Method for securing transmission of identifier for accessing portable device of motor vehicle

Abstract

The invention relates to a method for securing the transmission of an identifier for accessing a portable device (20) of a motor vehicle (10), said vehicle comprising an electronic control unit (11), said device (20) comprising a control module (21), said method comprising the following steps: a management module (21) commands the transmission of a high-frequency signature request and its characteristics; the vehicle (10) receives a high-frequency signature request; the vehicle (10) generates a high-frequency signature and sends the generated high-frequency signature to the device (20); the device (20) analyzes the received high-frequency signature; if the high-frequency signature has a desired characteristic, the control module (21) sends a signal comprising an identifier; the vehicle (10) receiving the transmitted signal; the vehicle (10) identifies the device and activates a function of the vehicle (10).

Description

[Technical Field]

[0001] This invention relates to the field of motor vehicles, and more particularly to a method for protecting the transmission of identifiers of portable devices used to control vehicles. [Background Technology]

[0002] For convenience, an increasing number of vehicle functions can be remotely accessed by users using portable devices. Therefore, contactless unlocking allows users equipped with portable access devices such as keys or badges to remotely unlock the vehicle when they are near it.

[0003] This contactless unlocking is achieved through radio frequency (RF) wave exchange between the device and the vehicle. Typically, when the vehicle detects the device, it sends a message to the device, which then sends back its identifier. Once the vehicle receives the identifier, the onboard electronic control unit commands the unlocking of the device.

[0004] However, this unlocking method is vulnerable to hacking attempts when the user is away from the vehicle, particularly so-called "relay" attacks. These attacks involve recording and retransmitting signals exchanged between the vehicle and the device to force detection and trigger the transmission of an identifier when they are far apart. Equipped with this identifier, a third party could unlock the vehicle and enter it to steal items or the vehicle itself when the user is not present.

[0005] Several technologies have been developed to enhance the security of radio frequency switching.

[0006] For example, a vehicle can measure the strength of the received signal to determine whether the signal was transmitted by the user's device or by a third party attempting to relay it. However, these techniques are complex because signal strength can vary significantly under legitimate circumstances, such as if the user has their device in their pocket or near a metal object.

[0007] Other techniques include disabling vehicle modules that analyze radio frequency waves to protect them from hacking attempts, specifically based on the user's movement and distance. However, disabling this module is only effective in some cases and not in other cases (e.g., if a relay attack occurs while the user is moving or before the module enters standby mode) in terms of protecting the vehicle.

[0008] The vehicle module can also record the relative position of the user equipment to deduce the user's trajectory and determine the legitimacy of received signals. However, this technology is complex because the module must be able to analyze path trajectories with significantly different altitudes to determine those corresponding to legitimate users as well as those associated with hacking attempts.

[0009] Therefore, a simple, reliable, and effective solution to at least partially overcome these shortcomings would be advantageous. [Summary of the Invention]

[0010] Therefore, the present invention first relates to a method for protecting the transmission of an identifier of a portable device used to access a motor vehicle, the vehicle including an electronic control unit, a radio frequency antenna module, and a high frequency antenna module, the device including a control module, the radio frequency antenna module, and the high frequency antenna module, the control module including a memory region therein storing the identifier of the device, the method comprising the following steps:

[0011] The device's control module commands a high-frequency signature request transmitted via the device's radio frequency antenna module. The high-frequency signature request includes the characteristics of the signature.

[0012] - The electronic control unit receives the high-frequency signature request via the vehicle's radio frequency antenna module.

[0013] -The electronic control unit generates a high-frequency signature containing these characteristics.

[0014] - The generated high-frequency signature is sent to the device via the vehicle's high-frequency antenna module.

[0015] - The control module receives the transmitted high-frequency signature via the device's high-frequency antenna module.

[0016] - This control module analyzes the received high-frequency signatures.

[0017] When the high-frequency signature has the characteristics sent in the high-frequency signature request, the control module sends a signal containing the identifier via the device's radio frequency antenna module, the electronic control unit receives the sent signal via the vehicle's radio frequency antenna module, the electronic control unit identifies the device and activates at least one function of the vehicle after identifying the device.

[0018] Therefore, the method according to the invention can protect the device from transmitting identifiers to the vehicle by pre-implementing the exchange of high-frequency signature requests and high-frequency signatures. High-frequency signals have a reduced range compared to other types of radio frequency signals, thus limiting the opportunity for a third party to allow a capturing device to receive and repeat the received signal. Pre-exchange also protects the device because if it receives a fraudulent command to transmit the identifier, it will not transmit the identifier since no high-frequency signature was received beforehand. This protection also covers the case where a third party transmits a fraudulent high-frequency signature that does not correspond to any pre-sent high-frequency signature request.

[0019] Preferably, the electronic control unit (ECU) temporarily stores the received high-frequency signature requests in its memory, and when the ECU identifies a device, it only identifies the device if it receives the identifier and the received high-frequency signature request is still in the ECU's memory. Therefore, even if a third party successfully steals the device's identifier, it cannot activate the vehicle's functions without first triggering the exchange of the high-frequency signature request and the high-frequency signature.

[0020] According to another aspect, the present invention relates to a method for protecting the transmission of an identifier of a portable device used to access a motor vehicle, the method being implemented by a device including a control module, a radio frequency antenna module, and a high frequency antenna module, the control module including a memory region therein storing the identifier of the device, the method comprising the following steps:

[0021] The device's control module commands a high-frequency signature request transmitted via the device's radio frequency antenna module. The high-frequency signature request includes the characteristics of the signature.

[0022] - The control module receives the transmitted high-frequency signature via the device's high-frequency antenna module.

[0023] - This control module analyzes the received high-frequency signatures.

[0024] When the high-frequency signature has the characteristics sent in the high-frequency signature request, the control module sends a signal containing the identifier via the device's radio frequency antenna module.

[0025] According to another aspect, the present invention relates to a method for protecting the transmission of an identifier for accessing a portable device in a motor vehicle, the method being implemented by a vehicle including an electronic control unit, a radio frequency antenna module, and a high frequency antenna module, the method comprising the following steps:

[0026] - The electronic control unit receives a high-frequency signature request via the vehicle's radio frequency antenna module, the high-frequency signature request including the characteristics of the signature.

[0027] -The electronic control unit generates a high-frequency signature containing these characteristics.

[0028] - The generated high-frequency signature is transmitted via the vehicle's high-frequency antenna module.

[0029] - The electronic control unit receives a signal containing the identifier via the vehicle's radio frequency antenna module.

[0030] - The electronic control unit recognizes the identifier and activates the vehicle's functions.

[0031] Advantageously, the vehicle includes a locking system connected to the electronic control unit, and the function of the vehicle activated during the step of identifying the device in the method according to the invention is the function of unlocking the vehicle's locking system.

[0032] As an alternative, the vehicle functions activated during the device identification process could include starting the engine, turning on the air conditioning, etc.

[0033] In a preferred operating mode, the control module triggers a timer when sending a high-frequency signature request, stops the timer when a high-frequency signature is received, compares the measured time with a reference time, and triggers the signature analysis step only if the measured time is less than the reference time. This timer can identify legitimate exchanges between the vehicle and the user-carried device. If a third party attempts to capture and retransmit the RF signature, the resulting delay causes a hysteresis, thus preventing the method from fraudulently capturing the identifier.

[0034] Preferably, the value of the high-frequency signature request's characteristics is randomly generated each time the method is implemented. Therefore, if the high-frequency signature is captured by a third party during an exchange between the vehicle and the device, it cannot be reused later.

[0035] Preferably, the high-frequency signature request is a square wave signal, characterized by the number of square waves, their duration, and / or their intervals. Therefore, the high-frequency signature can be a PWM (Pulse Width Modulation) signal. This type of signal is easy to transmit and does not cause excessive power consumption for stationary vehicles or equipment.

[0036] In a preferred embodiment, both the vehicle's high-frequency antenna module and the device's high-frequency antenna module include high-frequency antennas that resonate with each other. Resonance should be understood as the two antennas transmitting and receiving signals at the same frequency. Therefore, if a third party seeks to use a device without antennas whose resonant frequencies correspond to the resonant frequencies of the vehicle's and device's resonant antennas, the resulting signals will be severely scrambled and thus difficult to identify and / or utilize.

[0037] Also preferably, both resonant antennas have a quality factor, preferably greater than or equal to 80. A high quality factor ensures signal quality over a longer range. Therefore, if a third party seeks to recover a transmitted high-frequency signal using an antenna with a low quality factor, the signal will be severely scrambled unless the third party is very close to the user's equipment or vehicle.

[0038] Advantageously, as presented, the method includes evaluating the quality of the signal during the step of the control module analyzing the high-frequency signature; if the signal quality is poor, the control module blocks the method. Thus, the control module detects fraudulent attempts and prevents the transmission of the identifier through poor signal quality.

[0039] The present invention also relates to a device comprising a control module, a radio frequency antenna module, and a high frequency antenna module, wherein the control module includes a memory region therein storing identifiers and is configured to:

[0040] - Connect to the RF antenna module and high-frequency antenna module in this device.

[0041] The command transmits a high-frequency signature request via the radio frequency antenna module, the high-frequency signature request including the characteristics of the high-frequency signature.

[0042] - The high-frequency signature transmitted via this high-frequency antenna module is received.

[0043] -Analyze the received high-frequency signatures,

[0044] - When the high-frequency signature has the characteristics sent in the high-frequency signature request, a signal containing the identifier is sent via the radio frequency antenna module of the device.

[0045] The present invention also relates to an electronic control unit for a motor vehicle, the electronic control unit being configured to:

[0046] - Connects to the RF antenna module and the high-frequency antenna module.

[0047] - A high-frequency signature request is received via the vehicle's radio frequency antenna module, the high-frequency signature request including the characteristics of the signature.

[0048] - Generate high-frequency signatures that contain these features.

[0049] - The generated high-frequency signature is transmitted via the vehicle's high-frequency antenna module.

[0050] - The signal containing the identifier is received via the vehicle's radio frequency antenna module.

[0051] - Identify the identifier and activate the vehicle's functionality.

[0052] The present invention also relates to a vehicle comprising an electronic control unit, a radio frequency antenna module, and a high frequency antenna module as shown.

[0053] The present invention also relates to a system comprising the vehicle as presented and the portable access device as presented, the system being capable of implementing the method according to the invention. [Image Description]

[0054] Further features and advantages of the invention will become more apparent upon reading the following description. This description is purely illustrative and should be read with reference to the accompanying drawings, in which:

[0055] [ Figure 1 ] Figure 1 A system comprising a vehicle and an apparatus configured to implement the method according to the invention is illustrated schematically.

[0056] [ Figure 2 ] Figure 2 An embodiment of the method according to the present invention is illustrated schematically. [Detailed Implementation]

[0057] Figure 1 A system 1 is shown that implements a method for protecting the transmission of an identifier for accessing a portable device 20 in a motor vehicle 10.

[0058] System 1

[0059] like Figure 1 As shown, system 1 includes a vehicle 10 and a device 20 carried by a user of the vehicle 10.

[0060] Vehicle 10

[0061] The vehicle 10 includes an electronic control unit 11, a radio frequency antenna module 12, a high frequency antenna module 13, and a locking system 14.

[0062] In a manner known per se, vehicle 10 includes multiple antennas designed to periodically transmit detection signals to detect the presence of device 20 in the vicinity of vehicle 10. For clarity, these antennas are not shown in the figures.

[0063] These detection signals are low-frequency signals of approximately 100 kHz that are periodically emitted.

[0064] Electronic control unit 11

[0065] The electronic control unit 11 is configured to be connected to the radio frequency antenna module 12, the high frequency antenna module 13, and the locking system 14.

[0066] The electronic control unit 11 is configured to receive a high-frequency signature request via a radio frequency antenna module 12 of the vehicle 10, the high-frequency signature request including the characteristics of the signature.

[0067] The electronic control unit 11 is configured to generate a high-frequency signature containing these features and transmit the generated high-frequency signature via the high-frequency antenna module 13 of the vehicle 10.

[0068] The electronic control unit 11 can send high-frequency signatures multiple times to ensure complete reception.

[0069] Advantageously, if the control module 21 has encrypted the high-frequency signature request in advance, the electronic control unit 11 can decrypt the signature request and encrypt the high-frequency signature to be transmitted.

[0070] The electronic control unit 11 is configured to store the received high-frequency signature request and / or the generated high-frequency signature in the memory for a limited time.

[0071] The electronic control unit 11 is configured to receive a signal containing an identifier via the radio frequency antenna module 12 of the vehicle 10.

[0072] The electronic control unit 11 is configured to recognize the identifier.

[0073] The electronic control unit 11 is configured to send a signal to the locking system 14.

[0074] Alternatively, the electronic control unit 11 is configured to send a signal to activate another function of the vehicle 10, such as starting the engine of the vehicle 10 or activating the air conditioning.

[0075] RF antenna module 12

[0076] The radio frequency antenna module 12 of the vehicle 10 can transmit and receive radio frequency signals between 200MHz and 500MHz, preferably between 300MHz and 450MHz.

[0077] The radio frequency antenna module 12 of vehicle 10 can transmit radio frequency signals to the device 20 carried by the user of vehicle 10.

[0078] The radio frequency antenna module 12 of the vehicle 10 is configured to receive radio frequency signals transmitted by the user-carried device 20.

[0079] High-frequency antenna module 13

[0080] The high-frequency antenna module 13 includes a resonant antenna 13A.

[0081] The high-frequency antenna module 13 is configured to transmit a square wave radio frequency signal to the high-frequency antenna module 23 of the device 20.

[0082] Radio frequency signals are transmitted in the high-frequency range, that is, between 3MHz and 30MHz.

[0083] Resonant Antenna 13A

[0084] The resonant antenna 13A is an electronic component that can transmit radio frequency signals.

[0085] The resonant antenna 13A has a quality factor, preferably greater than or equal to 80.

[0086] The resonant antenna 13A is configured to receive radio frequency signals at a precise frequency (e.g., 14 MHz) that corresponds to the resonant frequency of the resonant antenna 23A present in the high-frequency antenna module 23 of the device 20.

[0087] Locking System 14

[0088] The locking system 14 can prevent and release the opening of the opening element of the vehicle 10 according to the user's command.

[0089] When the locking system 14 receives the appropriate identifier, the locking system 14 triggers the opening of the opening element of the vehicle 10.

[0090] The user can then open the opening element of vehicle 10 to enter its interior.

[0091] The locking system 14 may become a target for malicious third-party attacks that seek to gain access to vehicle 10 through fraudulent means.

[0092] Equipment 20

[0093] The user has a handheld device 20. Device 20 can release the opening element of vehicle 10 by sending an identifier.

[0094] Device 20 may be located on the key of vehicle 10 or may be a separate accessory.

[0095] The device 20 includes a control module 21, a radio frequency antenna module 22, and a high frequency antenna module 23.

[0096] In a manner known per se, device 20 is configured to receive detection signals transmitted by vehicle 10.

[0097] Control Module 21

[0098] The control module 21 includes a memory area that stores identifiers of opening elements that enable the opening of the vehicle 10.

[0099] The control module 21 is configured to be connected to the radio frequency antenna module 22 and the high frequency antenna module 23 of the device 20.

[0100] The control module 21 is configured to command the transmission of high-frequency signature requests via the radio frequency antenna module 22.

[0101] The high-frequency signature request includes the characteristics of the signature.

[0102] Preferably, the high-frequency signature is a square wave signal or a PWM (pulse width modulation) signal, characterized by the number of square waves, their duration, and / or their intervals.

[0103] For example, the expected characteristics of a high-frequency signature could be "four 10ms square waves, spaced 50ms apart".

[0104] High-frequency signatures are characterized by being randomly generated, thus ensuring that each high-frequency signature is unique for each use.

[0105] Advantageously, the control module 21 can encrypt high-frequency signature requests to reduce the risk of the request being intercepted.

[0106] The control module 21 is configured to receive the transmitted high-frequency signature via the high-frequency antenna module 23.

[0107] If the high-frequency signature sent by vehicle 1 is encrypted, then control module 21 is configured to decrypt the encrypted high-frequency signature.

[0108] The control module 21 is configured to analyze the received high-frequency signature by comparing the characteristics of the received high-frequency signature with the characteristics of the request transmitted by the device 20.

[0109] The control module 21 is configured to also consider the quality of the signal containing the high-frequency signature.

[0110] The control module 21 is configured to transmit a signal containing an identifier via the radio frequency antenna module 22 of the device 20.

[0111] The control module 21 is configured to have a reference time in memory to start and stop the timer and compare the value when the timer stops with the stored reference time.

[0112] RF antenna module 22

[0113] The radio frequency antenna module 22 of the device 20 can transmit and receive radio frequency signals between 200MHz and 500MHz, preferably between 300MHz and 450MHz.

[0114] The radio frequency antenna module 22 of the device 20 is configured to send a radio frequency signal to the locking system 14 of the vehicle 10, the radio frequency signal including an identifier that can release the opening element.

[0115] High-frequency antenna module 23

[0116] The high-frequency antenna module 23 includes a resonant antenna 23A.

[0117] The high-frequency antenna module 23 is configured to receive square wave radio frequency signals transmitted by the high-frequency antenna module 23 of the vehicle 10.

[0118] Radio frequency signals are transmitted in the high-frequency range, that is, between 3MHz and 30MHz.

[0119] Resonant Antenna 23A

[0120] The resonant antenna 23A is an electronic component that can receive radio frequency signals.

[0121] The resonant antenna 23A has a quality factor, preferably greater than or equal to 80.

[0122] The resonant antenna 23A is configured to receive radio frequency signals at a precise frequency (e.g., 14 MHz) that corresponds to the resonant frequency of the resonant antenna 13A present in the high-frequency antenna module 13 of the vehicle 10.

[0123] The high quality factor and precise resonant frequency ensure that the high-frequency signal transmitted by the high-frequency antenna module 13 and received by the high-frequency antenna module 23 has a high signal-to-noise ratio at a distance of approximately 2 meters.

[0124] Exemplary Implementation

[0125] In a manner known per se, after the user leaves the vehicle 10, the locking system 14 prevents the opening elements of the vehicle 10 from being opened to prevent intrusion.

[0126] In order to detect the user's return, vehicle 10 periodically transmits a detection signal with a range of several meters to detect the device 20 carried by the user.

[0127] When a user approaches vehicle 10, device 20 receives these radio frequency detection signals.

[0128] The method according to the invention begins when the device 20 has received the detection signal emitted by the vehicle 10 and is therefore located at a predetermined distance from the vehicle 10.

[0129] In the first step E1, the control module 21 of device 20 generates a high-frequency signature request.

[0130] The request includes values ​​for the characteristics of the expected high-frequency signature.

[0131] Preferably, the expected high-frequency signature is a square wave signal or a PWM signal, and its characteristics include the number of square waves, their duration, and / or their intervals.

[0132] In step E1, control module 21 also starts a timer.

[0133] Advantageously, the control module 21 encrypts the high-frequency signature request.

[0134] In the second step E2, the high-frequency signature request is transmitted to the radio frequency antenna module 22 of the device 20, which transmits the high-frequency signature request in the form of a radio frequency signal.

[0135] In the third step E3, the radio frequency antenna module 12 of vehicle 10 receives the high-frequency signature request.

[0136] In the fourth step E4, the radio frequency antenna module 12 sends the high-frequency signature request to the electronic control unit 11.

[0137] Advantageously, if the control module 21 has encrypted the high-frequency signature request in advance, the electronic control unit 11 decrypts the high-frequency signature request.

[0138] In step E5, the electronic control unit 11 generates a high-frequency signature whose characteristics correspond to the characteristics of the received high-frequency signature request.

[0139] In step E6, the high-frequency signature is transmitted to the high-frequency antenna module 13 of the vehicle 10. Then, the high-frequency signature is transmitted as a high-frequency signal through the resonant antenna 13A.

[0140] In step E7, the high-frequency signature is received by the high-frequency antenna module 23 of device 20.

[0141] The high-frequency signature is received via resonant antenna 13A. The resonant antenna 13A resonates at a precise frequency corresponding to the resonant frequency of the resonant antenna 23A of device 20.

[0142] Because the two resonant antennas 13A and 23A have high quality factors, the information in the high-frequency signature received by device 20 is complete and of high quality.

[0143] The high quality factor of resonant antennas 13A and 23A allows for a longer distance for high-frequency signals at their frequencies, approximately 2 meters. Outside of these precise frequencies, the distance for high-frequency signals will be much shorter, approximately a few centimeters.

[0144] Therefore, the distance of high-frequency signals is shorter than that of radio frequency signals transmitted and received by radio frequency antenna modules 12 and 22. Consequently, if a third party wishes to capture a high-frequency signature, they must be located close to device 20 and / or vehicle 10, making it impossible for them to act with caution.

[0145] Furthermore, if a third party does not use the resonant antenna at the correct frequency corresponding to the frequencies of the resonant antennas 13A and 23A, they must also be within a few centimeters of the vehicle 10 or equipment 20 to intercept the exchange of high-frequency signals.

[0146] In step E8, the control module 21 receives the high-frequency signature via the high-frequency antenna module 23 of the device 20.

[0147] Upon receiving the high-frequency signature, the control module 21 stops the timer started in step E1 in step E9 and compares the timer with the stored reference time.

[0148] If a third party seeks to capture high-frequency signatures via a relay attack, the delay between transmitting the high-frequency signature request and receiving the high-frequency signature will be longer than the time for a legitimate exchange. Therefore, a longer delay will indicate a fraudulent attempt.

[0149] In step E10, the control module 21 analyzes the received high-frequency signature by comparing the features of the received high-frequency signature with the features corresponding to the request generated in step E5.

[0150] The analysis performed by control module 21 also involves the quality of the signal that forms the high-frequency signature. Due to the resonant antennas 13A and 23A, the signal quality is expected to be high, meaning it contains very little noise compared to the "payload" signal. If a third party attempts to capture the high-frequency signature using an antenna that does not match the resonant frequency of resonant antenna 23A, the signal will be severely degraded and will therefore indicate a fraudulent attempt.

[0151] If the features match, the control module 21 generates a signal including the identifier in step E11 and sends the signal to the radio frequency antenna module 22.

[0152] In step E12, the radio frequency antenna module 22 transmits a radio frequency signal including an identifier.

[0153] In step E13, the electronic control unit 11 receives a signal including an identifier via the radio frequency antenna module 12 of the vehicle 10.

[0154] In this step, the electronic control unit 11 checks its memory to see if a high-frequency signature request has been received in advance and / or if a high-frequency signature has been generated in advance. If no instance of receipt or generation is found in the memory, a fraudulent attempt is detected, and the electronic control unit 11 does not send a signal to the locking system 14.

[0155] If an instance of receiving and / or generating exists in the memory, the electronic control unit 11 sends a signal including an identifier to the locking system 14 in step E14, which triggers the release of the opening element of the vehicle 10.

[0156] Therefore, when users arrive, they are able to open one of the opening elements of vehicle 10 without performing any additional actions.

[0157] Since the transmission of a signal including an identifier is triggered when the user-carried device 20 approaches the vehicle 10, the chances of any third party placing a capture device to fraudulently capture that identifier are reduced.

[0158] Furthermore, the transmission of identifiers requires prior high-frequency signature exchange.

[0159] If a third party sends a signal to device 20 seeking to automatically trigger the transmission of the identifier, device 20, which has not received the high-frequency signature beforehand, will not transmit the identifier.

[0160] Similarly, if a third party that has successfully captured the identifier sends the identifier to vehicle 10 without first sending a high-frequency signature, electronic control unit 11 can therefore block the signal and not send the signal to locking system 14, thereby preventing the unlocking element from being opened.

[0161] Finally, a third party might attempt a relay attack by sending and capturing a high-frequency signature request, then retransmitting the request near vehicle 10, thereby capturing the high-frequency signature.

[0162] First, if the third party does not have a resonant antenna with the correct frequency, the signal quality will be poor and the identifier will not be sent.

[0163] Secondly, capturing and retransmitting will cause a waiting time for receiving high-frequency signatures, which the control module 21 will interpret as a fraudulent attempt, thereby preventing the sending of the identifier.

Claims

1. A method for protecting the transmission of an identifier of a portable device (20) for accessing a motor vehicle (10), the vehicle (10) including an electronic control unit (11), a radio frequency antenna module (12), and a high-frequency antenna module (13), the high-frequency antenna module operating in a frequency band different from that of the radio frequency antenna module (12), the device (20) including a control module (21), a radio frequency antenna module (22), and a high-frequency antenna module (23), the control module (21) including a memory region therein storing the identifier of the device (20), the method comprising the steps of: - The control module (21) of the device (20) commands (E1) to transmit a high-frequency signature request via the radio frequency antenna module (22) of the device (20), the high-frequency signature request including the characteristics of the signature. - The electronic control unit (11) receives (E4) the high-frequency signature request via the radio frequency antenna module (22) of the vehicle (10). -The electronic control unit (11) generates (E5) a high-frequency signature containing these features, - The generated high-frequency signature is sent (E6) to the device (20) via the high-frequency antenna module (13) of the vehicle (10). -The control module (21) receives the high-frequency signature sent by (E8) via the high-frequency antenna module (13) of the device (20). - The control module (21) analyzes the high-frequency signature received by (E10), - When the high-frequency signature has the characteristics sent in the high-frequency signature request, the control module (21) sends (E11) a signal containing the identifier via the radio frequency antenna module (22) of the device (20), the electronic control unit (11) receives (E13) the sent signal via the radio frequency antenna module (12) of the vehicle (10), the electronic control unit (11) identifies the device (20) and activates (E14) the function of the vehicle (10) after identifying the device (20).

2. The method as described in claim 1, wherein, The vehicle (10) includes a locking system (14) connected to the electronic control unit (11), wherein the function of the vehicle (10) activated in the step of identifying the device (20) is the function of unlocking the locking system (14) of the vehicle (20).

3. The method as described in any one of the preceding claims, wherein, The control module (21) triggers a timer when sending the high-frequency signature request, stops the timer when receiving the high-frequency signature, compares the time measured therefrom with a reference time (E9), and triggers the step of analyzing (E10) the signature only when the measured time is less than the reference time.

4. The method as described in any of the preceding claims, wherein, Each time this method is implemented, the value of the characteristic of the high-frequency signature request is randomly generated.

5. The method as described in any one of the preceding claims, wherein, The high-frequency signature is a square wave signal. Its characteristics include the number of square waves, their duration, and / or their intervals.

6. The method as described in any of the preceding claims, wherein, The high-frequency antenna module (13) of the vehicle (10) and the high-frequency antenna module (23) of the device (20) each include a high-frequency antenna (13A, 23A), which are resonant with each other.

7. A device (20) comprising a control module (21), a radio frequency antenna module (22), and a high-frequency antenna module (23), the high-frequency antenna module operating in a frequency band different from that of the radio frequency antenna module (12), the control module (21) including a memory region therein storing identifiers and configured to: - Connect to the radio frequency antenna module (22) and the high frequency antenna module (23) in the device (20), - The command transmits a high-frequency signature request via the radio frequency antenna module (22), the high-frequency signature request including the features of the high-frequency signature. - The high-frequency signature transmitted is received via the high-frequency antenna module (23). -Analyze the received high-frequency signatures, - When the high-frequency signature has the characteristics sent in the high-frequency signature request, a signal containing the identifier is sent via the radio frequency antenna module (22) of the device (20).

8. An electronic control unit (11) for a motor vehicle, said electronic control unit (11) being configured to: - Connected to the radio frequency antenna module (12) and the high-frequency antenna module (13), the high-frequency antenna module operating in a frequency band different from that of the radio frequency antenna module (12). - A high-frequency signature request is received via the radio frequency antenna module (12) of the vehicle (10), the high-frequency signature request including the characteristics of the signature. - Generate high-frequency signatures that contain these features. - The generated high-frequency signature is transmitted via the high-frequency antenna module (13) of the vehicle (10). - The signal containing the identifier is received via the radio frequency antenna module (12) of the vehicle (10). -The function of recognizing the identifier and activating the vehicle (10).

9. A vehicle (10) comprising an electronic control unit (11) as described in the preceding claim, a radio frequency antenna module (12) and a high frequency antenna module (13).

10. A system (1) comprising a vehicle (10) as claimed in the preceding claim and an apparatus (20) as claimed in claim 7.

Images