Authentication system, in-vehicle authentication system, and authentication method

Abstract

The present application provides an authentication system, an in-vehicle authentication system, and an authentication method, which can shorten the response time for user operations. The authentication system includes a first communication device having a first transmission unit that communicates in a first frequency band and a first transceiving unit that communicates in a second frequency band, and a second communication device having a first reception unit that communicates in the first frequency band and a second transceiving unit that communicates in the second frequency band. The first communication device transmits a command in the first frequency band from the first transmission unit. If the command is received by the first reception unit, the second communication device activates the second transceiving unit and generates an authentication key for a response signal, and transmits a response signal in the second frequency band including the generated authentication key from the second communication device.

Description

Technical Field

[0001] This disclosure relates to authentication systems, in-vehicle authentication systems, and authentication methods. Background Technology

[0002] Conventionally, a first communication device is provided for transmitting and receiving data with a second communication device. This first communication device includes a first transceiver circuit and a second transceiver circuit. The first transceiver circuit transmits and receives a determination signal with the second communication device for determining the location of the second communication device. The second transceiver circuit transmits and receives a ranging signal with the second communication device for measuring the distance to the second communication device. The transmission of the ranging signal occurs before the transmission of the determination signal. "Before transmission" means simultaneously with transmission (for example, see Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2020 / 090507

[0006] [The problem the invention aims to solve]

[0007] However, although in systems including existing first and second communication devices, the ranging signal is transmitted before the determination signal is transmitted, no research has been conducted on how the second communication device quickly sends a response signal containing the authentication key to the first communication device after the first communication device transmits a WAKEUP signal (command) via the LF band to activate the second communication device from its dormant state. Therefore, systems including existing first and second communication devices cannot shorten the response time to user operations. Summary of the Invention

[0008] Therefore, the purpose of this disclosure is to provide an authentication system, an in-vehicle authentication system, and an authentication method that can shorten the response time for user operations.

[0009] [Methods used to solve problems]

[0010] The authentication system according to embodiments of this disclosure includes: a first communication device having a first transmitting unit for communication in a first frequency band and a first transceiver unit for communication in a second frequency band; and a second communication device having a first receiving unit for communication in the first frequency band and a second transceiver unit for communication in the second frequency band. The first communication device transmits an instruction for the first frequency band from the first transmitting unit. If the second communication device receives the instruction from the first receiving unit, it activates the second transceiver unit and generates an authentication key for a response signal, and transmits a response signal for the second frequency band including the generated authentication key from the second communication device.

[0011] [The effects of the invention]

[0012] It can provide an authentication system, vehicle authentication system, and authentication method that can shorten the response time for user operations. Attached Figure Description

[0013] Figure 1 This is a diagram illustrating an in-vehicle authentication system implemented in this way.

[0014] Figure 2 This diagram illustrates an example of the mounting locations of the LF transmitter, UWB anchor, and RF receiver in a vehicle.

[0015] Figure 3 This is a timing diagram illustrating an example of the operation of the communication device and two remote keys (key fob) in an in-vehicle authentication system.

[0016] Figure 4 This is a flowchart illustrating an example of the processing performed by the control device of a communication device.

[0017] Figure 5 This is a flowchart illustrating an example of the processing performed by a remote key.

[0018] [Explanation of Symbols]

[0019] 100 Communication devices (an example of the first communication device, an example of a vehicle-mounted device)

[0020] 101 Control Device

[0021] 110LF Control Unit

[0022] 110A LF Transmitter (An example of the first transmitter)

[0023] 120UWB Control Unit

[0024] 120A UWB anchor (an example from the first transceiver unit)

[0025] 130RF Control Unit

[0026] 130A RF receiver (an example of a second receiver)

[0027] 151LF antenna

[0028] 152UWB antenna

[0029] 153RF antenna

[0030] 200 remote control keys (an example of a second communication device, an example of a portable device)

[0031] 201LFIC

[0032] 210LF Control Unit

[0033] 210A LF receiver (an example of the first receiver)

[0034] 220UWBIC

[0035] 220A UWB transceiver unit (an example of the second transceiver unit)

[0036] 221UWB Control Unit

[0037] 222 Power Control Department

[0038] 223 load

[0039] 230RF Control Unit

[0040] 230A RF Transmitter (An example of the second transmitter)

[0041] 251 LF antenna

[0042] 252 UWB antenna

[0043] 253RF antenna

[0044] 270 battery (an example from the main power supply section)

[0045] 300 vehicle authentication system (an example of an authentication system). Detailed Implementation

[0046] The following describes the implementation methods of the authentication system, vehicle authentication system, and authentication method disclosed herein.

[0047] <Implementation Method>

[0048] Figure 1 This is a diagram illustrating an in-vehicle authentication system 300 according to an embodiment. The in-vehicle authentication system 300 applies the authentication system of the embodiment to a vehicle and is an example of the authentication system of the embodiment. Furthermore, the in-vehicle authentication system 300 executes the authentication method of the embodiment.

[0049] <Structure of Vehicle Authentication System 300>

[0050] The vehicle authentication system 300 includes a communication device 100 and a remote key 200, enabling intelligent vehicle entry. The communication device 100 is an example of a first communication device and an example of an in-vehicle unit, mounted on a vehicle. The remote key 200 is an example of a second communication device and an example of a portable device. Multiple remote keys 200 may actually exist for one communication device 100, but... Figure 1 Only one is represented in the text.

[0051] <Structure of Communication Device 100>

[0052] The communication device 100 is the vehicle's ECU (Electronic Control Unit), which includes: a control unit (MicroController) 101, an LF (Low Frequency) antenna 151, a UWB (Ultra Wide Band) antenna 152, and an RF (Radio Frequency) antenna 153. The control unit 101 is implemented by a computer including a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), input / output interfaces, and an internal bus. Figure 1 In this context, it is represented as a single control device 101, but it can also be a collection of multiple physically separate control devices.

[0053] The control device 101 includes an LF control unit 110, a UWB control unit 120, and an RF control unit 130. The LF control unit 110 and the LF antenna 151 constitute the LF transmitter 110A.

[0054] The LF transmitter 110A is an example of a first transmitter that communicates in the LF band, which is an example of a first frequency band. The UWB control unit 120 and the UWB antenna 152 constitute the UWB anchor 120A. The UWB anchor 120A is an example of a first transceiver that communicates in the UWB band, which is an example of a second frequency band. The RF control unit 130 and the RF antenna 153 constitute the RF receiver 130A. The RF receiver 130A is an example of a second receiver that communicates in the RF band, which is an example of a third frequency band.

[0055] The LF control unit 110, UWB control unit 120, and RF control unit 130 respectively perform communication control in the LF transmitter 110A, UWB anchor 120A, and RF receiver 130A. Furthermore, multiple LF transmitters 110A and UWB anchors 120A are installed in the vehicle. For details regarding communication control, please refer to... Figure 3 as well as Figure 4 To be described later.

[0056] The LF antenna 151, UWB antenna 152, and RF antenna 153 are antennas optimized for communication in the LF band, UWB band, and RF band, respectively. For example, the LF band is 20kHz–25kHz or 120kHz–135kHz; here, 125kHz is used as an example. The UWB band is 2GHz–10GHz; here, 8GHz is used as an example. The RF band is 300MHz–3GHz; here, 315MHz is used as an example.

[0057] <Structure of Remote Key 200>

[0058] The remote key 200 is a smart key held by the vehicle owner. The remote key 200 can be a smart key provided with the vehicle or a user's mobile phone.

[0059] The remote control key 200 includes: an LFIC (Low Frequency Integrated Circuit) 201, a UWBIC (UltraWide Band Integrated Circuit) 220, an LF antenna 251, a UWB antenna 252, an RF antenna 253, and a battery 270. The battery 270 is an example of the main power supply unit.

[0060] The LFIC201 is implemented as an example by an MCU (Micro Controller Unit) including a CPU, RAM, ROM, input / output interfaces, and an internal bus. The LFIC201 has an LF control unit 210 and an RF control unit 230. The LF control unit 210 and the LF antenna 251 constitute an LF receiver 210A. The LF receiver 210A is an example of a first receiver that communicates in the LF band, which is an example of a first frequency band. The RF control unit 230 and the RF antenna 253 constitute an RF transmitter 230A. The RF transmitter 230A is an example of a second transmitter that communicates in the RF band, which is an example of a third frequency band. The LF control unit 210 and the RF control unit 230 respectively perform communication control in the LF receiver 210A and the RF transmitter 230A. For details regarding communication control, please refer to... Figure 3 as well as Figure 4 To be described later.

[0061] The UWBIC220 includes a UWB control unit 221, a power control unit 222, and a load 223. The UWB control unit 221 and the UWB antenna 252 constitute a UWB transceiver unit 220A. The UWB transceiver unit 220A is an example of a second transceiver unit that communicates in the UWB band, which is an example of a second frequency band.

[0062] UWB control unit 221 performs communication control in UWB transceiver unit 220A. UWB control unit 221 receives power from battery 270, but details of the power supply path between UWB control unit 221 and battery 270 are omitted. For details regarding communication control, please refer to... Figure 3 as well as Figure 4 To be described later.

[0063] The power control unit 222 is connected between the battery 270 and the load 223, and controls the amount of power supplied from the battery 270 to the load 223. The power control unit 222 is controlled by the UWB control unit 221.

[0064] Load 223 is a load circuit that consumes power from UWBIC 220. Since load 223 is a load circuit that consumes power from UWBIC 220, it can be any load. For example, load 223 can be an auxiliary power supply unit that charges UWBIC 220 with power supplied from battery 270 and supplies power to UWB control unit 221. The auxiliary power supply unit can be an auxiliary power source that supplies power to UWB control unit 221 independently of battery 270, and can be implemented, for example, by a buffer capacitor. Alternatively, load 223 can also be located outside of UWBIC 220. Even in this case, it is assumed that UWBIC 220 has load 223.

[0065] After the ranging signal transmission and reception processing is completed, the power control unit 222, from the UWB control unit 221 sending data including markers to the communication device 100 to the RF control unit 230 sending the position determination signal (described later) to the communication device 100, suppresses the amount of power supplied from the battery 270 to the load 223 and enters standby mode, allowing the battery 270 voltage to recover quickly. This power control unit 222 is controlled by the UWB control unit 221. For more details, please refer to... Figure 3 To be described later.

[0066] The LF antenna 251, UWB antenna 252, and RF antenna 253 are antennas optimized for communication in the LF band, UWB band, and RF band, respectively.

[0067] Battery 270 is the power source for the portable remote key 200, and is, for example, a lithium-ion battery. Battery 270 can also be a rechargeable battery other than a lithium-ion battery, preferably a rechargeable secondary battery. Battery 270 supplies DC power to LFIC201 and UWBIC220.

[0068] <Summary of the operation of the vehicle authentication system 300>

[0069] One of the multiple LF transmitters 110A sends a command for the LF band. After the command is sent, the multiple LF transmitters 110A sequentially send a signal strength measurement signal for the LF band in a time-division manner. That is, the multiple LF transmitters 110A sequentially send a signal strength measurement signal for the LF band. As an example, when the user touches the door handle on the driver's side of the vehicle 10, a command is sent from the LF transmitter 110A, and the received remote key 200 is activated.

[0070] If the remote key 200 receives a command through the LF receiver 210A, it activates the UWB transceiver 220A and generates an authentication key for the response signal, and sends a response signal containing the generated authentication key from the remote key 200 via a UWB band.

[0071] Furthermore, the signal strength measurement signal is a carrier wave that is sequentially transmitted by multiple LF transmitters 110A in a time-division manner to determine the position of each remote key 200. Each remote key 200 determines the relative position of the multiple LF transmitters 110A and the remote key 200 based on the signal strength of the carrier wave received from the multiple LF transmitters 110A (for example, the RSSI (Received Signal Strength Indicator) value).

[0072] One or more remote keys 200 that receive the instruction will send a response signal to the communication device 100. The remote key 200 that receives the response signal first by the communication device 100 wins and continues the authentication process with the communication device 100.

[0073] As an example, there are two UWB anchors 120A. When the two UWB anchors 120A are transmitting and receiving distance measurement signals with the remote control key 200 which wins in a first-come, first-served manner, each of them sends a distance measurement signal to the remote control key 200 once.

[0074] After the ranging signal transmission and reception processing is completed, the RF receiver 130A receives the position determination signal from the remote key 200. The position determination signal is a signal that indicates the relative position of the multiple LF transmitters 110A and the remote key 200 based on the reception strength of the multiple carriers transmitted from the multiple LF transmitters 110A to the remote key 200.

[0075] If the communication device 100 receives a position determination signal from the RF receiver 130A, it determines the position of the remote key 200 based on the relative positions of the plurality of LF transmitters 110A and the remote key 200 indicated by the position determination signal. Specifically, it determines whether the remote key 200 exists near a certain LF transmitter 110A among the plurality of LF transmitters 110A.

[0076] Furthermore, if the remote key 200 determines that the distance between itself and the communication device 100, inferred from the carrier signal strength, is greater than a first predetermined distance, it will not send a response signal. The first predetermined distance is an example of a predetermined distance. When the distance between the remote key 200 and the communication device 100 is greater than the first predetermined distance, the access is ultimately not considered legitimate. Therefore, at the point when the distance is determined to be too great, the number of response signals sent to the communication device 100 is reduced, improving the overall processing speed of the vehicle authentication system 300. The first predetermined distance, for example, is 1 meter.

[0077] <Vehicle mounting location>

[0078] Figure 2 This diagram shows an example of the mounting positions of the LF transmitter 110A, UWB anchor 120A, and RF receiver 130A in vehicle 10.

[0079] Figure 2 This is a diagram showing a vehicle 10 equipped with the communication device 100 of the embodiment. Figure 2 The figure represents the XY coordinate system with the center of vehicle 10 as the origin O when viewed from above. The +X direction is forward, which is the direction in which vehicle 10 moves. The +Y direction is to the left in the direction in which vehicle 10 moves. Vehicle 10 is assumed to be a right-hand drive vehicle as an example.

[0080] Figure 2 The diagram illustrates, as an example, the positions of the six LF transmitters 110A (#1 to #6) and two UWB anchors 120A (#1 and #2) provided in the communication device 100; the control device 101 is omitted. Here, the six LF transmitters 110A are identified by the numbers #1 to #6, and the two UWB anchors 120A are identified by the numbers #1A and #2A. Furthermore, Figure 2 The example shown is 2 remote control keys 200.

[0081] #1 LF transmitter 110A is located near the driver's side door (right front door). #2 LF transmitter 110A is located near the passenger side door (left front door). #3 LF transmitter 110A is located at the rear of vehicle 10, and #4 LF transmitter 110A is located at the front end of the interior of vehicle 10. #5 LF transmitter 110A is located at the front of the center section of the interior of vehicle 10, and #6 LF transmitter 110A is located at the rear of the center section of the interior of vehicle 10.

[0082] The UWB anchor 120A of #1A is positioned adjacent to the LF transmitter 110A of #5, and the UWB anchor 120A of #2A is positioned adjacent to the LF transmitter 110A of #6. The RF receiver 130A, as an example, is positioned in the center of the interior of the vehicle 10, between the UWB anchor 120A of #1A and the LF transmitter 110A of #5, and between the UWB anchor 120A of #2A and the LF transmitter 110A of #6.

[0083] <Sequence Diagram>

[0084] Figure 3 This is a timing diagram illustrating an example of the operation of the communication device 100 and two remote keys 200 (FOB1, FOB2) in the vehicle authentication system 300. Here, as an example, the vehicle authentication system 300 is described with two remote keys 200 (FOB1, FOB2), but the same applies even when it has three or more remote keys 200. Here, to distinguish between the two remote keys 200, they are sometimes simply referred to as FOB1 or FOB2.

[0085] At time t1, the LF transmitter 110A of #1 sends an instruction containing a challenge code to the LF band. The LF transmitter 110A of #1 sends the instruction when the user touches the door handle on the driver's side of the vehicle 10. As a result, the LFIC 201 of the remote key 200 that received the instruction is activated, and the challenge code is transferred to the UWB control unit 221 of the UWB transceiver 220A. Thus, the UWBIC 220 is activated. Here, it is assumed that two remote keys 200 (FOB1 and FOB2) receive the instruction.

[0086] At time t2, the UWBIC220 of FOB1 and FOB2 are activated, generating key 1 and key 2 respectively. Key 1 and key 2 are authentication keys used by the remote control key 200 to respond to the communication device 100 with a response signal.

[0087] At time t3, communication device 100 transmits carriers in the LF band in the order of LF transmitting units 110A (#2 to #6 and #1). LF receiving units 210A of FOB1 and FOB2 receive the carriers and measure the received signal strength (RSSI value) when each carrier is received. Carrier transmission occurs after the command is sent.

[0088] Here, since the UWBIC220 of FOB1 and FOB2 generates key 1 and key 2 in parallel during the carrier reception by the LF receiving units 210A of FOB1 and FOB2, respectively, the carrier reception processing and key generation processing can be performed in parallel, thus shortening the processing time. Therefore, the response time for user operations can be shortened.

[0089] At time t4, FOB1's UWBIC220 sends the data containing key 1 to communication device 100 before FOB2. At this time, FOB2's UWBIC220 has not yet sent the data containing key 2, and sends it slightly later than at time t4. Therefore, in a first-come, first-served manner, FOB1 and communication device 100 continue the authentication process.

[0090] If the communication device 100 determines that the key 1 contained in the response signal received from the remote key 200 is valid, then at time t5, it sends a ranging request signal to FOB1, and FOB1 receives the ranging request signal R from the communication device 100. The ranging request signal R is a signal from the communication device 100 requesting FOB1 to send a ranging signal containing an ID (Identifier).

[0091] At time t6, the UWBIC220 of FOB1 sends a ranging signal containing the ID UWB band to the communication device 100, and the communication device 100 receives the ranging signal from FOB1 through the UWB anchor 120A of #1A.

[0092] At time t7, communication device 100 sends a ranging signal from UWB anchor 120A of #1A to FOB1, and FOB1 receives the ranging signal from communication device 100. FOB1 determines the phase and other parameters upon receiving the ranging signal.

[0093] At time t8, communication device 100 sends a ranging signal from UWB anchor 120A of #2A to FOB1, and FOB1 receives the ranging signal from communication device 100. When FOB1 receives the ranging signal, it determines the phase, etc.

[0094] At time t9, FOB1's UWBIC transmits a ranging signal containing the ID to communication device 100 via the UWB band, and communication device 100 receives the ranging signal from FOB1. The ranging signal transmitted from FOB1 to communication device 100 includes data such as phase received from UWB anchors 120A of #1A and #2A. The processing from time t6 to t9 involves the transmission and reception of ranging signals between communication device 100 and FOB1.

[0095] At time t10, after the ranging signal transmission and reception processing is completed, FOB1's UWBIC220 transmits data to communication device 100 in the UWB band. This data includes information related to FOB1's clock, a flag, and FOB1's ID. The flag indicates that FOB1 has correctly performed the ranging signal transmission and reception processing.

[0096] In this way, the communication device 100 transmits the ranging signal (t7, t8) and receives the ranging signal (t6, t9). As an example, the distance between the vehicle and FOB1 is determined in the form of TOF based on the phase of the ranging signal.

[0097] At time t11, the UWB control unit 221 of the LFIC201 of FOB1 controls the power control unit 222 to control the amount of power supplied from the battery 270 to the load 223, and enters standby mode until the voltage of the battery 270 recovers to the specified voltage. The standby time is from time t11 to time t12 after the specified time. The time required for the voltage of the battery 270 to recover to the specified voltage after the remote control key 200 performs distance measurement signal transmission and reception processing can be determined in advance through experiments, etc.

[0098] At time t12, the RF control unit 230 of the LFIC201 of FOB1 sends a position determination signal to the communication device 100 via the RF band. The remote key 200 sends the position determination signal after sending the ranging signal. The RF receiver 130A of the communication device 100 receives the position determination signal from the RF band of the remote key 200.

[0099] The position determination signal is a signal that indicates the relative position of the multiple LF transmitters 110A and the remote key 200 based on the reception strength of the multiple carriers transmitted from the multiple LF transmitters 110A to the remote key 200, and includes an authentication key for RF communication.

[0100] More specifically, the relative positions of the multiple LF transmitters 110A and the remote key 200 are represented by the distances between FOB1 and LF transmitters 110A #1 to #6, calculated based on the signal strength (RSSI value) of the carrier received after time t3. Using the distances between FOB1 and LF transmitters 110A #1 to #6, it can be determined which of the LF transmitters 110A #1 to #6 FOB1 is closest to. The distances between FOB1 and LF transmitters 110A #1 to #6 (6 distances) indicate which of the LF transmitters 110A #1 to #6 FOB1 is closest to.

[0101] Through the above-described processing, communication device 100, FOB1, and FOB2 determine, based on the communication content with FOB1 (which wins in a first-come, first-served manner), whether the source of the ranging signal is the legitimate remote key 200 or an illegitimate (illegal) relay device impersonating the remote key 200. This determination is based on the markers contained in the data received at time t10 after the completion of the ranging signal transmission and reception processing, the distance between communication device 100 and remote key 200 calculated by control device 101, and the authentication key for UWB communication contained in the position determination signal, and is executed by communication device 100.

[0102] If the communication device 100 determines that the source of the ranging signal is a legitimate remote key 200, it will unlock the doors and other locks of the vehicle 10.

[0103] <Processing performed by communication device 100>

[0104] Figure 4 This is a flowchart illustrating an example of the processing performed by the control device 101 of the communication device 100.

[0105] The control device 101 causes the LF transmitting unit 110A of #1 to send an instruction for the LF band containing a challenge code, and causes the six LF transmitting units 110A to transmit carriers in the LF band in a time-division manner in the order of #2 to #6 and #1 (step S1).

[0106] The control device 101 determines whether the ranging signal transmission and reception processing has been performed (step S2).

[0107] If the control device 101 determines that the ranging signal transmission and reception process has been performed (S2: Yes), it then determines whether the position determination signal has been received (step S3).

[0108] If the control device 101 determines that it has received a position determination signal (S3: Yes), it determines whether the remote key 200 exists within the area of ​​any LF transmitter 110A (step S4). The area of ​​the LF transmitter 110A is the region within a range of 110A that is at least a second predetermined distance from the LF transmitter 110A. The determination of whether the remote key 200 exists within the area of ​​any LF transmitter 110A is made by determining whether the distance between the remote key 200 and the nearest LF transmitter 110A, as indicated by the position determination signal, is at least a second predetermined distance. Therefore, the remote key 200 is determined to be within the area of ​​the nearest LF transmitter 110A (within the range of the second predetermined distance). For example, the second predetermined distance is 2 meters.

[0109] Therefore, if the distance between the remote key 200 and the nearest LF transmitter 110A is not below the second predetermined distance, then the remote key 200 does not exist within the area of ​​any LF transmitter 110A. That is, the remote key 200 exists outside the area of ​​all LF transmitters 110A. Through the processing in step S4, the relative position of the remote key 200 and the nearest LF transmitter 110A can be determined, and it can be determined whether the remote key 200 exists within the area of ​​multiple LF transmitters 110A (within the range below the second predetermined distance).

[0110] If the control device 101 determines that the remote key 200 exists within the area of ​​any LF transmitter 110A (S4: Yes), it then determines whether the access is legitimate (step S5). The control device 101 determines whether the access is legitimate based on the marker contained in the data received after the ranging signal transmission and reception processing is completed, the distance between the communication device 100 and the remote key 200 calculated by the control device 101, and the authentication key for RF communication contained in the position determination signal.

[0111] Regarding the marker, it is sufficient to determine whether the marker value indicates that the remote key 200 has correctly performed communication for transmitting and receiving distance measurement signals. Regarding the distance calculated by the control device 101, it is sufficient to determine whether the distance between the communication device 100 and the remote key 200 is below the first predetermined distance. Regarding the authentication key used for UWB communication, it is sufficient to determine whether the authentication is successful.

[0112] If the control device 101 determines that the access is legitimate (S5: Yes), it unlocks the lock on the door, etc. (step S6A). The control device 101 then completes the series of processes (end).

[0113] On the other hand, if the control device 101 determines in step S5 that the access is not legitimate (S5: No), it will not unlock the lock on the door, etc. (step S6B). The control device 101 ends a series of processes (end). Legitimate access refers to illegitimate access, for example, a relay attack carried out by an illegitimate relay device impersonating the remote control key 200.

[0114] Furthermore, if the control device 101 determines in step S2 that the transmission and reception of the ranging signal has not been processed (S2: No), it will not unlock the lock of the door, etc. (step S6B). The control device 101 then ends the series of processes (end).

[0115] Furthermore, if the control device 101 determines in step S3 that it has not received a position determination signal (S3: No), it will not unlock the lock on the door, etc. (step S6B). The control device 101 then ends the series of processes (end).

[0116] Furthermore, if the control device 101 determines in step S4 that the remote key 200 does not exist in any area of ​​the LF transmitting unit 110A (S4: No), then it will not unlock the lock of the door, etc. (step S6B). The control device 101 then ends the series of processes (end).

[0117] <Processing executed by remote key 200>

[0118] Figure 5 This is a flowchart illustrating an example of the processing performed by the remote key 200. The remote key 200's LFIC201 or UWBIC220 executes... Figure 5 The processing shown.

[0119] The LF receiver 210A of the remote key 200 receives the command (step S11). The processing of the remote key 200 begins upon receiving the command via the LF receiver 210A.

[0120] LFIC201 is started by receiving a command (step S12).

[0121] LFIC201 starts UWBIC220 (step S13). The LF control unit 210 of LFIC201 executes the processing of step S13.

[0122] LFIC201 transmits the challenge code contained in the received instruction to UWBIC220 (step S14). The LF control unit 210 of LFIC201 executes the processing of step S14.

[0123] UWBIC220 generates an authentication key for UWB communication (equivalent to...). Figure 3 (Keys 1 and 2 in the process) (step S15A).

[0124] The processes of steps S15B1 to S15B4 are executed in parallel with the processes of step S15A performed by LFIC201 and UWBIC220.

[0125] Specifically, LFIC201 generates an authentication key for RF communication (step S15B1). The RF control unit 230 of LFIC201 performs the processing of step S15B1.

[0126] LFIC201 determines whether the distance between itself and the communication device 100, inferred from the carrier signal strength, is below the first predetermined distance (step S15B2). The RF control unit 230 of LFIC201 executes the processing of step S15B2.

[0127] If LFIC201 determines that the distance between itself and the communication device 100, inferred from the signal strength of the carrier, is less than or equal to a first predetermined distance (S15B2: Yes), it receives the carrier multiple times and determines whether the distance between itself and the LF transmitter 110A, determined based on the signal strength (RSSI value) of the received carrier, is less than or equal to a second predetermined distance (step S15B3). The LF control unit 210 of LFIC201 executes the processing in step S15B3.

[0128] If LFIC201 receives carrier waves multiple times and determines that the distance between it and LF transmitter 110A, based on the signal strength (RSSI value) of the received carrier waves, is less than a predetermined distance (S15B3: Yes), then it notifies UWBIC220 that the distance is less than the second predetermined distance (step S15B4). UWBIC220 then determines whether there is a notification that the distance is less than the second predetermined distance (step S16).

[0129] UWBIC220 determines whether a ranging request signal has been received (step S17).

[0130] If the UWBIC220 determines that a ranging request signal has been received (S17: Yes), it then determines whether the ranging signal transmission and reception process has ended (step S18A).

[0131] If UWBIC220 determines that the ranging signal transmission and reception processing has ended (S18A: Yes), it controls the power control unit 222 to standby for a specified time (step S18B). The standby time is... Figure 3 The time shown is from time t11 to time t12 after a specified time.

[0132] After the standby time ends, the RF control unit 230 sends a position determination signal to the communication device 100 via the RF band (step S19). The LFIC 201 then completes a series of processes (end).

[0133] Furthermore, in step S15B2, if LFIC201 determines that the distance between itself and the communication device 100, inferred from the carrier signal strength, is not below the first predetermined distance (S15B2: No), then LFIC201 and UWBIC220 enter sleep mode (step S18C). Sleep mode is an energy-saving mode that does not perform the aforementioned determination process. If sleep mode is entered, LFIC201 and UWBIC220 end a series of processes (end). As a result, the remote key 200 does not send a response signal.

[0134] Furthermore, in step S15B3, if LFIC201 receives carriers multiple times and determines that the distance between it and LF transmitter 110A, determined based on the signal strength (RSSI value) of the received carriers, is not below the second predetermined distance (S15B3: No), then LFIC201 and UWBIC220 enter sleep mode (step S18C).

[0135] Furthermore, in step S16, if UWBIC220 determines that there is no notification below the second specified distance (S16: No), then LFIC201 and UWBIC220 enter sleep mode (step S18C).

[0136] Furthermore, in step S17, if UWBIC220 determines that it has not received a ranging request signal (S17: No), then LFIC201 and UWBIC220 enter sleep mode (step S18C).

[0137] Furthermore, in step S18, if UWBIC220 determines that the transmission and reception processing of the ranging signal has not ended (S18A: No), then LFIC201 and UWBIC220 enter sleep mode (step S18C).

[0138] <Effect>

[0139] As described above, if the remote key 200 receives a command through the LF receiver 210A, it activates the UWB transceiver 220A and generates an authentication key for the response signal. The remote key 200 then transmits the response signal containing the generated authentication key via UWB. Therefore, while the LF receiver 210A of the remote key 200 is receiving the carrier, the UWBIC 220 generates the authentication key. This allows for parallel execution of carrier reception and key generation processes, thus shortening the processing time.

[0140] Therefore, an in-vehicle authentication system 300, an authentication system, and an authentication method can be provided that can shorten the response time for user operations. The authentication system and authentication method of the embodiments can be installed in devices or facilities other than the vehicle 10.

[0141] Furthermore, after the communication device 100 sends a command from the LF transmitter 110A, it sends a carrier wave of the LF band from the LF transmitter 110A, and the remote key 200 obtains the signal strength when the carrier wave is received by the LF receiver 210A. Therefore, it is possible to provide an in-vehicle authentication system 300, an authentication system, and an authentication method that can determine the relative position of the remote key 200 relative to the LF transmitter 110A based on the signal strength when the carrier wave is received, and can shorten the response time for user operations.

[0142] Furthermore, if the communication device 100 determines that the authentication key contained in the response signal received from the remote key 200 is valid, it sends a ranging request signal in UWB band from the UWB anchor 120A, requesting the transmission of a ranging signal including the ID of the remote key 200. If the remote key 200 receives a ranging request signal containing its own ID, it sends a ranging signal in UWB band from the UWB transceiver unit 220A. Based on the ranging request signal and the ranging signal, the communication device 100 calculates the distance between itself and the remote key 200, and based on the calculated distance, determines whether the source of the ranging signal is the legitimate remote key 200 or an illegitimate relay device impersonating the remote key 200. Therefore, an in-vehicle authentication system 300, an authentication system, and an authentication method can be provided that effectively eliminates illegitimate access such as relay attacks and can shorten the response time for user operations.

[0143] Furthermore, the communication device 100 includes an RF receiver 130A for communication over an RF band, and the remote control key 200 includes an RF transmitter 230A for communication over an RF band. After transmitting a ranging signal from the UWB transceiver 220A, the remote control key 200 transmits a position determination signal over an RF band from the RF transmitter 230A. The position determination signal is a signal that indicates the relative position of the multiple LF transmitters 110A and the remote control key 200 based on the received strength of multiple signal strength measurement signals transmitted from multiple LF transmitters 110A. If the communication device 100 receives the position determination signal from the RF receiver 130A, it determines the position of the remote control key 200 based on the relative position of the multiple LF transmitters 110A and the remote control key 200 indicated by the position determination signal. Therefore, it is possible to provide: a vehicle authentication system 300, an authentication system, and an authentication method that can determine the position of the remote key 200 based on the relative position of the communication device 100 with the relative position of the multiple LF transmitters 110A and the remote key 200, and can shorten the response time for user operations.

[0144] Furthermore, after sending the ranging signal, the remote key 200 suppresses the power supply to the UWB transceiver 220A for a predetermined period of time before sending the position determination signal. This allows the battery 270 voltage to recover quickly before sending the position determination signal, enabling rapid transmission of the position determination signal. Therefore, an in-vehicle authentication system 300, an authentication system, and an authentication method are provided that can quickly determine the relative positions of multiple LF transmitters 110A and the remote key 200, and can shorten the response time to user operations.

[0145] The remote key 200 includes a battery 270, and the UWB transceiver 220A includes a load 223 serving as an auxiliary power supply unit, and a power control unit 222 that controls the power supply from the battery 270 to the auxiliary power supply unit (load 223). The power control unit 222 of the remote key 200 suppresses the power supply to the UWB transceiver 220A for a predetermined time by limiting the power supply from the battery 270 to the auxiliary power supply unit (load 223). That is, by suppressing the charging of the load 223 serving as the auxiliary power supply unit, the voltage of the battery 270 can be quickly restored to a predetermined voltage, and a position determination signal can be quickly transmitted to the communication device 100. Therefore, an in-vehicle authentication system 300, an authentication system, and an authentication method can be provided that can quickly determine the relative position of multiple LF transmitters 110A and the remote key 200 by suppressing the charging of the load 223 serving as the auxiliary power supply unit, and can shorten the response time for user operations.

[0146] Furthermore, if the remote key 200 determines that the distance between itself and the communication device 100, inferred from the signal strength of the signal used for signal strength measurement, is greater than a first predetermined distance, it will not send a response signal. Since access is ultimately not considered legitimate when the distance between the remote key 200 and the communication device 100 is greater than the first predetermined distance, reducing the number of response signals sent to the communication device 100 at times when a greater distance is known improves the overall processing speed of the vehicle authentication system 300. By reducing the number of remote keys 200 sending response signals, a vehicle authentication system 300, authentication system, and authentication method that further shortens the response time to user operations can be provided.

[0147] The authentication system, vehicle authentication system and authentication method of the present disclosure have been described above according to exemplary embodiments. However, the present disclosure is not limited to the specific embodiments disclosed. Various modifications and alterations can be made without departing from the scope of the claims.

Claims

1. An authentication system, comprising: The first communication device includes a first transmitting unit for communication in a first frequency band and a first transceiver unit for communication in a second frequency band; and The second communication device includes a first receiving unit for communication in the first frequency band and a second transceiver unit for communication in the second frequency band. The first communication device transmits instructions for the first frequency band from the first transmitting unit. If the second communication device receives the instruction from the first receiving unit, it activates the second transceiver unit and generates an authentication key for a response signal, and then transmits a response signal in the second frequency band containing the generated authentication key from the second communication device. The first communication device has a plurality of first transmitting units. After transmitting the instruction from any one of the plurality of first transmitting units, the signal strength measurement signal of the first frequency band is sequentially transmitted from the plurality of first transmitting units. The second communication device acquires the signal strength when the first receiving unit receives multiple signals for signal strength measurement. If the first communication device determines that the authentication key contained in the response signal received from the second communication device is valid, then the first transceiver unit sends a ranging request signal in the second frequency band requesting the transmission of ranging signals including the ID of the second communication device. If the second communication device receives the ranging request signal containing its own ID, it then transmits the ranging signal of the second frequency band from the second transceiver unit. The first communication device calculates the distance to the second communication device based on the ranging request signal and the ranging signal, and determines whether the source of the ranging signal is the legitimate second communication device or an illegitimate relay device based on the calculated distance. The first communication device has a second receiving unit that communicates in the third frequency band. The second communication device has a second transmitting unit that communicates in the third frequency band. After transmitting the ranging signal from the second transceiver unit, the second communication device transmits the position determination signal for the third frequency band from the second transmitting unit. The position determination signal is a signal that indicates the relative position of the plurality of first transmitting units and the second communication device based on the received strength of the plurality of signal strength measurement signals transmitted from the plurality of first transmitting units. If the first communication device receives the position determination signal from the second receiving unit, it determines the position of the second communication device based on the relative positions of the plurality of first transmitting units and the second communication device represented by the position determination signal. After sending the ranging signal and before sending the position determination signal, the second communication device suppresses the power supply to the second transceiver for a specified period of time.

2. The authentication system according to claim 1, wherein, The second communication device has a main power supply unit. The second transceiver unit includes an auxiliary power supply unit and a power control unit that controls the power supply from the main power supply unit to the auxiliary power supply unit. The second communication device, through the power control unit, continuously limits the power supply from the main power supply unit to the auxiliary power supply unit for the predetermined time, thereby continuously suppressing the power supply to the second transceiver unit for the predetermined time.

3. The authentication system according to claim 1 or 2, wherein, If the second communication device determines that the distance between itself and the first communication device, inferred from the signal strength of the signal strength measuring signal, is greater than a predetermined distance, then it will not send the response signal.

4. An in-vehicle authentication system, comprising: The vehicle-mounted unit includes a first transmitting unit for communication in a first frequency band and a first transceiver unit for communication in a second frequency band; and A portable device comprising a first receiving unit for communication in the first frequency band and a second transceiver unit for communication in the second frequency band. The vehicle-mounted device transmits instructions for the first frequency band from the first transmitting unit. If the portable device receives the instruction from the first receiving unit, it activates the second transceiver unit and generates an authentication key for a response signal, and then sends a response signal in the second frequency band containing the generated authentication key from the portable device. The vehicle-mounted device has a plurality of first transmitting units. After transmitting the command from any one of the plurality of first transmitting units, the device sequentially transmits the signal strength measurement signal of the first frequency band from the plurality of first transmitting units. The portable device acquires the signal strength when the first receiving unit receives multiple signals for signal strength measurement. If the vehicle-mounted device determines that the authentication key contained in the response signal received from the portable device is valid, it sends a ranging request signal in the second frequency band from the first transceiver unit, requesting the transmission of ranging signals including the ID of the portable device. If the portable device receives the ranging request signal containing its own ID, it then transmits the ranging signal of the second frequency band from the second transceiver unit. The vehicle-mounted device calculates the distance to the portable device based on the ranging request signal and the ranging signal, and determines whether the source of the ranging signal is the legitimate portable device or an illegitimate relay device based on the calculated distance. The vehicle-mounted device has a second receiver that communicates in the third frequency band. The portable device has a second transmitter that communicates in the third frequency band. After transmitting the ranging signal from the second transceiver unit, the portable device transmits the position determination signal for the third frequency band from the second transmitting unit. The position determination signal is a signal that indicates the relative position of the plurality of first transmitting units and the portable device based on the received strength of the plurality of signal strength measurement signals transmitted from the plurality of first transmitting units. If the vehicle-mounted device receives the position determination signal from the second receiving unit, it determines the position of the portable device based on the relative positions of the plurality of first transmitting units and the portable device represented by the position determination signal. After sending the ranging signal and before sending the position determination signal, the portable device suppresses the power supply to the second transceiver for a specified period of time.

5. An authentication method, which is an authentication method in an authentication system, said authentication system comprising: The first communication device includes a first transmitting unit for communication in a first frequency band and a first transceiver unit for communication in a second frequency band; and The second communication device includes a first receiving unit for communication in the first frequency band and a second transceiver unit for communication in the second frequency band. The first communication device transmits instructions for the first frequency band from the first transmitting unit. If the second communication device receives the instruction from the first receiving unit, it activates the second transceiver unit and generates an authentication key for a response signal, and then transmits a response signal in the second frequency band containing the generated authentication key from the second communication device. The first communication device has a plurality of first transmitting units. After transmitting the instruction from any one of the plurality of first transmitting units, the signal strength measurement signal of the first frequency band is sequentially transmitted from the plurality of first transmitting units. The second communication device acquires the signal strength when the first receiving unit receives multiple signals for signal strength measurement. If the first communication device determines that the authentication key contained in the response signal received from the second communication device is valid, then the first transceiver unit sends a ranging request signal in the second frequency band requesting the transmission of ranging signals including the ID of the second communication device. If the second communication device receives the ranging request signal containing its own ID, it then transmits the ranging signal of the second frequency band from the second transceiver unit. The first communication device calculates the distance to the second communication device based on the ranging request signal and the ranging signal, and determines whether the source of the ranging signal is the legitimate second communication device or an illegitimate relay device based on the calculated distance. The first communication device has a second receiving unit that communicates in the third frequency band. The second communication device has a second transmitting unit that communicates in the third frequency band. After transmitting the ranging signal from the second transceiver unit, the second communication device transmits the position determination signal for the third frequency band from the second transmitting unit. The position determination signal is a signal that indicates the relative position of the plurality of first transmitting units and the second communication device based on the received strength of the plurality of signal strength measurement signals transmitted from the plurality of first transmitting units. In the first communication device, if the second receiving unit receives the position determination signal, the position of the second communication device is determined based on the relative positions of the plurality of first transmitting units and the second communication device represented by the position determination signal. After sending the ranging signal and before sending the position determination signal, the second communication device suppresses the power supply to the second transceiver for a specified period of time.

6. The authentication method according to claim 5, wherein, The second communication device has a main power supply unit. The second transceiver unit includes an auxiliary power supply unit and a power control unit that controls the power supply from the main power supply unit to the auxiliary power supply unit. The second communication device, through the power control unit, continuously limits the power supply from the main power supply unit to the auxiliary power supply unit for the predetermined time, thereby continuously suppressing the power supply to the second transceiver unit for the predetermined time.

7. The authentication method according to claim 5 or 6, wherein, If the second communication device determines that the distance between itself and the first communication device, inferred from the signal strength of the signal strength measuring signal, is greater than a predetermined distance, then it will not send the response signal.

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