JP2018020611A - Vehicle door unlocking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly unlock a vehicle door by determining a relay attack with high accuracy.SOLUTION: A request signal is transmitted to a portable machine, and an answer signal transmitted by the portable machine according to the request signal is received. At the time, a response time until the answer signal is received after transmitting the request signal is measured. When the response time is shorter than a threshold time stored corresponding to identification information included in the answer signal received by the reception section, a door is unlocked. When the response time is longer than the threshold time, the door is not unlocked. The threshold time used for the determination at the time is determined on the basis of a result obtained by an actual measurement of the response time in the measurement section of a vehicle door unlocking device.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a technique for unlocking a vehicle door by being mounted on a vehicle and communicating with a portable device of a vehicle user.

  As a technique for unlocking a door of a vehicle, a technique is known in which when a vehicle user operates a button of a portable device (so-called portable key), a signal is transmitted from the portable device to the vehicle and the door is unlocked. It has been. When such a technique is adopted, it is possible to save the trouble of inserting the key into the keyhole when unlocking the door, and it is not necessary to provide the keyhole, so that picking can be prevented.

  In recent years, if a vehicle user has a portable device, the portable device and the vehicle automatically communicate with each other and unlock the door without performing a special operation such as a button operation. Is spreading. Although such a technique can further improve the convenience of the vehicle user, there is a risk that an illegal act called a so-called relay attack may be performed.

That is, in the above-described technology, when the portable device enters the communication range of the vehicle (for example, within a range of 1 to 2 m from the vehicle), the portable device receives a request signal from the vehicle, and identifies information (ID) according to the request signal. ) Is sent to the vehicle. The vehicle unlocks the door if the identification information included in the answer signal is correct. Therefore, if the portable device does not exist within the communication range of the vehicle, for example, if the portable device is present in a vehicle user's residence away from the vehicle, the request signal does not reach the portable device. Is not transmitted to the vehicle and the vehicle door is not unlocked.
Relay attack is a technology that allows unauthorized unlocking of doors by transmitting and receiving request signals and answer signals between the vehicle and the portable device even when the portable device is not within the communication range of the vehicle. It is. Specifically, relay devices are arranged at a plurality of locations including within the communication range of the vehicle, and the request signal and the answer signal are transmitted between the portable device and the vehicle that are located away from the vehicle via these relay devices. It is a technology that allows unauthorized door unlocking by transmitting and receiving. Therefore, when the relay attack is performed, for example, even when the vehicle user is sleeping and the portable device exists in the residence of the vehicle user about 10 m away from the vehicle, the door is illegally unlocked. The vehicle may be stolen.

  In order to prevent such unauthorized unlocking by relay attack, the response time from when the request signal is transmitted until the answer signal is received is measured, and this response time is equal to or longer than a predetermined threshold time. Has proposed a vehicle door unlocking device that does not unlock the door (Patent Document 1). That is, when a relay attack is performed, the request signal and the answer signal pass through the relay device, so it is estimated that the response time is longer than when the relay device is not passed. Therefore, in this vehicle door unlocking device, if the response time is equal to or greater than a predetermined threshold time, it is determined that the relay device has been used (relay attack has been performed) and the door is not unlocked. It is said.

Japanese Patent No. 3909226

  However, in the above-described vehicle door unlocking device, it is difficult to determine the relay attack with high accuracy, and thus there is a problem that the vehicle door cannot be unlocked appropriately. That is, since the vehicle door unlocking device described above is produced in units of lots (a plurality of units are collected together), the threshold time is stored in the vehicle door unlocking device in the following procedure. First, in the development stage, a response time when no relay device is used is estimated, and a threshold time is determined based on this response time. In the manufacturing stage, the threshold time is uniformly stored in a plurality of vehicle door unlocking devices. However, even when the vehicle door unlocking device is produced in units of lots, there are individual differences such as manufacturing errors, and thus there is a variation in response time among the produced vehicle door unlocking devices. For this reason, the uniformly stored threshold time may not correspond to the actual response time of each vehicle door unlocking device, and in this case, the relay attack cannot be determined with high accuracy. There was a problem.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a technique for appropriately unlocking a vehicle door by performing a relay attack determination with high accuracy.

  In order to solve the above-described problem, the vehicle door unlocking device of the present invention transmits a request signal to the portable device and receives an answer signal transmitted by the portable device in response to the request signal. At this time, the response time from when the request signal is transmitted to when the answer signal is received is measured. When the response time is shorter than the threshold time stored in association with the identification information included in the answer signal received by the receiving unit, the door is unlocked. When the response time is longer than the threshold time, the door is unlocked. It is decided not to unlock. The above threshold time used for the determination at this time is determined based on the result of actual measurement of the response time by the measurement unit of the vehicle door unlocking device.

  In such a vehicle door unlocking device, the threshold time is determined based on the result of the response time actually measured by the measurement unit of the vehicle door unlocking device, and therefore the threshold time is the response time of the vehicle door unlocking device. It will correspond to. For this reason, determination of relay attack can be performed with high accuracy, and the door of the vehicle can be unlocked appropriately.

It is explanatory drawing which shows the rough internal structure of the door lock control apparatus 100 of a present Example. It is a flowchart of the unlocking process which the door lock control apparatus 100 of a present Example performs. It is explanatory drawing which shows a rough structure when a relay attack is performed with respect to the door lock control apparatus 100 of a present Example. It is explanatory drawing which shows the difference in the response time by the presence or absence of a relay attack. It is explanatory drawing which shows the threshold time memorize | stored in the conventional door lock control apparatus. It is explanatory drawing which shows the problem at the time of utilizing the threshold time of the conventional door lock control apparatus. It is explanatory drawing which shows the threshold time memorize | stored in the door lock control apparatus 100 of a present Example. It is explanatory drawing which shows the effect at the time of utilizing the threshold time of the door lock control apparatus 100 of a present Example. It is explanatory drawing which shows the threshold time memorize | stored in the door lock control apparatus 100 of the modification 1. It is explanatory drawing which shows the threshold time memorize | stored in the door lock control apparatus 100 of the modification 2. It is explanatory drawing which shows the rough internal structure of the door lock control apparatus 300 of the modification 3. It is a flowchart of the threshold time memory | storage process performed by the door lock control apparatus 300 of the modification 3. FIG. 3 is an explanatory diagram showing a configuration for permitting the start of the engine of the vehicle 1.

Hereinafter, examples will be described in order to clarify the contents of the present invention described above.
A. Device configuration :
FIG. 1 shows a rough configuration of the “door lock control device 100” of the present embodiment. In this embodiment, the “door lock control device 100” corresponds to the “vehicle door unlocking device” in the present invention.
The door lock control device 100 is provided in the vehicle 1 and is a device that unlocks and locks the door of the vehicle 1 by communicating with a portable device 200 carried by a user of the vehicle 1. Specifically, the door lock control device 100 transmits a “request signal” to the portable device 200 and, based on an “answer signal” transmitted from the portable device 200 in response to the “request signal”, A device for unlocking and locking a door. As shown in the figure, the door lock control device 100 includes an RF receiving unit 11, an out-of-vehicle LF transmitting unit 12, an in-vehicle LF transmitting unit 13, an ID determining unit 14, a storage unit 15, and a response time measuring unit 16. The relay attack determination unit 17, the unlock instruction unit 18, and the lock instruction unit 19 are provided. These nine “parts” are abstract concepts classified for convenience in the interior of the door lock control device 100, and represent that the door lock control device 100 is physically divided into nine parts. is not. Therefore, these “units” can be realized as a computer program executed by the CPU, can be realized as an electronic circuit including an LSI or a memory, or can be realized by combining them. it can.

An RF receiving antenna 11 a is connected to the RF receiving unit 11. The RF reception unit 11 receives an RF signal (for example, a signal having a frequency of 315 MHz) transmitted as an “answer signal” from the portable device 200 via the RF reception antenna 11a.
An out-of-vehicle LF transmitting unit 12 is connected to an out-of-vehicle LF transmitting antenna 12a provided outside the door of the vehicle 1 (for example, a grip portion outside the door). The LF transmission unit 12 outside the vehicle transmits an LF signal (for example, a signal having a frequency of 125 kHz) as a “request signal” via the LF transmission antenna 12a outside the vehicle. The reachable range of the “request signal” transmitted from the outside-LF transmission antenna 12a (hereinafter referred to as “outside-vehicle reachable range”) is outside the vehicle 1 and close to the vehicle 1 (for example, the vehicle 1 (Within 1 m from the door). Therefore, the “request signal” transmitted from the outside LF transmitter 12 is in the portable device 200 existing in the “outside vehicle reach (outside the vehicle 1 and in the vicinity of the vehicle 1)”, that is, beside the vehicle 1. It is received by the portable device 200 carried by the user of the vehicle 1.
An in-vehicle LF transmission antenna 13 a provided in the vehicle 1 is connected to the in-vehicle LF transmission unit 13. The in-vehicle LF transmitter 13 transmits an LF signal (for example, a signal having a frequency of 125 kHz) as a “request signal” via the in-vehicle LF transmission antenna 13a. The reach range of the “request signal” transmitted from the in-vehicle LF transmitting antenna 13 a (hereinafter “in-vehicle reach range”) is set in the vehicle interior of the vehicle 1. Therefore, the “request signal” transmitted from the in-vehicle LF transmission unit 13 is a portable device 200 existing in the “in-vehicle reachable range (vehicle interior of the vehicle 1)”, that is, the portable device 200 carried by the passenger of the vehicle 1. Will be received.

The ID determination unit 14 detects the ID (identification information) of the portable device 200 based on the “answer signal” received by the RF reception unit 11, and the detected ID is set to the ID stored (registered) in the storage unit 15 in advance. It is determined whether or not they match. That is, the portable device 200 has a unique ID, and the “answer signal” transmitted from the portable device 200 includes this unique ID. Therefore, the ID determination unit 14 determines whether or not this ID matches a previously registered ID.
The response time measurement unit 16 transmits the “request signal” from the vehicle LF transmission unit 12 (or starts the transmission process) until the RF reception unit 11 receives the “answer signal” (or performs the reception process). Measure the response time until it is finished.
The relay attack determination unit 17 determines whether or not a relay attack has been performed based on the response time described above. As will be described in detail later, the relay attack is an action for illegally unlocking the door of the vehicle 1. When the relay attack is performed, the above-described response time becomes longer than when the relay attack is not performed. Therefore, the relay attack determination unit 17 performs the relay attack when the above-described response time is longer than a predetermined threshold time. Is determined to have been performed.

  The unlocking instruction unit 18 transmits an unlocking signal for unlocking the door of the vehicle 1 based on the determination results of the ID determination unit 14 and the relay attack determination unit 17. That is, the ID determination unit 14 determines that the ID of the portable device 200 detected from the “answer signal” matches the ID registered in the storage unit 15, and the relay attack determination unit 17 has no relay attack ( When it is determined that the relay attack is not performed), an unlock signal is transmitted to the door lock actuator (door lock driving device). When receiving the unlock signal, the door lock actuator drives the door lock to unlock the door of the vehicle 1.

  The locking instruction unit 19 transmits a locking signal for locking the door of the vehicle 1 when the occupant exits (gets off) from the passenger compartment of the vehicle 1. Specifically, if the RF receiver 11 receives an “answer signal” in response to the “request signal” transmitted from the in-vehicle LF transmitter 13, it is determined that the passenger is present in the passenger compartment, and then the engine is stopped. If the RF receiver 11 receives an “answer signal” corresponding to the “request signal” transmitted from the outside LF transmitter 12 when the door is closed, the occupant is outside the vehicle compartment ) And a lock signal is transmitted to the door lock actuator. When receiving the locking signal, the door lock actuator drives the door lock to lock the door of the vehicle 1.

  The outside LF transmission unit 12 corresponds to the “transmission unit” in the present invention, the RF reception unit 11 corresponds to the “reception unit” in the present invention, and the response time measurement unit 16 corresponds to the “measurement unit” in the present invention. The unlocking instruction unit 18 corresponds to the “unlocking unit” in the present invention.

B. Unlocking process:
Below, the unlocking process performed by the door lock control apparatus 100 of a present Example is demonstrated. FIG. 2 shows a flowchart of the unlocking process executed by the door lock control device 100. This process is executed as a timer interrupt process (for example, every 0.1 second).
When the unlocking process is started, the door lock control device 100 first transmits a “request signal” from the outside LF transmitting unit 12 (S101). This “request signal” is transmitted toward the portable device 200 existing in the “external reach (outside of the vehicle 1 and in the vicinity of the vehicle 1)”. Subsequently, after the outside LF transmitter 12 transmits the “request signal” (or after the transmission process is started), until the RF receiver 11 receives the “answer signal” (or until the reception process ends). The response time measurement unit 16 starts measuring the response time (S102).

  In this way, the “request signal” is transmitted from the outside LF transmitter 12 (S101), and when the response time measurement is started (S102), whether or not the “answer signal” is received from the portable device 200, that is, the processing of S101 Then, it is determined whether or not the RF receiver 11 has received an “answer signal” in response to the “request signal” transmitted from the LF transmitter 12 outside the vehicle (S103). As a result, if the “answer signal” has not been received yet (S103: no), whether or not the time since the transmission of the “request signal” has exceeded a time limit (eg, 50 milliseconds) (whether a timeout has occurred) (S104). As a result, if it has not timed out yet (S104: no), it waits for reception of an "answer signal" (S103), and if timed out (S104: yes), the unlocking process is terminated as it is.

When the “answer signal” is received before the timeout occurs (S103: yes), the measurement of the response time is terminated and the measured response time is stored in the storage unit 15 (S105). The ID determination unit 14 detects the ID from the received “answer signal” (S106), and determines whether or not the detected ID matches the ID stored (registered) in the storage unit 15 in advance ( S107). As a result, when the ID detected from the “answer signal” is not registered (S107: no), it is determined that the “answer signal” is transmitted from a device different from the portable device 200 corresponding to the vehicle 1. In this case, the door of the vehicle 1 is not unlocked (the unlock signal is not transmitted).
On the other hand, when the ID detected from the “answer signal” is registered (S107: yes), it can be determined that the “answer signal” is transmitted from the portable device 200 corresponding to the vehicle 1. In this case, subsequently, the relay attack determination unit 17 determines whether or not the response time stored in the process of S105 is less than the threshold time (S108). As a result, when the response time is less than the threshold time (S108: yes), it can be determined that there is no relay attack (relay attack was not performed), so the vehicle 1 is transmitted by transmitting an unlock signal to the door lock actuator. The door is unlocked (S109). On the other hand, when the response time is equal to or longer than the threshold time (S108: no), it can be determined that there is a relay attack (relay attack has been performed), so the door of the vehicle 1 is not unlocked (unlock signal) Is not transmitted), the fact that the relay attack has been performed is stored (S110).

  When it is determined that there is a relay attack, a warning sound may be issued from the vehicle 1. This can prevent the relay attack from being performed. If it is determined that there is a relay attack, the user of the vehicle 1 (the owner of the portable device 200) may be notified that the relay attack has been performed. For example, information indicating that a relay attack has been performed may be displayed on the display unit provided in the vehicle 1, or a warning sound may be issued from the portable device 200 owned by the user of the vehicle 1. It is good also as transmitting the information which shows that the relay attack was performed to portable terminals, such as a smart phone which the user of the vehicle 1 owns. If it carries out like this, the attention with respect to the relay attack of the user of the vehicle 1 can be called. The notification as described above is performed by the relay attack determination unit 17. Therefore, the relay attack determination unit 17 corresponds to a “notification unit” in the present invention.

  As described above, the door lock control device 100 according to the present embodiment unlocks the door of the vehicle 1 when the ID detected from the “answer signal” is registered and the response time is less than the threshold time. To do. That is, in this case, the relay attack is not performed, and the user of the vehicle 1 carrying the portable device 200 corresponding to the vehicle 1 is “a vehicle reachable range (outside the vehicle 1 and in the vicinity of the vehicle 1)”. Therefore, the door of the vehicle 1 is unlocked. In contrast, even if the ID detected from the “answer signal” is registered, if the response time is equal to or longer than the threshold time, it is determined that the relay attack has been performed and the door of the vehicle 1 is not unlocked. It is said.

  FIG. 3 shows a rough configuration when a relay attack is performed on the door lock control device 100 of the present embodiment. For example, even when the portable device 200 does not exist in the “external reach (outside the vehicle 1 and in the vicinity of the vehicle 1)”, the relay attack is, for example, the use of the vehicle 1 in which the portable device 200 is separated from the vehicle 1 Even if it exists in a person's residence etc., a "request signal" and an "answer signal" are transmitted / received between the portable device 200 and the door lock control device 100, and the door of the vehicle 1 is unlocked (non- Technology for correct unlocking). Specifically, as illustrated in FIG. 3, relay devices R <b> 1 and R <b> 2 that relay the “request signal” transmitted from the vehicle exterior LF transmission unit 12 to the portable device 200 are arranged. Among these, the relay device R1 is arranged in the “external reach (outside the vehicle 1 and in the vicinity of the vehicle 1)” so that the “request signal” transmitted from the external LF transmitter 12 can be directly received. Then, the relay device R1 amplifies the “request signal” transmitted from the outside LF transmission unit 12 or converts the frequency (for example, converts it to an RF signal), and transmits it to the relay device R2. The relay device R2 sets the frequency of the “request signal” received from the relay device R1 to be the same as the frequency of the “request signal” transmitted from the outside LF transmission unit 12 (for example, converts it to an LF signal). 200. By doing so, the portable device 200 is transmitted from the outside LF transmission unit 12 even when the portable device 200 does not exist in the “outside vehicle reachable range (outside the vehicle 1 and in the vicinity of the vehicle 1)”. A “request signal” is received.

  Also, relay devices R3 and R4 that relay the “answer signal” transmitted from the portable device 200 to the RF receiver 11 are arranged. Even when the portable device 200 receives the “request signal” via the relay devices R1 and R2, the relay device R3 receives the “answer signal” because it transmits the “answer signal”. Then, the relay device R3 amplifies this “answer signal” and transmits it to the relay device R4, and the relay device R4 amplifies this “answer signal” and transmits it to the RF receiver 11. In this way, even when the portable device 200 does not exist in the “external reach (outside of the vehicle 1 and in the vicinity of the vehicle 1)”, the RF receiver 11 is transmitted from the portable device 200. An answer signal is received. In addition, since the “answer signal” transmitted from the portable device 200 is an RF signal, the reach distance is naturally longer than the LF signal (request signal). For this reason, the relay attack may be performed without arranging the relay devices R3 and R4 for relaying the above-mentioned “answer signal”.

When the relay attack is performed as described above, the portable device 200 and the door lock control device even if the portable device 200 does not exist in the “external reach (outside of the vehicle 1 and in the vicinity of the vehicle 1)”. Since the “request signal” and the “answer signal” are transmitted to and received from 100, the door of the vehicle 1 may be unlocked.
Therefore, in the door lock control device 100 of the present embodiment, the response time (when the vehicle exterior LF transmission unit 12 transmits a “request signal” (or when the relay attack is not performed and when the relay attack is performed) (or When a relay attack is performed focusing on the fact that there is a difference in the time from when the transmission process is started until the RF receiver 11 receives the “answer signal” (or until the reception process ends) The door of the vehicle 1 is prevented from being unlocked. That is, when a relay attack is performed, the “request signal” transmitted from the LF transmitter 12 outside the vehicle passes through the relay devices R1 and R2, and the “answer signal” transmitted from the portable device 200 is transmitted to the relay devices R3 and R4. Via. Therefore, as shown in FIG. 4, when a relay attack is performed (without RA in the figure), the response time is longer than when a relay attack is not performed (with RA in the figure). Therefore, when a predetermined threshold time is set and the response time is less than the threshold time, it is determined that there is no relay attack (no relay attack was performed), the door of the vehicle 1 is unlocked, and the response time is the threshold value. If it is more than the time, it is determined that there is a relay attack (relay attack has been performed), and the door of the vehicle 1 is not unlocked.

  Here, the door lock control device 100 and the portable device 200 as described above are generally produced in batches (multiple units are collected). Accordingly, the door lock control device 100 stores the threshold time in the following procedure. First, in the development stage, the response time when not using the relay device as described above is estimated, and the threshold time is determined based on this response time. For example, several door lock control devices 100 are prototyped, an actual response time when no relay device is used is measured, and a time obtained by adding a margin (allowable amount) to the response time is set as a threshold time. In the manufacturing stage, this threshold time is uniformly stored in the plurality of door lock control devices 100 in the lot. For example, as shown in FIG. 5, the storage units 15 of a plurality of door lock control devices 100a, door lock control devices 100b, door lock control devices 100c,... Manufactured in the same lot are different from each other. Although ID is stored, Tth is uniformly stored as the threshold time.

  Of course, even when the door lock control device 100 and the portable device 200 are produced in batch units, there are individual differences such as manufacturing errors. Therefore, the response time depends on the combination of the door lock control device 100 and the portable device 200. There are variations. Therefore, the uniformly stored threshold time may not correspond to the response time of each door lock control device 100. In this case, the relay attack cannot be determined with high accuracy, and the vehicle There was a problem that the door 1 could not be unlocked properly. For example, when Tth is uniformly stored as the threshold time in the door lock control device 100a, the door lock control device 100b, the door lock control device 100c,..., The same portable device 200 is used for each. Even in this case, as shown in FIG. 6, the determination of the relay attack may be wrong. For example, in the case of the door lock control device 100a, the response time when there is no relay attack is shorter than the threshold time Tth, and the response time when there is a relay attack is longer than the threshold time Tth. It can be carried out. For this reason, the door of the vehicle 1 can be unlocked when there is no relay attack, and the door of the vehicle 1 can be prevented from being unlocked when there is a relay attack. On the other hand, in the case of the door lock control device 100b, the response time in the case of no relay attack is also shorter than the threshold time Tth in the case of the relay attack. It will be judged. For this reason, the door of the vehicle 1 is unlocked not only when there is no relay attack but also when there is a relay attack. In the case of the door lock control device 100c, the response time without the relay attack and the response time with the relay attack are longer than the threshold time Tth. Therefore, in both cases, it is determined that there is the relay attack. End up. For this reason, the door of the vehicle 1 cannot be unlocked not only when there is a relay attack but also when there is no relay attack.

  Therefore, in this embodiment, the threshold time corresponding to each individual is stored even in the door lock control device 100 produced in lot units. Specifically, in the manufacturing stage, for each door lock control device 100, the response time when the relay device is not passed is measured by the response time measurement unit 16, and the threshold time is determined based on the response time. Is stored in each door lock control device 100. For example, as shown in FIG. 7, for the door lock control device 100a, the response time when the relay device is not passed is measured by each response time measurement unit 16, and a margin (allowable amount) is added to the response time. Is stored in the storage unit 15 as the threshold time Ta. Similarly, with respect to the door lock control device 100b and the door lock control device 100c, the response time when the relay device is not used is measured, and the time obtained by adding a margin (allowable amount) to the response time is defined as the threshold time Tb and the threshold value. The time Tc is stored in each storage unit 15.

  Thus, the threshold time stored in the storage unit 15 of each door lock control device 100 corresponds to the response time when the relay device of each door lock control device 100 is not passed. The determination can be performed with high accuracy, and the door of the vehicle 1 can be unlocked appropriately. For example, as shown in FIG. 8, even if there is a variation in response time between the door lock control devices 100a to 100c, the threshold times Ta to Tc correspond to the response times of the respective door lock control devices 100a to 100c. Therefore, it is possible to accurately determine the relay attack. As a result, even if there is a variation in response time between the door lock control devices 100a to 100c, the door of the vehicle 1 can be unlocked when there is no relay attack, and the door of the vehicle 1 when there is a relay attack. Can be unlocked.

C. Modified example:
C-1. Modification 1
In the above-described embodiment, the case where one portable device 200 can be used for one door lock control device 100 has been described. However, a plurality of portable devices 200 may be used for one door lock control device 100. is there. For example, when one vehicle 1 is used by a couple, the husband may use the portable device 200a and the wife may use the portable device 200b.
In such a case, since there are individual differences such as manufacturing errors between the portable device 200a and the portable device 200b, the case where the door of the vehicle 1 is unlocked using the portable device 200a and the portable device 200b are It is estimated that the response times are different from each other when the door of the vehicle 1 is unlocked. That is, even if one door lock control device 100 transmits / receives “request signal” and “answer signal” to / from portable device 200a, “request signal” and “answer” to / from portable device 200b. It is estimated that the response times are different from those in the case of transmitting / receiving the “signal”. Therefore, if the same threshold time is used in a plurality of portable devices 200, the relay attack cannot be determined with high accuracy, and the door of the vehicle 1 may not be unlocked appropriately.

  Therefore, in the first modification, the ID and threshold time corresponding to each of a plurality of portable devices 200 used for one door lock control device 100 are stored. Specifically, in the manufacturing stage, when each portable device 200 is used, the response time when the relay device is not used is measured, the threshold time is determined based on the response time, and the threshold time is determined for each portable device. The information is stored in association with the ID of the machine 200. For example, as shown in FIG. 9, for the door lock control device 100a, the response time when using the portable device 200 with the ID 00100a1 is measured, and the time obtained by adding a margin (allowable amount) to this response time is a threshold value. The time Ta1 is stored in association with this ID (00100a1). Further, the response time when using the portable device 200 with the ID 00100a2 is measured, and the time obtained by adding a margin (allowable amount) to the response time is stored as a threshold time Ta2 in association with 00100a2. Similarly, for the door lock control device 100b and the door lock control device 100c, the response time when each portable device is used is measured, and the time obtained by adding a margin (allowable amount) to this response time is the respective threshold time. And stored in association with each ID.

  In this case, when receiving the “answer signal”, the door lock control device 100 detects the ID from the “answer signal” and specifies the threshold time corresponding to the ID. If the response time is less than the specified threshold time (threshold time corresponding to the ID), it is determined that there is no relay attack, the door of the vehicle 1 is unlocked (an unlock signal is transmitted), and the response time is specified. If it is equal to or greater than the threshold time (threshold time corresponding to the ID), it is determined that there is a relay attack and the door of the vehicle 1 is not unlocked (unlock signal is not transmitted).

  If it is set as the structure like the modification 1, the threshold time memorize | stored in the memory | storage part 15 of each door lock control apparatus 100 will respond | correspond to the response time at the time of using each portable device 200. FIG. For this reason, even when a plurality of portable devices 200 are used for one door lock control device 100, the determination of the relay attack can be performed with high accuracy, and the door of the vehicle 1 is appropriately unlocked. Can do.

  Even when it is determined that there is a relay attack in the first modification, a warning sound may be issued from the vehicle 1. This can prevent the relay attack from being performed. If it is determined that there is a relay attack in the first modification, the ID of the portable device 200 that transmitted the “answer signal” at that time is used as the user of the vehicle 1 (the portable device 200). To the owner). For example, information indicating that a relay attack has been performed and information indicating an ID may be displayed on the display unit provided in the vehicle 1, or a warning sound may be generated from the portable device 200 having the ID owned by the user of the vehicle 1. It is good also as reporting, and it is good also as transmitting the information which shows that relay attack was performed and ID showing to portable terminals, such as a smart phone which the user of the vehicle 1 owns. If it carries out like this, the user's attention of the vehicle 1 with respect to the relay attack to the portable device 200 of specific ID can be called. The notification as described above is performed by the relay attack determination unit 17.

C-2. Modification 2
In the above-described embodiment and Modification 1, the case where one threshold time is stored for each portable device (ID) has been described. However, a plurality of threshold times may be stored for each portable device (ID). . Here, the electric field intensity E detected by the door lock control device 100 when the portable device 200 transmits an “answer signal” varies depending on the positional relationship between the door lock control device 100 and the portable device 200. The response time described above varies depending on the magnitude of the electric field strength E. Specifically, in general, the response time becomes shorter as the electric field strength E becomes larger, and the response time becomes longer as the electric field strength E becomes smaller. Therefore, if the same threshold time is used regardless of the electric field strength E, the relay attack cannot be determined with high accuracy, and the door of the vehicle 1 may not be unlocked properly.

  In the second modification, therefore, a plurality of threshold times are stored for each portable device (ID) corresponding to the magnitude of the electric field strength E. Specifically, in the manufacturing stage, when the portable device 200 is used with various electric field strengths E (various positional relationships), the response time when the relay device is not used is measured, and the threshold time is determined based on the response time. This threshold time is stored in association with the magnitude of the electric field intensity E. For example, as shown in FIG. 10, for the door lock control device 100a, the threshold time Ta10 is stored in correspondence with the case where the magnitude of the electric field strength E by the portable device 200 with the ID 00100a1 is less than x1, and x1 or more The threshold time Ta20 is stored in correspondence with the case where it is less than x2, and the threshold time Ta30 is stored in correspondence with the case where it is greater than x2. Similarly, the door lock control device 100b and the door lock control device 100c also store the threshold time corresponding to the magnitude of the electric field strength E by the portable device 200 of each ID.

  In this case, when receiving the “answer signal”, the door lock control device 100 detects the ID from the “answer signal” and also detects the electric field strength E of the “answer signal”. A threshold time corresponding to E is specified. If the response time is less than the specified threshold time (threshold time corresponding to the electric field strength E), it is determined that there is no relay attack, the door of the vehicle 1 is unlocked (an unlock signal is transmitted), and the response time is reached. Is greater than the specified threshold time (threshold time corresponding to the electric field strength E), it is determined that there is a relay attack and the door of the vehicle 1 is not unlocked (unlock signal is not transmitted). The electric field strength E is detected by the RF receiver 11.

  With the configuration as in the second modification, the threshold time stored in the storage unit 15 of each door lock control device 100 corresponds to the magnitude of the electric field strength E. For this reason, even when the response time varies depending on the magnitude of the electric field strength E, the determination of the relay attack can be performed with high accuracy, and the door of the vehicle 1 can be unlocked appropriately.

  Even when it is determined that there is a relay attack in the second modification, a warning sound may be issued from the vehicle 1. This can prevent the relay attack from being performed. Further, when it is determined that there is a relay attack in the second modification, the relay attack is performed and the electric field strength E at that time is notified to the user of the vehicle 1 (owner of the portable device 200). Also good. For example, information indicating that the relay attack has been performed and the electric field strength E is provided on the display unit provided in the vehicle 1, and the relay attack may be displayed on a mobile terminal such as a smartphone owned by the user of the vehicle 1. Information indicating what has been done and the electric field strength E may be transmitted. In this way, not only can the user of the vehicle 1 be alerted to the relay attack, but also the relay device (the RF receiver 11 can send the request signal directly when the relay attack is performed by notifying the electric field strength E). It is possible to make the user of the vehicle 1 recognize the approximate position of the transmitting relay device R4). The notification as described above is performed by the relay attack determination unit 17.

  In the second modification, the threshold time is stored in correspondence with the electric field strength E detected by the door lock control device 100 (the electric field strength of the answer signal (RF signal) received by the door lock control device 100). The threshold time may be stored in association with the electric field strength detected by the portable device 200 (the electric field strength of the request signal (LF signal) received by the portable device 200). In such a case, the portable device 200 includes the detected electric field strength in the answer signal and transmits it to the door lock control device 100. By doing so, the door lock control device 100 can recognize the electric field strength detected by the portable device 200, and can determine the relay attack based on the electric field strength.

C-3. Modification 3
In the above-described embodiment, modification 1, and modification 2, the threshold time is stored in the door lock control device 100 at the manufacturing stage. However, the threshold time is stored after the use of the door lock control device 100 is started. It is good as well. Specifically, a situation that is presumed that a relay attack is not being performed (a situation in which there is a high possibility that a relay attack is not being performed) is detected, and a response time in this situation (response time when not via a relay device) And the time obtained by adding a margin (allowable amount) to this response time is stored as a threshold time.

  FIG. 11 shows a rough configuration of the door lock control device 300 of the third modification. As shown in FIG. 11, the door lock control device 300 has a configuration in which a getting-off detection unit 20 and a threshold time determination unit 21 are added to the configuration of the door lock control device 100 of the embodiment. Among these, the getting-off detection unit 20 detects the timing when the occupant exits (gets off) from the passenger compartment of the vehicle 1 as a situation where it is estimated that the relay attack is not performed. That is, at the timing when the occupant gets off, the portable device 200 carried by the occupant is present in the vicinity of the vehicle 1, and therefore it can be estimated that the relay attack is not performed. Further, the threshold time determination unit 21 acquires the response time in a situation where it is estimated that the relay attack is not performed from the response time measurement unit 16, determines the threshold time based on the response time, and stores the response time in the storage unit 15. Remember me.

  FIG. 12 shows a flowchart of threshold time storage processing executed by the door lock control device 300 of the third modification. This process is executed as a timer interrupt process (for example, every 0.1 second). When starting the threshold time storage process, the door lock control device 300 first determines whether or not it is the timing when the occupant gets out of the vehicle 1 (S201). This determination process is performed as follows. For example, a camera that captures the interior of the vehicle is provided, and it is determined whether there is an occupant in the vehicle based on the image of the camera. When the door of the vehicle 1 is opened and closed and no occupant is present in the passenger compartment, it is determined that it is the timing when the occupant got off the vehicle. Alternatively, while the “request signal” is transmitted from the in-vehicle LF transmission unit 13 every predetermined time and the “answer signal” is received according to the “request signal”, it is determined that the occupant is present in the passenger compartment. When the door of the vehicle 1 is opened and closed and no occupant is present in the passenger compartment, the “answer signal” cannot be received), and it is determined that it is time for the occupant to get off.

  As a result of the determination process of S201, when it is the timing when the occupant gets off (S201: yes), a “request signal” is transmitted from the outside LF transmission unit 12 (S202), and the response time is measured by the response time measurement unit 16. Starts (S203). Thus, the “request signal” is transmitted from the outside LF transmitter 12 (S202), and when the response time measurement is started (S203), whether or not the “answer signal” is received from the portable device 200, that is, the process of S202. Then, it is determined whether or not the RF receiver 11 has received an “answer signal” in response to the “request signal” transmitted from the LF transmitter 12 outside the vehicle (S204). As a result, if the “answer signal” has not been received yet (S204: no), whether or not the time since the transmission of the “request signal” has exceeded the time limit (for example, 50 milliseconds) (whether it has timed out) (S205). As a result, if the time-out has not yet occurred (S205: no), the reception of the “answer signal” is awaited (S204). If the time-out occurs (S205: yes), the threshold time storing process is terminated as it is.

When the “answer signal” is received before the time-out occurs (S204: yes), the response time measurement is finished and the measured response time is stored in the storage unit 15 (S206). The ID determination unit 14 detects the ID from the received “answer signal” (S207), and determines whether or not the detected ID matches the ID stored (registered) in the storage unit 15 in advance ( S208). As a result, when the ID detected from the “answer signal” is not registered (S208: no), the threshold time storing process is terminated as it is.
On the other hand, when the ID detected from the “answer signal” is registered (S208: yes), the threshold time is determined by adding a margin (allowable amount) to the response time stored in the process of S206. The threshold time is stored in association with the registered ID.

  With the configuration as in Modification 3, even if the threshold time corresponding to each individual is not stored at the manufacturing stage, the threshold time corresponding to each individual can be automatically stored, and the determination of relay attack is accurate. Can be done. In addition, the response time may change depending on various situations (for example, due to aging, etc.). In such a case, the threshold time is automatically corrected, and the relay attack is accurately determined. Can be done.

  In the above-described embodiments and modifications, the case where the present invention is applied to the technology for unlocking the door of the vehicle 1 using the portable device 200 has been described. However, the engine of the vehicle 1 using the portable device 200 is described. The present invention can also be applied to a technology that permits the starting of the system. In this case, as shown in FIG. 13, an engine start permission unit 30 that permits engine start of the vehicle 1 is provided. The engine start permission unit 30 transmits an engine start permission signal for permitting engine start based on the determination results of the ID determination unit 14 and the relay attack determination unit 17 described above. That is, the above-described ID determination unit 14 determines that the unique ID included in the “answer signal” transmitted from the portable device 200 matches a pre-registered ID, and the above-described relay does not indicate that there is no relay attack. When the attack determination unit 17 determines, an engine start permission signal is transmitted. Upon receiving an engine start permission signal from the engine start permission unit 30, a control unit (for example, an ECU for engine start) that controls the engine start of the vehicle 1 thereafter performs a predetermined operation (for example, a predetermined switch operation or key operation). ) Is started, the engine is started. Of course, when the above-described ID determination unit 14 determines that the unique ID included in the “answer signal” transmitted from the portable device 200 does not match a pre-registered ID, or when there is a relay attack, the above-described relay If the attack determination unit 17 determines, the engine start permission signal is not transmitted.

As mentioned above, although the Example and the modification were demonstrated, this invention is not restricted to said Example, In the range which does not deviate from the summary, it can implement in a various aspect.
For example, in the above-described third modification, the threshold time is stored when it is estimated that the relay attack is not performed. However, a user of the vehicle 1 or a dealer (so-called dealer) performs a predetermined operation. In this case, the response time may be measured, and the threshold time may be stored from this response time. In addition, as predetermined operation here, operation of the switch provided in the vehicle 1 or connection of an external device to the vehicle 1 and transmission of predetermined information from the external device to the vehicle 1 specify a specific vehicle 1. For example, an operation for setting the registration mode state can be given.
In the above-described embodiment and modification, when determining the threshold time, the response time may be measured a plurality of times (for example, 100 times), and the threshold time may be determined based on the measurement result (for example, the average). Good. In this way, the accuracy of the threshold time can be increased.

DESCRIPTION OF SYMBOLS 1 ... Vehicle, 11 ... RF receiving part, 12 ... Outside LF transmitting part,
13 ... In-vehicle LF transmission unit, 14 ... ID determination unit, 15 ... Storage unit,
16 ... Response time measurement unit, 17 ... Relay attack determination unit, 18 ... Unlock instruction unit,
19 ... Locking instruction unit, 20 ... Alighting detection unit, 21 ... Threshold time determination unit,
30 ... Engine start permission unit, 100, 300 ... Door lock control device,
200: A portable device.

Claims (7)

A vehicle door unlocking device (100, 200) which is mounted on a vehicle (1) and unlocks the door of the vehicle by communicating with a portable device (200) having identification information,
A transmission unit (12) for transmitting a request signal to the portable device;
A receiver (11) for receiving an answer signal transmitted by the portable device in response to the request signal;
A measuring unit (16) for measuring a response time from when the transmitting unit transmits the request signal to when the receiving unit receives the answer signal;
A storage unit (15) for storing a threshold time in association with the identification information;
When the response time is shorter than the threshold time stored in the storage unit in association with the identification information included in the answer signal received by the receiving unit, the door is unlocked, and the door is shorter than the threshold time. When the response time is long, the door is not unlocked (18), and
The vehicle door unlocking device, wherein the threshold time is a time determined based on a result of actual measurement of the response time by the measurement unit of the vehicle door unlocking device. The vehicle door unlocking device according to claim 1,
The storage unit stores the threshold time in association with each of a plurality of pieces of identification information,
The threshold time is determined based on a result of actual measurement of the response time for each of the plurality of pieces of identification information by the vehicle door unlocking device. The vehicle door unlocking device according to claim 1 or 2,
The storage unit stores the threshold time in association with the magnitude of the electric field strength in addition to the identification information,
The unlocking unit detects the electric field strength when the receiving unit receives the answer signal, and stores the threshold stored in the storage unit in association with the identification information and the electric field strength included in the answer signal. Read the time, if the response time is shorter than the threshold time, unlock the door, if the response time is longer than the threshold time, do not unlock the door,
The threshold time stored in the storage unit is determined based on the result of actual measurement of the value of the electric field strength when the vehicle door unlocking device receives the answer signal and the response time at this time. A vehicle door unlocking device. The vehicle door unlocking device according to claim 1 or 2,
The storage unit stores the threshold time in association with the magnitude of the electric field strength in addition to the identification information,
The unlocking unit detects the electric field strength when the portable device receives the request signal, and determines the threshold time stored in the storage unit in association with the identification information of the portable device and the electric field strength. Read, if the response time is shorter than the threshold time, unlock the door, if the response time is longer than the threshold time, do not unlock the door,
The threshold time stored in the storage unit is a result of actual measurement of the value of the electric field intensity when the portable device receives the request signal from the vehicle door unlocking device and the response time at this time. The vehicle door unlocking device characterized by being determined based on. The vehicle door unlocking device according to any one of claims 1 to 4,
A getting-off detection unit (20) for detecting that the vehicle occupant got off,
The threshold time is determined when the getting-off detection unit detects that an occupant of the vehicle has got off the vehicle door unlocking device. The vehicle door unlocking device according to any one of claims 1 to 5,
When the door is not unlocked by the unlocking unit because the response time is longer than the threshold time, information indicating that the door has not been unlocked is notified to the owner of the portable device. A vehicle door unlocking device comprising an informing unit (17). The vehicle door unlocking device according to any one of claims 1 to 6,
When the response time is shorter than the threshold time stored in the storage unit in association with the identification information included in the answer signal received by the reception unit, the engine of the vehicle is permitted to start, and the threshold time The vehicle door unlocking device further includes an engine start permission unit (30) that does not permit the start of the engine when the response time is longer than the above.

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