RU2650329C2 - Method of vehicle protection - Google Patents

Abstract

FIELD: security systems.

SUBSTANCE: after leaving a vehicle, an additional portable device is placed in a close proximity of the smart key, which monitors the presence of the access system signal on the low carrier frequency. When this signal is detected, the interference signal is also emitted on the low carrier frequency.

EFFECT: protects any car with a smart key when attacking with repeaters.

7 cl, 4 dwg

Description

The invention relates to the equipment of vehicles to prevent their unauthorized use or theft.

Known comfort access systems with the so-called smart key (smart key), which have the commercial name "KEYLESS GO" or "KEYLESS ENTTRY". These systems provide the owner without key access to the car only having a smart key in his pocket. In the frequent case of execution, the system operates with a series of low-frequency transmitting antennas inside the vehicle located in the door handles. The owner, for example, touching the handle of the car, initiates the transfer of the low-frequency signal from the antenna enclosed in the handle to the smart key. A smart key is activated if it is close enough, due to the fact that the signal from the antenna is induction and decays quickly. The signal generated by the smart key, in response to the signal from the antenna of your car, is transmitted to the vehicle identifier using the high-frequency package, to the receiver located on the vehicle. If the key transmits the correct identifier, the front doors are unlocked and access is granted to the owner in the car.

This system is at risk of attack by attackers working according to the following scheme (Fig. 1). There are two relay modules. One module is available to the attacker, which is located at the car. When the door handle is touched, the low-frequency signal is received by the first repeater and transmitted to the second repeater, which is located near the owner and emits a low-frequency signal to its smart key. Having received such a signal, the smart key emits a high-frequency package received by the car receiver. Entrance doors are unlocked for intruders. After that, the engine can be started, and the car is set in motion in a similar way.

A similar hacking system with the help of two repeaters is known to manufacturers of systems with a smart key. And various methods have been developed to protect the car from such attacks. These methods are aimed at improving the car system in conjunction with a smart key. Briefly, these enhancements to relay attack recognition come down to the following tricks:

- measurement of signal distortion, consisting in a different phase shift of the frequency components of the signal;

- measurement of response time at a low frequency;

- measurement of electric field strength;

- the use of more complex modulation of signals and others.

The following patent documents can be cited as examples of improving the automotive system from this type of attack: patent KR 101455801, publication 03.11.2014, IPC B60R-025/10; KR 20130117094, publication 10.25.2013, IPC B60R-025/10; KR 20130117426, publication 10.28.2013; JP 2012060482, publication 03/22/2012, IPC B60R-025/01.

The closest analogue is a method of protecting a car from theft with an access system with a smart key, disclosed in application US 20130271273, publication 10/17/2013, IPC B60R-025/10, which consists in notifying the owner and security agencies that the car is being used without a passenger compartment smart key. This method provides for the location of an additional low-frequency transceiver in the passenger compartment, which in a normal situation exchanges signals with a smart key, if the owner has it in the passenger compartment when he opens the car and starts it. If there is a smart key in the cabin, the alarm does not rise. If intruders using repeaters manage to open the cabin, start the engine and try to leave, the system with an additional transceiver determines the absence of a smart key in the cabin and raises an alarm. The alarm is transmitted by sending a CMC, via the Internet and other possible channels to alert the car owner and special services.

Quite a few car manufacturers have a unique system with a smart key, which can involve various methods of protection against hacking by intruders working with repeaters. However, systems with a smart key are still used on the market, which do not imply any protection against hacking when using repeaters.

Therefore, the urgent task is to create a simple method that could provide reliable protection against hacking of any car with a smart key in the case when attackers use the method with signal transmitters.

The technical result achieved in this invention is that the proposed method can be used with any system with a smart key, that is, it is quite universal and can be used for cars manufactured by different manufacturers. In addition, it does not involve any alterations inside the car; the owner only needs to carry the device with him in the form of an additional small key fob.

A method of protecting a car with an access system with a smart key from an attack using repeaters is characterized in that after leaving the vehicle, an additional wearable device is located in the immediate vicinity of the smart key. Using this additional wearable device, the presence of an access system signal is monitored at a low carrier frequency and upon detection of said signal, an interference signal is also emitted at a low carrier frequency.

When leaving the car, the owner of the car includes an additional wearable device that monitors the presence of an access signal at a low frequency, on which all systems with a smart key work. As soon as such a signal is detected, the system transmits an interference signal also at this carrier frequency. It is very important that the additional wearable device of the car owner is located in the immediate vicinity of the smart key. Thus, two positive properties are achieved. Due to the design features of car security systems with a smart key, the low-frequency signal with distance quickly attenuates. The repeater of the second attacker is naturally further away than the additional wearable device from the smart key. Therefore, the interference signal can be much less power than the signal from the repeater, sufficient to spoil its signal so that the smart key does not respond to the signal of the repeater. This circumstance, the location of the additional wearable device in the immediate vicinity of the smart key, provides another positive result. The interference signal of an additional wearable device cannot interfere with the security systems of other vehicles, as it will not affect their signals. Naturally, when the owner approaches the car for the purpose of its operation, the additional wearable device must be turned off so as not to clog the low-frequency signal from the car system.

Thus, the method provides protection of any systems with smart keys, because the additional wearable device only responds to the presence of a signal at a low frequency, without evaluating the type, structure and content of this signal, which differ between systems of different car manufacturers.

In the particular case, an interference signal is emitted with a duration of at least 1-2 milliseconds, which is enough to distort the signal from the repeater.

In this case, the interference signal is emitted after detecting the signal by superimposing the interference signal on at least a portion of the received signal of the access system. An interference signal is typically a pulse interference.

In addition to the distortion of the signal of the repeater of the attacker, in addition, upon detection of the signal of the access system at the low-carrier frequency, a notification of the user by means of an audio or vibration signal can be included.

In addition, in addition, when an access system signal is detected on a low frequency carrier, an alarm code can be transmitted to the vehicle.

An additional wearable device can be made in the form of a key fob.

The invention is illustrated by drawings.

In FIG. Figure 1 shows a diagram of an attacker using a system of two relays for breaking a security system with a smart key.

In FIG. 2 is a diagram showing how the proposed method of protecting a car with an access system with a smart key from an attack using repeaters works.

In FIG. Figure 3 shows the protection scheme against attacks on the system with a smart key.

In FIG. 4 shows a block diagram of an additional wearable device.

In order to understand the essence of the method, we clarify the attack scheme of attackers (Fig. 1) using two relays connected by a stable communication channel. When the owner 5 of car 1 with smart key 6 is away from his car, the first attacker 3 with repeater 7 stands at car 1 and activates a dialogue between the transmitting unit with a low-frequency antenna 2, located, for example, in the car's handle, using low-frequency LF Signals at a frequency of 125 kHz. The response signal is transmitted by the relay 7 of the first attacker 3 to the relay 8 of the second attacker 4, which is located near the smart key 6 of the owner 5, on the high-frequency channel using an RF signal at a frequency lying in the range 900-2400 MHz. In turn, the relay 8 transmits a low-frequency signal (LF signal) to the smart key 6, which receives this signal from the relay 8 as a signal from the system 2 of the automobile 1 and transmits a high-frequency signal (RF signal) to the car for opening. Signal transmission also goes through a chain of repeaters 8 and 7.

Consider the essence of the method of protecting a car with an access system with a smart key from an attack using repeaters. Attackers 3 and 4 act in the same way as described above (Fig. 2). However, next to the smart key, in close proximity, there is an additional wearable device 9, made, for example, in the form of a key fob. The attack protection circuitry is shown in FIG. 3. The signal, the LF signal transmitted by the antenna 10 of the relay 8, is received by the antenna 12 of the additional wearable device 9. Upon receipt of the beginning of this signal, which usually consists of several bursts with a duration of 120 μs at a carrier frequency of 125 kHz, the additional wearable device 9 generates LF- an interference signal lasting 1-2 ms at the same frequency of 125 kHz and radiates it using the antenna 13. The antenna 11 of the smart key 6 receives both the signal from the relay 8 and the interference signal from the additional wearable device 9. Thus, the signal from the repeater 8, and by an additional portable device 9 are formed in the sum signal, which is not perceived by the smart key, and it does not respond to the parcel from the repeater intruders. The interference signal may consist of several packages separated in time to ensure unconditional "signal damage" from the relay 8. It should be noted that it is important to find the smart key 6 and the key fob of the additional wearable device 9 in close proximity to each other, for example, in one a bunch.

The connection of the car with a smart key is induction, i.e. using a magnetic field. Field strength is related to distance — inversely proportional to the cube of distance. The antenna 10 of the relay 8 creates a magnetic field by irradiating the smart key 6 with a magnetic field of the LF request signal from a distance of several meters. When the smart key 6 and the keyfob of the additional wearable device 9 are located on the same bundle, the antenna 13 is approximately 100 times closer to the antenna 11 of the protected smart key 6 in comparison with the antenna 10 of the relay 8, which means that the interference field created by it can be about a million times less. Thus, even with such a low power that, by the way, extends the life of the additional wearable device, the interference signal does not interfere with the operation of other devices, for example, car security systems operating at the same frequency. The interference signal is needed so that the correct request code "does not reach" smart key 6; then he will "keep silent" and will not respond to the request.

In this method of protecting a car, an alert may also be provided to the owner of the car about an attack using the sound or vibration signal of the device 14 of the additional wearable device 9.

In addition, the additional wearable device 9 may transmit an alarm to the vehicle security system 15 (FIG. 3).

When the owner approaches his car 1, the additional wearable device 9 must be turned off so as not to interfere with the normal operation of the car system with a smart key.

The block diagram of the additional wearable device 9 can be performed as follows (Fig. 4). 3D antenna 12 is available as a separate chip. Three channels of signal processing from a 3D antenna include an amplifier, a detector, and a threshold device in series. The outputs of the threshold devices are combined by an OR circuit and fed to the microcontroller 16 to generate the corresponding commands. The antenna signal processing channels, the microcontroller, and the switch 17 of the additional wearable device 9 can be in a single chip, for example, of the type PIC 16F 639. The interference signal power amplifier 18, the RF signal transmitter 19 to the vehicle security system 15 and sound or vibration devices 14 Signals are also commercially available.

In this application, the term “access system with a smart key” is synonymous with the terms: “system without key access”, “KEYLESS GO” system, “KEYLESS ENTTRY” system.

The proposed method can be implemented for any security systems of cars with a smart key. Moreover, it does not require alterations of these security systems and will ensure reliable and trouble-free operation.

Claims (7)

1. A method of protecting a car with an access system with a smart key from an attack using repeaters, characterized in that after leaving the vehicle include an additional wearable device located in the immediate vicinity of the smart key, with which the presence of the signal of the access system on the carrier is monitored low frequency, and upon detection of said signal, an interference signal is also emitted at a low frequency carrier. 2. The method according to p. 1, characterized in that the interference signal emit a duration of at least 1-2 ms. 3. The method according to p. 1, characterized in that the interference signal is emitted after detecting the signal by applying an interference signal to at least a portion of the received signal of the access system. 4. The method according to p. 1, characterized in that the said interference signal is a pulsed interference. 5. The method according to p. 1, characterized in that in addition, upon detection of the access system signal at a low carrier frequency, the user is notified by means of an audio or vibration signal. 6. The method according to p. 1, characterized in that in addition, upon detection of a signal from the access system at a low carrier frequency, an alarm code is transmitted to the vehicle. 7. The method according to p. 1, characterized in that the additional wearable device is in the form of a key fob.

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