JP2013100717A - Smart keyless entry system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a smart keyless entry system that improves antitheft security by preventing so called a relay attack.SOLUTION: Impersonation determination means 50 and 60 of determining whether a person nearby a vehicle 14 is a regular user U or first thief are provided to both the vehicle 14 and a mobile machine 15. The smart keyless entry system has a door unlocking stop part 52 which stops doors 3, 3 of the vehicle 14 from being unlocked disallowing a door lock driving driver circuit 51 to transmit an unlock signal to door lock actuators 7, 7 of the doors when the impersonate determination means 50, 60 determine that a repeater that the person nearby the vehicle 14 has is not the mobile machine 15 or that the regular user U having the portable machine 15 is not nearby the vehicle 14.

Description

  The present invention mainly relates to a smart keyless entry system that performs two-way communication between a vehicle and a portable device that can be carried by a user and locks / unlocks the door of the vehicle after verifying an identification code. In particular, the present invention relates to a smart keyless entry system with improved antitheft function.

  Conventionally, a smart keyless entry system as shown in FIG. 11 or FIG. 12 is known (see, for example, Patent Document 1).

  First, in terms of configuration, in this smart keyless entry system, the two-way communication is performed between the vehicle 1 and the portable device 2 carried by the authorized user U, thereby locking and unlocking the doors 3 and 3 of the vehicle 1. Used in the vehicle locking device 4 for unlocking.

  That is, in this conventional smart keyless entry system, a vehicle that locks and unlocks the door lock actuators 7 and 7 in accordance with a signal transmitted from the outside by the authorized user U to the control unit 6 mounted on the vehicle 1. Locking device 4, engine starter device 5 for starting the engine based on the engine start signal, and door request switch (request signal transmission operation means) 8 set on the door knob portion 10 provided on the outer surface of the door 3. And is connected mainly.

  The control unit 6 of the vehicle locking device 4 is provided with a function of determining whether to start the engine in addition to permitting the locking and unlocking by storing a unique identification code of the vehicle 1. Yes.

  A vehicle antenna unit (portable device request signal transmission means) 9 is connected to the control unit 6 mounted on the vehicle 1 side.

  In the control unit 6, when the door lock actuators 7 and 7 perform locking and unlocking of the keys of the doors 3 and 3 based on the identification code placed on the received signal, Whether the identification code is the same as the identification code unique to the vehicle 1 is collated, and when the collation is matched, unlocking is permitted.

  In addition, when the passenger rides, the engine starter device 5 is allowed to start the engine when the identification code matches.

  Further, on the portable device 2 side carried by the authorized user U, a key antenna unit (identification code signal transmitting means) 11 and a key ID storage unit 12 for storing and storing the same identification code as the unique identification code of the vehicle 1 are stored. And a key-side request switch 13 for locking and unlocking the door 3 by the operation of the authorized user U from the portable device 2 side.

  And according to the request signal (LF signal: Low Frequency; the reach distance from the vehicle antenna unit 9 is about 1 m) transmitted from the vehicle antenna unit 9, the key antenna unit 11 on the portable device 2 side is interposed, After being received on the authorized user U side, the identification code signal stored in the key ID storage unit 12 is placed on the long distance signal (RF signal: Radio Frequency; high frequency, long reachable range), and vehicle By replying to the first side, two-way communication is performed between the vehicle 1 and the portable device 2 so that the collation can be performed.

  Next, the effect of this conventional smart keyless entry system will be described.

  That is, in this conventional smart keyless entry system, first, when the key-side request switch 13 is pressed by the authorized user U as a remote control operation by one-way communication of the remote control entry function, the key ID storage unit 12 stores the key-side request switch 13. The identification code signal thus transmitted is placed on the RF signal and transmitted from the key antenna unit 11 on the portable device 2 side to the vehicle 1 side.

  On the vehicle 1 side, when the RF signal is received by the vehicle antenna unit 9, this RF signal is sent to the control unit 6, and a unique identification code of the vehicle 1 stored in the control unit 6, The received identification code signal is collated.

  And when collation matches, the doors 3 and 3 of the vehicle 1 are unlocked by the door lock actuators 7 and 7.

  Next, a case where the door 3 is locked and unlocked by bidirectional communication in this conventional smart keyless entry system will be described.

  In this smart keyless entry system, for example, when the authorized user U operates the door request switch 8 installed in the door knob portion 10 of the vehicle 1, an LF signal as a request signal is transmitted from the vehicle antenna portion 9 on the vehicle 1 side. The

  On the portable device 2 side, when the request signal is received by the key antenna unit 11, an identification code signal is returned to the vehicle 1 side together with a response signal (RF signal).

  Then, when the identification code of the identification code signal and the unique identification code stored in the control unit 6 on the vehicle 1 side are collated and the collation is matched, the door of the vehicle 1 is locked / unlocked. Done.

  The distance that enables bidirectional communication between the vehicle 1 and the portable device 2 is within a range of about 1 m from the vehicle antenna unit 9 of the door 3 because the reach of the LF signal is limited. .

JP 2006-144259 A (paragraphs 0011 to 0029, FIGS. 1 and 2)

  However, in the conventional smart keyless entry system configured as described above, even if the authorized user U does not operate the key-side request switch 13 on the portable device 2 side, the verification of the identification code is performed by the so-called “relay attack” method. May be performed until door unlocking and engine start.

  That is, as shown in FIG. 12, when the authorized user U with the portable device 2 is away from the vehicle 1, the first thief K <b> 1 approaches the vehicle 1, and the door request built in the door knob unit 10. When the switch 8 is operated, a request signal (LF signal) is transmitted from the vehicle antenna unit 9.

  The first repeater J1 possessed by the first thief K1 receives this LF signal, demodulates it, modulates it to an RF signal, and transmits this RF signal.

  The second repeater J2 possessed by the second thief K2 receives this RF signal, demodulates it, and remodulates it to a request signal (LF signal).

  Even if the authorized user U is away from the vehicle 1 because the second thief K2 who possesses the second repeater J2 approaches the authorized user U, the possessed portable device 2 cannot Receive at a distance and respond with an RF signal.

  Therefore, the vehicle antenna unit 9 of the vehicle 1 is loaded with the regular identification code without being noticed without the authorized user U performing the unlocking operation and engine starting operation using the key-side request switch 13. When the RF signal is received, the doors 3 and 3 may be unlocked and the engine may be started.

  Therefore, the present invention has been made in view of such problems, and it is an object of the present invention to provide a smart keyless entry system in which a so-called relay attack is prevented and an antitheft property is improved.

In order to solve such a problem, the invention described in claim 1 is such that two-way communication is performed between the vehicle and the portable device carried by the user, and the door of the vehicle is locked and unlocked. Smart keyless entry system used in the smart keyless entry system corresponding to the relay relay theft technique consisting of the first and second theft,
The relay relay theft technique is that the first thief impersonates an authorized user using the first repeater, and sends the LF signal sent from the vehicle to the second repeater owned by the second thief. The RF signal obtained by the conversion is sent out, and the second repeater converts it again into the LF signal sent to the first theft, and the second theft who owns the second repeater approaches The mobile phone owned by the authorized user is sent out in a manner similar to the LF signal from the vehicle, and the unique identification code stored in the mobile device is placed on the RF signal transmitted from the mobile device, and the vehicle Is a smart keyless entry system that supports spoofing theft as if a person in the vicinity of the vehicle is returning a legitimate identification code from the mobile device,
Impersonation determination means for determining whether a person existing in the vicinity of the vehicle is a regular user or a first theft is provided in both the vehicle and the portable device, and with the impersonation determination means, When the relay device held by a person in the vicinity of the vehicle is not the portable device, or when the authorized user who owns the portable device determines that the vehicle does not exist in the vicinity of the vehicle, the vehicle door is unlocked. It features a smart keyless entry system having a door unlocking prevention unit that is not performed.
According to a second aspect of the present invention, in the case where the impersonation determination means returns a response to the portable device by an LF signal sent from the vehicle, the output value of the RF signal transmitted is the vehicle The smart keyless entry system according to claim 1, further comprising an RF signal strength setting unit for reducing the LF signal output from the LF signal so as to reach a reachable distance.
Further, according to a third aspect of the present invention, in the impersonation determination unit, the response time data from the reception of the LF signal added to the returned data to the portable device until the output of the RF signal is received by the impersonation determination unit. A response time measurement unit that measures the response time, and the response time measurement unit that adds the response time data measured to the RF signal and returns a portable device response time addition unit. A reply time measuring unit that measures a reply time required from when the LF signal is transmitted until the RF signal is received; the response time data; and a reply time measured by the reply time measuring unit; The smart keyless entry system according to claim 1, further comprising a reaction time comparison / determination unit for determining whether or not the user is a regular user.

In the invention according to claim 1 configured as described above, when an LF signal from a vehicle is sent to the portable device held by the approaching regular user, the unique identification code stored in the portable device is: It is sent on the RF signal transmitted from the portable device and returned to the vehicle.
For this reason, the identification code unique to the vehicle matches the unique identification code stored in the portable device, so that the door key can be locked and unlocked, or the engine can be started.
Then, the impersonation determination means determines that the relay device held by a person in the vicinity of the vehicle is not the portable device, or that the authorized user who owns the portable device does not exist in the vicinity of the vehicle. In this case, the door unlocking block prevents the door key from being locked and unlocked or the engine is started so that the vehicle door is not unlocked.
For this reason, in the so-called relay attack method, when the identification code is collated, the impersonation determining means determines that impersonation is being performed, and the door unlocking prevention unit performs unlocking of the door. I will not.
Therefore, the door of the vehicle cannot be opened and the engine cannot be started, so that the anti-theft function can be improved.
In addition, the output of the RF signal transmitted when the RF signal strength setting unit of the impersonation determination means returns to the portable device by the LF signal sent from the vehicle. The value is set to be low so that the reach is about the reach of the LF signal output from the vehicle.
For this reason, even if a person in the vicinity of the vehicle impersonates a regular user, an RF signal that does not have a reachable distance to the vehicle is output from a portable device of a regular user that exists at a long distance. Cannot receive.
Therefore, the impersonation theft technique cannot be unlocked to open the door, so-called relay attack is prevented, and the anti-theft property is improved.
Further, in the present invention, the RF signal is output after the LF signal added to the data to be returned is received by the response time measuring unit of the impersonation determining unit provided in the portable device. Response time until is measured as response time data.
In the portable device response time adding unit of the portable device, the response time data measured by the response time measuring unit is added to the RF signal and returned to the vehicle.
In the vehicle, the reply time measuring unit measures the time required from when the LF signal is transmitted until the RF signal is received.
Then, the response time data and the time measured by the response time measurement unit are compared by the response time comparison and determination unit, and the response time data and the time measured by the response time measurement unit are compared. In the case of coincidence, since the theft relay device is not interposed, it is determined that the user is a legitimate user, the time measured by the response time measurement unit is longer than the response time data, etc. In the case of a significant difference, it is determined that a theft relay device is present and that the user is not an authorized user.

1 is a schematic side view of a vehicle showing a smart keyless entry system according to an embodiment of the present invention. It is a typical perspective view explaining the relay attack theft technique of the smart keyless entry system of Example 1 of the best embodiment of this invention. It is a block diagram which shows the structure of the smart keyless entry system of Example 1 of the best mode of this invention. It is a flowchart figure explaining operation | movement of the smart keyless entry system of Example 1 of the best mode of this invention. It is a typical perspective view explaining the relay attack theft technique of the smart keyless entry system of Example 2 of the best embodiment of this invention. It is a block diagram which shows the structure of the smart keyless entry system of Example 2 of the best mode of this invention. It is a flowchart figure explaining operation | movement of the smart keyless entry system of Example 2 of the best mode of this invention. It is a typical perspective view explaining the relay attack theft technique of the smart keyless entry system of Example 3 of the best mode of this invention. It is a block diagram which shows the structure of the smart keyless entry system of Example 3 of the best mode of this invention. It is a flowchart figure explaining operation | movement of the smart keyless entry system of Example 3 of the best mode of this invention. It is a typical vehicle side view which shows the smart keyless entry system of a prior art example. It is a typical perspective view explaining the whole structure in the smart keyless entry system of a prior art example.

  Next, a smart keyless entry system according to the best mode for carrying out the present invention will be described with reference to the drawings.

  The same or equivalent parts as those in the conventional example will be described with the same reference numerals.

  1 to 10 show a smart keyless entry system according to the preferred embodiment of the present invention.

  First, the overall configuration will be described. In the smart keyless entry system of this embodiment, two-way communication is performed between the vehicle 14 and the portable device 15 carried by the authorized user U, and the door 3 of the vehicle 14. , 3 are configured to be locked and unlocked by door lock actuators 7, 7 provided inside.

  That is, in the smart keyless entry system of this embodiment, the smart keyless ECU 16 as the control unit mounted on the vehicle 14 determines whether to permit the locking / unlocking according to the signal transmitted from the outside by the authorized user U. The CPU 17 has a door lock driving function for performing the locking / unlocking operation of the door lock actuators 7 and 7 by sending a locking / unlocking signal and an engine start permission function for determining whether to start the engine. Is provided.

  Further, the smart keyless ECU 16 of this embodiment includes an engine starter device 5 for starting the engine based on an engine start signal, a door request switch (set on the door knob portion 10 provided on the outer surface of the door 3), and the like. Request signal transmission means) 8 is connected.

  An EEPROM 18 as a storage unit is connected to the CPU 17 of the smart keyless ECU 16. The EEPROM 18 stores a unique identification code of the vehicle 14 and can be read out by the CPU 17.

  An RF tuner device 20 as a vehicle antenna unit is connected to the smart keyless ECU 16 mounted on the vehicle 14 side via an interface unit 19.

  The RF tuner device 20 includes a data line 20d and an RSSI line 20e with respect to the interface unit 19, a tuner side interface unit 20c connected via a data line 20a and an RSSI line 20b, and the tuner side interface unit 20c. And an RF demodulation IC 20f that demodulates an RF signal received by the RF antenna unit 23.

  Further, in the smart keyless ECU 16 mounted on the vehicle 14 side, an LF antenna driver 21 that outputs a transmission signal to the LF antenna unit 22 is provided connected to the CPU 17, and the portable device 15 as a portable device is provided. On the side, an LF antenna unit 26 that transmits a request signal is connected.

  In the smart keyless ECU 16, when the doors 3 and 3 are locked and unlocked by the door lock actuators 7 and 7, the identification code placed on the received RF signal is displayed on the vehicle. Whether the identification code is the same as the unique identification code stored in the EEPROM 18 is checked.

  And when collation matches, it is judged that it is a regular user U and permission of unlocking is performed.

  Further, when the occupant is in the vehicle, the RF signal is received by the antenna in the passenger compartment and the coincidence of the identification code is determined so that the engine starter device 5 is permitted to start the engine. It is configured.

  In addition, on the portable device 15 side carried by the authorized user U, an LF demodulation circuit 25 that performs demodulation is connected to the LF antenna unit 26 that receives the request signal.

  The LF demodulation circuit 25 is connected to a CPU 27 as a portable device side control unit via a data line 25a and an RSSI line 25b.

  The CPU 27 of this embodiment is connected to an RF transmission circuit 29 that transmits an RF signal from an RF antenna unit (identification code signal transmission means) 28.

  In addition, the CPU 27 is provided with a key ID storage unit 12 including a memory for storing and storing the same identification code as the unique identification code of the vehicle 14. The key-side request switch 13 for performing the locking and unlocking operations of the door lock actuators 7 and 7 of the door 3 is connected and provided.

  Next, the operational effects associated with the general operation of the smart keyless entry system of this embodiment will be described.

  In this embodiment, when the door request switch 8 provided on the vehicle 14 side is turned on, an LF signal is transmitted from the LF antenna unit 22 via the LF antenna driver 21.

  On the portable device 15 side, when the LF signal is received by the LF antenna unit 26, it is demodulated by the LF demodulation circuit 25 and sent to the CPU 27.

  In the CPU 27, the identification code signal stored in the key ID storage unit 12 is placed on the LF signal received on the authorized user U side and sent to the RF transmission circuit 29.

  In the RF transmission circuit 29, an RF signal is returned from the RF antenna unit 28 to the vehicle 14 side, whereby bidirectional communication is performed between the vehicle 14 and the portable device 15 to perform the collation. It is configured to be

  For this reason, in such a smart keyless entry system, as shown in FIG. 3, a relay relay comprising a first thief K1 having a first repeater J1 and a second thief K2 having a second repeater J2. Possible theft.

  The first repeater J1 used for the relay relay theft technique is provided with an LF receiving antenna unit 31 connected to the CPU 32 and receiving the request signal, whereby an LF demodulation circuit 30 for demodulating the request signal is provided. Is provided.

  The LF demodulation circuit 30 is configured to generate an RF signal having a relatively long reach by the RF transmission circuit 33 and transmit the demodulated request signal from the RF transmission antenna unit 34 as an RF signal.

  The second repeater J2 used for the relay relay theft technique is provided with an RF receiving antenna unit 44 that receives the RF signal transmitted from the first repeater J1.

  The RF receiving antenna unit 44 is connected to the CPU 42 via the RF receiving circuit 43.

  In the CPU 42, when the RF receiving antenna unit 44 receives the RF signal transmitted from the first repeater, an LF signal is generated.

  And it is comprised so that this LF signal may be transmitted from LF antenna part 41 of LF drive circuit 40 to which this CPU42 is connected.

  Next, a so-called relay attack theft technique assumed in this embodiment will be described.

  In this embodiment, as shown in FIG. 2, the first thief K1 uses the first repeater J1 to impersonate the authorized user U and approaches the vehicle 14 to be stolen.

  An RF signal obtained by converting the LF signal sent from the vehicle to the second repeater J2 held by the second thief K2 approaching the regular user U who is away from the vehicle 14 Is sent out.

  In the second repeater J2 that has received this RF signal by the RF receiving antenna unit 44, the RF signal is converted so that it becomes the same signal as the LF signal sent from the vehicle 14 to the first thief K1 again. The

  Then, the second thief K2 possessing the second repeater J2 transmits the LF signal to the portable device 15 possessed by the close authorized user U, by imitating the LF signal from the vehicle 14 to the LF antenna unit. 41.

  The portable device 15 that has received the LF signal by the LF antenna unit 26 places the unique identification code stored in the key ID storage unit 12 on the RF signal transmitted from the RF antenna unit 28 of the portable device 15. To the vehicle 14.

  For this reason, it is as if a person (first theft person K1) existing in the vicinity of the vehicle 14 is returning a proper identification code from the portable device 15, and the door lock of the vehicle 14 is unlocked. You can start the engine.

  For such a so-called relay attack theft mechanism, in the smart keyless entry system of this embodiment, at least one or both of the CPU 17 of the smart keyless ECU 16 and the CPU 27 of the portable device 15 are provided. Impersonation determination means for determining whether a person existing in the vicinity of the vehicle 14 is a regular user U or a theft is provided.

  The impersonation determination means of this embodiment has a door unlocking prevention unit 52.

  In this door unlocking prevention unit 52, the relay device held by a person in the vicinity of the vehicle 14 is not the portable device 15, or the authorized user U who owns the portable device 15 does not exist in the vicinity of the vehicle 14. The door lock actuators 7 and 7 of the doors 3 and 3 of the vehicle 14 are prevented from being unlocked without transmitting the unlock signal from the door lock drive driver circuit 51. It is.

  In this embodiment, the CPU 17 of the vehicle 14 is provided with an engine start blocking unit 56 that blocks engine start by the engine starter device 5.

  The engine start prevention unit 56 permits the engine start by the engine starter device 5 when the determination by the impersonation determination unit is the authorized user U, and the engine starter device when the determination is not the authorized user U. 5 is configured to prevent engine start by 5.

  In the smart keyless entry system according to Example 1 of this embodiment, the CPU 17 on the vehicle 14 side has a spoof determination unit 50 and the CPU 27 on the portable device 15 side has a pair with the spoof determination unit 50. Spoofing determination means 60 is provided for each.

  Among these, as the impersonation determination means 50, the CPU 17 of the vehicle 14 is provided with an RF signal reception intensity measurement circuit 53 for measuring the reception intensity of the RF signal transmitted from the portable device 15.

  A data extraction unit 54 is provided for extracting LF signal strength data included in the RF signal received by the RF antenna unit 23 of the vehicle 14.

  A signal strength comparison / determination unit 55 is provided for comparing the LF signal strength data of the LF signal measured by the portable device 15 and the received strength of the RF signal measured by the RF signal received strength measuring circuit 53. Yes.

  This signal strength comparison / determination unit 55 pays attention to the fact that the signal strength of transmission / reception is inversely proportional to the transmission / reception distance, compares the signal strength of transmission / reception, and receives the LF signal in the vicinity of the vehicle. It is configured that it is determined whether or not the person is the authorized user U who has transmitted the RF signal toward the vehicle 14.

  When the user is an authorized user U, the door lock driving driver circuit 51 permits the door unlocking prevention unit 52 to unlock the door lock actuators 7 and 7 and is not the authorized user U. In this case, the door lock driving driver circuit 51 is configured to prevent the door unlock actuators 7 and 7 from unlocking the door unlocking block 52.

  Further, the impersonation determination means 60 on the portable device 15 side has an LF signal reception intensity measurement circuit 61 for measuring the signal intensity of the LF signal received by the LF antenna unit 26 in the CPU 27, and the measured LF. A synthesis reply circuit 62 is provided which places the signal strength on the RF signal as LF signal strength data and sends the signal strength back to the vehicle.

  Next, the effect of the smart keyless entry system of the first embodiment will be described with reference to the flowchart shown in FIG.

  When the vehicle-side on-board device control is started in Step 1, the request signal wait state is entered in Step 2.

  In this request signal waiting state, it is determined whether or not the door request switch 8 provided in the door knob 10 has been pressed.

  That is, in Step 3, when the door request switch 8 is turned on, the process proceeds to the next Step 4. When the door request switch 8 is not turned on but remains OFF, the process returns to Step 2, and is in a standby state. The request signal waiting state is maintained.

  In Step 4, the LF antenna driver 21 transmits an LF signal as a challenge signal from the LF antenna unit 22.

  Then, at Step 5, the RF signal reception wait state is entered.

  On the other hand, on the portable device 15 side, when portable device control is started at Step 6, at Step 7, the LF signal is received by the LF antenna unit 26 on the portable device 15 side, or the key side request switch It will be in a state waiting for whether 13 is input ON.

  In Step 8, it is determined whether or not an LF signal has been received.

  When the LF signal is received by the LF antenna unit 26 on the portable device 15 side, the process proceeds to the next Step 9, and when not received, the process returns to Step 7 to maintain the standby state.

  In Step 9, the LF signal received by the LF antenna unit 26 is demodulated by the LF demodulation circuit 25, and a unique identification code of the vehicle 14 placed on the LF demodulated signal is stored on the portable device 15 side. It is verified whether or not it matches the identification code.

  In Step 10, when the unique identification code of the vehicle 14 included in the LF demodulated signal matches the identification code stored on the portable device 15 side, the process proceeds to the next Step 11, and if not, the process returns to Step 7. .

  In Step 11, the electric field strength of the received LF signal is set to RSSI (received power) by the LF signal reception strength measuring circuit 61 provided in the CPU 27 for measuring the signal strength of the LF signal received by the LF antenna unit 26. Is calculated from the signal level).

  In Step 12, the measured LF signal strength is synthesized by the synthesis reply circuit 62 as LF signal strength data including the LF reception RSSI level and response data including the identification code ID on the portable device 15 side. From the RF antenna unit 28 of the RF transmission circuit 29, it is placed on the RF signal and sent back to the vehicle 14.

  In Step 13, when the RF signal is received by the RF antenna unit 23 on the vehicle 14 side, in Step 14, the RF demodulation IC 20f demodulates the RSSI level of the LF signal from the RF signal as the RSSI level.

  The RSSI level is transmitted from the tuner-side interface unit 20c connected via the data line 20d and the RSSI line 20e to the interface unit 19 on the smart keyless ECU 16 side through the data line 20a and the RSSI line 20b.

  In Step 15, the RF signal reception intensity measurement circuit 53 provided in the impersonation determination means 50 of the smart keyless ECU 16 determines the electric field intensity of the LF signal received by the LF antenna unit 26 on the portable device 15 side from the RSSI level of the LF signal. Calculated.

  In Step 16, the data extraction unit 54 extracts the electric field strength of the LF signal received by the portable device 15, and the distance between the LF antenna unit 22 on the vehicle 14 side and the portable device 15 is calculated from the electric field strength.

  In Step 17, the RF electric field strength is calculated from the RSSI level of the RF signal received by the RF antenna unit 23 on the vehicle 14 side.

  In Step 18, the distance between the portable device 15 and the RF antenna unit of the vehicle 14 is calculated from the RF electric field strength.

  In Step 19, the signal strength comparison / determination unit 55 of the impersonation determination unit 50 determines whether or not there is a significant difference between the distance calculated from the LF signal and each distance calculated from the RF signal.

  If there is a difference, the process returns to Step 2 to maintain the request signal standby state, and if there is no difference, the process proceeds to the next Step 20.

  In Step 20, it is checked whether or not the unique identification code stored in the EEPROM 18 provided in the smart keyless ECU 16 of the vehicle 14 matches the identification code stored on the portable device 15 side.

  If they match as a result of the collation, the process proceeds to Step 21 and permits the door unlocking prevention unit 52 to release the door lock, and the engine start prevention unit 56 uses the engine starter device 5 as an engine start control. License to be able to

  As described above, when the signal strength of the LF signal is measured by the LF signal reception strength measurement circuit 61 of the impersonation determination means 60 provided in the portable device 15, the measured LF signal strength is converted into the synthesized signal. The reply circuit 62 places the RF signal as LF signal strength data on the RF signal and sends it back to the vehicle 14 from the RF antenna unit 28.

  When the reception intensity is measured from the RF signal transmitted from the portable device 15 by the RF signal reception intensity measurement circuit 53 provided in the vehicle 14, the LF signal of the LF signal measured by the portable device 15. The intensity data and the received intensity of the RF signal are compared by the signal intensity comparison / determination unit 55.

  As a result of this comparison, if the LF signal strength data matches the received strength of the RF signal, the transmission / reception distance is the same.

  When the authorized user U holds the portable device 15 and pushes the door request switch 8 or the key-side request switch in the vicinity of the vehicle 14, the distance of the RF signal and the distance of the LF signal Matches.

  For this reason, it is determined that the person who is present in the vicinity of the vehicle 14 and has received the LF signal is the authorized user U that has transmitted the RF signal toward the vehicle 14.

  In addition, when the first thief K1 exists in the vicinity of the vehicle 14 and the authorized user U is away from the vehicle 14, the distance of the RF signal and the distance of the LF signal do not match, The signal strength is different.

  Thus, as shown in FIG. 1, the LF from the vehicle 14 is transferred to the portable device 15 held by the authorized user U approaching the vehicle 14 when there is no first theft user K1 and the second theft user K2. When the signal is transmitted, the unique identification code stored on the portable device 15 side is put on the RF signal transmitted from the portable device 15 side and returned to the vehicle 14.

  In the vehicle 14, the unique identification code stored in the EEPROM 18 matches the unique identification code stored in the portable device 15, so that the doors 3 and 3 via the door lock drive driver circuit 51, The door lock actuators 7 and 7 are locked and unlocked, and engine start control using the engine starter device 5 can be performed.

  In addition, if the LF signal strength data does not match the reception strength of the RF signal and the LF signal strength data is stronger than the reception strength of the RF signal, the LF signal is The person who has received the first LF J1 in the vicinity of the vehicle 14 and has received the LF signal having a strong signal strength impersonates the authorized user U who has sent the RF signal toward the vehicle 14 at a distance. It is determined that it is not the authorized user U who is the first thief K1 who is close to the second thief K2 who owns the second repeater J2 at a distance.

  In this way, in the impersonation determination means 50 on the vehicle 14 side, the first relay device J1 possessed by a person in the vicinity of the vehicle 14 is not the portable device 15 or the authorized user U who owns the portable device 15 When it is determined that the signal does not exist in the vicinity of the vehicle 14 based on a difference in signal strength, the door unlocking prevention unit 52 is configured to prevent the doors 3 and 3 of the vehicle 14 from being unlocked. The door lock drive driver circuit 51 prevents locking and unlocking of the key using the door lock actuators 7 and 7, and the engine start blocking unit 56 blocks engine start using the engine starter device 5.

  For this reason, in the so-called relay attack method, when the identification code is collated, it is determined by the impersonation determination means 50 and 60 that impersonation is being performed, and the door 3 by the door unlocking prevention unit 52 is determined. , 3 is not unlocked.

  Accordingly, the doors 3 and 3 of the vehicle 14 cannot be opened and the engine cannot be started, so that the anti-theft function can be improved.

  Other configurations and operational effects are the same as or equivalent to those of the above-described embodiment, and thus description thereof is omitted.

  5 to 7 show a smart keyless entry system according to the second embodiment of the present invention.

  In addition, the same code | symbol is attached | subjected and demonstrated about the same thru | or equivalent part as the said embodiment and Example 1. FIG.

  First, the configuration will be described focusing on the differences from the first embodiment. In the smart keyless entry system for the vehicle 114 according to the second embodiment, the CPU 127 on the portable device 115 side as a portable device is used as the impersonation determination means 160. The response time measuring unit 161 is provided.

  The response time measuring unit 161 is configured to measure the response time from the reception of the LF signal added to the returned data to the portable device 115 until the output of the RF signal as response time data. .

  Further, the CPU 127 on the portable device 115 side is provided with a portable device response time adding unit 162 as an impersonation determining means 160.

  The portable device response time adding unit 162 is configured to add the response time data measured by the response time measuring unit 161 to the RF signal and send it back.

  In addition, the impersonation determination means 150 on the vehicle 114 side of the second embodiment is provided with a timer unit 153 as a reply time measuring unit and a reply time measuring unit 151.

  The reply time measuring unit 151 is configured to measure the reply time required from when the LF signal is transmitted until the RF signal is received.

  Furthermore, the impersonation determination means 150 on the vehicle 114 side of the second embodiment is provided with a reaction time comparison determination unit 152.

  The reaction time comparison / determination unit 152 is configured to compare the response time data with the response time measured by the response time measurement unit 151 to determine whether or not the user is a regular user U. Yes.

  Next, the effect of the smart keyless entry system of the second embodiment will be described.

  In the second embodiment, as shown in Step 101 in FIG. 7, when control of the vehicle-mounted device on the vehicle 114 side is started, Step 102 waits for a request signal.

  In the request signal waiting state, it is determined in Step 103 whether or not the door request switch 8 provided in the door knob unit 10 has been pressed.

  That is, in Step 103, when the door request switch 8 is turned ON, the process proceeds to the next Step 104. When the door request switch 8 is not turned ON but remains OFF, the process returns to Step 102 and is in a standby state. A request signal waiting state is maintained.

  In Step 104, the LF antenna driver 21 transmits an LF signal as a challenge signal from the LF antenna unit 22.

  From this point, in Step 105, the timer unit 153 starts measuring time.

  At Step 106, the RF signal reception wait state is entered.

  On the other hand, on the portable device 115 side, when the portable device control is started at Step 104, at Step 108, the LF signal is received by the LF antenna unit 26 on the portable device 115 side, or the key-side request switch It is in a standby state whether 13 is turned ON.

  In Step 109, it is determined whether or not an LF signal has been received.

  When the LF signal is received by the LF antenna unit 26 on the portable device 115 side, the process proceeds to the next Step 110, and when not received, the process returns to Step 108 to maintain the standby state.

  In Step 110, the LF signal received by the LF antenna unit 26 is demodulated by the LF demodulation circuit 25, and a unique identification code of the vehicle 114 placed on the LF demodulated signal is stored on the portable device 115 side. It is verified whether or not it matches the identification code.

  In Step 111, if the unique identification code of the vehicle 114 placed on the LF demodulated signal matches the identification code stored on the portable device 115 side, the process proceeds to the next Step 112. If not, the process returns to Step 108. .

  In Step 112, the response time measured by the response time measuring unit 161 of the impersonation determination means 160 provided in the CPU 127 is added by the portable device response time adding unit 162 and synthesized as response data including an identification code ID. Then, an RF signal is placed on the RF signal from the RF antenna unit 28 of the RF transmission circuit 29 and returned to the vehicle 114.

  In Step 113, when the RF signal is received by the RF antenna unit 23 on the vehicle 114 side, the RF demodulation IC 20f demodulates the identification code from the RF signal and demodulates the synthesized response time data.

  In Step 114, the time measurement value of the timer unit 153 is read.

  In Step 115, the demodulated timer value is compared with the measured timer value to determine whether or not the time measured by the timer unit 153 is appropriate.

  That is, when the time until the RF signal is transmitted from the RL antenna unit 28 on the portable device 115 side coincides with the time measured by the timer unit 153 on the vehicle 114 side, the process proceeds to the next Step 115 and is different. In the case, return to Step 102.

  In Step 116, it is verified whether or not the unique identification code stored in the EEPROM 18 provided in the smart keyless ECU 116 of the vehicle 114 matches the identification code stored on the portable device 115 side.

  If they match as a result of the collation, the process proceeds to Step 117, the door unlocking prevention unit 52 is permitted to release the door lock, and the engine start prevention unit 56 uses the engine starter device 5 for the engine start control. License to be able to

  If they do not match, the process returns to Step 102 and the request signal waiting state is maintained.

  As described above, in the second embodiment, the response until the RF signal is output after the LF signal added to the returned data is received by the response time measurement unit 161 of the impersonation determination unit 160 on the portable device 115 side. Time is measured as response time data.

  In the portable device response time adding unit 162 of the portable device 115, the response time data measured by the response time measuring unit 161 is added to the RF signal and returned to the vehicle 114 side.

  In the vehicle 114, the timer unit 153 measures the time required from when the LF signal is transmitted until the RF signal is received.

  Then, as shown in FIG. 6, the response time comparison unit 152 compares the response time data with the time measured by the timer unit 153, and the response time data and the timer unit 153 If the measured time matches, it is determined that the user is a legitimate user U because the theft relay device is not interposed, and the time measured by the timer unit 153 rather than the response time data. In the case where the first user K1 and the second user K2 are relayed by the first repeater J1 and the second repeater J2, and the authorized user U is away from the vehicle 114. Thus, it is determined that the response signal is transmitted from the portable device 115, and it is determined that there is no regular user U in the vicinity of the vehicle 114.

  Other configurations and operational effects are the same as or equivalent to those of the above-described embodiment and Example 1, and thus description thereof is omitted.

  8 to 10 show a smart keyless entry system according to the third embodiment of the present invention.

  In addition, the same code | symbol is attached | subjected and demonstrated about the same thru | or equivalent part as the said embodiment and Example 1 and 2. FIG.

  First, the configuration will be described focusing on the differences from the first and second embodiments.

  In the smart keyless entry system for the vehicle 214 according to the third embodiment, the smart keyless ECU 216 on the vehicle 214 side is provided with an LF signal strength setting unit 251 serving as an impersonation determination unit 250.

  The LF signal strength setting unit 251 keeps the strength of the LF signal transmitted from the LF antenna unit 22 constant and attenuates the LF signal strength setting unit 251 in response to an increase in the separation distance from the LF antenna unit 22. A signal is sent to the driver 21.

  In the smart keyless entry system for the vehicle 214 of the third embodiment, the CPU 227 on the portable device 215 side as a portable device is provided with an RF signal intensity setting unit 261 as impersonation determination means 260.

  When the RF signal strength setting unit 261 sends a response by an LF signal sent from the vehicle, the output value of the RF signal to be transmitted is an arrival distance that is about the reach of the LF signal output from the vehicle 214. It is comprised so that it may become.

  Further, the impersonation determination means 260 of the third embodiment is provided with a distance calculation unit 262.

  The distance calculation unit 262 is configured to calculate the distance between the LF antenna unit 22 on the vehicle 214 side and the portable device 215 from the measured LF signal strength and generate distance data. Yes.

  Further, in the third embodiment, when the RF request signal is output when the key-side request switch 13 is turned on, the output value of the transmitted RF signal is output as it is without decreasing. Has been.

  In the third embodiment, when the reach distance of the LF signal is about 0.5 m, the reach distance of the RF signal is also set to be about 0.5 m.

  Next, the effect of the smart keyless entry system of the third embodiment will be described with reference to the flowchart shown in FIG.

  When vehicle-side onboard control is started at Step 201, a request signal wait state is entered at Step 202.

  In this request signal waiting state, it is determined whether or not the door request switch 8 provided in the door knob 10 has been pressed.

  That is, in Step 203, when the door request switch 8 is turned ON, the process proceeds to the next Step 204. When the door request switch 8 is not turned ON but remains OFF, the process returns to Step 202 and is in a standby state. The request signal waiting state is maintained.

  In Step 204, the LF antenna driver 21 transmits an LF signal as a challenge signal from the LF antenna unit 22.

  Then, in step 205, the RF signal reception wait state is entered.

  On the other hand, on the portable device 215 side, when portable device control is started in Step 206, in Step 207, the LF signal is received by the LF antenna unit 26 on the portable device 215 side, or the key-side request switch 13 is received. Whether or not is input ON is in a standby state.

  In Step 208, it is determined whether or not an LF signal has been received.

  When the LF signal is received by the LF antenna unit 26 on the portable device 215 side, the process proceeds to the next Step 209, and when not received, the process returns to Step 207 to maintain the standby state.

  In Step 209, the LF signal received by the LF antenna unit 26 is demodulated by the LF demodulation circuit 25, and the unique identification code of the vehicle 214 placed on the LF demodulated signal is stored on the portable device 215 side. It is verified whether or not it matches the identification code.

  In Step 210, if the unique identification code of the vehicle 214 placed on the LF demodulated signal matches the identification code stored on the portable device 215 side, the process proceeds to the next Step 211, and if not, the process returns to Step 207. .

  In Step 211, the RF signal strength setting unit 261 provided in the CPU 227 for measuring the signal strength of the LF signal received by the LF antenna unit 26 converts the field strength of the received LF signal to RSSI (reception power). It is calculated from the signal level converted to DC voltage.

  In Step 212, the distance between the LF antenna unit 22 on the vehicle 214 side and the portable device 215 is calculated from the measured LF signal intensity by the distance calculation unit 262.

  The distance calculated by the distance calculation unit 262 is used as distance data, and is used for setting the signal strength of the RF signal returned from the RF antenna unit 28 of the RF transmission circuit 29.

  That is, in Step 213, the distance data calculated and generated by the distance calculation unit 262 is used by the RF signal intensity setting unit 261 to set the output of the RF signal to be set, and according to a predetermined distance. The RF signal output value is set.

  In Step 214, the RF signal is transmitted as response data from the RF antenna unit 28 of the RF transmission circuit 29.

  In Step 215, if the RF signal can be received, the process proceeds to Step 216, and the unique identification code stored in the EEPROM 18 provided in the smart keyless ECU 16 of the vehicle 14 matches the identification code stored in the portable device 215 side. It is verified whether or not.

  If they match as a result of the collation, the process proceeds to Step 214, the door unlocking prevention unit 52 is permitted to release the door lock, and the engine start prevention unit 56 uses the engine starter device 5 for engine start control. License to be able to

  In step 216, if the collation results do not match, the process returns to step 202, and the request signal waiting state is maintained.

  If the RF signal cannot be received at Step 215, the output of the returned RF signal is set weak because the first theft person K1 near the door 3 of the vehicle 214 received the LF signal at a short distance. Thus, it is considered that the RF antenna unit 23 of the vehicle 214 was not reached by the output from the portable device possessed by the authorized user U away from the door 3.

  Therefore, the door unlocking prevention unit 52 is not permitted to release the door lock, and the engine start prevention unit 56 is prevented from performing the engine start control using the engine starter device 5.

  As described above, in the third embodiment, when the RF signal strength setting unit 261 of the impersonation determination unit 260 returns to the portable device 215 by the LF signal sent from the vehicle 214, the output from the vehicle 214 is output. The output value of the transmitted RF signal is set low so that the reachable distance is about the reachable distance of the LF signal that has been transmitted.

  For this reason, even if a person existing in the vicinity of the vehicle 214 impersonates the authorized user U, an RF signal that does not have a reachable distance to the vehicle 214 is output from the portable device 215 side of the authorized user U existing at a long distance. Therefore, it does not reach and cannot be received on the vehicle 214 side.

  Therefore, the impersonation theft technique cannot unlock and open the door, so-called relay attack is prevented and the anti-theft performance is improved.

  As described above, this embodiment and Examples 1 to 3 have been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment and Examples 1 to 3, but departs from the gist of the present invention. Design changes to the extent that they are not included are included in the present invention.

  That is, in the embodiment and Examples 1 to 3, the door request switch 8 is provided as the request signal transmission means. However, the present invention is not limited to this. For example, a proximity sensor is connected to the smart keyless ECU 16. When the authorized user U approaches, the request signal may be transmitted.

  Further, in the second embodiment, the response time from when the LF signal added to the returned data is received by the response time measuring unit 161 of the impersonation determining means 160 on the portable device 115 side until the RF signal is output. However, the present invention is not limited to this. For example, in the portable device response time adding unit 162 of the portable device 115, the response time data measured by the response time measuring unit 161 is The RF signal may not be added to the vehicle 114 and sent back to the vehicle 114. The timer unit 153 on the vehicle 114 transmits the LF signal and then receives the RF signal. When the time required until the user is measured and the authorized user U is in the authorized door unlock position near the door 3 in advance and uses the portable device 115, By comparison with, it may be configured to perform the determination.

  In this case, since the impersonation determination means 160 on the portable device 115 side can be simplified or omitted, an increase in manufacturing cost can be further suppressed.

14, 114, 214 Vehicle
15, 115, 215 portable device
16, 116, 216 Smart keyless ECU (key side control unit)
17, 117, 217 CPU (vehicle-side control unit)
50, 60, 150, 160, 250, 260
Impersonation determination means
52 Door unlocking prevention part
53 RF signal reception strength measurement circuit
54 Data Extraction Department
55 Signal strength comparison / determination unit
56 Engine start prevention part
61 LF signal reception strength measurement circuit
62 Composite reply circuit
151 Response time measurement unit
152 Reaction time comparison / determination unit
153 Timer section
161 Response time measurement unit
162 Mobile device response time adding section
261 RF signal strength setting section
262 Distance calculator
U Regular user
J1 first repeater
J2 Second repeater
K1 first theft
K2 Second theft

Claims (3)

A smart keyless entry system in which two-way communication is performed between the vehicle and the portable device carried by the user to lock and unlock the door of the vehicle. Used in smart keyless entry systems that support relay relay theft techniques,
The relay relay theft technique is that the first thief impersonates an authorized user using the first repeater, and sends the LF signal sent from the vehicle to the second repeater owned by the second thief. The RF signal obtained by the conversion is sent out, and the second repeater converts it again into the LF signal sent to the first theft, and the second theft who owns the second repeater approaches The mobile phone owned by the authorized user is sent out in a manner similar to the LF signal from the vehicle, and the unique identification code stored in the mobile device is placed on the RF signal transmitted from the mobile device, and the vehicle Is a smart keyless entry system that supports spoofing theft as if a person in the vicinity of the vehicle is returning a legitimate identification code from the mobile device,
Impersonation determination means for determining whether a person existing in the vicinity of the vehicle is a regular user or a first theft is provided in both the vehicle and the portable device, and with the impersonation determination means, When the relay device held by a person in the vicinity of the vehicle is not the portable device, or when the authorized user who owns the portable device determines that the vehicle does not exist in the vicinity of the vehicle, the vehicle door is unlocked. A smart keyless entry system, comprising: a door unlocking prevention unit that does not perform.   In the impersonation determination means, when returning to the portable device by the LF signal sent from the vehicle, the output value of the transmitted RF signal is set to reach the reach of the LF signal output from the vehicle. 2. The smart keyless entry system according to claim 1, further comprising an RF signal intensity setting unit for reducing the distance so as to be a distance.   In the impersonation determination means, a response time measuring unit that measures response time from reception of an LF signal added to data to be returned to output of an RF signal as response time data to the portable device, and the response time A measuring unit that adds the measured response time data to the RF signal and returns a portable device response time adding unit, and transmits the LF signal to the vehicle before the RF signal A response time measurement unit that measures the response time required until receiving the response time, the response time data and the response time measured by the response time measurement unit are compared to determine whether or not the user is a legitimate user. A smart keyless entry system according to claim 1, further comprising a reaction time comparison / determination unit for determining.