user.

[0012] The present invention involves a communication device that is an authenticated side, and a control device having a control unit that performs authentication processing to authenticate the other communication device using information obtained by communication with the communication device. In the example shown in FIG. 1, the portable device 100 is an example of a communication device, and the control device 200 is an example of a control device. In the system 1, when a user such as a driver of a vehicle 20 approaches the vehicle while carrying the portable device 100, wireless communication for authentication is performed between the portable device 100 and the control device 200 mounted on the vehicle 20. Then, if the authentication is successful, the door lock of the vehicle 20 is unlocked and the engine is started, and the vehicle 20 becomes available for use by the user. The system 1 is also called a smart entry system. Each component will be described in order below.

[0013] (1-1) Portable device 100 The portable device 100 is configured as an arbitrary device. Examples of the arbitrary device include devices such as an electronic key, a smartphone, and a wearable terminal that are carried by a user such as a driver. As shown in FIG. 1, the portable device 100 includes a first wireless communication unit 110, a second wireless communication unit 120, a storage unit 130, and a control unit 140.

[0014] The first wireless communication unit 110 has a function of performing communication with the control device 200 in accordance with a first wireless communication standard. The second wireless communication unit 120 has a function of performing communication with the control device 200 in accordance with a second wireless communication standard different from the first wireless communication standard. In particular, the second wireless communication standard is more suitable for ranging than the first wireless communication standard, and the second wireless communication unit 120 is mainly responsible for communication related to ranging.

[0015] Here, the first wireless communication standard may satisfy at least one of the following requirements: a higher gain and a lower power consumption on the receiving side compared to the second wireless communication standard. As a specific example of satisfying these requirements, the second wireless communication standard may use a carrier wave with a higher frequency than that of the carrier wave in the first wireless communication standard. The higher the frequency of the carrier wave, the greater the attenuation according to distance, and therefore the lower the gain, and the lower the frequency of the carrier wave, the smaller the attenuation according to distance, and therefore the higher the gain, thereby satisfying the above requirement regarding gain. Also, if the frequency of the carrier wave is high, the human body influence, such as absorption by the human body, increases, and the gain decreases.

[0016] In addition, considering that the sampling frequency is set according to the maximum frequency of the carrier wave, it is sufficient that the maximum frequency of the carrier wave in the second wireless communication standard is higher than the maximum frequency of the carrier wave in the first wireless communication standard.

[0017] For example, in the first wireless communication standard, a radio frequency (RF) band signal and a low frequency (LF) band signal may be used. In a typical smart entry system, an RF band signal is used for transmission from the portable device 100 to the control device 200 of the vehicle 20, and an LF band signal is used for transmission from the control device 200 of the vehicle 20 to the portable device 100. In the following, the first wireless communication unit 110 will be described as being configured as a communication interface capable of communication with an RF band signal and an LF band signal. That is, in the following, an RF band signal is used for transmission to the control device 200 of the vehicle 20, and an LF band signal is used for reception from the control device 200 of the vehicle 20.

[0018] For example, in the second wireless communication standard, signals using UWB (Ultra-Wide Band) may be used. Impulse signals using UWB have the characteristic of being able to perform positioning and ranging with high accuracy. In other words, by using radio waves with a very short pulse width of less than nanoseconds, the air propagation time of radio waves can be measured with high accuracy, and positioning and ranging based on the propagation time can be performed with high accuracy. In the following, it is assumed that the second wireless communication unit 120 is configured as a communication interface capable of communication with signals using UWB.

[0019] Signals using UWB can be transmitted and received as ranging signals and data signals. The ranging signals are signals transmitted and received in ranging processing, which will be described later. The ranging signals may be configured in a frame format that does not have a payload portion for storing data, or may be configured in a frame format that has a payload portion. The data signals are signals for carrying data. It is desirable that the data signals be configured in a frame format that has a payload portion for storing data. In the following, it is assumed that the ranging signals are configured in a frame format that does not have a payload portion for storing data. It is also assumed that the data signals are configured in a frame format that has a payload portion for storing data.

[0020] The storage unit 130 has a function of storing various information for the operation of the portable device 100. For example, the storage unit 130 stores a program for the operation of the portable device 100, as well as an ID (an example of identification information) for authentication, a password, an authentication algorithm, and the like. The storage unit 130 is composed of, for example, a storage medium such as a flash memory, and a processing device that executes recording and reproduction to and from the storage medium.

[0021] The control unit 140 has a function of controlling the overall operation of the portable device 100. As an example, the control unit 140 controls the first wireless communication unit 110 and the second wireless communication unit 120 to communicate with the vehicle control device 200. The control unit 140 also reads information from the storage unit 130 and writes information to the storage unit 130. The control unit 140 also functions as an authentication control unit that controls authentication processing performed with the vehicle control device 200. The control unit 140 is configured with electronic circuits such as a CPU (Central Processing Unit) and a microprocessor.

[0022] (1-2) Control device 200 The control device 200 is provided in association with the vehicle. Here, the control device 200 is assumed to be mounted on the vehicle 20. Examples of the mounting location include the control device 200 being installed in the cabin of the vehicle 20, or being built into the vehicle 20 as a control module or a communication module. In addition, the control device 200 may be configured as a separate entity from the user's target of use, such as the control device 200 being provided in a parking lot of the vehicle 20. In that case, the control device 200 may wirelessly transmit a control signal to the vehicle 20 based on the communication result with the portable device 100, and remotely control the vehicle 20. As shown in FIG. 1, the control device 200 includes a first wireless communication unit 210, a second wireless communication unit 220, a storage unit 230, and a control unit 240.

[0023] The first wireless communication unit 210 has a function of performing communication in compliance with a first wireless communication standard with the portable device 100. In the following, the first wireless communication unit 210 is assumed to be configured as a communication interface capable of communication using RF band signals and LF band signals.

[0024] The second wireless communication unit 220 has a function of performing communication with the portable device 100 in accordance with a second wireless communication standard different from the first wireless communication standard. In the following, the second wireless communication unit 220 is configured as a communication interface capable of communication by a signal using UWB. A plurality of second wireless communication units 220 may be mounted on the vehicle 20.

[0025] The storage unit 230 has a function of storing various information for the operation of the control device 200. For example, the storage unit 230 stores a program for the operation of the control device 200, as well as an ID (an example of identification information) for authentication, a password, an authentication algorithm, and the like. The storage unit 230 is composed of, for example, a storage medium such as a flash memory, and a processing device that executes recording and reproduction to and from the storage medium.

[0026] The control unit 240 has a function of controlling the overall operation of the control device 200 and the in-vehicle devices mounted on the vehicle. As an example, the control unit 240 controls the first wireless communication unit 210 and the second wireless communication unit 220 to communicate with the portable device 100. The control unit 240 also reads information from the storage unit 230 and writes information to the storage unit 230. The control unit 240 also functions as an authentication control unit that controls authentication processing performed between the control unit 240 and the portable device 100. The control unit 240 also functions as a door lock control unit that controls the door lock of the vehicle and locks and unlocks the door lock. The control unit 240 also functions as an engine control unit that controls the engine of the vehicle and starts / stops the engine. The power source provided in the vehicle may be a motor or the like in addition to the engine. The control unit 240 is configured as, for example, an ECU (Electronic Control Unit).

[0027] The control device 200 shown in FIG. 1 is an example of the control device according to the present invention. The configuration of the control device according to the present invention is not limited to the example shown in FIG. 1, and may be composed of, for example, a communication module including a first wireless communication unit 210, a communication module including a second wireless communication unit 220, and a control module including a control unit 240. The configuration of the control device according to the present invention may be realized as a communication module including the first wireless communication unit 210, a communication module including the second wireless communication unit 220, or a control module including the control unit 240. Each module is connected by a wired or wireless communication network. The communication network may be, for example, an in-vehicle communication network conforming to any standard such as CAN (Controller Area Network), LIN (Local Interconnect Network), or LAN (Local Area Network).

[0028] The configuration of each device shown in FIG. 1 is an example. For example, in the configuration shown in FIG. 1, the portable device 100 and the control device 200 each have a first wireless communication unit and a second wireless communication unit, but the present invention is not limited to this. For example, the portable device 100 and the control device 200 may each have a wireless communication unit that performs communication in accordance with one wireless communication standard. A plurality of wireless communication units may be provided in the vehicle 20. The wireless communication unit transmits and receives a signal used in the authentication process. In addition, the frequency band used when the wireless communication unit transmits a signal used in the authentication process is arbitrary. For example, the signal used in the authentication process may be transmitted as a signal using UWB, may be transmitted as a signal in the LF band, may be transmitted as a signal in the RF band, or may be transmitted as a signal of BLE (Bluetooth Low Energy (registered trademark)).

[0029] <2. Authentication process> In the smart entry system, authentication of the portable device 100 may be performed based on the distance between the portable device 100 and the control device 200 of the vehicle. The authentication process according to this embodiment includes a process of measuring the distance between the portable device 100 and the control device 200 (hereinafter, also referred to as a "distance measurement process" in this specification), and a process of performing authentication based on the measurement result of the distance. By performing authentication based on the distance, a repeater is used to relay a transmission signal from the control device (authentication device) of the vehicle, thereby indirectly realizing communication between the portable device (authenticated device) and the control device, thereby reducing spoofing of the authenticated device and spoofing of the distance, such as a relay attack that fraudulently establishes authentication of the portable device by the control device, and effectively improving authentication accuracy.

[0030] Fig. 2 is a sequence diagram showing an example of a basic flow of authentication processing according to this embodiment. As shown in Fig. 2, first, the portable device 100 transmits a distance measurement trigger signal (step S103). In this embodiment, as an example, prior to transmission of a first distance measurement signal from the control device 200, a signal (distance measurement trigger signal) instructing transmission of the first distance measurement signal is transmitted from the portable device 100. The distance measurement trigger signal is also an example of a distance measurement signal. For example, a signal using UWB is used as the distance measurement trigger signal. Specifically, the portable device 100 may transmit the distance measurement trigger signal by the second wireless communication unit 120.

[0031] Next, when the control device 200 receives the ranging trigger signal, it transmits a ranging request signal as a first ranging signal to request a response for ranging processing (step S106). For example, a signal using UWB is used as the ranging request signal. Specifically, the control device 200 may transmit the ranging request signal by the second wireless communication unit 220.

[0032] Next, when the portable device 100 receives a ranging request signal (first ranging signal) from the control device 200, the portable device 100 transmits a ranging response signal as a second ranging signal in response to the ranging request after a time ΔT2 has elapsed since the portable device 100 received the ranging request signal (step S109). For example, a signal using UWB is used for the ranging response signal. Specifically, the portable device 100 may transmit the ranging response signal by the second wireless communication unit 120. The time ΔT2 is a predetermined time. The time ΔT2 is set to be longer than the time assumed to be required for processing in the portable device 100 from receiving the first ranging signal to transmitting the second ranging signal. This makes it possible to reliably complete preparation for transmitting the second ranging signal before the time ΔT2 has elapsed since the portable device 100 received the first ranging signal. The time ΔT2 may also be known to the control device 200.

[0033] Next, when the control unit 240 of the control device 200 receives the distance measurement response signal (second signal for distance measurement), it calculates the distance between the portable device 100 and the control device 200 (step S112). In detail, the control device 200 measures the time ΔT1 from the transmission time of the first signal for distance measurement to the reception time of the second signal for distance measurement, and calculates the distance based on the measured ΔT1 and the known time ΔT2. The control device 200 calculates the time required for one-way signal transmission and reception by subtracting ΔT2 from ΔT1 and dividing the result by 2, and can calculate the distance between the portable device 100 and the control device 200 by multiplying the time by the speed of the signal. Note that the time ΔT2 does not have to be known to the control device 200. For example, the portable device 100 may measure the time ΔT2 and report it to the control device 200. Such a report can be made by transmitting a data signal including information in which information indicating the time ΔT2 is encrypted. The data signal is another example of a signal for distance measurement processing. A data signal is a signal that stores and carries data. The data signal is configured in a frame format having a payload portion that stores data. The data signal can be transmitted and received as a signal using UWB.

[0034] The calculation of the distance shown in step S112 may be performed by a control unit of the communication unit when the second wireless communication unit 220 is configured as a communication unit. In this case, the communication unit transmits the calculation result to the control unit 140 via an in-vehicle communication network. Furthermore, the vehicle 20 may be equipped with a plurality of second wireless communication units 220. The control unit 240 may calculate the distance between the portable device 100 and the control device 200 based on data transmitted and received between the portable device 100 and the plurality of second wireless communication units 220, respectively.

[0035] Then, the control unit 240 of the control device 200 authenticates the portable device 100 depending on whether the calculated distance satisfies a predetermined condition (step S115). For example, the control unit 240 determines that the authentication is successful if the calculated distance is equal to or less than a predetermined value, and determines that the authentication is unsuccessful if not. In addition, the control unit 240 may determine that the authentication is successful for performing a corresponding predetermined control if the calculated distance is within a predetermined range. For example, when the distance between the user carrying the portable device 100 and the vehicle 20 in which the control device 200 is mounted is within a predetermined range, the control unit 240 determines that the authentication is successful for performing a control to turn on a light provided in the vehicle 20, and performs a control to turn on the light. Then, when the user approaches the vehicle 20 further, the control unit 240 may determine that the authentication is successful for performing a control to unlock a door lock of the vehicle 20, and perform a control to unlock the door lock.

[0036] <3. Identifying issues> Here, the above-mentioned ranging trigger signal, ranging request signal, and ranging response signal include predetermined information for authentication. Such "predetermined information for authentication" is referred to as "authentication information" in this specification. The device receiving the signal determines whether the signal is transmitted from a partner paired with the device based on the authentication information included in the signal. The authentication information may be the ID of the device, or may be information in which some specified information is encrypted. The encryption may be performed, for example, by an encryption key shared in advance between the device transmitting the signal and the device receiving the signal. In the case of encrypted information, the device receiving the signal decrypts the encrypted information, and if the decryption is successful, it can be determined that the signal is transmitted from a partner paired with the device receiving the signal.

[0037] However, when the distance measurement process is repeated multiple times, if the authentication information used for the distance measurement trigger signal, distance measurement request signal, and distance measurement response signal transmitted and received in each distance measurement process is changed for each distance measurement process from the viewpoint of security, a single missed signal will cause a discrepancy in the recognition of the signals between the portable device 100 and the control device 200. In this case, even if the signal is successfully received, there is a risk that the distance measurement process cannot be performed. Hereinafter, a specific description will be given with reference to FIG. 3.

[0038] Fig. 3 is a diagram for explaining a case where a deviation occurs in signal recognition during a distance measurement process that is repeated multiple times, resulting in authentication failure. In Fig. 3, a deviation in signal recognition is explained using a control device 201 according to a comparative example. The control device 201 is a device having multiple second wireless communication units 221a, 221b, and is mounted on a vehicle 20. By calculating and combining the distances between the vehicle 20 and the multiple second wireless communication units 221a, 221b provided at different positions on the vehicle 20, the position of the portable device 100 relative to the vehicle 20 can be calculated more accurately.

[0039] As shown in Fig. 3, first, the portable device 100 transmits a first ranging trigger signal as a first ranging process r1 (step S203). The ranging trigger signal is, for example, a signal using UWB. The portable device 100 also transmits the ranging trigger signal including predetermined authentication information a used in the first ranging process r1. The predetermined authentication information a may be predetermined information used in the first ranging process r1 encrypted with a common encryption key.

[0040] Next, the second wireless communication unit 221a that has successfully received the ranging trigger signal transmits a ranging request signal (step S206). Specifically, the control device 201 decrypts the encrypted information included in the ranging trigger signal, and if the decrypted information matches pre-known specified information, it can be determined that the signal is transmitted from the other party paired with the control device 201, and a transmission process of the ranging request signal is executed. The ranging request signal is, for example, a signal using UWB. The control device 201 also transmits the ranging request signal including specified authentication information a used in the first ranging process r1. The specified authentication information a may be the specified information used in the first ranging process r1 encrypted with a common encryption key.

[0041] Next, the portable device 100 transmits a distance measurement response signal after a predetermined time (the above-mentioned ΔT2) has elapsed since receiving the distance measurement request signal (step S209). In this case as well, the portable device 100 decrypts the encrypted information included in the distance measurement request signal, and if the decrypted information matches the pre-known specified information, it can be determined that the signal is transmitted from the other party paired with the portable device 100, and a transmission process of the distance measurement response signal is executed. The distance measurement response signal is, for example, a signal using UWB. The portable device 100 also transmits the distance measurement response signal including the specified authentication information a used in the first distance measurement process r1. The specified authentication information a may be the specified information used in the first distance measurement process r1 encrypted with a common encryption key.

[0042] Then, the second wireless communication unit 221a, which has successfully received the ranging response signal, notifies the control unit 241 of the reception of the ranging response signal, and the control unit 241 calculates the distance between the second wireless communication unit 221a and the portable device 100 (first ranging) (step S212).

[0043] Next, a second distance measurement process r2 is performed. In this authentication process, the above-mentioned distance measurement process r can be repeated multiple times. The control device 201 repeats the distance measurement process r corresponding to steps S103 to S112 shown in FIG. 2 multiple times, obtains a representative value (distance) based on the results of each distance measurement process repeated multiple times, and performs final authentication corresponding to the above-mentioned step S115. This allows authentication based on a more reliable distance between the portable device 100 and the control device 201.

[0044] In the second distance measurement process r2, it may be possible to change the authentication information used for each signal in consideration of security. For example, the portable device 100 transmits a second distance measurement trigger signal as the second distance measurement process r2 (step S215). The portable device 100 transmits the specified authentication information b used in the second distance measurement process r2 by including it in the distance measurement trigger signal. The specified authentication information b may be the specified information used in the second distance measurement process r2 encrypted with a common encryption key.

[0045] Here, it is assumed that the second wireless communication unit 221b, which missed the ranging trigger signal transmitted in step S203, succeeds in receiving the second ranging trigger signal transmitted in step S215. In this case, the control unit 241 recognizes and determines that the ranging trigger signal is the ranging trigger signal in the first ranging process r1, and ranging fails (step S218). Specifically, the control unit 241 makes the determination based on the authentication information included in the ranging trigger signal. The control unit 241 decrypts the encrypted information, which is the authentication information included in the ranging trigger signal, and makes the determination based on whether the decrypted information matches pre-known specified information. However, since different specified information is to be used for each ranging process from the viewpoint of security consideration here, the control unit 241 recognizes that the ranging process is the first ranging process r1, and makes the determination based on the authentication information, even though it is actually the second ranging process r2. Therefore, the control unit 241 determines that the authentication information does not match, and the process of transmitting a ranging request signal from the second wireless communication unit 221b is not performed, which may result in a failure of ranging. This determination may be made by the second wireless communication unit 221b.

[0046] On the other hand, for the second wireless communication unit 221a, the second distance measurement process r2 is normally performed, like the first distance measurement process r1 (steps S221 to S227).

[0047] In this way, when the authentication process is repeated multiple times to calculate the distance more reliably, if the authentication information used for each authentication process is changed for security reasons, the distance cannot be measured due to a recognition error, and the reliability of the calculated distance decreases. In addition, it becomes difficult for the control unit 241 to grasp the relative position of the portable device 100 with respect to the vehicle 20 based on the respective distances between the multiple second wireless communication units 221 and the portable device 100. Grasping the relative position includes, for example, grasping whether the portable device 100 is located inside or outside the vehicle.

[0048] Therefore, in one embodiment of the present invention, the authentication information used for signals related to the authentication process between devices is changed for each processing group in which the authentication process is repeated multiple times, thereby realizing more reliable calculation of distance and improved security. For example, the authentication information used for each signal, such as a distance measurement trigger signal or a distance measurement request signal, is not changed when the authentication process is repeated multiple times, thereby realizing more reliable calculation of distance. Furthermore, when starting a new processing group in which the authentication process is repeated a specified number of times, the authentication information is changed, thereby also realizing improved security.

[0049] The second wireless communication unit 221b may be controlled to a reception waiting state in advance before receiving the ranging trigger signal transmitted from the portable device 100 in step S203. The reception waiting state refers to a state in which a process for capturing a received signal is executed. The second wireless communication unit 221b may be controlled to a reception waiting state assuming reception of a ranging trigger signal at any timing based on communication between the portable device 100 and the control device 201 that is performed prior to transmission of the ranging trigger signal from the portable device 100 using UWB. The communication that is performed prior to the transmission may be performed by the first wireless communication unit that is capable of communication with RF band signals and LF band signals.

[0050] The technical features of the embodiments of the present invention are described in detail below.

[0051] <4. Technical features> FIG. 4 is a sequence diagram showing an example of the flow of the authentication process based on the distance according to the present embodiment. In this specification, the "authentication process based on the distance" includes a distance measurement process for measuring the distance between the portable device 100 and the control device 200, and an authentication process for performing authentication based on the distance measured by the distance measurement process. The operation process shown in FIG. 4 explains the flow of the distance measurement process. The distance measurement process may be repeated multiple times, and the control device 200 acquires a representative value (distance) based on the results (distance) of each distance measurement process performed multiple times, and performs final authentication corresponding to the above step S115. This allows authentication based on a more reliable distance between the portable device 100 and the control device 200. In addition, the control device 200 has multiple second wireless communication units 220a, 220b. The control device 200 calculates the distances between the vehicle 20 and the multiple second wireless communication units 220a, 220b provided at different positions in the vehicle 20, respectively, and combines them to more accurately calculate the position of the portable device 100 relative to the vehicle 20 in each distance measurement process.

[0052] As shown in FIG. 4, first, the portable device 100 transmits a first ranging trigger signal as a first ranging process r1 (step S303). Before transmitting a ranging request signal from the control device 200, the portable device 100 transmits a ranging trigger signal notifying the start of ranging process, thereby reducing power consumption due to unnecessary waiting time, improving the success rate of ranging, and improving responsiveness. The ranging trigger signal is, for example, a signal using UWB. The portable device 100 transmits the ranging trigger signal including the specified authentication information a used in the first ranging process r1. The specified authentication information a may be the specified information A for the ranging trigger signal in the first ranging process r1 encrypted with a common encryption key. By using the encrypted information, security can be further improved. The original information to be encrypted, such as the specified information A, may be information shared with the portable device 100 in advance, or may be a random numerical value. The common key used for encryption may be different for each ranging signal, or may be the same. In this specification, the signal for distance measurement includes, for example, a trigger signal for distance measurement, a request signal for distance measurement, and a response signal for distance measurement. By including authentication information for each signal for distance measurement, it is possible to suppress erroneous recognition of the signal as true or false even if another second wireless communication unit 220 receives the signal or an attempt is made to spoof the distance using an illegal tool. Note that, in this embodiment, it is described that information obtained by encrypting prescribed information is used as authentication information, but this embodiment is not limited to this, and for example, unique identification information possessed by the portable device 100 or unique identification information possessed by the control device 200 may be used.

[0053] On the other hand, the second wireless communication units 220a and 220b of the control device 200 are controlled to a reception waiting state in advance, and wait for reception of a ranging trigger signal transmitted from the portable device 100. Here, the reception waiting state refers to a state in which various processes for capturing a received signal are executed. The various processes include, for example, receiving a signal by an antenna constituting the second wireless communication unit 220, sampling the received signal by the second wireless communication unit 220, and further performing processing based on the signal obtained by sampling by the control unit 240. The control unit 240 according to this embodiment transitions the second wireless communication unit 220 to a reception waiting state for a ranging trigger signal at an arbitrary timing, and waits for reception of the ranging trigger signal. Note that the arbitrary timing is, for example, a timing at which communication between the portable device 100 and the control device 200 is established prior to transmission of a ranging trigger signal using UWB from the portable device 100. When communication between the portable device 100 and the control device 200 is established, the control unit 240 controls one or more second wireless communication units 220 to a reception waiting state in anticipation of receiving a ranging trigger signal. The communication performed in advance may be performed by, for example, a first wireless communication unit capable of communication by RF band signals and LF band signals.

[0054] Next, the second wireless communication unit 220a that has successfully received the ranging trigger signal transmits a ranging request signal (step S306). Specifically, the control device 200 decrypts the encrypted information included in the ranging trigger signal, and if the decrypted information matches the pre-known specified information, it can be determined that the signal is transmitted from the other party paired with the control device 200, and a transmission process of the ranging request signal is executed. The ranging request signal is, for example, a signal using UWB. The control device 200 also transmits the ranging request signal including the specified authentication information b used in the first ranging process r1. The specified authentication information b may be the specified information B for the ranging request signal in the first ranging process r1 encrypted with a common encryption key.

[0055] Next, the portable device 100 transmits a ranging response signal after a predetermined time (the above-mentioned ΔT2) has elapsed since receiving the ranging request signal (step S309). In this case, the portable device 100 also decrypts the encrypted information included in the ranging request signal, and if the decrypted information matches the pre-known specified information, it can be determined that the signal is transmitted from the other party paired with the portable device 100, and a process of transmitting the ranging response signal is executed. The ranging response signal is, for example, a signal using UWB. The portable device 100 also transmits the ranging response signal including the specified authentication information c used in the first ranging process r1. The specified authentication information c may be the specified information C for the ranging response signal in the first ranging process r1 encrypted with a common encryption key.

[0056] In the present embodiment, as an example, different authentication information is used in the ranging trigger signal, ranging request signal, and ranging response signal, which are signals for ranging, to reduce spoofing and improve security. The different authentication information may be information A to C that is different from each other and encrypted with one common encryption key. Alternatively, the same specified information may be information that is different from each other and encrypted with one common encryption key. The present invention is not limited to this, and the same authentication information may be used in the ranging trigger signal, ranging request signal, and ranging response signal, which are signals for ranging. The same authentication information may be information that is the same specified information that is encrypted with one common encryption key. By using the same authentication information, the burden of preparing the specified information and the encryption process can be reduced.

[0057] Then, the second wireless communication unit 220a, which has successfully received the ranging response signal, notifies the control unit 240 of the reception of the ranging response signal, and the control unit 240 calculates the distance between the second wireless communication unit 220a and the portable device 100 (first ranging) (step S312).

[0058] Next, a second distance measurement process r2 is performed. For the distance measurement signal in the second distance measurement process r2, the same authentication information as that used for the distance measurement signal in the first distance measurement process r1 is used. This allows the second distance measurement process r2 to be performed even if a signal cannot be received in the first distance measurement process r1, increasing the probability of successful distance measurement and enabling more reliable distance measurement. In addition, by similarly using the same authentication information as the first time in the distance measurement processes repeated thereafter, such as the third distance measurement process and the fourth distance measurement process, the next distance measurement process can be performed even if a signal cannot be received in the second or third distance measurement process. A specific description will be given below.

[0059] As the second distance measurement process r2, the portable device 100 transmits a second distance measurement trigger signal (step S315). The portable device 100 transmits the distance measurement trigger signal including the same authentication information a as that used in the distance measurement trigger signal in the first distance measurement process r1.

[0060] Here, it is assumed that the second wireless communication unit 220b, which missed the ranging trigger signal transmitted in step S303, successfully receives the second ranging trigger signal transmitted in step S315. In this case, the control unit 240 recognizes the ranging trigger signal as the ranging trigger signal in the first ranging process r1, but since the received ranging trigger signal contains the same authentication information a as the first ranging trigger signal, it can be determined to be a legitimate ranging trigger signal, and communication for ranging is established (step S318). Note that this determination may be performed by the second wireless communication unit 220b.

[0061] Next, the control unit 240 transmits a ranging request signal from the second wireless communication unit 220b (step S324). Since the control unit 240 recognizes that this is the first ranging process r1, the ranging request signal includes authentication information b for the ranging trigger signal in the first ranging process r1.

[0062] On the other hand, for the second wireless communication unit 220a, the second distance measurement process r2 is normally performed like the first distance measurement process r1 (steps S321, S327, S330). That is, the calculation of the distance between the second wireless communication unit 220a and the portable device 100 (second distance measurement) is performed (step S330).

[0063] Next, the portable device 100 receives the distance measurement request signal transmitted from the second wireless communication unit 220b, recognizing it as the first distance measurement process r1, and transmits a distance measurement response signal after a predetermined time (above ΔT2) has elapsed since receiving the distance measurement request signal (step S333). The portable device 100 recognizes and determines that the received distance measurement request signal is a distance measurement request signal for the second distance measurement process r2, but since the distance measurement request signal contains the same authentication information b as the first time, it can be determined to be a legitimate distance measurement request signal. This allows the portable device 100 to transmit a distance measurement response signal.

[0064] Then, the second wireless communication unit 220b that has successfully received the ranging response signal notifies the control unit 240 of the reception of the ranging response signal, and the control unit 240 calculates the distance between the second wireless communication unit 220b and the portable device 100 (first ranging) (step S312). The control unit 240 recognizes and determines that the received ranging response signal is a ranging response signal in the first ranging process r1, but since the ranging response signal contains the same authentication information c as the first time, it can be determined that the ranging response signal is legitimate. Note that such determination may be performed by the second wireless communication unit 220b.

[0065] In this way, when the authentication process is repeated, the authentication information used for each distance measurement signal is the same for all times, thereby reducing the occurrence of a failure to measure distance due to a recognition error, and the distance can be calculated more reliably. Furthermore, the control unit 240 can more reliably obtain the distance between each of the second wireless communication units 220 and the portable device 100, and can more reliably grasp the relative position of the portable device 100 with respect to the vehicle 20. Grasping the relative position includes, for example, grasping whether the portable device 100 is located inside or outside the vehicle 20.

[0066] Furthermore, in this embodiment, the distance measurement process r described with reference to Fig. 4 is repeated a specified number of times as a process group L, and the authentication information is changed when the next process group L is performed, thereby achieving reliable distance calculation and improving security. The type of authentication information to be changed to may be specified in advance. Changing the authentication information when executing a new process group L according to this embodiment will be described with reference to Fig. 5.

[0067] FIG. 5 is a sequence diagram showing an example of the flow of a process for changing authentication information when starting the process group L according to this embodiment. As shown in FIG. 5, first, as the first process group L1, a plurality of distance measurement processes r1 to rN are executed between the portable device 100 and the control device 200. For example, as the distance measurement process r1, a distance measurement trigger signal, a distance measurement request signal, and a distance measurement response signal are transmitted and received (step S410). Also, as the distance measurement process rN, a distance measurement trigger signal, a distance measurement request signal, and a distance measurement response signal are transmitted and received (step S413). Details are as described above with reference to FIG. 4. The authentication information a to c used for each signal is the same each time. This allows the distance to be calculated more reliably. The control device 200 acquires a representative value in the first process group L1 based on each distance obtained by repeating the distance measurement process r a specified number of times. In addition, when the authentication process is repeated within one processing group, the authentication information used for the ranging trigger signal, the ranging request signal, and the ranging response signal may be different for each signal (authentication information a to c) as shown in FIG. 5, or may be the same. "May be different for each signal" means that authentication information used for each type of signal is different, such as authentication information a for the ranging trigger signal, authentication information b for the ranging request signal, and authentication information c for the ranging response signal. In this case, transmission and reception of each signal using different authentication information for each type of signal is repeated within one processing group. Also, "may be the same" means that the same authentication information (e.g. authentication information a) is used for all of the ranging trigger signal, the ranging request signal, and the ranging response signal. In this case, transmission and reception of each signal using the same authentication information is repeated within one processing group.

[0068] Next, the portable device 100 notifies the start of the next processing group L2 (step S416). The start notification may be a signal using UWB, or a signal using the RF band, LF band, Bluetooth, or the like.

[0069] Next, the portable device 100 changes the authentication information to be used in the next process group L2 (step S419). Also, the control device 200 that has received the start notification changes the authentication information to be used in the next process group L2 (step S421). The authentication information to be changed may be predefined. Also, the start notification may indicate which authentication information to use.

[0070] Then, as the second processing group L2, a plurality of distance measurement processes r1 to rN are executed between the portable device 100 and the control device 200. For example, as the distance measurement process r1, a distance measurement trigger signal, a distance measurement request signal, and a distance measurement response signal are transmitted and received (step S424). Also, as the distance measurement process rN, a distance measurement trigger signal, a distance measurement request signal, and a distance measurement response signal are transmitted and received (step S427). The authentication information d to f used for each signal is the same each time, but is different from that of the first processing group L1. This allows the distance to be calculated more reliably, and security to be improved. The control device 200 acquires a representative value in the second processing group L2 based on each distance obtained by repeating the distance measurement process r a specified number of times. The control device 200 acquires the distance between the portable device 100 and the control device 200 to be used for authentication finally based on the representative value acquired in each processing group L, and authenticates the portable device 100 based on whether it is within a predetermined range. This allows authentication to be performed based on a more accurate distance. Alternatively, the system 1 may execute a process group L2 that repeats the authentication process multiple times again when authentication based on a representative value acquired in a process group L1 that repeats the authentication process multiple times fails. Also, the number of times that the process group L is executed may be a predetermined number of times.

[0071] The above-described operation process shown in Fig. 4 and Fig. 5 is an example of the present embodiment, and the present invention is not limited thereto. For example, when the second wireless communication unit 220 is configured as a communication unit, at least one of the processes shown in the above steps S312, S318, S330, S336, and S421 may be controlled by a control unit (not shown) provided in the second wireless communication unit 220.

[0072] Furthermore, the arbitrary timing for transitioning the second wireless communication unit 220 to the reception waiting state before the above step 303 may be when the control device 200 receives a predetermined signal from the portable device 100 by the first wireless communication unit 210, while the control device 200 is authenticating the portable device 100 based on the received predetermined signal, or after the authentication is completed. That is, it is also assumed that a predetermined signal is transmitted and received between the portable device 100 and the control device 200 before the above step 303. The predetermined arbitrary signal may be transmitted and received between the portable device 100 and the control device 200 between the first wireless communication unit 110 of the portable device 100 and the first wireless communication unit 210 of the control device 200.

[0073] For example, request-response authentication is performed between the portable device 100 and the control device 200. In the request-response authentication, an authentication request signal and an authentication response signal generated based on the authentication request are transmitted and received. The request-response authentication is a method in which the authenticator generates an authentication request signal and transmits it to the person to be authenticated, the person to be authenticated generates an authentication response signal based on the authentication request signal and transmits it to the authenticator, and the authenticator authenticates the person to be authenticated based on the authentication response signal. Typically, the authentication request signal is a random number and changes every time authentication is performed, so the request-response authentication is resistant to replay attacks. In addition, the authentication response signal is generated based on the information of the person to be authenticated. The information of the person to be authenticated is, for example, an ID and a password. Since the ID and password themselves are not transmitted and received, eavesdropping is reduced. More specifically, for example, in response to a first authentication signal transmitted by the control device 200 as an authentication request, the portable device 100 transmits a second authentication signal calculated based on the first authentication signal and key information such as a password stored in advance as an authentication response. If it is determined that the second authentication signal transmitted as an authentication response indicates a legitimate value calculated from the first authentication signal, which is an authentication request, and the above-mentioned key information, the control device 200 may determine that the authentication of the portable device 100 has been successful.

[0074] A wake-up signal instructing startup and a response to the wake-up signal may be transmitted and received between the portable device 100 and the control device 200. The wake-up signal can wake up the receiving side from a sleep state. Responses to the wake-up signal include an acknowledgement (ACK) signal indicating startup and a negative acknowledgement (NACK) signal indicating no startup.

[0075] Alternatively, prior to waiting for reception of the distance measurement trigger signal, a wake-up signal response and request response authentication may be performed between the portable device 100 and the control device 200. In response to such a wake-up signal response or request response authentication, the control device 200 starts waiting for reception of the distance measurement trigger signal.

[0076] The control device 200 can shorten the waiting period by starting waiting for reception in response to a wake-up signal or request-response authentication. Also, by performing another authentication process before the distance-based authentication process, the accuracy of authentication can be further improved.

[0077] In response to a wake-up signal or in request response authentication, a signal transmitted from one device to another device is also referred to as a first notification signal. A signal transmitted from a device that has received the first notification signal to a device that has transmitted the first notification signal is also referred to as a second notification signal. Each device succeeds in authenticating the other device only when a regular second authentication signal corresponding to the first authentication signal is transmitted in response to the first authentication signal. Any frequency band is used when transmitting the first and second notification signals. For example, the notification signal may be transmitted using the same frequency band as a ranging signal such as a ranging trigger signal or a ranging request signal, or may be transmitted using a frequency band different from that of the ranging signal. In addition, the notification signal may be transmitted as a signal using UWB, a signal in the LF band, a signal in the RF band, or a signal in BLE (Bluetooth Low Energy (registered trademark)).

[0078] Furthermore, the authentication information according to this embodiment is made the same each time and is changed when the processing group is changed, and this can also be applied to the above-mentioned first notification signal and second notification signal, etc. For example, when request-response authentication is performed multiple times, the authentication information used each time may be made the same, and when the processing group is changed and the request-response authentication is performed multiple times again, the authentication information may be changed.

[0079] <5. Summary> Although the preferred embodiment of the present invention has been described in detail above with reference to the accompanying drawings, the present invention is not limited to such an example. It is clear that a person having ordinary knowledge in the technical field to which the present invention pertains can conceive of various modified or altered examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present invention.

[0080] For example, in the above embodiment, an example in which the authenticator transmits the first distance measurement signal has been described, but the present invention is not limited to such an example. The authenticator is, for example, the control device 200 of the vehicle 20. For example, the authenticatee may transmit the first distance measurement signal. The authenticatee may be, for example, the portable device 100. When the control device 200 receives the first distance measurement signal from the portable device 100, it transmits a second distance measurement signal in response to the first distance measurement signal. When the portable device 100 receives the second distance measurement signal, it measures a time ΔT1 from the transmission time of the first distance measurement signal to the reception time of the second distance measurement signal. Next, the portable device 100 transmits a data signal including information in which information indicating the measured ΔT1 is encrypted. On the other hand, the control device 200 measures a time ΔT2 from the reception time of the first distance measurement signal to the transmission time of the second distance measurement signal. Then, when the control device 200 receives a data signal from the portable device 100, it calculates the distance between the portable device 100 and the control device 200 based on ΔT1 indicated by the data signal received from the portable device 100 and the measured ΔT2. For example, the time required for one-way signal transmission and reception is calculated by dividing ΔT1-ΔT2 by 2, and the distance between the portable device and the communication unit is calculated by multiplying the time by the signal speed. In this way, when the directions of transmission and reception of the first and second ranging signals are reversed, the control device 200 performs control to transition to a waiting state in which the control device 200 waits for the first ranging signal transmitted from the portable device 100. The transition to the waiting state in which the control device 200 waits for the first ranging signal can be performed at any timing.

[0081] In the above embodiment, an example has been described in which the authenticatee is the portable device 100 and the authenticator is the control device 200 of the vehicle 20, but the present invention is not limited to such an example. The roles of the portable device 100 and the control device 200 of the vehicle 20 may be reversed, or the roles may be dynamically exchanged. Furthermore, distance measurement and authentication may be performed between the control devices 200 of the vehicles 20.

[0082] In the above embodiment, the portable device 100 is an example of a communication device, and the control device 200 is an example of a control device, but the present invention is not limited to such examples. The portable device 100 may be an example of a control device, and the control device 200 may be an example of a communication device.

[0083] For example, in the above embodiment, an example in which the present invention is applied to a smart entry system has been described, but the present invention is not limited to such an example. The present invention is applicable to any system that performs distance measurement and authentication by transmitting and receiving a signal. For example, objects used by a user include drones, vehicles, ships, airplanes, buildings, robots, lockers, home appliances, etc. Buildings include houses, etc. In addition, the present invention is applicable to a pair including any two devices among a portable device, a vehicle, a ship, an airplane, a smartphone, a drone, a building, a robot, a locker, and a home appliance. Note that the pair may include two devices of the same type, or may include two devices of different types. In this case, one device operates as a first communication device, and the other device operates as a second communication device.

[0084] For example, in the above embodiment, the wireless communication standard uses UWB, but the present invention is not limited to this example. For example, the wireless communication standard may use infrared rays.

[0085] As another example, in the above description, the control unit 240 is configured as an ECU and controls the overall operation of the control device 200, but the present invention is not limited to such an example. For example, the first wireless communication unit 210 and the second wireless communication unit 220 may each include an ECU. In this case, the first wireless communication unit 210 and the second wireless communication unit 220 are also referred to as a mobile-mounted communication device. The mobile-mounted communication device may execute a process based on authentication information included in a received signal and a process for controlling a transition to a reception waiting state, similar to the above-mentioned control device 200.

[0086] The series of processes performed by each device described in this specification may be realized using any of software, hardware, and a combination of software and hardware. The programs constituting the software are stored in advance, for example, in a recording medium (non-transitory medium) provided inside or outside each device. Then, each program is loaded into a RAM when executed by a computer, for example, and executed by a processor such as a CPU. The recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, etc. Also, the computer program may be distributed, for example, via a network, without using a recording medium.

[0087] In addition, the processes described in this specification using sequence diagrams and flow charts do not necessarily have to be performed in the order shown in the drawings. Some processing steps may be performed in parallel. In addition, additional processing steps may be employed, and some processing steps may be omitted. [Explanation of symbols]

[0088] 1: system, 100: portable device, 110: first wireless communication unit, 120: second wireless communication unit, 130: storage unit, 140: control unit, 20: vehicle, 20: control device, 210: first wireless communication unit, 220: second wireless communication unit, 230: storage unit, 240: control unit

Claims

1. a control unit that controls an authentication process for performing a process related to authentication of at least one communication device based on information included in a signal received through wireless communication with the communication device; the control unit performs control to change authentication information, which is information used in the authentication process, for each process group in which the authentication process is repeated a plurality of times; Each signal transmitted or received in the authentication process includes a trigger signal notifying the start of the authentication process, a request signal that is returned when the trigger signal is received and requests a response, and a response signal that is returned when the request signal is received and responds to the request. Control device.

2. The control device according to claim 1 , wherein the authentication information is encrypted information.

3. 3. The control device according to claim 1, wherein when the control unit is notified that a process group in which the authentication process is repeated a specified number of times is to be executed, the control unit changes the authentication information to a different authentication information than the authentication information used in the process group executed prior to the notification.

4. The control unit is executing a process group for repeating the authentication process a plurality of times using different pieces of authentication information for the trigger signal, the request signal, and the response signal; The control device according to claim 1, wherein the authentication information used for each signal is changed for each of the processing groups.

5. The control unit is execute a process group for repeating the authentication process a plurality of times using the same authentication information for each of the trigger signal, the request signal, and the response signal; The control device according to claim 1, wherein the authentication information used for each signal is changed for each of the processing groups.

6. The control unit executes distance measurement authentication to measure a distance between the communication device and the control device as the authentication process, the trigger signal is a distance measurement trigger signal that notifies the start of the distance measurement authentication, the request signal is a ranging request signal requesting a response in order to calculate the distance, The control device according to any one of claims 1 to 5, wherein the response signal is a distance measurement response signal that responds when the distance measurement request signal is received.

7. The control device according to any one of claims 1 to 6, wherein the control unit obtains a representative value from each result of an authentication process repeated multiple times within a processing group, and performs final authentication based on the representative value of each processing group that has been performed multiple times.

8. The control device is mounted on a moving body, The control device according to any one of claims 1 to 7, wherein the communication device is carried by a user of the mobile object.

9. The control device includes: One or more communication units that wirelessly communicate with the communication device; The control unit, The control device according to claim 8.

10. The control device includes: Controlling one or more mobile-mounted communication devices mounted on the mobile body and wirelessly communicating with the communication device; The control device according to claim 8 , which controls transmission and reception of signals to and from the communication device via the mobile-mounted communication device.

11. The communication device is mounted on a moving object, The control device according to any one of claims 1 to 7, wherein the control device is carried by a user of the mobile object.

12. The communication device includes: A plurality of communication units that wirelessly communicate with the control device; The control unit, The control device includes: The control device according to claim 11 , wherein the control device transmits or receives signals used in the authentication process to or from the plurality of communication units.

13. The processor: Controlling an authentication process for performing a process related to authentication of at least one communication device based on information included in a signal received through wireless communication with the communication device; changing authentication information used in the authentication process for each process group in which the authentication process is repeated a plurality of times; Including, Each signal transmitted or received in the authentication process includes a trigger signal notifying the start of the authentication process, a request signal that is returned when the trigger signal is received and requests a response, and a response signal that is returned when the request signal is received and responds to the request. Control methods.

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