Vehicle theft protection

Abstract

The invention relates to a protection system (1) for a vehicle (2), comprising a base station (3) with a first transmitter (4) and a first receiver (5) capable of transmitting a signal in a long wavelength band, a first vehicle key (6) with a second transmitter (7) and a second receiver (8), and a detector (9) with a third receiver (10) capable of receiving a signal in the long wavelength band, wherein the detector (9) outputs an alarm signal if the detector (9) detects a fraudulent signal in the long wavelength band and if the base station (3) is arranged at a distance from the first vehicle key (6) at which the first receiver of the base station (3) can receive a signal transmitted by the second transmitter (7) of the first vehicle key (6), if the second receiver of the first vehicle key (6) is arranged out of the range of the first transmitter (4) to the second receiver (8), and the third receiver (10) is arranged out of the range of the first transmitter (4) to the third receiver (10) and at a certain distance from the first vehicle key (6).

Description

Technical Field

[0001] The invention relates to a protection system for a vehicle, the protection system having a base station with a first transmitter and a first receiver, and a first vehicle key with a second transmitter and a second receiver. Background Art

[0002] There are currently vehicle protection systems that prevent vehicle theft attempts using radio range extenders. This type of vehicle theft is also known as a repeater attack. In a repeater attack, a signal transmitted by a vehicle base station is received by a radio range extender and retransmitted in an amplified form. The amplified signal is received by the vehicle key, which may be out of range. Due to the reception of the amplified signal, the vehicle key transmits a signal to the base station that triggers the process of opening and / or even starting the vehicle.

[0003] US 2014 / 0067161 A1 discloses a system for preventing relay station attacks. To prevent vehicle theft, the protection system described in the article is equipped with a portable unit. The portable unit is designed so that the location of the unit can be sent to a base station. This requires a component that detects the location of the portable unit, such as a GPS system.

[0004] US2016 / 0027226A1 discloses a protection system having an evaluation unit that can execute a fingerprint program. The fingerprint program is used to determine the relative position between the vehicle key and the base station. In this case, the evaluation unit can also include, for example, an acceleration sensor.

[0005] The protection system against relay station attacks described in WO 2015 / 084852 has multiple antennas that perform a plausibility check of the measured distance of the vehicle key from the base station. In addition to the antenna for communication between the base station and the vehicle key, two additional antennas are required.

[0006] The aforementioned known protection systems have the disadvantage that, in addition to relatively simple components (such as a transmitter and a receiver), they also require other electronic components of other types (such as a GPS system or an accelerometer); or in other cases the base station must be equipped with additional hardware (such as two additional antennas). Summary of the invention

[0007] Against this background, the object of the present invention is to create a protection system with a simpler design.

[0008] It should be noted that the features listed individually in the claims can be combined with one another in any technically suitable manner and describe additional embodiments of the invention.The detailed description, in particular with reference to the drawings, additionally characterizes and describes the invention.

[0009] In order to provide a protection system against a relay station attack with a simpler design, a protection system for a vehicle is proposed. The protection system has: a base station with a first transmitter and a first receiver, the first transmitter being capable of transmitting a signal in a long wavelength band; a first vehicle key with a second transmitter and a second receiver; and a detector with a third receiver, the third receiver being capable of receiving a signal in the long wavelength band. If the detector detects a fraudulent signal in the long wavelength band and if the base station is set at a distance from the first vehicle key where the first receiver of the base station can receive a signal transmitted by the second transmitter of the first vehicle key, if the second receiver of the first vehicle key is set out of the range of the first transmitter to the second receiver, and if the third receiver is set out of the range of the first transmitter to the third receiver and is set at a certain distance from the first vehicle key, the detector transmits an alarm signal.

[0010] Advantageously, the detector enters an enabled state when the third receiver is arranged outside the range of the first transmitter to the third receiver, and enters a disabled state when the third receiver is arranged within the range of the first transmitter to the third receiver. In the enabled state, the detector is set to an alarm state, and if the detector detects a fraudulent signal, the detector can trigger an alarm. In a preferred alternative design, the detector can be manually activated.

[0011] The fraudulent signal may be a signal transmitted by the first transmitter and amplified by the radio range extender. The fraudulent signal may be generated not only by amplification but also by a signal generator.

[0012] An advantageous configuration provides that the detector has a microcontroller, wherein the microcontroller has a memory in which at least one first information item is stored, the memory being associated with an identification feature of the vehicle that can be transmitted by the first transmitter. In this configuration, the detector detects a fraudulent signal that includes a second information item associated with the identification feature of the vehicle based on the first information item. The microcontroller can compare the first information item with the second information item.

[0013] The invention is based on the idea that the detector detects fraudulent signals based on a frequency range covering signals in the long wavelength band or based on a first information item, detecting fraudulent signals comprising a second information item relating to an identification feature of the vehicle.

[0014] The first information item is related to an identification feature of the vehicle that can be transmitted by the first transmitter, meaning that the identification feature can be made readable by the first information item. For example, the identification feature can be encrypted in the form of the first information item. The same applies to the second information item related to the identification feature of the vehicle. The first information item can also be identical to the second information item.

[0015] In a modified alternative design, the first information item differs from the second information item, for example based on a different encoding process. The identification feature may be the vehicle identification number of the vehicle. The identification feature may also be generated from the vehicle identification number and a personal data item of the vehicle owner, such as a digital PIN (personal identification number) code or a password.

[0016] The range of the first transmitter to the second receiver is intended to mean that the range depends on the transmit power of the first transmitter and the sensitivity of the second receiver. Thus, the range of the first transmitter to the second receiver may be different from the range of the first transmitter to the third receiver.

[0017] The proposed protection system has the following advantages: on the one hand, a complex design of the base station (e.g. with an additional antenna) can be avoided; and on the other hand, no further components are required except for the third receiver (and in an advantageous design except for the microcontroller). Compared to a GPS system or an accelerometer, the third receiver and the microcontroller are relatively simple electronic components. The detector can preferably be operated using the same protocols, signals, and / or technical equipment as the first vehicle key. This has the advantage that the complexity of the protection system is lower than in alternative designs with a GPS system or an accelerometer, and the proposed protection system is therefore simpler in its design.

[0018] Particularly advantageously, the third receiver is identical to the first and / or second receiver. A particular advantage of the particular alternative design of the protection system is that an existing system comprising a base station with a first transmitter and a first receiver and a first vehicle key with a second transmitter and a second receiver can be upgraded to the proposed protection system without requiring modifications to hardware components of the base station or the first vehicle key.

[0019] It is even possible to upgrade an existing system to the proposed protection system without making any changes to the software of the existing system. Due to the proposed protection system, it is no longer necessary to store the first vehicle key in a shielded box to prevent attacks by relay stations. In particular, the protection system can prevent the most common application of relay station attacks, especially if the vehicle is parked near the residence of the vehicle owner.

[0020] Since the third receiver is arranged outside the range of the first transmitter to the third receiver, the signal of the first transmitter in the long wavelength band, which optionally contains the identification feature of the vehicle, cannot reach the third receiver. If the third receiver is arranged in this way, any signal received by the third receiver in the long wavelength band and preferably including the identification feature is detected as a fraudulent signal. The detector can be positioned, for example, in a house, in particular permanently in a house. In another alternative design, the detector can be stored near the driver of the vehicle.

[0021] The microcontroller may in particular comprise a learning function which enables the first information item stored in the memory to be adapted to a new vehicle. This can be achieved in the following way: the detector is brought into the range of the first transmitter to the third receiver (hereinafter referred to as the enabling range) and is set to programming mode (preferably by pressing a button). The signal emitted by the first transmitter containing the identification feature of the new vehicle is received by the third receiver and the identification feature is stored in the memory in the form of the first information item. The programming mode is then exited.

[0022] In an alternative design, outputting the alarm signal by the detector means that the detector has a third transmitter and uses the third transmitter to send the alarm signal to the first receiver of the base station. In this case, people near the protection system cannot perceive the alarm signal. The base station then triggers the alarm system of the protection system connected to the base station. The alarm device can be a horn or a light that is acoustically or visually perceptible to people near the base station.

[0023] In another alternative design, outputting an alarm signal is understood to mean that the detector outputs an alarm signal in the form of an alarm signal that is audibly or visually perceptible to a person near the detector. Thus, the detector may trigger an audio generator of the detector that generates an audible alarm tone, or trigger a flashing light in the detector.

[0024] Particularly advantageously, the protection system comprises a mobile device and the detector sends an alarm signal to the mobile device. The mobile device can be a mobile phone, a laptop, or other mobile device that can be connected to the detector or the base station. The alarm signal in this embodiment is advantageously implemented as a digital alarm signal, such as an email, a text message, a Twitter message, and / or a WhatsApp (web messenger) message, and is preferably sent via the Internet. In this case, a third transmitter can establish a connection to the Internet. This alternative design has the advantage that an existing system with a first vehicle key, a base station, and a mobile device can be upgraded to the proposed protection system. In this case, the base station or the detector does not need an alarm system, which means that components can be saved.

[0025] Secondly, in a configuration with a mobile device, the user is susceptible to perceiving the alarm signal, particularly if the mobile device is located at a distance of about two meters from the user at most. In addition, this alternative design does not require a loud alarm signal emitted by the vehicle, which means that disturbing the quietness of the area surrounding the vehicle can be avoided.

[0026] If, according to another design, the detector sends a warning signal to a second receiver and the first vehicle key has a warning device which is activated upon receipt of the warning signal, a disturbance of the quiet can also be avoided.

[0027] In a special design, it is provided that the third receiver can only receive signals in the long wavelength band. Additionally, but also independently of this, it is advantageous that the detector only detects fraudulent signals that are emitted as waves in the long wavelength band. The wavelength of the long wavelength band is between approximately one and ten kilometers. The design also preferably provides that the first transmitter only emits signals in this band.

[0028] Since long wavelength transmitters can be designed more simply than high frequency or ultra high frequency radio wave transmitters, the complexity of the protection system can be further reduced. Furthermore, in some cases, the range of the first transmitter to the third receiver when using communication in the long wavelength band can be limited more easily and more safely than when using communication in the radio frequency range, for example. The range is advantageously in the range of about two meters. Thus, the protection system can be used particularly advantageously as protection against vehicle theft.

[0029] In a design where the detector transmits an alarm signal if the third receiver receives a signal in the long wavelength band, the protection system can be used for several parked vehicles near the detector even if the signal does not contain information related to the identification characteristics of the vehicle. This saves the multi-user cost of the protection system.

[0030] In a particularly advantageous embodiment, the protection system has a second vehicle key, wherein the second vehicle key is designed as a detector. Since the second vehicle key is usually equipped with a transmitter and a receiver like the first vehicle key, the second vehicle key can instead act as a detector with a third receiver and preferably a third transmitter. For this purpose, the second vehicle key preferably also has a microcontroller, which is reprogrammed so that the vehicle key can be used as a detector. Thus, components of the detector, such as the third receiver or the third transmitter, or, if the second vehicle key originally had a microcontroller, the microcontroller can also be retained.

[0031] Since the second vehicle key is usually a spare and is not usually needed as a vehicle key, this design of a protection system is very advantageous. The second vehicle key is also usually equipped with software that provides the above-mentioned learning function. This means that deploying the protection system also requires less work.

[0032] The second vehicle key can advantageously use a control element (eg a button) to switch from the first operating mode to the second operating mode. In this case, the second vehicle key is used as the first vehicle key in the first operating mode and as a detector in the second operating mode.

[0033] In a further configuration, it is provided that the protection system has a jamming transmitter, the warning signal activates the jamming transmitter, and the jamming signal in the activated state interferes with the signal of the second transmitter. In this way, it is possible to prevent the signal of the second transmitter from reaching the base station and triggering the opening or starting of the vehicle. This is also advantageous in addition to the emission of the warning signal, since the protection action is additionally performed automatically.

[0034] It can also be provided that the protection system has a vehicle component to which the base station can be connected as soon as the first receiver receives the alarm signal and the base station locks the vehicle component. The vehicle component used can be a vehicle lock or a drive element, such as an internal combustion engine or an electric motor. Thus, for example, the base station can be connected to a control unit of the vehicle and disable the starter of the drive element. In this alternative design, the user does not need to react immediately, because the protection system can automatically prevent the vehicle from being stolen.

[0035] As mentioned above, the proposed protection system can be deployed with the help of an existing system, the system consists of a base station with a first receiver and a first transmitter, a first vehicle key with a second transmitter and a second receiver, and a detector. Independent of the existing design of the protection system, a detector is therefore proposed to achieve this purpose.

[0036] The detector is suitable for a vehicle having a base station having a first transmitter and a first receiver capable of transmitting signals in the long wavelength band, and having a first vehicle key with a second transmitter and a second receiver. The detector according to the invention has a third receiver capable of receiving signals in the long wavelength band, and preferably has a microcontroller with a memory storing at least a first information item related to an identification feature of the vehicle that can be transmitted by the first transmitter. The detector can detect fraudulent signals in the long wavelength band. In a particular embodiment, the detector can detect fraudulent signals in the long wavelength band that include a second information item related to an identification feature of the vehicle based on the first information item. In the process, the microcontroller preferably compares the first information item with the second information item.

[0037] The detector transmits an alarm signal if the detector detects a fraud signal and if the base station is set at a distance from the first vehicle key at which the first receiver of the base station can receive a signal transmitted by the second transmitter of the first vehicle key, if the second receiver of the first vehicle key is set out of the range of the first transmitter to the second receiver, and if the third receiver is set out of the range of the first transmitter to the third receiver and at a certain distance from the first vehicle key.

[0038] According to the concept of the present invention, a method for protecting a vehicle is also proposed, which uses a protection system according to any of the above-mentioned alternative designs. The method has the following steps: in a first step, a first information item related to an identification feature of the vehicle that can be transmitted by a first transmitter is stored in a memory. In a second step, a detector is used to detect a fraudulent signal based on the first information item, wherein the fraudulent signal includes a second information item related to the identification feature of the vehicle.

[0039] If the third receiver receives the fraud signal and if the base station is located at a distance from the first vehicle key where the first receiver of the base station can receive the signal transmitted by the second transmitter of the first vehicle key, if the second receiver of the first vehicle key is located out of range of the first transmitter to the second receiver, and if the third receiver is located out of range of the first transmitter to the third receiver and is located at a distance from the first vehicle key, detection occurs. In a third step, an alarm signal is transmitted by the detector if the detector signal detects the fraud signal.

[0040] Preferably, the detector is enabled when the third receiver is disposed out of range of the first transmitter to the third receiver, and the detector is disabled when the third receiver is disposed within range of the first transmitter to the third receiver.

[0041] The protection system may be used in such a way that the range of the first transmitter to the third receiver, hereinafter referred to as the activation range, is known. In particular, the activation range may be known for a specific location in a specific environment, the specific environment being defined by the setting of buildings etc. The activation range may be variable depending on the weather and other vehicles parked around the vehicle.

[0042] In a particular configuration of the method, provision can therefore be made that after stopping the engine of the vehicle, a connection is established between the first transmitter and the second receiver and the connection is maintained until the second receiver moves out of the range of the first transmitter to the second receiver (hereinafter referred to as the contact range). When there is a connection between the first transmitter and the second receiver, the second transmitter advantageously transmits a contact indicator signal with a value of 1, which the third receiver can receive close to the second transmitter.

[0043] For example, if the detector and the first vehicle key are located on the body of the vehicle driver, the third receiver can always receive the contact mark signal. If the first vehicle key is removed from the vehicle after the engine is stopped, the connection between the first transmitter and the second receiver is interrupted once the first vehicle key moves out of the contact range.

[0044] If the interruption of the connection is detected by the microprocessor of the first vehicle key, the second transmitter sends a contact flag signal with a value of zero to the third receiver. The detector is advantageously designed so that it switches to the enabled state when the third receiver detects a falling edge of the contact flag signal (i.e. the value of the contact flag signal changes from 1 to 0). In this way, it can be ensured that the detector is in the enabled state as long as the first vehicle key is out of the contact range. In addition, the user of the protection system does not need to know the activation range.

[0045] In an advantageous manner, once the detector enters the activated state, the detector sends a signal to the second receiver or the mobile device by means of the third receiver of the detector. This allows the driver to know whether the detector is activated by the first vehicle key or by the mobile device. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Other features and advantages of the invention can be obtained from the following description of exemplary embodiments of the invention, which description should not be interpreted as limiting and is explained in more detail below with reference to the accompanying drawings. The accompanying drawings schematically show:

[0047] Figure 1 It is a protection system for a vehicle having a detector;

[0048] Figure 2 is another protection system for a vehicle having a second vehicle key that acts as a detector.

[0049] In the various figures, functionally identical components are always provided with the same reference symbols, so that these components are usually described only once. DETAILED DESCRIPTION

[0050] Figure 1 A protection system 1 is shown for a vehicle 2 , which has a base station 3 with a first transmitter 4 and a first receiver 5 , a first vehicle key 6 with a second transmitter 7 and a second receiver 8 , and a detector 9 with a third receiver 10 and a microcontroller 11 .

[0051] The microcontroller 11 has a memory 12 storing at least one first information item 13 associated with an identification feature of the vehicle 11 that can be transmitted by the first transmitter 4. The detector 9 detects a fraud signal including a second information item related to the vehicle identification feature based on the first information item 13. The detector 9 detects the fraud signal if the base station 3 is arranged at a distance from the first vehicle key 6 where the first receiver 5 of the base station 3 can receive a signal transmitted by the second transmitter 7 of the first vehicle key 6, if the second receiver 8 of the first vehicle key 6 is arranged out of the range of the first transmitter 4 to the second receiver 8, and if the third receiver 10 is arranged out of the range of the first transmitter 4 to the third receiver 10 and is separated from the first vehicle key 6 by a distance. When the detector 9 detects the fraud signal, the detector 9 transmits an alarm signal.

[0052] Figure 1 Also shown is an activation range 14 corresponding to the range of the first transmitter 4 to the third receiver 10 . Figure 1 It is also shown that a signal transmitted by the first transmitter 4 which is not supposed to reach the first vehicle key 6 or the detector 9 is amplified by the radio range extender 15. The radio range extender 15 transmits the amplified signal of the first transmitter 4 in the form of a fraudulent signal, wherein the fraudulent signal has an increased range 16 to the second transmitter 7 of the first vehicle key 6 and the third receiver 10 of the detector 9 due to the amplification by the radio range extender 15.

[0053] The following describes how to use the protection system 1 to prevent the vehicle 2 from being opened or started with the radio range extender 15. Because the detector 9 is arranged outside the activation range 14 (which may be 2 m), the signal transmitted by the first transmitter 4 and not amplified cannot reach the third receiver 10. However, if the signal transmitted by the first transmitter 4 is amplified by the radio range extender 15, the third receiver 10 receives the signal transmitted by the first transmitter 4 in the form of a fraudulent signal.

[0054] The microcontroller can theoretically also receive signals other than fraudulent signals. Therefore, the information contained in the signal received using the third receiver 10 is advantageously compared with the first information item 13 contained in the memory 12 by means of the microcontroller 11. If the result of this comparison is that the information contained in the signal received using the third receiver 10 is associated with the same identification feature as the first information item 13, the signal received by the third receiver 10 is detected as a fraudulent signal.

[0055] As soon as the detector 9 detects a fraudulent signal transmitted by the radio range extender 15 using the third receiver 10, the detector 9 transmits an alarm signal. In particular, the detector 9 does not transmit an alarm signal when no fraudulent signal is detected. In a first alternative design, the alarm signal is implemented in the form of a tone. In a second alternative design, the alarm signal is sent to the first receiver 5 of the base station 3 by means of the third transmitter 17 of the detector 9. As soon as the first receiver 5 receives the alarm signal, the base station 3 activates the first alarm system 18 of the protection system 1, wherein the first alarm system 18 is connected to the base station 3.

[0056] The alarm signal may also be sent via the third transmitter 17 to a second alarm system 19 of the protection system 1. The second alarm system 19 may be arranged, for example, in a building 20 and preferably has a battery-powered tone generator. Figure 1 In the example shown, the first vehicle key 6 and the detector 9 are also arranged in the building 20 .

[0057] In a particular design, the detector 9 has a jamming transmitter 21. When the third receiver 10 detects a fraudulent signal, the jamming transmitter 21 is preferably activated. Once the jamming transmitter 21 is activated, the signal transmitted by the first vehicle key 6 is jammed so that the first receiver 5 of the base station 3 can no longer process the signal transmitted by the first vehicle key 6 in the same way as if the jamming signal had not been emitted. Thus, for example, a signal transmitted by the first vehicle key 6 and which would cause the vehicle 2 to be opened or started will no longer trigger the start or opening of the vehicle 2.

[0058] The third receiver 10 is preferably designed as a long-wave receiver, which preferably receives signals with a frequency of about 125 kHz. The third transmitter 17 of the detector 9 preferably transmits radio waves in the range of 315 MHz to 433 MHz. In a specific design, the first information item 13 stored in the memory 12 can be adjusted for the first vehicle 2 using the microcontroller 11. For example, if the vehicle 2 and the identification characteristics of the vehicle 2 (such as the vehicle identification number) change, the first information item 13 is modified so that the identification characteristics of the new vehicle 2 can be obtained from the first information item 13.

[0059] In a further design it may be provided that the detector 9 is connected to an external power source 22. Moreover, in a particular embodiment, the detector 9 may be able to transmit a plurality of signals at different frequencies simultaneously with the third transmitter 17. Thus, on the one hand, the third transmitter 17 may send an alarm signal at a radio frequency to the first receiver 5. At the same time, the third transmitter 17 may transmit an interference signal in the long wavelength band, which interferes with the signal of the first vehicle key 6 in the long wavelength band.

[0060] Furthermore, provision can be made for the base station 3 to ignore any signal transmitted by the second transmitter 7 as soon as the first receiver 5 receives an alarm signal.

[0061] Figure 2 A second protection system 100 is shown for a second vehicle 102. The protection system 100 has a base station 103 with a first transmitter 104 and a first receiver 105, a first vehicle key 106 with a second transmitter 107 and a second receiver 108, and a detector 109 with a third receiver 110 and a microcontroller 111. Figure 2 In the second protection system 100 shown, the detector 109 is designed as a second vehicle key.

[0062] The microcontroller 111 has a memory 112 storing at least one first information item 113 relating to an identification feature of the vehicle 111 which can be transmitted by the first transmitter 104. The detector 109 detects based on the first information item 113 a fraudulent signal comprising a second information item relating to the vehicle identification feature.

[0063] The detector 109 detects a fraud signal when the base station 103 is disposed at a distance from the first vehicle key 106 where the first receiver 105 of the base station 103 can receive a signal transmitted by the second transmitter 107 of the first vehicle key 106, when the second receiver 108 of the first vehicle key 106 is disposed out of the range of the first transmitter 104 to the second receiver 108, and if the third receiver 110 is disposed out of the range of the first transmitter 104 to the third receiver 110 and is spaced a distance from the first vehicle key 106. If the detector 109 detects a fraud signal, the detector 109 transmits an alarm signal.

[0064] Figure 2 Also shown in FIG. 1 is an enabled range 114 corresponding to the range of the first transmitter 104 to the third receiver 110 .

[0065] Figure 2A specific design of the second protection system 100 is also shown, with which a relay station attack from a second radio range extender 115 can be prevented. In this configuration, the radio range extender 115 is arranged so that a signal with an extended range 116 does not reach the detector 109 when it does reach the first vehicle key 106. For this purpose, the second protection system 100 has an additional detector 119 with a fourth receiver 120. The additional detector 119 also has a microcontroller 121 with a memory 122, wherein the memory 122 stores at least one first information item 123 related to the identification feature of the second vehicle 102 that can be transmitted by the first transmitter 104. The additional detector 119 can be designed in the same way as the detector 9 or 109 according to any of the different embodiments of the detectors 9 or 109 described above. The additional detector 119 is located at a distance from the detector 109 to enlarge the secure area for storing the first vehicle key 106.

Claims

1. A protection system (1) for a vehicle (2), comprising a base station (3) with a first transmitter (4) and a first receiver (5) capable of transmitting a signal in a long wavelength band, a first vehicle key (6) with a second transmitter (7) and a second receiver (8), and a detector (9) with a third receiver (10) capable of receiving a signal in a long wavelength band, wherein if the detector (9) detects a fraudulent signal in the long wavelength band and if the base station (3) is located at a distance from the first vehicle key (6) where the first receiver of the base station (3) can receive a signal transmitted by the second transmitter (7) of the first vehicle key (6), the first vehicle key (6) ) is arranged outside the range of the first transmitter (4) to the second receiver (8), and the third receiver (10) is arranged outside the range of the first transmitter (4) to the third receiver (10) and is at a certain distance from the first vehicle key (6), then the detector (9) outputs an alarm signal, wherein the second transmitter (7) transmits a contact mark signal indicating whether the first transmitter (4) and the second receiver (8) are connected, the third receiver receives the contact mark signal, and the detector (9) switches to a use state when the contact mark signal indicates that the connection between the first transmitter (4) and the second receiver (8) is disconnected.

2. The protection system (1) according to claim 1, Features The detector (9) comprises a microcontroller (11), wherein the microcontroller (11) has a memory (12) in which is stored at least one first information item (13) related to the identification feature of the vehicle (2) emitted by the first transmitter (4), and the fraud signal comprises a second information item related to the identification feature of the vehicle (2), and the detector (9) detects the fraud signal based on the first information item.

3. The protection system (1) according to claim 1 or 2, Features The protection system (1) has an alarm system (18) connected to the base station (3), and the detector (9) has a third transmitter, wherein the third transmitter sends the alarm signal to the first receiver (5) and the base station (3) triggers the alarm system (18).

4. The protection system (1) according to claim 1, Features The protection system (1) comprises a mobile device and the detector (9) sends the alarm signal to the mobile device.

5. The protection system (1) according to claim 1 Features The detector (9) sends the alarm signal to the second receiver (8) and the first vehicle key (6) has an alarm system that is activated upon receipt of the alarm signal.

6. The protection system (1) according to claim 1, Features The protection system (1) has a second vehicle key, wherein the second vehicle key is designed as a detector.

7. The protection system (1) according to claim 1, Features The protection system (1) has a jammer transmitter (21), and the alarm signal activates the jammer transmitter (21) and the jammer transmitter jams the signal of the second transmitter (7) in the activated state.

8. The protection system (1) according to claim 1, Features The protection system (1) has a vehicle component, the base station (3) is connected to the vehicle component, and the base station (3) locks the vehicle component as soon as the first receiver receives the alarm signal.

9. The protection system (1) according to claim 8, Features The vehicle component is a vehicle lock.

10. The protection system (1) according to claim 8, Features The vehicle component is a drive element of the vehicle (2).

11. The protection system (1) according to claim 1, Features The protection system (1) comprises an additional detector (119) having a fourth receiver (120), and an additional microcontroller (121) having an additional memory (122) in which at least one additional information item (123) is stored, the additional information item being related to the identification feature of the vehicle (2) transmitted by the first transmitter (4), wherein if the base station (3) is arranged at a distance from the first vehicle key (6) in which the first receiver of the base station (3) can receive the signal transmitted by the second transmitter (7) of the first vehicle key (6), if the The second receiver of the first vehicle key (6) is arranged outside the range of the first transmitter (4) to the second receiver (8), and the fourth receiver (120) is arranged outside the range of the first transmitter (4) to the fourth receiver (120) and is at a certain distance from the first vehicle key (6), then the additional detector (119) detects a fraud signal including a second information item related to the identification feature of the vehicle (2) based on the additional information item (123), and when the additional detector (119) detects the fraud signal, the additional detector (119) transmits an alarm signal.

12. A detector (9) for a vehicle (2), the vehicle (2) having a base station (3) with a first transmitter (4) and a first receiver (5) capable of transmitting a signal in a long wavelength band, and having a first vehicle key (6) with a second transmitter (7) and a second receiver (8), wherein the detector (9) has a third receiver (10) capable of receiving a signal in the long wavelength band, and if the detector (9) detects a fraudulent signal in the long wavelength band and if the base station (3) is arranged at a distance from the first vehicle key (6) where the first receiver of the base station (3) can receive a signal transmitted by the second transmitter (7) of the first vehicle key (6), if the detector (9) detects a fraudulent signal in the long wavelength band and if the base station (3) is arranged at a distance from the first vehicle key (6) where the first receiver of the base station (3) can receive a signal transmitted by the second transmitter (7) of the first vehicle key (6), if the The second receiver of the first vehicle key (6) is arranged outside the range of the first transmitter (4) to the second receiver (8), and if the third receiver (10) is arranged outside the range of the first transmitter (4) to the third receiver (10) and is at a certain distance from the first vehicle key (6), the detector (9) outputs an alarm signal, wherein the second transmitter (7) transmits a contact mark signal indicating whether the first transmitter (4) and the second receiver (8) are connected, the third receiver receives the contact mark signal, and the detector (9) switches to a use state when the contact mark signal indicates that the connection between the first transmitter (4) and the second receiver (8) is interrupted.

13. The detector (9) according to claim 12, Features The detector (9) comprises a microcontroller (11), wherein the microcontroller (11) has a memory (12), wherein the memory (12) stores at least one first information item (13) related to an identification feature of the vehicle (2) emitted by the first transmitter (4), the fraud signal comprises a second information item related to the identification feature of the vehicle (2), and the detector (9) detects the fraud signal based on the first information item.

14. The detector (9) according to claim 13, Features The memory may be modified, and the first information item stored in the memory may be modified such that the first information item is associated with another identification feature of another vehicle (2).

15. A method for protecting a vehicle (2) using a protection system (1), the protection system having a base station (3) with a first transmitter (4) and a first receiver (5), a first vehicle key (6) with a second transmitter (7) and a second receiver (8), a detector (9) with a third receiver (10) and a microcontroller, wherein the microcontroller has a memory, the method comprising the following steps: - storing in said memory a first item of information relating to an identification feature of said vehicle (2) emitted by said first transmitter (4), - detecting a fraud signal by means of the detector (9) based on the first information item, wherein the fraud signal comprises a second information item relating to the identification feature of the vehicle (2), and detection is performed when the third receiver (10) receives the fraud signal and the base station (3) is arranged at a distance from the first vehicle key (6) at which the first receiver of the base station (3) can receive a signal transmitted by the second transmitter (7) of the first vehicle key (6), the second receiver of the first vehicle key (6) is arranged out of range of the first transmitter (4) to the second receiver (8), and the third receiver (10) is arranged out of range of the first transmitter (4) to the third receiver (10) and is located at a distance from the first vehicle key (6), - outputting an alarm signal through the detector (9), The second transmitter (7) transmits a contact mark signal indicating whether the first transmitter (4) and the second receiver (8) are connected, the third receiver receives the contact mark signal, and the detector (9) switches to a use state when the contact mark signal indicates that the connection between the first transmitter (4) and the second receiver (8) is interrupted.

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