JP6253004B1 - Electronic key system - Google Patents

Abstract

An electronic key system capable of facilitating a transition operation to a relay attack countermeasure when there are a plurality of electronic keys. An electronic key system (1) having an in-vehicle device (10) and a plurality of electronic keys (30) includes a master key (30A) and a spare key (30B), and a key search that the in-vehicle device (10) transmits at a predetermined time. The master key 30A is configured to return a presence response signal in response to the reception of the signal, and the control mode information indicating the control mode of the master key 30A in the presence response signal in response to the reception of the key search signal. The in-vehicle device 10 transmits the key search signal including the shared control mode information indicating the control mode of the master key 30A based on the control mode information, and the spare key 30B receives the key search signal. In response, the control mode of spare key 30B is set to the control mode indicated by the shared control mode information. [Selection] Figure 4

Description

  The present invention relates to an electronic key system, and more particularly to an electronic key system in which a predetermined vehicle operation is executed by an operation of a user carrying an electronic key.

  Conventionally, a vehicle having a smart keyless function is known. In such a vehicle, a user carrying an electronic key performs a predetermined operation only by performing a predetermined operation. By using the smart keyless function, for example, when the door is automatically unlocked and the door is closed simply by touching a sensor provided on the door knob (or simply pressing a switch provided on the door). The door is automatically locked only by operating the operation unit provided in the vehicle, and the engine is started only by pressing the engine switch.

  In order to execute such a smart keyless function, the in-vehicle device mounted on the vehicle due to the above operation and the electronic key carried by the user execute a predetermined communication process between them. Then, when this communication process is established (that is, authentication is established), a predetermined process is executed in the vehicle via the in-vehicle device.

  In the above communication processing, normally, the communicable distance from the electronic key to the in-vehicle device is relatively long (for example, several tens of meters or more), but the communicable distance from the in-vehicle device to the electronic key is set short (for example, about 1 m) Has been. For this reason, the user carrying the electronic key can effectively operate the smart keyless function when in the vicinity of the vehicle or in the vehicle. That is, when the user (that is, the electronic key) is located at a position away from the communication distance of about 1 m from the vehicle, for example, even if a third person touches the door knob sensor, the door is not unlocked.

  However, in recent years, it has become clear that there is a theft technique called relay attack. This technique activates the smart keyless function by amplifying communication radio waves with a repeater and establishing the communication process between the electronic key and the vehicle-mounted device far away from each other. In order to prevent theft by such a relay attack, as a relay attack countermeasure, a technique for stopping the smart keyless function by the user's intention has been proposed (for example, see Patent Document 1). With the technique described in Patent Document 1, for example, the user can temporarily stop the smart keyless function by performing a specific stop operation using an electronic key.

JP-A-2016-79600

  However, in the technique described in Patent Document 1, when there are a plurality of electronic keys for one vehicle, even if the smart keyless function is temporarily stopped using a certain electronic key as a countermeasure against a relay attack. This relay attack countermeasure may not function effectively for other electronic keys.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide an electronic key system capable of facilitating a transition operation to a relay attack countermeasure when a plurality of electronic keys are present. It is said.

  In order to achieve the above object, the present invention comprises an in-vehicle device mounted on a vehicle and a plurality of electronic keys capable of wireless communication with the in-vehicle device. In the normal mode, the in-vehicle device and the electronic key are provided. When a predetermined wireless communication process is established between the two, the in-vehicle device is configured to execute the predetermined process, and in the stop mode, the in-vehicle device is configured not to execute the predetermined process. In the electronic key system, the plurality of electronic keys include a master key and one or a plurality of spare keys, and a presence response signal is returned in response to reception of a key search signal transmitted by the in-vehicle device at a predetermined time. Control mode information indicating whether the master key control mode is the stop mode or the normal mode in response to the reception of the key search signal. Based on the control mode information included in the presence response signal received from the master key, the in-vehicle device transmits the key search signal including the shared control mode information indicating the control mode of the master key, and the spare key is The spare key control mode is set to the control mode indicated by the shared control mode information included in the key search signal in response to reception of the key search signal.

  According to the present invention configured as described above, the in-vehicle device transmits a key search signal at a predetermined time, and the electronic key that has received the key search signal is configured to return a presence response signal. The electronic key includes one master key and one or more spare keys, and each electronic key operates in a control mode of either a stop mode or a normal mode. When receiving the key search signal, the master key returns a presence response signal including the control mode information. The in-vehicle device includes the shared control mode information (indicating the control mode of the master key) in the key search signal based on the control mode information included in the presence response signal received from the master key. On the other hand, when the spare key receives the key search signal, the spare key updates the spare key control mode so that the spare key control mode matches the master key control mode based on the shared control mode information included in the key search signal.

  Accordingly, in the present invention, the user can automatically match the control mode of the spare key with the control mode of the master key without performing a special operation. Therefore, it is difficult for a situation in which the control modes of the master key and the spare key are different, and it is possible to improve the security level for relay attack countermeasures and the convenience of the smart keyless function. For example, if the user temporarily disables the smart keyless function in the master key (stop mode), the smart keyless function is automatically disabled in the spare key, and the relay attack countermeasures in the vehicle can function effectively. Become. Also, when the user returns the master key control mode to the normal mode, the spare key control mode can be automatically returned to the normal mode.

In the present invention, preferably, at least the master key includes a control mode switching operation unit for switching the control mode between the normal mode and the stop mode.
According to the present invention configured as described above, the user can switch the control mode of the master key between the normal mode and the stop mode by operating the control mode switching operation unit on the master key.

Also, in the present invention, preferably, in the predetermined wireless communication processing, when the electronic key control mode is the normal mode, the electronic key outputs a predetermined wireless signal in response to reception of the wireless signal transmitted by the in-vehicle device. When the electronic key control mode is the stop mode, a predetermined wireless signal is not returned even if the wireless signal transmitted by the in-vehicle device is received.
According to the present invention configured as described above, in the predetermined wireless communication process, the electronic key does not return a wireless signal to the in-vehicle device in the stop mode, and therefore the predetermined wireless communication process is not established. For this reason, a predetermined process is not performed by the vehicle equipment. As a result, in the present invention, when the control mode of each electronic key is the stop mode, the smart keyless function can be disabled (the countermeasure against relay attack is enabled).

In the present invention, preferably, the in-vehicle device transmits a key search signal toward the vehicle interior of the vehicle.
According to the present invention configured as described above, when the electronic key is present in the passenger compartment, the control mode of the electronic key can be automatically set to match the control mode of the master key. As a result, in the present invention, the user can automatically set the control mode of the electronic key without carrying out any special operation only by carrying the electronic key and getting on.

  According to the electronic key system of the present invention, it is possible to facilitate the transition operation to the relay attack countermeasure when there are a plurality of electronic keys.

It is a block diagram of the electronic key system of embodiment of this invention. It is explanatory drawing of the flow of a basic process of the smart keyless function in the electronic key system of embodiment of this invention. It is explanatory drawing of the flow of the switching process of the control mode of a smart keyless function in the electronic key system of embodiment of this invention. It is explanatory drawing of the flow of the sharing process of the control mode in the electronic key system of embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
First, the configuration of the electronic key system of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of an electronic key system.

  As shown in FIG. 1, the electronic key system 1 of this embodiment includes an in-vehicle device 10 mounted on a vehicle 2 and an electronic key 30 (30A, 30B) that can be carried by a user. In the electronic key system 1, a predetermined process is executed in the vehicle 2 only by a user carrying the electronic key 30 performing a predetermined operation by the smart keyless function. Specifically, the door lock mechanism is automatically unlocked when the user simply touches the door knob to open the door of the vehicle 2, and the door switch provided on the vehicle 2 is pressed when the door is closed. Only the door lock mechanism is automatically locked, and the engine is started only by pressing the engine switch.

  Each component of the electronic key system 1 is either a normal mode in which the smart keyless function is effectively activated or a stop mode in which the smart keyless function is temporarily disabled for relay attack countermeasures. On the other hand, it works selectively.

The in-vehicle device 10 includes a control unit 11, an LF transmission unit 13, an RF reception unit 15, a memory 17, and an operation unit 19.
The control unit 11 includes a CPU and the like, and controls signals (lock command signal, unlock command signal, engine start command signal) to the door lock mechanism 50 and the engine control system 52 of the vehicle 2 based on communication processing with the electronic key 30. ) Is output.

The LF transmission unit 13 includes a transmitter and a transmission antenna, and transmits an LF signal to the electronic key 30 based on a command from the control unit 11. The communicable distance of communication using the LF signal is set to be short so that communication is possible when the user is in the vicinity of the vehicle 2 or in the vehicle, and is, for example, about 1 m.
The RF receiving unit 15 includes a receiver and a receiving antenna, and outputs an RF signal received from the electronic key 30 to the control unit 11. The communicable distance of communication using the RF signal is set longer than that of the LF signal, and is, for example, about several tens of meters to 100 m.

  The memory 17 stores an application for the control unit 11 and necessary data. The memory 17 includes a key ID 20, a vehicle ID 22, and a stop mode flag 24 as data. The key ID 20 (20A, 20B) is unique ID information of each of the plurality of electronic keys 30 (30A, 30B) dedicated to the vehicle 2 (that is, the in-vehicle device 10). The vehicle ID 22 is unique ID information of the vehicle 2. The stop mode flag 24 (24A, 24B) is set corresponding to the key ID 20 (20A, 20B) of the plurality of electronic keys 30 (30A, 30B), and the smart keyless function is executed for each electronic key 30. Turns on when temporarily stopped (stop mode), and turns off when execution of the smart keyless function is valid (normal mode).

  In this embodiment, as will be described later, the electronic key 30A is a master key, the electronic key 30B is a spare key, and in the in-vehicle device 11, the memory 17 has a key ID 20A and a stop mode flag 24A as a master key. Set as a thing.

  The operation unit 19 includes a touch sensor 19a, a door switch 19b, and an engine switch 19c. The touch sensor 19a is provided on the door knob of the vehicle 2, and is arranged so that the user's hand touches when the user puts his hand on the door knob to open the door. The touch sensor 19a outputs a detection signal (operation signal) when the user's hand touches or approaches. The door switch 19b is provided in the vehicle 2 and can be pressed by the user when closing the door. The door switch 19b outputs an operation signal when pressed. The engine switch 19c is provided in the passenger compartment and can be pressed by the user when starting the engine. The engine switch 19c outputs an operation signal when pressed.

The door lock mechanism 50 is provided at each door of the vehicle 2, and when receiving a lock command signal and an unlock command signal from the vehicle-mounted device 10, the door lock mechanism 50 locks (unlocks) and unlocks the door, respectively. It has become.
The engine control system 52 includes a control unit that controls the engine of the vehicle 2, and starts the engine when an engine start command signal is received from the in-vehicle device 10.

  The electronic key 30 includes a plurality of electronic keys 30A and 30B. Note that there may be three or more electronic keys. Among the plurality of electronic keys 30, the electronic key 30 </ b> A (only one) is set as a master key (hereinafter also referred to as “master key 30 </ b> A”), and the other electronic key 30 </ b> B (s) is a spare key (hereinafter referred to as “master key 30 </ b> A”). Also referred to as “spare key 30B”. The basic configuration of the electronic keys 30A and 30B is the same.

  Each electronic key 30 includes a control unit 31, an LF reception unit 33, an RF transmission unit 35, a memory 37, and an operation unit 39. The in-vehicle device 10 and the electronic key 30 also function as a remote entry system in addition to the electronic key system. For this reason, the electronic key 30 is also used as a remote controller for the remote entry function.

  The control unit 31 includes a CPU and the like, and is configured to execute a communication process with the in-vehicle device 10, a smart keyless function pause process based on an operation of the operation unit 39, a return process from the pause, and the like. .

The LF reception unit 33 includes a receiver and a reception antenna, and outputs the LF signal received from the in-vehicle device 10 to the control unit 31.
The RF transmission unit 35 includes a transmitter and a transmission antenna, and transmits an RF signal to the in-vehicle device 10 based on a command from the control unit 31.

  The memory 37 stores an application for the control unit 31 and necessary data. The memory 37 includes a key ID 40, a vehicle ID 42, and a stop mode flag 44 as data. The key ID 40 is unique ID information of each electronic key 30. The vehicle ID 42 is unique ID information of the vehicle 2. The stop mode flag 44 is turned on when the execution of the smart keyless function is temporarily stopped (stop mode), and is turned off when the execution of the smart keyless function is valid (normal mode). .

  The operation unit 39 includes a lock switch 39a and an unlock switch 39b. In the electronic key system 1, the user uses the master key 30A to execute a specific stop operation with the lock switch 39a (for example, long press for 2 seconds, multiple presses, etc.) to activate the smart keyless function. It can be paused (i.e. transition to stop mode). In addition, the user operates from the pause state of the smart keyless function by executing a specific return operation with the unlock switch 39b using the master key 30A (for example, long press for 2 seconds, multiple presses, etc.). It is possible to return to the state (that is, shift to the normal mode).

  In this embodiment, in the master key 30A, the control mode can be switched between the stop mode and the normal mode by the operation of the operation unit 39. The control mode may be switched by operating the operation unit 39. However, even in this case, as described below, the control mode of the spare key 30B is changed so as to coincide with the control mode of the master key 30A at a predetermined time.

  Further, when the electronic key system 1 functions as a remote entry system, the user can unlock and lock the door of the vehicle 2 by operating the operation unit 39 of the electronic key 30. That is, when the user presses the lock switch 39a and the unlock switch 39b, RF signals (lock signal and unlock signal) are output from the electronic key 30, and the vehicle-mounted device 10 that has received these RF signals causes the door lock mechanism 50 to receive the RF signal. Lock or unlock

  In the present embodiment, the lock switch 39a and the unlock switch 39b are used for the temporary stop and return of the smart keyless function. However, the present invention is not limited to this, and a separate switch may be provided. Moreover, the vehicle equipment 10 and the electronic key 30 may have a display part (for example, LED etc.) which displays the control mode (normal mode or stop mode) which is operate | moving.

  Next, an outline of the smart keyless function in the electronic key system of this embodiment will be described with reference to FIG. FIG. 2 is an explanatory diagram of a basic processing flow of the smart keyless function. In FIG. 2, the electronic key 30 and the vehicle-mounted device 10 operate in either the normal mode or the stop mode.

  First, when a user carrying the electronic key 30 (30A or 30B) operates one of the operation units 19 provided in the vehicle 2 (S10), the control unit 11 of the in-vehicle device 10 is operated from the operation unit 19. An operation signal corresponding to the selected sensor or switch is received (S11). The control unit 11 transmits an LF signal based on the operation signal (S12). This LF signal is an authentication request signal and includes a vehicle ID 22.

  In the electronic key 30, the control unit 31 receives the LF signal via the LF receiving unit 33 (S21). When receiving the LF signal, the control unit 31 determines whether or not the electronic key 30 is in the stop mode (whether the stop mode flag 44 is on or off) (S22). If it is in the stop mode (S22; Yes), the process is terminated. On the other hand, when not in the stop mode (S22; No, normal mode), the control unit 31 transmits the RF signal via the RF transmission unit 35 and ends the process. This RF signal is an authentication response signal and includes a vehicle ID 42 and a key ID 40 of the electronic key 30.

  Note that, when the electronic key 30 receives the LF signal, the control unit 31 may execute the authentication process of the LF signal. In this authentication process, the vehicle ID 22 included in the LF signal and the vehicle ID 42 stored in the memory 37 can be collated. If they match, the control unit 31 executes the above processing (S22, S23). If they do not match, the control unit 31 ignores the received LF signal and ends the process.

  In the in-vehicle device 10, when the control unit 11 receives the RF signal returned from the electronic key 30 via the RF receiving unit 15 within a predetermined time from the transmission of the LF signal (S 13), the control unit 11 performs an authentication process of the RF signal. (S14). Specifically, the control unit 11 collates the vehicle ID 42 and key ID 40 included in the RF signal with the vehicle ID 22 and key ID 20 stored in the memory 17. If the RF signal is not received within a predetermined time from the transmission of the LF signal, the control unit 11 ends the process.

  In this authentication process, when the vehicle ID 42 and the vehicle ID 22 match, and the key ID 40 matches one of the stored key IDs 20A and 20B (authentication is established), the vehicle-mounted device 10 receives an RF signal from the corresponding electronic key 30. Therefore, the control unit 11 transmits a predetermined control signal (S15) and ends the process. On the other hand, when these IDs do not match (authentication is not established), the RF signal received by the in-vehicle device 10 is transmitted from other than the corresponding electronic key 30, and therefore the control unit 11 ignores the received RF signal. To end the process.

  As the predetermined control signal, when the touch sensor 19a is operated, an unlock command signal is output to the door lock mechanism 50, and when the door switch 19b is operated, a lock command signal is output to the door lock mechanism 50. When the engine switch 19c is operated, an engine start command signal is output to the engine control system 52.

  Thus, in the electronic key system 1, each electronic key 30 (30 </ b> A, 30 </ b> B) stores the stop mode flag 44, and the stop mode flag 44 is set regardless of the stop mode flag 24 stored in the in-vehicle device 10. It operates in the stop mode when on, and operates in the normal mode when the stop mode flag 44 is off.

  In the normal mode, the smart keyless function is in a valid state, and a predetermined process is executed in the vehicle 2 when a user carrying the electronic key 30 performs a predetermined operation. That is, in the normal mode, a predetermined wireless communication process (S12-S14, S21-S23) including transmission of an authentication request signal and return of an authentication response signal is executed between the in-vehicle device 10 and the electronic key 30. If communication is established, a predetermined process is automatically executed.

  On the other hand, in the stop mode, the smart keyless function is in an invalid state, and the electronic key 30 does not return an RF signal (authentication response signal) even if it receives an LF signal (authentication request signal). For this reason, since the vehicle equipment 10 cannot perform the process of step S13-S15, a predetermined process is not performed. Therefore, the user can prevent the door of the vehicle 2 from being opened by the relay attack by shifting the control mode of each electronic key 30A, 30B to the stop mode.

  In the example of FIG. 2, in the stop mode, the electronic key 30 is configured not to return an RF signal in order to temporarily disable the smart keyless function. You may comprise so that RF signal may be returned including the control mode information which shows operating in the stop mode. In this case, the in-vehicle device 10 is configured not to execute at least step S15 when the control mode information included in the received RF signal indicates the stop mode.

  In the example of FIG. 2, the control mode of each electronic key 30 is determined according to the stop mode flag 44 stored in the electronic key 30. However, the present invention is not limited to this, or in addition to this, You may comprise so that the control mode of each electronic key 30 may be determined according to stop mode flag 24A, 24B which the vehicle equipment 10 memorize | stores corresponding to the keys 30A, 30B.

  Specifically, due to the user (or a third party attempting a relay attack) operating the operation unit 19 of the vehicle 2, transmission / reception of LF signals (S12, S21), transmission / reception of RF signals (S23, S13) When the authentication process (S14) (and the stop mode determination process (S22) as necessary) is executed, in the in-vehicle device 10, the control unit 11 stores the stop mode flag 24 stored in the in-vehicle device 10. Accordingly, the control mode of the electronic key 30 that has transmitted the RF signal (authentication response signal) can be determined. That is, the control mode is determined by the stop mode flag 24 corresponding to the key ID 20 that matches the key ID 40 included in the received RF signal (authentication response signal).

  In this case, when the determined control mode is the stop mode (when the stop mode flag 24 is on), the control unit 11 does not execute the process of step S15, and when the control mode is the normal mode (the stop mode flag 24). If is OFF), the process of step S15 is executed. Therefore, when configured in this way, the control mode of each electronic key 30A, 30B is determined according to at least the stop mode flag 24 stored in the in-vehicle device 10.

  In the stop mode, the user who carries the electronic key 30 cannot open the door even if the operation unit 19 (touch sensor 19a) is operated. However, in this case, the user can open the door by operating the unlock switch 39b of the electronic key 30 using the normal remote entry function.

  Next, referring to FIG. 3, the control mode switching process of the smart keyless function in the electronic key system of this embodiment will be described. FIG. 3 is an explanatory diagram of the flow of the process for changing the control mode of the smart keyless function.

  The user can temporarily disable the smart keyless function for relay attack countermeasures or the like by his / her own intention. First, in the master key 30A, when the user executes a control mode switching operation (stop operation, return operation) using the operation unit 39 (control mode switching operation unit), the control unit 31 receives a control signal (stop) from the operation unit 39. (Operation signal, return operation signal) is received (S31), the on / off state of the stop mode flag 44 is switched in accordance with the control signal to change the control mode to the stop mode or the normal mode (S32), and the process is terminated.

  Therefore, when the user performs a stop operation on the operation unit 39 using the master key 30A, the stop mode flag 44 is set to ON and the control mode is set to the stop mode. On the other hand, when the user performs a return operation on the operation unit 39 using the master key 30A, the stop mode flag 44 is set to OFF and the control mode becomes the normal mode.

  As described above, in the case where the control mode can be switched also in the spare key 30B, similarly, the stop mode flag 44 is set to ON by the stop operation, and the control mode is set to the stop mode. The stop mode flag 44 is set to OFF, and the control mode becomes the normal mode.

Next, control mode sharing processing in the electronic key system 1 of the present embodiment will be described with reference to FIG. FIG. 4 is an explanatory diagram of the flow of control mode sharing processing.
In the present embodiment, the control mode of the master key 30A (and the spare key 30B) is individually switched by a control mode switching operation. Therefore, the control modes of the master key 30A and the spare key 30B can be different. For example, even if the control mode of the master key 30A is the stop mode, there may be a situation where the control mode of the spare key 30B is the normal mode.

  In this case, as can be seen with reference to FIG. 2, in the combination of the spare key 30 </ b> B and the vehicle-mounted device 10, the door of the vehicle 2 may be opened by the relay attack. That is, since the spare key 30B is not in the stop mode (S22; No), the RF signal is transmitted (S23). The in-vehicle device 10 receives the RF signal (S13), and authentication is established (S14), so that a predetermined control signal is transmitted (S15).

  For this reason, in the present embodiment, in a predetermined situation, a control mode sharing process for automatically matching the control mode of the spare key 30B with the control mode of the master key 30A is executed. Therefore, when the control mode of the master key 30A is changed to the stop mode, the control mode of the spare key 30B is automatically changed to the stop mode.

  As shown in FIG. 4, for example, the in-vehicle device 10 exists in the vehicle interior at regular intervals, irregular intervals, or in response to occurrence of a specific event (specific vehicle operation or the like) while the engine is operating. An LF signal (key search signal) for searching for the electronic key 30 is transmitted (S41).

  That is, in the in-vehicle device 10, the control unit 11 transmits an LF signal (key search signal) to the vehicle interior via the LF transmission unit 13 at a predetermined time. The key search signal includes the vehicle ID 22 and the shared control mode information, and instructs the electronic key 30 that has received this signal to return the presence response signal, and updates the control mode to the electronic key 30 (spare key 30B). Is commanded.

  The shared control mode information indicates the control mode (normal mode or stop mode) of the master key 30A recognized by the in-vehicle device 10. That is, the shared control mode information indicates the control mode indicated by the stop mode flag 24A corresponding to the master key 30A among the stop mode flags 24A and 24B stored in the in-vehicle device 10. Therefore, when the stop mode flag 24A is on, the shared control mode information indicates the stop mode, and when the stop mode flag 24A is off, the shared control mode information indicates the normal mode.

  In the electronic key 30 present in the passenger compartment, the control unit 31 receives an LF signal (key search signal) via the LF receiving unit 33 (S51). When the electronic key 30 receives the LF signal and the electronic key 30 is the spare key 30B (S52; Yes), the control unit 31 updates the stop mode flag 44 (S53), and proceeds to the process of step S54. Transition. On the other hand, when the electronic key 30 that has received the LF signal is the master key 30A (S52; No), the control unit 31 proceeds to the process of step S54.

  In the process of step S53, the control unit 31 sets the stop mode flag 44 to ON when the share control mode information indicates the stop mode based on the share control mode information included in the received LF signal. When the shared control mode information indicates the normal mode, the stop mode flag 44 is set to OFF. As a result, the control mode of the spare key 30B matches the control mode of the master key 30A.

  Next, in the process of step S54, the control unit 31 returns an RF signal (presence response signal) via the RF transmission unit 35 (S54), and ends the process. This presence response signal includes the key ID 40 and vehicle ID 42 of the electronic key 30 and control mode information, and informs the vehicle-mounted device 10 that the electronic key 30 exists in the vehicle interior and the control mode of the electronic key 30. It is.

  The control mode information indicates the current control mode (normal mode or stop mode) of the electronic key 30. That is, when the stop mode flag 44 stored in the electronic key 30 is on, the control mode information indicates the stop mode, and when the stop mode flag 44 is off, the control mode information indicates the normal mode.

  Note that, when the electronic key 30 receives an LF signal (key search signal), the control unit 31 may perform authentication processing of the LF signal. In this authentication process, the vehicle ID 22 included in the LF signal and the vehicle ID 42 stored in the memory 37 can be collated. And when these correspond, the said process (S52-S54) is performed, and when these do not correspond, the received LF signal is disregarded and a process is complete | finished.

  In the in-vehicle device 10, when the control unit 11 receives the RF signal returned from the electronic key 30 in the vehicle interior within the predetermined time from the transmission of the LF signal via the RF receiving unit 15 (S 42), this RF signal (existence) On the basis of the response signal), the stop mode flag 24 corresponding to the electronic key 30 that transmitted the RF signal is updated (S43), and the process is terminated.

  Specifically, the control unit 11 selects the stop mode flag 24 corresponding to the key ID 20 that matches the key ID 40 included in the received RF signal from the stop mode flags 24A and 24B stored in the memory 17, The selected stop mode flag 24 is set to match the control mode specified by the control mode information included in the received RF signal (S43). Thereby, the stop mode flag 24 (on or off) of the in-vehicle device 10 matches the stop mode flag 44 (on or off) of the electronic key 30.

  Note that authentication may be performed when receiving an RF signal (presence response signal). In this authentication process, the control unit 11 collates the vehicle ID 42 and the key ID 40 included in the RF signal with the vehicle ID 22 and the key ID 20 stored in the memory 17 as in step S14 of FIG. In this authentication process, when the vehicle ID 42 and the vehicle ID 22 match, and the key ID 40 matches one of the stored key IDs 20A and 20B (authentication is established), the in-vehicle device 10 is one of the corresponding electronic keys 30. Since the RF signal is received from the controller 11, the control unit 11 executes the process of step S43. On the other hand, in the authentication process, when these IDs do not match (authentication is not established), the RF signal received by the in-vehicle device 10 is transmitted from other than the corresponding electronic key 30, and therefore the control unit 11 receives the received RF Ignore the signal and end the process.

  Note that when any electronic key 30 is not present in the vehicle interior, the RF signal (presence response signal) is not received within a predetermined time. The process is terminated without changing 24.

  When a plurality of electronic keys 30 are present in the passenger compartment, the control mode sharing process shown in FIG. 4 is performed between all of these electronic keys 30 and the vehicle-mounted device 10.

  Thus, in the present embodiment, the control mode of the spare key 30B can be automatically updated so as to match the control mode of the master key 30A. Therefore, in the present embodiment, the user can automatically change the control mode of each of the plurality of electronic keys 30 to the control mode of the master key 30A using the vehicle interior key search function without performing a special operation. Can be matched.

Next, the operation of the electronic key system 1 of the present embodiment will be described.
In the present embodiment, the vehicle-mounted device 10 is configured to transmit a key search signal at a predetermined time, and the electronic key 30 (30A, 30B) that has received the key search signal returns a presence response signal. The electronic key 30 includes one master key 30A and one or more spare keys 30B, and each electronic key 30 operates in a control mode of either a stop mode or a normal mode. When receiving the key search signal, the master key 30A returns a presence response signal including the control mode information. The in-vehicle device 10 includes the shared control mode information (indicating the control mode of the master key 30A) in the key search signal based on the control mode information included in the presence response signal received from the master key 30A. On the other hand, when the spare key 30B receives the key search signal, the spare key 30B control mode is set so that the control mode of the spare key 30B matches the control mode of the master key 30A based on the shared control mode information included in the key search signal. Update.

  Thereby, in this embodiment, the user can automatically match the control mode of the spare key 30B with the control mode of the master key 30A without performing any special operation. Therefore, a situation in which the control modes of the master key 30A and the spare key 30B are different is unlikely to occur, and it is possible to improve the security level for relay attack countermeasures and improve the convenience of the smart keyless function. For example, when the user temporarily disables the smart keyless function in the master key 30A (stop mode), the smart keyless function is automatically disabled in the spare key 30B, and the relay attack countermeasures in the vehicle 2 are made to function effectively. Is possible. Even when the user returns the control mode of the master key 30A to the normal mode, the control mode of the spare key 30B can be automatically returned to the normal mode.

  In the present embodiment, at least the master key 30A includes an operation unit 39 (control mode switching operation unit) for switching the control mode between the normal mode and the stop mode. Thereby, in this embodiment, the user can switch the control mode of the master key 30A between the normal mode and the stop mode by operating the operation unit 39 on the master key 30A.

  In the present embodiment, the electronic key 30 is mounted on the vehicle when the control mode of the electronic key 30 is the normal mode (S22; No) in a predetermined wireless communication process (S12-S14, S21-S23 in FIG. 2). In response to reception of the LF signal (authentication request signal) transmitted by the machine 10 (S21), an RF signal (authentication response signal) is returned (S23), but when the control mode of the electronic key 30 is the stop mode ( S22; Yes) Even if the LF signal (authentication request signal) transmitted by the in-vehicle device 10 is received (S21), the RF signal (authentication response signal) is not returned. Thereby, in this embodiment, in the predetermined wireless communication process, the electronic key 30 does not return an RF signal to the in-vehicle device 10 in the stop mode, and therefore the predetermined wireless communication process is not established. For this reason, a predetermined process (S15) is not performed by the vehicle equipment 10. Thereby, in this embodiment, when the control mode of each electronic key 30 is a stop mode (S22; Yes), a smart keyless function can be made invalid (a countermeasure against a relay attack is effective).

  In the present embodiment, the in-vehicle device 10 transmits a key search signal toward the vehicle interior of the vehicle 2. Thereby, in this embodiment, when the electronic key 30 exists in a vehicle interior, the control mode of the electronic key 30 can be automatically set to match the control mode of the master key 30A. As a result, the user can automatically set the control mode of the electronic key 30 without carrying out any special operation just by carrying the electronic key 30 and getting on.

DESCRIPTION OF SYMBOLS 1 Smart keyless system 2 Vehicle 10 Car equipment 30, 30A, 30B Electronic key 50 Door lock mechanism 52 Engine control system

Claims (4)

A vehicle-mounted device mounted on a vehicle and a plurality of electronic keys capable of wireless communication with the vehicle-mounted device, and in a normal mode, a predetermined wireless communication process is established between the vehicle-mounted device and the electronic key. A predetermined process is executed by the in-vehicle device, and in the stop mode, the predetermined process is not executed by the in-vehicle device.
The plurality of electronic keys include a master key and one or a plurality of spare keys, and are configured to return presence response signals in response to reception of a key search signal transmitted by the in-vehicle device at a predetermined time,
At least the master key transmits control mode information indicating whether the control mode of the master key is the stop mode or the normal mode in response to reception of the key search signal in the presence response signal. And
Based on the control mode information included in the presence response signal received from the master key, the in-vehicle device transmits the key search signal including the shared control mode information indicating the master key control mode,
The spare key sets the control mode of the spare key to the control mode indicated by the shared control mode information included in the key search signal in response to receiving the key search signal.   The electronic key system according to claim 1, wherein at least the master key includes a control mode switching operation unit for switching a control mode between the normal mode and the stop mode.   When the electronic key control mode is the stop mode in the predetermined wireless communication process, the electronic key does not send back a predetermined wireless signal even if it receives a wireless signal transmitted by the in-vehicle device. Item 2. The electronic key system according to Item 1.   The electronic key system according to claim 1, wherein the in-vehicle device transmits the key search signal toward a vehicle interior of the vehicle.

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