JP2011052505A - Electronic key system and electronic key - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic key system which prevents the occurrence of illegal operation of a communication object due to relay attack. <P>SOLUTION: This electronic key system can perform the operation such as door locking and engine operation in a vehicle 2 when an electronic key 1 receives a request signal Srq transmitted from the vehicle 2 and ID checking through smart communication for making the electronic key 1 return an ID code signal Sid into the vehicle 2 is satisfied. This electronic key system includes a travel detection sensor 14 for detecting travel of the electronic key 1, an inside/outside determining part 11c for determining whether the electronic key 1 exists outside the vehicle 2 or inside the vehicle, and a start control part 11b permitting the smart communication so far as it is determined that the electronic key 1 is outside the vehicle based on the result of determination by the inside/outside determining part 11c and the travel detection sensor 14 detects travel of the electronic key 1 and permitting the smart communication irrespective of the result of detection by the travel detection sensor 14 when it is determined that the electronic key 1 is inside the vehicle based on the result of determination by the inside/outside determining part 11c. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electronic key system and an electronic key that use an electronic key capable of wirelessly transmitting an ID code and check the correctness of the key by performing ID verification with the communication target.

  2. Description of the Related Art In recent years, in vehicle key systems, an electronic key system that uses an electronic key that can wirelessly transmit an ID code as a unique key code of the key is used as a vehicle key in various vehicle types. In this electronic key system, there is a key operation free system that does not require button operation on the electronic key when the ID code is transmitted from the electronic key, that is, the ID code is automatically transmitted from the electronic key. In this system, a request communication area is formed by a LF band signal as an ID code return request around the vehicle, and when the electronic key enters the communication area and receives the request, the electronic key sends the ID code to the RF band signal. Reply to the vehicle with When the vehicle receives the ID code, the vehicle performs ID verification. If the ID verification is established, the vehicle permits or executes door lock locking / unlocking and engine start (for example, see Patent Document 1).

JP 2002-29385 A

  By the way, as a technique for performing ID verification illegally, for example, by using a repeater that can relay a request from the vehicle and an ID code from the electronic key, the electronic key does not exist in the communication area of the vehicle. There is also a relay attack that enables transmission and reception between the electronic key and the vehicle. For this reason, when the user is far away from the vehicle and indifferent to the vehicle, the malicious third party can illegally reach the vehicle by the relay attack with the ID code of the electronic key possessed by the user, There is no denying the possibility that ID verification will be established unintentionally.

  The distance between the vehicle and the repeater and the distance between the electronic key and the repeater must be less than the communication distance between the vehicle and the electronic key, that is, less than a few meters, and the communication time must be less than a few nanoseconds. As such, it has not been realized with current technology and no actual damage has been reported. However, if this relay attack is realized, the door lock may be unlocked by a third party and the engine may be started. Therefore, it has been desired to suppress unauthorized operation of equipment mounted on the vehicle due to relay attack.

  In addition, this problem is not limited to the electronic key applied to the vehicle as described above. For example, in an electronic key system in which the electronic key is used as a key for a building (house) door, the door is similarly opened by a relay attack. It can be assumed that the lock is illegally unlocked. Therefore, even in such an electronic key system for buildings, there is a situation that requires a means for preventing various devices provided in the building from being operated illegally by a relay attack.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an electronic key system and an electronic key that can prevent an unauthorized operation of a communication target due to a relay attack from occurring.

Hereinafter, means for achieving the above-described object and its operation and effects will be described.
According to the first aspect of the present invention, when the electronic key receives a reply request for the ID code transmitted from the communication target, ID verification is performed by smart communication in which the electronic key returns the ID code to the communication target. In the electronic key system that enables operation of the device installed in the communication target if the ID verification is established, the electronic key system is provided on the electronic key and detects that the electronic key is carried by the user and moved. A movement detection means; a key position inside / outside determination means provided on at least the electronic key side of the electronic key and the communication object, for determining whether the electronic key exists outside or inside the communication object; and the electronic When the electronic key is provided outdoors according to a determination result of the key position inside / outside determination means, the smart communication performed outdoors is performed by the movement detection means. Therefore, if the movement of the electronic key is detected as a condition, and the electronic key is in the room based on the determination result of the key position inside / outside determination means, the smart communication performed indoors is detected by the movement detection means. The gist of the invention is that it includes communication permission / prohibition setting means that permits regardless of the result.

  Normally, when a device installed in a communication target is operated with an electronic key from outside, the user can operate the device if the user approaches the communication target with the electronic key and ID verification by smart communication is established. . Therefore, according to the above configuration, the electronic key is provided with movement detection means capable of detecting movement (movement) of the key, and only when the movement of the electronic key is detected by the movement detection means, execution of smart communication is permitted. To do. For this reason, even if a non-moving electronic key placed far away from the communication target is communicated with the communication target by a relay attack by a third party, the electronic key is not moving at this time, The electronic key does not perform smart communication. Therefore, since it is possible to make smart communication based on relay attack unsuccessful, it is possible to make it difficult for an unauthorized operation of a communication target by a third party to occur.

  In addition, smart communication in the room can be executed without restriction regardless of whether or not the electronic key is moved. By the way, in the case of indoor smart communication, if the movement of the electronic key is the same as in the outdoor environment, for example, if the electronic key is left unattended in the room or if the electronic key is left in the room, the smart communication will be performed in the vehicle. Even you will not be able to do this. However, in the case of this configuration, indoor smart communication can be executed without restriction, and thus the above-described processing can be performed without any problem. Therefore, even if the electronic key is misplaced or the like, the communication target can notice the presence of the electronic key, and an operation such as a misplacement notification can be performed assuming that the electronic key exists in the room.

  According to a second aspect of the present invention, in the electronic key system according to the first aspect, the key position inside / outside determination means is provided in the communication target, and the electronic key is placed outdoors during the smart communication outside the room. Sending control means for sending inside / outside information for notifying that there is an outside information from the room information sending means, and for sending out the inside / outside information for notifying that the electronic key is in the room at the time of the smart verification in the room. And a determination unit that is provided in the electronic key and determines whether the electronic key exists outside or inside the room based on the inside / outside information transmitted from the outdoor information transmission unit or the indoor information transmission unit. Its gist is that it has been prepared.

  According to this configuration, it is possible to recognize whether the electronic key is present outdoors or indoors based on the inside / outside information transmitted from the outdoor information transmitting unit and the indoor information transmitting unit. For this reason, the electronic key can easily confirm whether the electronic key is outside or indoors from the radio signal received from the communication target.

  According to a third aspect of the present invention, in the electronic key system according to the first or second aspect, the communication enable / disable setting unit is configured such that the electronic key is in a state where the movement detection unit detects movement of the electronic key. The gist of the present invention is to limit the operation of smart communication of the electronic key by executing the smart key in an outdoor state for a certain period of time.

  According to this configuration, since the operation restriction applied to the electronic key during outdoor smart communication is determined to keep the electronic key activated for a certain period of time, it is easy to turn on the electronic key for a certain period of time. By controlling, it becomes possible to restrict the operation of the electronic key.

  The invention according to claim 4 performs ID verification by smart communication that returns an ID code to the communication target when receiving a reply request of the ID code transmitted from the communication target, and if the ID verification is established, In an electronic key capable of operating a device installed in a communication target, movement detection means for detecting that the electronic key is carried by a user, and the electronic key is located outside and indoors of the communication target A key position inside / outside determination means for determining whether the electronic key is present, and when the electronic key is outside the room according to a determination result of the key position inside / outside determination means, the movement detection means detects the movement of the electronic key. If the condition permits the smart communication and the electronic key is in the room according to the determination result of the key position inside / outside determination means, regardless of the detection result of the movement detection means That a communication availability setting means for permitting the serial smart communication has as its gist.

  ADVANTAGE OF THE INVENTION According to this invention, the electronic key system and electronic key which can make it difficult to generate | occur | produce the unauthorized operation of the communication object by a relay attack can be provided.

The block diagram which shows schematic structure of an electronic key system. The top view of the vehicle which shows the communication area of an electronic key system. The time chart which shows the communication operation | movement at the time of ID collation outside a vehicle. The schematic diagram which shows a relay attack. The time chart which shows the communication operation | movement at the time of ID collation in a vehicle.

Hereinafter, an embodiment in which an electronic key system according to the present invention is embodied in a vehicle will be described with reference to FIGS.
As shown in FIG. 1, the vehicle 2 can perform vehicle operations such as locking / unlocking a door lock as an apparatus and starting and stopping an engine without actually operating a vehicle key. The electronic key system, so-called key operation free system is installed. Here, the vehicle 2 is a communication target of the electronic key 1. In the key operation free system, an electronic key 1 capable of transmitting a key-specific ID code by wireless communication is used as a vehicle key, and ID verification is executed with the vehicle 2 by narrow area wireless communication.

  In the key operation free system, there is an entry system in which ID verification is automatically performed when the vehicle 2 approaches or leaves the vehicle 2 and door lock / unlock is permitted. This will be described below. The vehicle 2 includes a verification ECU (Electronic Control Unit) 21 that performs ID verification when performing narrow-area wireless communication (hereinafter referred to as smart communication) with the electronic key 1, and the vehicle 2. And a main body ECU 31 for managing the power supply system. The verification ECU 21 includes an outside LF transmitter 22 embedded in each door of the vehicle 2 and capable of transmitting an LF (Low Frequency) band signal to the outside of the vehicle, and an LF band radio signal embedded in the vehicle under the floor of the vehicle. An in-vehicle LF transmitter 23 capable of transmitting and an RF receiver 24 embedded in a vehicle body or the like behind the vehicle and capable of receiving radio signals in an RF (Radio Frequency) band are connected. For example, a main body ECU 31 that manages door lock locking / unlocking and the like is connected to the verification ECU 21 via an in-vehicle LAN (Local Area Network) 30.

  On the other hand, the electronic key 1 is provided with a communication control unit 11 as a control unit for performing wireless communication with the vehicle 2 according to the electronic key system. The communication control unit 11 includes a memory 11a in which an ID code is stored as a unique key code. Connected to the communication control unit 11 are an LF reception unit 12 capable of receiving an LF band signal transmitted externally and an RF transmission unit 13 capable of transmitting an RF band signal in accordance with a command from the communication control unit 11. Yes. The communication control unit 11 corresponds to a control unit, the LF reception unit 12 corresponds to a reception unit, and the RF transmission unit 13 corresponds to a transmission unit.

  When the vehicle is parked, the verification ECU 21 intermittently transmits a vehicle exterior request signal Srqo from the vehicle exterior LF transmitter 22 to form a vehicle exterior communication area Ao (see FIG. 2) around the vehicle 2. Attempts to establish smart communication (external communication). When the electronic key 1 enters the outside communication area Ao and receives the outside request signal Srqo by the LF receiving unit 12 and the outside communication is established, the electronic key 1 responds to the outside request signal Srqo in its own memory 11a. An ID code signal Sid including the registered ID code is returned from the RF transmitter 13. The verification ECU 21 compares the ID code of the ID code signal Sid returned by the electronic key 1 with the ID code registered in its own memory 21a and confirms that ID verification (external vehicle verification) is established. Permits the locking and unlocking of In this permitted state, the verification ECU 21 causes the main body ECU 31 to drive the door lock device 38 to unlock the door lock when the touch sensor 28 of the outside door handle 27 as the operation means is touch-operated. On the other hand, when the lock button 29 of the vehicle exterior door handle 27 is pressed, the verification ECU 21 causes the main body ECU 31 to drive the door lock device 38 to lock the door lock.

  Further, the electronic key system includes a one-push engine start system as a function capable of performing an engine start / stop operation only by a simple switch operation without requiring an actual vehicle key operation at the time of engine start / stop operation. The one-push engine start system will be described below. The vehicle 2 is provided with an engine ECU 32 that performs engine ignition control and fuel injection control on the basis of the result of ID verification establishment by the verification ECU 21. The engine ECU 32 is connected to various ECUs such as the verification ECU 21 through the in-vehicle LAN 30. The driver's seat of the vehicle 2 is provided with an engine switch 33 that is operated when switching the power supply state (power supply position) of the vehicle 2. Each time the engine switch 33 is pushed, the power state is repeatedly changed in the order of ACC on → IG on → power off. When the engine is operated with the brake pedal depressed when the engine is stopped, the engine is switched to start. .

  When the verification ECU 21 recognizes, for example, by the courtesy switch 37 that the driver has boarded after the door lock is unlocked after the vehicle external verification has been established, the vehicle request signal from the vehicle LF transmitter 23 is detected. Srqi is transmitted to form an in-vehicle communication area Ai (see FIG. 2) throughout the vehicle. The verification ECU 21 receives the ID code signal Sid returned by the electronic key 1 entering the in-vehicle communication area Ai and the smart communication (in-vehicle communication) is established by the RF receiver 24, and is registered in its own memory 21a. By comparing the ID code with the ID code of the electronic key 1, smart verification (in-vehicle verification) is performed as ID verification, and when it is confirmed that the in-vehicle verification is established, switching of the power supply state by the engine switch 33 is permitted.

  The ID verification is encrypted communication encrypted by challenge response authentication. In challenge response authentication, the vehicle 2 sends a challenge signal Scc (external challenge signal Scco, in-vehicle challenge signal Scci) to the electronic key 1 at the time of ID verification, and causes the electronic key 1 to calculate the response of the challenge signal Scc. This is a kind of authentication in which the vehicle 2 confirms whether Sre takes a correct calculation result. When the verification ECU 21 receives the response signal Sre from the electronic key 1 as a calculation result for the challenge signal Scc, the verification ECU 21 compares the response of the electronic key 1 with the response calculated by itself and verifies the response verification. One condition for ID verification is established.

  As shown in FIG. 1, in the electronic key system of this example, a sensor function is added to the electronic key 1, and the electronic key 1 is fixed only when vibration or tilt of the electronic key 1 is detected by this sensor function. An electronic key power supply switching function is provided that enables the electronic key 1 to be in smart communication only for the time. Further, the electronic key power supply switching function of this example controls the power supply of the electronic key 1 by the sensor function at the time of external verification, but disables the power control of the electronic key 1 by the sensor function at the time of internal verification. The electronic key 1 is operated in a normal state.

  In this case, the electronic key 1 is provided with a movement detection sensor 14 as movement detection means for detecting whether vibration or tilt is generated with respect to the electronic key 1. By the way, when the user moves with the electronic key 1, the electronic key 1 is inclined or vibrated. Therefore, the movement detection sensor 14 can detect that the electronic key 1 is carried and moved by detecting vibrations and inclinations generated in the electronic key 1. The movement detection sensor 14 includes, for example, a vibration sensor, an inclination sensor, and the like, and outputs a detection signal to the communication control unit 11.

  The communication control unit 11 is provided with an activation control unit 11b as a communication availability setting unit that controls activation of the electronic key 1 based on a detection signal from the movement detection sensor 14. Based on the detection signal from the movement detection sensor 14, the activation control unit 11 b detects the presence or absence of vibration or tilt generated in the electronic key 1 when the electronic key 1 is carried and moved by the user. When the activation control unit 11b detects that the electronic key 1 is moving from the movement detection sensor 14, the activation control unit 11b is in a state where the smart communication is possible for a certain period of time, that is, during the activation time T necessary for the smart communication to make a round. The communication control unit 11 (electronic key 1) is switched to the energized state. The electronic key 1 returns to a stopped state (power-off state) when the activation time T has elapsed since the latest vibration detection. Note that the energized state includes, in a broad sense, a state in which power is supplied to the communication control unit 11 but is not in a power-on state.

  The verification ECU 21 is provided with a transmission control unit 21b as transmission control means for controlling signal transmission from the vehicle 2. The transmission control unit 21b causes the outside request signal Srqo sent from the outside LF transmitter 22 to include the outside information notifying that the electronic key 1 is outside the vehicle, and sends the request from the inside LF transmitter 23. The signal Srqi is transmitted by including in-vehicle information notifying that the electronic key 1 is in the vehicle. That is, the transmission control unit 21b transmits the signal transmitted from the vehicle 2 including the inside / outside information indicating whether the vehicle is outside or inside the vehicle, and the electronic key 1 receives the signal including the inside / outside information, thereby receiving the electronic key. The vehicle 2 is notified whether 1 is outside the vehicle or inside the vehicle. Here, the inside / outside information is a 1-bit code indicated by “0” when the information is outside the vehicle, and “1” when the information is inside the vehicle. Also, the internal / external information of this example is included in the response signal Sre returned from the electronic key 1 to the vehicle 2 at the time of response authentication in smart communication, and is transmitted to the vehicle 2. The outside LF transmitter 22 corresponds to outside information transmitting means, and the inside LF transmitter 23 corresponds to inside information transmitting means. Further, the outside of the vehicle corresponds to the outside, and the inside of the vehicle corresponds to the room.

  The LF receiver 12 is provided with an analog front end (AFE: Analog Front End) 12a as an interface circuit for a reception function. The analog front end 12a is, for example, a circuit that performs A / D conversion, amplification, demodulation, and the like of received radio waves. The analog front end 12a determines whether or not the wake signal Swk sent first from the vehicle 2 during smart communication corresponds to itself. The analog front end 12a performs this wake collation as a pair confirmation for checking whether the vehicle 2 in the communication established state forms a pair with the electronic key 1. When the electronic key 1 receives the wake signal Swk, the electronic key 1 recognizes that the vehicle 2 forms a pair, switches the communication control unit 11 to an activated state (power-on state), and starts smart communication.

  The communication control unit 11 is provided with an inside / outside determination unit 11c as key position inside / outside determination means for determining whether the electronic key 1 is located outside or inside the vehicle. The inside / outside determination unit 11c can determine only when the communication control unit 11 is in the activated state, and determines the key position by checking whether the smart communication is performed in the vehicle or outside the vehicle. When the inside / outside determination unit 11c recognizes that the vehicle exists outside the vehicle based on the inside / outside information of the signal received in the activated state, the inside / outside determination unit 11c sets a vehicle outside flag in the memory 11a. Further, when the inside / outside determination unit 11c recognizes that the vehicle is present in the vehicle based on the inside / outside information of the signal received in the activated state, the inside / outside determination unit 11c sets an in-vehicle flag in the memory 11a. Since any flag is set based on the last received internal / external information in the memory 11a, when a different flag has already been set, the different flag is defeated and a new flag is set.

  The activation control unit 11b sets whether or not the electronic key 1 is activated based on the determination result of the inside / outside determination unit 11c. For example, when the in-vehicle flag is set in the memory 11a, the activation control unit 11b invalidates the activation based on the presence / absence of the movement detection of the movement detection sensor 14, and sets the activation state regardless of the movement detection of the movement detection sensor 14. In addition, when the vehicle outside flag is set in the memory 11a, the activation control unit 11b operates so as to permit activation if there is a movement detection of the movement detection sensor 14, and not activate if there is no movement detection.

Next, a specific example of the communication operation by the electronic key system of this example will be described with reference to FIGS.
As shown in FIG. 3, when executing smart communication with the electronic key 1, the verification ECU 21 first sends a wake signal Swk to the outside LF transmitter to activate the electronic key 1 that is in a stopped state (sleep state). Make a call from 22. The wake signal Swk is repeatedly transmitted from the outside LF transmitter 22 at regular intervals, and the presence or absence of the electronic key 1 around the vehicle 2 is monitored. Since the electronic key 1 should have received the out-of-vehicle request signal Srqo when getting into the vehicle 2 and getting off during the previous smart communication, it is assumed that the out-of-vehicle flag is set in the memory 11a of the electronic key 1.

  Here, for example, it is assumed that a user who has the electronic key 1 registered in the vehicle 2 approaches the vehicle 2. At this time, since the electronic key 1 is carried and moved by the user, the electronic key 1 is vibrated or tilted. Therefore, the movement detection sensor 14 detects vibrations and tilts generated in the electronic key 1 and outputs this detection signal to the activation control unit 11b. Based on this detection signal, the activation control unit 11b recognizes that the electronic key 1 is being carried by the user and moves the communication control unit 11 from the previous stop state (power-off state). Switch to the energized state. At this time, the communication control unit 11 enters a sleep state (standby state) waiting for switching to power-on. The activation control unit 11b turns on the activation state, that is, the power source during the activation time T as the time required for one round of smart communication. The measurement of the activation time T is reset every time a movement detection signal is received from the movement detection sensor 14, and is calculated as the elapsed time from the movement detection signal received last.

  When the electronic key 1 enters the communication area of the wake signal Swk of the LF transmitter 22 outside the vehicle, the LF receiver 12 executes wake verification. Note that the LF receiving unit 12 is always activated without depending on the power on / off of the communication control unit 11, and therefore can always perform wake verification regardless of the power state of the communication control unit 11. When the LF reception unit 12 confirms the establishment of the wake collation, the LF reception unit 12 switches the communication control unit 11 from the sleep state (standby state) until then to the activated state. At this time, since the communication control unit 11 is in the energized state, it is possible to switch from the sleep state to the activated state without any problem. Then, when the communication control unit 11 switches to the activated state, the communication control unit 11 transmits an ACK signal Sac from the RF transmission unit 13.

  When the vehicle 2 receives the ACK signal Sac within a predetermined time after transmitting the wake signal Swk, the vehicle 2 recognizes that the electronic key 1 exists in the outside communication area Ao and transmits the vehicle ID signal Svi from the outside LF transmitter 22. . The vehicle ID signal Svi includes a vehicle ID as a vehicle-specific ID for identifying the vehicle 2. The electronic key 1 that has received the vehicle ID signal Svi performs vehicle ID collation against the code registered in the memory 11a, and when the collation matches, transmits an ACK signal Sac from the RF transmission unit 13.

  When the vehicle 2 receives the ACK signal Sac within a predetermined time after receiving the vehicle ID signal Svi, the vehicle 2 recognizes that the electronic key 1 corresponding to the vehicle 2 exists in the outside communication area Ao. The vehicle 2 transmits an out-of-vehicle challenge signal Scco from the out-of-vehicle LF transmitter 22. The challenge signal Scco outside the vehicle includes a challenge code whose value changes each time a call is made, a key number of the electronic key 1, and information outside the vehicle notifying that the electronic key 1 is outside the vehicle. Note that the key number notifies the master key of which number or the sub key of the key number.

  When the communication control unit 11 of the electronic key 1 receives the out-of-vehicle challenge signal Scco by the LF receiving unit 12, the communication control unit 11 performs number verification for checking whether the key number of the out-of-vehicle challenge signal Scco is correct, and is the communication partner at this time. Determine whether or not. This number verification is verification for determining the master or sub key type for the electronic key 1 of the communication partner. And if this number collation is materialized, the communication control part 11 will produce | generate a response code by calculating the challenge code contained in the challenge signal Scco outside a vehicle with its encryption key. When the generation of the response code is completed, the communication control unit 11 causes the RF transmission unit 13 to transmit a response signal Sre including the ID code registered in its own memory 11a and this response code. Note that the arrangement order of the ID code and the response code in the response signal Sre can be changed as appropriate.

  Further, when receiving the outside challenge signal Scco, the inside / outside determination unit 11c accepts the outside information from the vehicle 2, so that by receiving the outside information, the inside / outside determination unit 11c recognizes that the collation at this time is outside the vehicle collation, and the memory 11a Keep the out-of-vehicle flag set. Therefore, since the activation control unit 11b confirms that the vehicle outside flag is set in the memory 11a at this time, the activation control unit 11b performs an operation of permitting the smart communication of the electronic key 1 only for the activation time T from the latest vibration detection. For this reason, the electronic key 1 that has entered the activated state after sensor detection is activated during the activation time T, but automatically switches to the stopped state after the activation time T has elapsed, and subsequent smart communication is not possible. It becomes.

  When the verification ECU 21 transmits the challenge signal Scco outside the vehicle, the verification ECU 21 calculates a challenge code using its own encryption key and also generates a response code. When the verification ECU 21 receives the response signal Sre from the electronic key 1 by the RF receiver 24, the verification ECU 21 compares the response code of the electronic key 1 with the response code calculated by itself, and executes response verification. When the verification ECU 21 confirms that this response verification is established, the verification ECU 21 verifies whether the ID code included in the response signal Sre is correct. And if collation ECU21 confirms that response collation and ID code collation will be materialized, it will process by this as establishment outside vehicle collation. Then, the verification ECU 21 sets the door lock to the unlocking and unlocking permitted state when the vehicle exterior verification is established, and unlocks the door lock when the touch sensor 28 of the vehicle exterior door handle 27 is operated.

  On the other hand, as shown in FIG. 4, the relays 3 and 4 relay communication between the vehicle 2 and the electronic key 1, so that the vehicle 2 can be connected even if the electronic key 1 does not exist in the outside communication area Ao of the vehicle 2. Assume that a relay attack that performs unauthorized operation is attempted. When a relay attack is attempted, a wake signal Swk transmitted from the vehicle 2 is transmitted to the electronic key 1 via the repeaters 3 and 4. The electronic key 1 is placed at the user's home or the like, for example, and a third party approaches the vehicle 2 and tries to unlock the door lock.

  However, the movement detection sensor 14 of the electronic key 1 does not output the detection signal based on the movement detection to the communication control unit 11 because the movement of the electronic key 1 is not accompanied, that is, does not tilt or vibrate. Therefore, the activation control unit 11b does not activate the electronic key 1 and maintains the stopped state (power-off state). For this reason, the electronic key 1 does not send back the ACK signal Sac to the wake signal Swk transmitted from the vehicle 2. Therefore, smart communication between the vehicle 2 and the electronic key 1 is not established, and the door lock is not opened by a third party approaching the vehicle 2.

  Next, as shown in FIG. 5, the verification ECU 21 recognizes, for example, with the courtesy switch 37 that the driver has boarded by opening the door after the vehicle external verification is established and the door lock is unlocked. This time, a wake signal Swk is transmitted from the in-vehicle LF transmitter 23 to form an in-vehicle communication area Ai throughout the vehicle. And with a user's boarding, the electronic key 1 will approach into the in-vehicle communication area Ai from the previous outside-vehicle communication area Ao.

  Since the electronic key 1 is carried by the user and enters (moves) in the vehicle, the electronic key 1 enters the in-vehicle communication area Ai with vibration and inclination. For this reason, even when the electronic key 1 enters the in-vehicle communication area Ai, a movement detection detection signal is output from the movement detection sensor 14 to the activation control unit 11b, so that the communication control unit 11 can be switched to an energized state. That is, when the electronic key 1 enters the in-vehicle communication area Ai, the activation control unit 11b sets the out-of-vehicle flag in the memory 11a and detects movement, so that the activation time is the time required for one round of smart communication. During T, it is possible to keep the electronic key 1 energized. Therefore, even when the communication control unit 11 enters the in-vehicle communication area Ai, an ACK reply can be made to the wake signal Swk from the in-vehicle LF transmitter 23, as in the case of outside-vehicle communication. When the electronic key 1 receives the wake signal Swk, the electronic key 1 starts smart communication. Then, the electronic key 1 transmits an ACK signal Sac from the RF transmitter 13.

  When the vehicle 2 receives the ACK signal Sac within a predetermined time after transmitting the wake signal Swk, the vehicle 2 recognizes that the electronic key 1 exists in the in-vehicle communication area Ai, and transmits the vehicle ID signal Svi from the in-vehicle LF transmitter 23. . The vehicle ID signal Svi includes a vehicle ID as a vehicle-specific ID for identifying the vehicle 2. The electronic key 1 that has received the vehicle ID signal Svi performs vehicle ID collation against the code registered in the memory 11a, and when the collation matches, transmits an ACK signal Sac from the RF transmission unit 13.

  When the vehicle 2 receives the ACK signal Sac within a predetermined time after receiving the vehicle ID signal Svi, the vehicle 2 recognizes that the electronic key 1 corresponding to the vehicle 2 exists in the in-vehicle communication area Ai. The vehicle 2 transmits an in-vehicle challenge signal Scci from the in-vehicle LF transmitter 23. The in-vehicle challenge signal Scci includes a challenge code whose value changes each time a call is made, the key number of the electronic key 1, and in-vehicle information for notifying that the electronic key 1 is in the vehicle.

  When the communication control unit 11 of the electronic key 1 receives the in-vehicle challenge signal Scci at the LF receiving unit 12, the communication control unit 11 performs number verification for checking whether the key number of the in-vehicle challenge signal Scci is correct, and is the communication partner at this time. Determine whether or not. And if this number collation is materialized, the communication control part 11 will produce | generate a response code by calculating the challenge code contained in the in-vehicle challenge signal Scci with its encryption key. When the generation of the response code is completed, the communication control unit 11 causes the RF transmission unit 13 to transmit a response signal Sre including the ID code registered in its own memory 11a and this response code.

  Further, when receiving the in-vehicle challenge signal Scci, the inside / outside determination unit 11c accepts in-vehicle information from the vehicle 2, and therefore, by receiving this in-vehicle information, the inside / outside determining unit 11c recognizes that the collation at this time is in-vehicle collation, and the memory 11a Defeat the flag outside the vehicle standing, and raise the flag inside the vehicle instead. When the in-vehicle flag is set in the memory 11a, the activation control unit 11b invalidates activation due to the presence or absence of movement detection of the movement detection sensor 14, and continues the activation state, that is, the power-on state regardless of the movement detection of the movement detection sensor 14. . That is, at the time of in-vehicle verification, the control for allowing the communication control unit 11 to execute smart communication is ended only during the activation time T from the latest vibration detection, and the normal state, that is, normal without limitation on the execution of smart communication. The operation switches to the state. Accordingly, since the subsequent electronic key 1 is always activated, it is possible to execute in-vehicle collation with the vehicle 2 at any time.

  This is because the use of the electronic key 1 in a pocket or bag of clothing is taken inside the vehicle, so that no movement is given to the electronic key 1 and it starts based on movement detection as in the case of collation outside the vehicle. This is because the electronic key 1 does not move in the vehicle and smart communication may not be established. If the smart communication is not established even though the electronic key 1 is in the vehicle, the inside of the vehicle necessary to see the electronic key 1 in-vehicle monitoring (periodic monitoring of whether the electronic key 1 is in the vehicle) It becomes impossible to execute in-vehicle collation necessary for checking collation and forgetting to place the electronic key 1 in the car. Therefore, the electronic key 1 continues to be activated without being based on the movement detection when the in-vehicle flag is set, that is, when the electronic key 1 is in the vehicle.

  When the verification ECU 21 transmits the in-vehicle challenge signal Scci, the verification ECU 21 calculates a challenge code using its own encryption key and also generates a response code. When the verification ECU 21 receives the response signal Sre from the electronic key 1 by the RF receiver 24, the verification ECU 21 compares the response code of the electronic key 1 with the response code calculated by itself, and executes response verification. When the verification ECU 21 confirms that this response verification is established, the verification ECU 21 verifies whether the ID code included in the response signal Sre is correct. And if collation ECU21 confirms that response collation and ID code collation are materialized, it will process as vehicle collation establishment with this. When the in-vehicle verification is established, the verification ECU 21 sets the power supply state switching permission state, and repeatedly changes the power supply state in the order of ACC on → IG on → power off every time the engine switch 33 is pushed and operated. When operated with the pedal depressed, the engine is switched to start.

  In the electronic key system of this example, the movement detection sensor 14 is provided in the electronic key 1, and when the movement of the electronic key 1 is detected by the movement detection sensor 14, communication is performed during the activation time T from the latest vibration detection. The activation of the control unit 11 is permitted, and the outside verification of the electronic key 1 is executed. For this reason, even if a third party who is a theft agent tries to establish ID verification by relay attack, the electronic key 1 placed in the house or the like does not move, so the electronic key 1 does not start, and smart communication Cannot be established. Therefore, it becomes possible to suppress the unauthorized operation of the vehicle 2 due to the relay attack.

  Further, at the time of in-vehicle verification, the power control of the communication control unit 11 based on the detection signal of the movement detection sensor 14, that is, the operation of supplying power to the communication control unit 11 during the activation time T is invalidated, and the communication control unit 11 is in a normal state where power is always supplied. For this reason, the inside of the vehicle necessary to see whether the electronic key 1 is left in the vehicle (periodic monitoring of whether the electronic key 1 is in the vehicle) or the electronic key 1 is left in the vehicle. It is possible to execute collation without any problem as usual.

As described above, according to the embodiment described above, the following effects can be obtained.
(1) In the case of communication outside the vehicle, since the electronic key 1 is powered on for a certain period of time on the condition that the movement detection sensor 14 detects the movement (movement) of the electronic key, the communication outside the vehicle is permitted. In order to establish communication, the movement (movement) of the electronic key 1 is required. For this reason, even if an attempt is made to establish verification outside the vehicle by a relay attack, communication will be executed using the electronic key 1 that is not accompanied by movement placed on a table or the like. It is processed. Therefore, since it is impossible to operate the vehicle 2 in the relay attack, it is possible to prevent an unauthorized operation of the vehicle 2 by a third party. In addition, in the case of in-vehicle communication, processing that makes the movement of the electronic key 1 a condition for executing communication is invalidated, so that processing such as monitoring of the electronic key 1 in the vehicle and detection of misplacement of the electronic key 1 can be executed without any problem. You can also

  (2) Recognizing whether the electronic key 1 exists outside the vehicle or inside the vehicle based on the inside / outside information transmitted from the outside LF transmitter 22 and the inside LF transmitter 23 during smart communication. For this reason, the electronic key 1 can easily confirm whether the electronic key 1 is out of the vehicle or in the vehicle from the out-of-vehicle challenge signal Scco or the in-vehicle challenge signal Scci received from the vehicle 2.

  (3) Since a process of turning on the electronic key 1 for a certain period of time is adopted as the restricted operation permitted in the communication outside the vehicle, the operation restriction can be applied to the electronic key 1 by simple control.

  (4) When a certain period of time elapses after the smart communication operation is permitted, the communication control unit 11 of the electronic key 1 is in a stopped state (sleep state), so that the electronic key 1 can be more reliably switched to the stopped state.

In addition, the said embodiment can be implemented with the following forms which changed this suitably.
In the above embodiment, the inside / outside information is a 1-bit code of the outside information “0” and the inside information “1”, but it may be data that notifies the content of the signal as text information, for example.

In the above embodiment, the internal / external information is included in the response signal Sre. However, the information is not limited to the response signal Sre, and may be included in the wake signal Swk, for example.
In the above configuration, the vehicle 2 may be equipped with an immobilizer system that performs ID verification using the electronic key 1 and short-range wireless communication.

  In the above embodiment, a wireless key system that can lock and unlock the door by transmitting a lock signal or an unlock signal wirelessly to the vehicle 2 by operating the switch of the electronic key 1 may be mounted.

  In the above embodiment, the smart communication is performed when the communication control unit 11 of the electronic key 1 is changed from the stopped state to the activated state. However, the smart communication is performed when the LF receiver 12 is activated from the stopped state. You may make it perform. That is, when the movement detection signal is input from the movement detection sensor 14, the LF receiver 12 starts for the activation time T from the latest vibration detection, and stops after the activation time T has elapsed. The AFE 12a of the LF receiving unit 12 outputs a start command for instructing the communication control unit 11 to start smart communication based on the result of confirming whether the wake signal Swk is correct, and causes the communication control unit 11 to start smart communication. Therefore, the use of the power source can be suppressed without stopping uselessly by stopping the reception.

  In the above embodiment, the smart communication is performed when the communication control unit 11 of the electronic key 1 is changed from the stopped state to the activated state, but the smart communication is performed when the RF transmission unit 13 is activated from the stopped state. You may make it perform. That is, when the movement detection signal is input from the movement detection sensor 14, the RF transmission unit 13 is activated for the activation time T from the latest vibration detection, and is stopped after the activation time T has elapsed. Even if there is reception, the RF transmission unit 13 does not perform transmission unless movement is detected. Therefore, since the wireless signal can be received from the relay attack relays 3 and 4, the electronic key 1 can recognize that such a wireless signal has been received.

  In the above embodiment, the inside / outside determination of the electronic key 1 is not limited to the inside / outside information received from the vehicle 2 during smart communication. For example, the inside / outside information may be transmitted from the vehicle independently of the smart communication. In addition, the inside / outside determination of the electronic key 1 is not limited to being performed in cooperation between the electronic key 1 and the vehicle 2. For example, a sensor capable of looking outside the vehicle is mounted on the electronic key 1, and this sensor output The inside / outside determination may be made by

  In the above embodiment, the permission operation given to the electronic key 1 at the time of communication outside the vehicle is not necessarily limited to turning on the power only for a certain time, and may be an operation that allows only one smart communication, for example.

  -In the said embodiment, the operation | movement imposed on a user in communication outside a vehicle, ie, the motion of the electronic key 1, may be a thing of what kind of aspect, if a user can take at the time of boarding. For example, when it is detected that several vibrations are taken within a predetermined time, the electronic key 1 may be supplied with power for a certain time.

In the above embodiment, authentication is performed from number verification, response verification, and ID code verification, but various authentication formats can be adopted.
In the above embodiment, the frequency of the radio wave used in the electronic key system is not necessarily limited to LF or RF, and other frequencies can be used. Further, the frequency when the radio wave is transmitted from the vehicle 2 to the electronic key 1 and the frequency when the radio wave is returned from the electronic key 1 to the vehicle 2 are not necessarily different from each other, and may be the same frequency.

  In the above embodiment, if the idea of this example is described in another way, the communication outside the vehicle is in a restricted state in which the movement of the electronic key 1 is a condition for execution of communication, and this restriction is applied when switching from outside communication to in-vehicle communication. The state is canceled (invalidated).

  In the above embodiment, it is not always necessary to cancel the use restriction of the electronic key 1 by in-vehicle verification. For example, when the movement (movement) of the electronic key 1 is detected, the electronic key 1 is merely used for a certain period of time. The power supply of may be switched to the on state.

  -In the said embodiment, the electronic key system of this example is not necessarily applied only to the vehicle 2, If the communication object which uses an electronic key is communication object, the employ | adopting destination will not be specifically limited. For example, you may apply to buildings, such as a house. In other words, an electronic key as a key for a door or the like has a mode in which a building is not activated unless movement is detected without distinction between indoors and outdoors.

Next, the technical idea that can be grasped from the embodiment will be described together with the effects.
(A) In the electronic key system according to claim 1 or 2, the communication permission / inhibition setting means is configured such that the electronic key performs smart communication outside the room in a situation where the movement detection means detects movement of the electronic key. In this case, the electronic key system restricts the operation of smart communication of the electronic key by activating the control means, which is a control unit of the electronic key, for a predetermined time.

  According to this configuration, the electronic key control means enters the stopped state after a certain period of time has elapsed since the smart communication operation is permitted, so that the electronic key can be more reliably switched to the stopped state.

  (B) In the electronic key system according to claim 1 or 2, the communication permission / inhibition setting means performs the outdoor smart communication by the electronic key in a situation where the movement detecting means detects the movement of the electronic key. In this case, the electronic key system limits the operation of the electronic key for smart communication by allowing the electronic key receiving means to receive radio waves only for a certain period of time.

  According to this configuration, after a certain period of time since the smart communication operation is permitted, the electronic key receiving means becomes incapable of receiving, so that the electronic key does not receive useless radio waves when the electronic key is stopped. That's it.

  (C) The electronic key system according to claim 1 or 2, wherein the communication permission / inhibition setting means performs smart communication outside the room under the condition that the movement detecting means detects movement of the electronic key. In this case, the electronic key system restricts the operation of smart communication of the electronic key by allowing the electronic key transmitting means to transmit a radio wave only for a predetermined time.

  According to this configuration, after a certain time has elapsed since the smart communication operation is permitted, the electronic key transmitting means becomes unable to transmit. For example, when the electronic key is stopped, what is the radio wave received by the electronic key? It becomes possible to perform the process.

  (D) Upon receiving a reply request for the ID code transmitted from the communication target, ID verification is performed by smart communication for returning the ID code to the communication target. If the ID verification is established, the ID code is installed in the communication target. In the electronic key that enables the operation of the device, movement detection means for detecting that the electronic key is carried by the user and that the movement detection means detects the movement of the electronic key. An electronic key comprising: communication enabling / disabling setting means for switching from power-off to power-on for a predetermined time and permitting the smart communication.

  (E) Upon receiving a reply request for the ID code transmitted from the communication target, ID verification is performed by smart communication for returning the ID code to the communication target. If the ID verification is established, the ID code is installed in the communication target. In the electronic key communication enable / disable setting method that enables operation of the device, the movement detection means provided in the electronic key detects that the electronic key is carried by the user and moves, and the electronic key and A key position inside / outside determination means provided at least on the electronic key side to be communicated determines whether the electronic key exists outside or inside the communication target, and a communication availability setting means provided on the electronic key. On the condition that the movement detection means detects the movement of the electronic key when the electronic key is outside the room according to the determination result of the key position inside / outside determination means. Electronic key communication characterized in that smart communication is permitted regardless of the detection result of the movement detection means when mart communication is permitted and the electronic key is indoors according to the determination result of the key position inside / outside determination means. How to set availability.

  (F) When the electronic key receives a reply request for the ID code transmitted from the communication target, ID verification is performed by smart communication in which the electronic key returns the ID code to the communication target, and the ID verification is established. In the electronic key system that enables operation of the device installed in the communication target, the communication target is a building, provided in the electronic key, and the electronic key is carried by the user and moved. And a movement detection means for detecting the movement of the electronic key, provided that the movement detection means detects the movement of the electronic key. Electronic key system to do.

  Normally, when a device installed in a building is operated with an electronic key, the user can operate the device by holding the electronic key and performing smart communication by approaching the building. Therefore, according to the above configuration, it is possible to detect whether or not the electronic key is moving, and smart communication is performed when it is detected that the electronic key is moving. For this reason, when the electronic key is placed in the building, that is, when the relay attack is attempted by a third party without movement, the electronic key is not moved, so the electronic key does not perform smart communication, A relay attack can be failed. Therefore, it is possible to make it difficult for an unauthorized operation of the building due to the relay attack to occur.

  DESCRIPTION OF SYMBOLS 1 ... Electronic key, 2 ... Vehicle as communication object, 11 ... Communication control part as control means, 11a ... Memory, 11b ... Activation control part as communication availability setting means, 11c ... Key position inside / outside determination means and determination means Inside / outside determination unit, 12... LF reception unit, 12a... AFE, 13... RF transmission unit, 14..., Movement detection sensor as movement detection means, 21 ... verification ECU, 21a ... memory, 21b. Transmission control unit as control means, 22 ... Outside LF transmitter as outdoor information transmission means, 23 ... In-vehicle LF transmitter as indoor information transmission means, 24 ... RF receiver, 27 ... Outside door handle, 28 ... Touch sensor , 29 ... Lock button, 31 ... Main body ECU, 32 ... Engine ECU, 33 ... Engine switch, 37 ... Courtesy switch, 38 ... Door Device, Ai ... in-vehicle communication area, Ao ... outside vehicle communication area, Sac ... ACK signal, Scci ... in-vehicle challenge signal, Scco ... outside vehicle challenge signal, Sid ... ID code signal, Sre ... response signal, Srq ... request signal, Svi ... Vehicle ID signal, Swk ... Wake signal.

Claims (4)

When the electronic key receives a reply request for the ID code transmitted from the communication target, ID verification is performed by smart communication in which the electronic key returns the ID code to the communication target. If the ID verification is established, the communication is performed. In an electronic key system that enables operation of equipment installed in the target,
A movement detection means provided on the electronic key for detecting that the electronic key is carried by the user;
Key position inside / outside determination means that is provided on at least the electronic key side of the electronic key and communication target, and determines whether the electronic key is present outside or inside the communication target;
When the electronic key is provided outside the room according to the determination result of the key position inside / outside determination means, the smart communication performed outdoors is detected by the movement detection means. Communication enable / disable setting means for permitting the smart communication performed indoors regardless of the detection result of the movement detection means when the electronic key is in the room according to the determination result of the key position inside / outside determination means. An electronic key system characterized by comprising. The key position inside / outside determining means includes:
In the smart communication outside the room, the inside / outside information notifying that the electronic key is outside the room is transmitted from the outside information transmitting means, and the electronic verification is performed in the indoor smart verification. Transmission control means for transmitting inside / outside information notifying that the key is in the room from the room information transmission means,
A determination unit that is provided in the electronic key and that determines whether the electronic key is present outdoors or indoors based on the inside / outside information transmitted from the outdoor information transmission unit or the indoor information transmission unit. The electronic key system according to claim 1. The electronic key system according to claim 1 or 2,
The communication permission / inhibition setting unit is configured to activate the electronic key only for a certain period of time when the electronic key performs the outdoor smart communication under the situation where the movement detection unit detects the movement of the electronic key. An electronic key system that restricts the operation of smart communication of the electronic key. When an ID code reply request transmitted from the communication target is received, ID verification is performed by smart communication that returns the ID code to the communication target. If the ID verification is established, the operation of the device installed on the communication target is performed. In an electronic key that enables
Movement detecting means for detecting that the electronic key is carried by the user; and
A key position inside / outside determining means for determining whether the electronic key exists outside or inside the communication target;
When the electronic key is outside the room according to the determination result of the key position inside / outside determination means, the smart communication is permitted on condition that the movement detection means detects the movement of the electronic key, and the key position inside / outside determination means An electronic key comprising: communication enable / disable setting means for permitting the smart communication regardless of a detection result of the movement detection means when the electronic key is in a room based on a determination result.

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