Vehicle security system, electronic control device, and door unlocking method

Abstract

To provide a vehicle security system for preventing vehicle theft by a third party who tries to cancel biometric authentication by increasing the number of trials.SOLUTION: A vehicle security system that permits door unlocking of a vehicle 3 includes an electronic key 2, wireless information authentication units 41, 51, and 61 to 64, a biometric authentication unit 42, and an unlocking permission determination unit 64. The electronic key 2 is portable by a user 1. The wireless information authentication units 41, 51, and 61 to 64 are mounted in the vehicle 3 to perform wireless information authentication by wireless communication with the electronic key 2. The biometric authentication unit 42 is mounted in the vehicle 3 to perform biometric authentication of the user 1. The unlocking permission determination unit 64 permits door unlocking when a wireless information authentication is successful and the biometric authentication is successful within a number of times less than a predetermined number of times N, and does not permit door unlocking for a predetermined time duration when the biometric authentication fails the number of times equal to or more than the predetermined number of times N.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle security system, an electronic control device, and a door unlocking method. [Background technology]

[0002] Conventionally, there is known a smart entry system in which the door of a vehicle is unlocked by the user touching the door handle through wireless communication between the electronic key carried by the user and the vehicle. In recent years, there has been a problem with theft of smart entry systems caused by relay attacks, in which radio waves are relayed between the electronic key and the vehicle to unlock the door.

[0003] Patent Documents 1 and 2 disclose a method for preventing vehicle theft by using biometric authentication as a condition for permitting unlocking of the vehicle doors. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-25960 A [Patent Document 2] JP 2011-25903 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when fingerprint authentication is used as biometric authentication as in the technologies described in Patent Documents 1 and 2, a third party can copy biometric information from a fingerprint attached to the vehicle. Also, when face authentication is used as biometric authentication, a third party can copy biometric information from a facial photograph. According to these methods, even if the accuracy of the copied biometric information is low, a fraudulent third party may cancel the biometric authentication by increasing the number of attempts, which is called a brute force attack. Therefore, simply adding biometric authentication to the conditions for permitting door unlocking in the smart entry system as in the technologies described in Patent Documents 1 and 2 is not a complete countermeasure against vehicle theft.

[0006] In view of the above, an object of the present invention is to prevent vehicle theft by a third party who attempts to cancel biometric authentication by increasing the number of attempts. [Means for solving the problem]

[0007] In order to achieve the above object, according to the invention described in claim 1, a vehicle security system that permits unlocking of the doors of a vehicle (3) includes an electronic key (2), a wireless information authentication unit (41, 51, 61-64), a biometric authentication unit (42), and an unlocking permission determination unit (64). The electronic key is portable by a user (1). The wireless information authentication unit is mounted on the vehicle and performs wireless information authentication through wireless communication with the electronic key. The biometric authentication unit is mounted on the vehicle and performs biometric authentication of the user. The unlocking permission determination unit permits door unlocking when the wireless information authentication is successful and the biometric authentication is successful fewer than a predetermined number of times (N), Wireless information authentication is successful and If biometric authentication fails a certain number of times By stopping wireless communication from the vehicle to the electronic key for a specified period of time Door unlocking is not permitted for a specified period of time.

[0008] According to this, even if a third party succeeds in wireless information authentication by a relay attack, if the third party tries to release the biometric authentication multiple times and fails multiple times, door unlocking is not permitted for a predetermined period of time. Therefore, this vehicle security system can prevent theft of the vehicle by a third party performing unauthorized operations. In addition, this vehicle security system can detect unauthorized operation by a third party and prevent vehicle theft without adding new parts to a vehicle equipped with an electronic key, a function for performing wireless information authentication, and a function for performing biometric authentication, i.e., without incurring any costs.

[0009] Claim 3 The present invention relates to an electronic control device (6). The electronic control device is mounted on a vehicle (3) that has a function of wirelessly communicating with an electronic key (2) that is portable by a user (1) and a function of performing biometric authentication of the user. The electronic control device permits door unlocking when wireless information authentication via wireless communication with the electronic key is successful and biometric authentication is successful less than a predetermined number of times (N); Wireless information authentication is successful and If biometric authentication fails a certain number of times By stopping wireless communication from the vehicle to the electronic key for a specified period of time Door unlocking is not permitted for a specified period of time. According to this, claim 3 The invention according to claim 1 can achieve the same effects as the invention according to claim 1.

[0010] Claim 5 The present invention relates to a door unlocking method for determining whether the door of a vehicle (3) is unlocked. The door unlocking method includes the following steps: performing wireless information authentication by communication with an electronic key (2) that is portable by a user (1) (S10 to S40); performing biometric authentication of the user (S80, S90); permitting door unlocking if the wireless information authentication is successful and the biometric authentication is successful fewer than a predetermined number of times (N) (S70, S100); Wireless information authentication is successful and If biometric authentication fails a certain number of times By stopping wireless communication from the vehicle to the electronic key for a specified period of time Door unlocking is not permitted for a predetermined period of time (S70, S110). According to this, claim 5 The invention according to claim 1 can achieve the same effects as the invention according to claim 1.

[0011] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and specific components described in the embodiments described below. [Brief description of the drawings]

[0012] [Figure 1] 1 is a block diagram showing a configuration of a vehicle security system according to an embodiment of the present invention; [Diagram 2] 4 is a flowchart showing a control process executed by a verification ECU provided in the vehicle security system according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An embodiment of the present invention will be described below with reference to the drawings. As shown in Fig. 1, the vehicle security system of this embodiment includes an electronic key 2 that can be carried by a user 1, a door handle 4 mounted on a vehicle 3, a receiver 5, a verification electronic control device 6, and a body electronic control device 7. Hereinafter, the verification electronic control device 6 will be referred to as the "verification ECU 6," and the body electronic control device 7 will be referred to as the "body ECU 7." Note that ECU is an abbreviation for Electronic Control Unit.

[0014] First, the configuration of the electronic key 2 will be described.

[0015] The electronic key 2 has an LF receiver 21, a first encryption processor 22, and an RF transmitter 23. LF stands for low frequency, and RF stands for radio frequency. The LF receiver 21 receives a low frequency signal (hereinafter referred to as an “LF signal”) of, for example, 125 to 135 KHz transmitted from an LF transmitter 41 provided on the door handle 4 of the vehicle 3. The LF signal includes a random number generated by the verification ECU 6 of the vehicle 3. The LF signal received by the LF receiver 21 is transmitted to the first encryption processor 22.

[0016] The first encryption processing unit 22 is configured by an integrated circuit such as an ASIC, a microcomputer, etc. The first encryption processing unit 22 calculates a random number included in the LF signal received by the LF receiving unit 21 using a predetermined logic stored in the first encryption processing unit 22, and generates encrypted data. The encrypted data generated by the first encryption processing unit 22 is transmitted to the RF transmitting unit 23.

[0017] The RF transmission unit 23 includes the encrypted data generated by the first encryption processing unit 22 in a high frequency signal (hereinafter referred to as an "RF signal") of, for example, 300 to 400 MHz, and transmits the signal to the vehicle 3. The LF signal may be called a request signal, and the RF signal may be called an ID code signal.

[0018] Next, the configuration of the vehicle 3 will be described.

[0019] The door handle 4 of the vehicle 3 is provided with an LF transmission unit 41, a biometric authentication unit 42, and the like. The LF transmission unit 41 transmits an LF signal including a random number generated by the matching ECU 6 to the outside of the vehicle. The biometric authentication unit 42 has a function of performing biometric authentication of the user 1. The biometric authentication unit 42 performs biometric authentication after cryptographic authentication by the unlocking permission determination unit 64 described later is successful. When performing fingerprint authentication as the biometric authentication, for example, the biometric authentication unit 42 reads a fingerprint touching a detection surface (not shown) provided at a predetermined position of the door handle 4 (for example, the back surface of the door handle 4) and determines whether the read fingerprint matches a fingerprint of the user 1 registered in advance. In the following description, a determination result in which the fingerprint read on the detection surface matches a fingerprint of the user 1 registered in advance may be referred to as a "success of biometric authentication," and a determination result in which the fingerprints do not match may be referred to as a "failure of biometric authentication." The determination result of the biometric authentication performed by the biometric authentication unit 42 is transmitted to the unlocking permission determination unit 64 of the matching ECU 6 each time. The LF transmitter 41 and the biometric authentication unit 42 are not limited to being installed in the door handle 4, and may be installed in other locations.

[0020] The receiver 5 has an RF receiving unit 51 that receives the RF signal transmitted from the RF transmitting unit 23. The RF signal received by the RF receiving unit 51 is transmitted to an RF reception processing unit 63 of the verification ECU 6. The RF signal includes encrypted data generated by the first encryption processing unit 22 of the electronic key 2.

[0021] The verification ECU 6 is mainly composed of a microcomputer having a processor that performs control processing and arithmetic processing, and a memory that stores programs, data, etc. The processor is composed of a CPU and an MPU. The memory includes various non-transient tangible storage media such as a ROM, a RAM, and a non-volatile rewritable memory. The verification ECU 6 functions as an LF transmission processing unit 61, a second encryption processing unit 62, an RF reception processing unit 63, an unlocking permission determination unit 64, etc., by the processor executing the programs stored in the memory.

[0022] The LF transmission processing unit 61 generates an LF signal including a random number and transmits the LF signal to the above-mentioned LF transmission unit 41 and the second encryption processing unit 62 in the verification ECU 6. The second encryption processing unit 62 stores the same predetermined logic as that stored in the first encryption processing unit 22 of the electronic key 2. The second encryption processing unit 62 calculates the random number generated by the LF transmission processing unit 61 using the predetermined logic stored in the second encryption processing unit 62 to generate encrypted data. The encrypted data generated by the second encryption processing unit 62 is transmitted to the unlocking permission determination unit 64.

[0023] The RF reception processing unit 63 transmits the encrypted data contained in the RF signal transmitted from the RF reception unit 51 to the unlocking permission determination unit 64 .

[0024] The unlocking permission determination unit 64 performs encryption authentication to determine whether the encrypted data transmitted from the second encryption processing unit 62 matches the encrypted data transmitted from the RF reception processing unit 63. In the following description, a determination result in which the encrypted data transmitted from the second encryption processing unit 62 matches the encrypted data transmitted from the RF reception processing unit 63 may be referred to as "encryption authentication success", and a determination result in which the encrypted data do not match may be referred to as "encryption authentication failure". Note that the encryption authentication in this embodiment corresponds to an example of "wireless information authentication" as described in the claims.

[0025] The unlocking permission determination unit 64 permits the door to be unlocked if the cryptographic authentication is successful and the biometric authentication is successful less than a predetermined number of times. A signal permitting the door to be unlocked by the unlocking permission determination unit 64 is transmitted to the body ECU 7.

[0026] The body ECU 7 is also mainly composed of a microcomputer having a processor that performs control processing and arithmetic processing, and a memory that stores programs, data, etc. The processor is composed of a CPU and an MPU. The memory is equipped with various non-transient substantial storage media such as a ROM, a RAM, and a non-volatile rewritable memory. The body ECU 7 functions as an unlocking processing unit 71 that unlocks the doors by the processor executing a program stored in the memory. When a door unlock permission signal is transmitted, the unlocking processing unit 71 of the body ECU 7 drives a door lock motor (not shown) provided on each door of the vehicle 3 to unlock the doors.

[0027] On the other hand, if the cryptographic authentication is successful and the biometric authentication fails a predetermined number of times or more, the unlocking permission determination unit 64 does not permit door unlocking for a predetermined time. Specifically, the unlocking permission determination unit 64 stops the generation of the LF signal by the LF transmission processing unit 61, i.e., the generation of random numbers, for a predetermined time. This stops the transmission of the LF signal from the LF transmission unit 41 to the outside of the vehicle for a predetermined time. The predetermined time is set to a necessary and sufficient time (for example, about 10 minutes to several hours) for a third party who performs an unauthorized operation on the vehicle 3 to give up on stealing the vehicle 3.

[0028] In addition, the functional units that perform encryption authentication among the LF transmission processing unit 61, the LF transmission unit 41, the second encryption processing unit 62, the RF receiving unit 51, the RF receiving processing unit 63, and the unlocking permission determination unit 64 in this embodiment correspond to an example of a "wireless information authentication unit" in the claims. Also, the verification ECU 6 in this embodiment corresponds to an example of an "electronic control unit" in the claims.

[0029] Next, the control process executed by the verification ECU 6 will be described with reference to the flowchart of FIG.

[0030] This process is repeatedly executed at predetermined control time intervals after the vehicle 3 has stopped and the doors have been locked from outside the vehicle.

[0031] First, in step S10, the verification ECU 6 generates an LF signal including a random number in the LF transmission processing unit 61, and transmits the LF signal to the outside of the vehicle via the LF transmission unit 41 and also transmits it to the second encryption processing unit 62.

[0032] Next, in step S20, the verification ECU 6 detects whether or not the RF reception processing unit 63 has received an RF signal from the RF reception unit 51. If the RF reception processing unit 63 has not received an RF signal, the process returns to step S10. If the RF reception processing unit 63 has received an RF signal, the process proceeds to step S30.

[0033] Next, in step S30, the verification ECU 6 performs encryption authentication in the unlocking permission determination unit 64. As described above, in the encryption authentication, the unlocking permission determination unit 64 determines whether or not the encrypted data generated by the second encryption processing unit 62 based on the random number of the LF signal generated by the LF transmission processing unit 61 matches the encrypted data included in the RF signal transmitted from the RF reception processing unit 63.

[0034] In step S40, the verification ECU 6 determines whether the encrypted authentication is successful (i.e., the encrypted data matches) or unsuccessful (i.e., the encrypted data does not match) in the unlocking permission determination unit 64. If it is determined in step S40 that the encrypted authentication is unsuccessful, the process proceeds to step S50. In step S50, it is determined that door unlocking is not permitted, and the process ends for the time being.

[0035] On the other hand, if it is determined in step S40 that the encrypted authentication is successful, the process proceeds to step S60. In step S60, the unlocking permission determination unit 64 increments the number of times of biometric authentication performed by the biometric authentication unit 42. As will be described in step S80 below, the biometric authentication by the biometric authentication unit 42 is performed after the encrypted authentication is successful (i.e., after the positive determination in step S40), so the number of times of biometric authentication immediately after the encrypted authentication is successful (i.e., immediately after the positive determination in step S40) is set to 0.

[0036] Next, in step S70, the verification ECU 6 determines whether the number of biometric authentication attempts is smaller than a predetermined number N. The predetermined number N is set in advance through experiments or the like as the number of attempts at which biometric authentication will be successful for a legitimate user 1, and is stored in the memory of the verification ECU 6. If the number of attempts at biometric authentication is smaller than the predetermined number N, the process proceeds to step S80.

[0037] In step S80, biometric authentication is performed by the biometric authentication unit 42. The biometric authentication determines whether or not biometric information read by the biometric authentication unit 42 (e.g., a fingerprint touching the detection surface on the back side of the door handle 4) matches pre-registered biometric information of the user 1 (e.g., a fingerprint of the user 1).

[0038] In step S90, it is determined whether the biometric authentication is successful (i.e., the biometric information matches) or not (i.e., the biometric information does not match). If it is determined in step S90 that the biometric authentication is successful, the process proceeds to step S100. In step S100, door unlocking is permitted, and a signal to that effect is transmitted to the unlocking processing unit 71 of the body ECU 7, and the process ends.

[0039] On the other hand, if it is determined in step S90 that the biometric authentication has failed, the process returns to step S60. As described above, in step S60, the unlocking permission determination unit 64 increments the number of biometric authentications performed by the biometric authentication unit 42. Then, in step 70, it is determined whether the number of biometric authentications is smaller than a predetermined number N. If the number of biometric authentications is equal to or greater than the predetermined number N, the process proceeds to step S110.

[0040] In step S110, the verification ECU 6 prohibits unlocking of the door for a predetermined time, stops generation of the LF signal by the LF transmission processing unit 61 for a predetermined time, and temporarily ends the process. As a result, transmission of the LF signal from the LF transmitter 41 to the outside of the vehicle is stopped for the predetermined time.

[0041] The vehicle security system, the verification ECU 6, and the door unlocking method according to the present embodiment described above provide the following advantages.

[0042] (1) In the vehicle security system of this embodiment, if biometric authentication fails a predetermined number of times N or more, the unlocking permission determination unit 64 does not permit door unlocking for a predetermined period of time. According to this, even if a third party succeeds in cryptographic authentication by a relay attack, if the third party tries to release the biometric authentication by multiple attempts, door unlocking will be prohibited for a predetermined period of time if the biometric authentication fails a predetermined number N of times. Therefore, this vehicle security system can prevent the theft of the vehicle 3 by a third party performing unauthorized operations.

[0043] Furthermore, this vehicle security system can detect unauthorized operations by a third party and prevent theft of the vehicle 3 without adding new parts to the vehicle 3 equipped with the electronic key 2, a function for performing wireless information authentication, and a function for performing biometric authentication, i.e., without incurring any costs. Note that the function for performing wireless information authentication corresponds to the functional units that perform encryption authentication among the LF transmission processing unit 61, the LF transmission unit 41, the second encryption processing unit 62, the RF receiving unit 51, the RF receiving processing unit 63, and the unlocking permission determination unit 64 in this embodiment.

[0044] (2) In detail, in the vehicle security system of this embodiment, if the cryptographic authentication (i.e., wireless information authentication) is successful and the biometric authentication fails a predetermined number of times N or more, the unlocking permission determination unit 64 does not permit door unlocking for a predetermined period of time. This makes it possible to prevent door unlocking from being unintentionally prohibited for a certain period of time when there is no theft, for example, when a child or other person mischievously touches the doorknob multiple times and biometric authentication fails multiple times. Furthermore, since the biometric authentication unit 42 does not need to be operated all the time, but can be operated only after cryptographic authentication (i.e., wireless information authentication) is successful, the power consumed by the biometric authentication unit 42 can be reduced.

[0045] (3) Generally, a third party who performs unauthorized operations such as a relay attack intercepts wireless communication from the vehicle 3 to the electronic key 2. In the vehicle security system of this embodiment, the unlocking permission determination unit 64 prohibits door unlocking for a predetermined period of time by suspending wireless communication from the vehicle 3 to the electronic key 2 for a predetermined period of time. According to this, a third party who performs unauthorized operations cannot intercept wireless communication from the vehicle 3 to the electronic key 2, which can encourage the third party to give up on stealing the vehicle 3.

[0046] (4) More specifically, in the vehicle security system of this embodiment, the generation of the LF signal transmitted from the vehicle 3 to the electronic key 2 is stopped for a predetermined period of time. According to this, the control process in the verification ECU 6 can prevent the vehicle 3 from being stolen by a third party without increasing the number of parts or costs.

[0047] (5) In the present embodiment, if biometric authentication fails a predetermined number of times N or more, the verification ECU 6 does not permit door unlocking for a predetermined period of time. (6) In detail, when the cryptographic authentication (that is, the wireless information authentication) is successful and the biometric authentication fails a predetermined number of times N or more, the verification ECU 6 does not permit the door to be unlocked for a predetermined time. (7) The verification ECU 6 also prohibits door unlocking for a predetermined period of time by suspending wireless communication from the vehicle 3 to the electronic key 2 for a predetermined period of time. (8) Specifically, the verification ECU 6 prohibits door unlocking for a predetermined time by stopping generation of the LF signal transmitted from the vehicle 3 to the electronic key 2 for a predetermined time. According to this, the verification ECU 6 of this embodiment, due to the configurations (5) to (8) above, provides the same effects as those (1) to (4) described above as the effects of the vehicle security system.

[0048] (9) In the door unlocking method of the present embodiment, if biometric authentication fails a predetermined number of times N or more, door unlocking is not permitted for a predetermined period of time. (10) More specifically, in this door unlocking method, when cryptographic authentication (that is, wireless information authentication) is successful and biometric authentication has failed a predetermined number of times N or more, door unlocking is not permitted for a predetermined period of time. (11) Furthermore, in this door unlocking method, when it is determined that door unlocking is not permitted for a predetermined period of time, wireless communication from the vehicle 3 to the electronic key 2 is stopped for a predetermined period of time. (12) Specifically, in this door unlocking method, when it is determined that door unlocking is not permitted for a predetermined time, generation of the LF signal transmitted from the vehicle 3 to the electronic key 2 is stopped for a predetermined time. As a result, the door unlocking method of this embodiment also achieves the same effects as those (1) to (4) described above as the effects of the vehicle security system by the above methods (9) to (12).

[0049] (Other embodiments) (1) In the above embodiment, the unlocking permission determination unit 64 does not permit door unlocking for a predetermined time period when the cryptographic authentication (i.e., wireless information authentication) is successful and the biometric authentication fails a predetermined number of times N or more. However, this is not limited to this. For example, the unlocking permission determination unit 64 may not permit door unlocking for a predetermined period of time if biometric authentication fails a predetermined number of times N or more, regardless of whether cryptographic authentication (ie, wireless information authentication) is successful or unsuccessful.

[0050] (2) In the above embodiment, the unlocking permission determination unit 64 prohibits door unlocking for a predetermined period of time by suspending wireless communication from the vehicle 3 to the electronic key 2 for a predetermined period of time. However, this is not limited to this. For example, the unlocking permission determination unit 64 may disallow door unlocking for a predetermined period of time by stopping the door unlocking permission signal from the matching ECU 6 to the body ECU 7 for a predetermined period of time, or by stopping biometric authentication for a predetermined period of time.

[0051] (3) In the above embodiment, fingerprint authentication has been described as an example of biometric authentication performed by the biometric authentication unit 42, but the present invention is not limited to this. For example, face, voiceprint, palmprint, iris, vein, etc. may be adopted as biometric authentication. For example, when biometric authentication unit 42 performs face authentication, it photographs the face of user 1 with a camera (not shown) mounted on vehicle 3, and determines whether the photographed face image data matches pre-registered face image data of user 1.

[0052] (4) In the above embodiment, cryptographic authentication is performed as the wireless information authentication between the vehicle and the electronic key. However, the present invention is not limited to this. A method other than cryptographic authentication may be used as the wireless information authentication.

[0053] The present invention is not limited to the above-mentioned embodiment, and can be appropriately modified within the scope of the claims. Moreover, the above-mentioned embodiments are not unrelated to each other, and can be appropriately combined, except when the combination is obviously impossible. Moreover, in the above-mentioned embodiment, it goes without saying that the elements constituting the embodiment are not necessarily essential, except when it is specifically stated that they are essential or when it is clearly considered essential in principle. Moreover, in the above-mentioned embodiment, when the numerical values ​​of the number, numerical value, amount, range, etc. of the components of the embodiment are mentioned, they are not limited to the specific number, except when it is specifically stated that they are essential or when it is clearly limited to a specific number in principle. Moreover, in the above-mentioned embodiment, when the shape, positional relationship, etc. of the components are mentioned, they are not limited to the shape, positional relationship, etc., except when it is specifically stated that they are essential or when it is clearly limited to a specific shape, positional relationship, etc. in principle.

[0054] The control unit and the method according to the present invention may be realized by a special-purpose computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Alternatively, the control unit and the method according to the present invention may be realized by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method according to the present invention may be realized by one or more special-purpose computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer. [Explanation of symbols]

[0055] 1 User 2 Electronic key 3. Vehicle 41 LF transmitter (wireless information authentication unit) 42 Biometric authentication section 51 RF receiver (wireless information authentication unit) 61 LF transmission processing unit (wireless information authentication unit) 62 Second encryption processing unit (wireless information authentication unit) 63 RF reception processing unit (wireless information authentication unit) 64 Unlock permission determination unit (wireless information authentication unit)

Claims

1. A vehicle security system for permitting unlocking of doors of a vehicle (3), An electronic key (2) that is portable by a user (1); a wireless information authentication unit (41, 51, 61 to 64) mounted on the vehicle and performing wireless information authentication with the electronic key through wireless communication; A biometric authentication unit (42) mounted in the vehicle and configured to perform biometric authentication of the user; and an unlocking permission determination unit (64) that permits door unlocking when the wireless information authentication is successful and the biometric authentication is successful less than a predetermined number of times (N), and that prohibits door unlocking for a predetermined time by stopping wireless communication from the vehicle to the electronic key for a predetermined time when the wireless information authentication is successful and the biometric authentication fails a predetermined number of times or more.

2. 2. The vehicle security system according to claim 1, wherein the unlock permission determination unit prohibits door unlocking for a predetermined period of time by stopping generation of a signal transmitted from the vehicle side to the electronic key for a predetermined period of time.

3. An electronic control device (6) mounted on a vehicle (3) having a function of wirelessly communicating with an electronic key (2) that is portable by a user (1) and a function of biometric authentication of the user, An electronic control device that permits door unlocking when wireless information authentication via wireless communication with the electronic key is successful and the biometric authentication is successful less than a predetermined number of times (N), and that does not permit door unlocking for a predetermined period of time by stopping wireless communication from the vehicle to the electronic key for a predetermined period of time when the wireless information authentication is successful and the biometric authentication fails a predetermined number of times or more.

4. 4. The electronic control device according to claim 3, wherein the disallowance of door unlocking for a predetermined period of time is executed by stopping generation of a signal transmitted from the vehicle side to the electronic key for a predetermined period of time.

5. A door unlocking method for determining whether a door of a vehicle (3) is unlocked, A user (1) performs wireless information authentication by communicating with a portable electronic key (2) (S10 to S40). Performing biometric authentication of the user (S80, S90); a step of permitting door unlocking when the wireless information authentication is successful and the biometric authentication is successful less than a predetermined number of times (N) (S70, S100), and disallowing door unlocking for a predetermined time by stopping wireless communication from the vehicle to the electronic key for a predetermined time when the wireless information authentication is successful and the biometric authentication fails a predetermined number of times or more (S70, S110).

6. 6. The door unlocking method according to claim 5, further comprising the step of: stopping generation of a signal to be transmitted from the vehicle side to the electronic key for a predetermined time period when it is determined that unlocking of the door is not permitted for the predetermined time period.

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