DE102019104096A1 - Procedure for securing an authentication - Google Patents

Abstract

The invention relates to a method for securing an authentication of a mobile identification transmitter (200) in an access system (2) of a vehicle (1), preferably for detecting a relay attack, the following steps being carried out: a) initiating a signal transmission (D) between at least one communication module (110) on the vehicle (1) and the identification transmitter (200) as a function of an activation signal (S.1), b) determining a security feature (M) by the identification transmitter (200) on the basis of the signal transmission (D), c ) Suppression of the authentication by the identification transmitter (200) as a function of the security feature (M).

Description

The present invention relates to a method for securing an authentication of a mobile identification transmitter in a vehicle according to the independent method claim. The invention also relates to an identification transmitter and a security system for a vehicle according to the respective independent device or system claim.

It is known from the prior art that so-called passive access systems are used in vehicles to increase comfort. Such access systems make it possible to trigger the authentication by approaching the vehicle without manual operation of the electronic key, that is to say the identification transmitter (ID transmitter). As a functional extension, such systems can also have the option of starting the engine without the ID transmitter having to be actively used for this purpose or having to be used on the vehicle. To enable the engine start, it is recognized that the user is in the interior of the vehicle with the identification transmitter. Other terms for such or comparable access systems are "Keyless-Go" or "Passive Entry Passive Start" systems.

In order to enable the authentication in such a comfortable manner, proximity sensors are often used by the vehicle in order to send out a wake-up signal for the ID transmitter when the proximity of the user to the vehicle is detected. This wake-up signal causes, provided it is received by the ID transmitter within a specified range of the vehicle - i.e. in the vicinity of the vehicle - to initiate authentication with the ID transmitter. E.g. the wake-up signal is transmitted from the vehicle to the ID transmitter via LF (Low Frequency) radio. The ID transmitter can then transmit an authentication signal to the vehicle. This authentication signal is transmitted, for example, via HF (high frequency) radio and can carry information for authentication, such as a code.

It is a disadvantage of some conventional solutions of such authentication that methods are known to manipulate the authentication process. A well-known attack is the so-called "Relay Station Attack" (or also "Relay Attack"). This attack makes it possible to initiate authentication by the ID transmitter outside of the intended range and therefore not in the vicinity of the vehicle. Some conventional vehicles cannot have the necessary technical precautions to reliably prevent such an attack.

It is therefore an object of the present invention to at least partially remedy the disadvantages described above. In particular, it is the object of the present invention to at least make it more difficult to manipulate the authentication in a large number of vehicles.

The above object is achieved by a method with the features of the independent method claim, an identification transmitter with the features of the independent device claim, and by a security system with the features of the independent system claim. Further features and details of the invention emerge from the respective subclaims, the description and the drawings. Features and details that are described in connection with the method according to the invention naturally also apply in connection with the identification transmitter according to the invention and the security system according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, mutual reference is or can always be made .

The object is achieved in particular by a method for securing an authentication of a mobile identification transmitter in an access system of a vehicle, preferably for detecting a manipulation attempt during authentication, specifically z. B. a relay attack or relay station attack.

It is advantageous here if the vehicle is designed as a motor vehicle, in particular as a hybrid vehicle or as an electric vehicle, preferably with a high-voltage electrical system and / or an electric motor. In addition, it can be possible for the vehicle to be designed as a fuel cell vehicle and / or passenger vehicle and / or semi-autonomous or autonomous vehicle. The vehicle advantageously has an access system (in particular a central locking system) and / or a security system (in particular according to the invention) which z. B. by communication with an (in particular according to the invention) identification transmitter (ID transmitter) enables authentication. Depending on the communication and / or the authentication, at least one function of the vehicle can be activated. If the authentication of the ID transmitter is necessary for this, the function can be a safety-relevant function, such as unlocking the vehicle or enabling an engine start. Thus, the security system and / or the access system can also provide the functionality of a passive access system, which without active manual actuation of the ID transmitter, the authentication and / or the activation of the function upon detection of the approach of the ID transmitter initiates the vehicle. For this purpose, for example, a wake-up signal is repeatedly sent out by the security system and / or by the access system of the vehicle, which can be received by the ID transmitter on approach, and then triggers the authentication. The function can also relate to activation of vehicle lighting and / or actuation (opening and / or closing) of a flap (e.g. front or rear or side flap or door). E.g. the vehicle lighting is activated automatically when the approach is detected and / or the flap is operated when a gesture by a user is detected.

1. a) Initiieren einer Signalübertragung zwischen wenigstens einem Kommunikationsmodul am Fahrzeug und dem Identifikationsgeber in Abhängigkeit von (wenigstens) einem Aktivierungssignal, insbesondere wenn das Aktivierungssignal durch das Kommunikationsmodul und/oder durch den Identifikationsgeber empfangen wird,
2. b) Bestimmen eines Sicherheitsmerkmals durch den Identifikationsgeber anhand der Signalübertragung,
3. c) Initiieren und/oder Unterdrücken der Authentifizierung durch den Identifikationsgeber jeweils in Abhängigkeit von dem Sicherheitsmerkmal.

In a method according to the invention, provision can be made for the following steps to be carried out, preferably one after the other in the order specified or in any order, with individual steps also being able to be carried out repeatedly if necessary:

1. a) initiating a signal transmission between at least one communication module on the vehicle and the identification transmitter as a function of (at least) one activation signal, in particular when the activation signal is received by the communication module and / or by the identification transmitter,
2. b) Determination of a security feature by the identification transmitter based on the signal transmission,
3. c) Initiation and / or suppression of the authentication by the identification transmitter in each case as a function of the security feature.

The initiation of the authentication can e.g. B. then be carried out when the security feature corresponds to a predetermined feature (such as a specification), z. B. a maximum distance in a distance determination. In contrast, the authentication can be suppressed when the security feature does not correspond to the specified feature. The security feature and / or the specified feature can accordingly be specific for the presence or absence of a manipulation attempt during authentication.

This has the advantage that a security feature can be provided for the identification transmitter in order to use it to secure the authentication. As a result, in addition to authentication (e.g. via a code exchange) as the vehicle's security mechanism, a further security mechanism can be provided in order to significantly reduce the risk of manipulation, which significantly increases the security of the access system. The use of the activation signal to initiate signal transmission can enable flexible use and, in particular, retrofitting of the communication module on the vehicle.

The at least one communication module can, for. B. be attached from the outside of the vehicle, and / or be attached to the vehicle later. The respective communication module can accordingly be designed to be retrofittable.

It is provided in particular that the initiation of the signal transmission takes place in that the identification transmitter sends an interrogation signal to the communication module as soon as the identification transmitter receives the activation signal from the vehicle. However, in the case of a retrofittable solution, there may be no fixed signal connection between the vehicle and the communication module. In this case, the communication module is not immediately aware of when the vehicle sends out the activation signal. In order to nevertheless ensure that the communication module is ready to receive the interrogation signal and is thus activated for the signal transmission, the communication module can advantageously also receive the activation signal. The receipt of the activation signal then leads to activation for signal transmission in the communication module. The receipt of the query signal by the communication module can trigger the transmission of a response signal to the ID transmitter by the communication module in order to determine the security feature on the basis of this signal transmission. In this case, the signal transmission is bidirectional.

According to a further embodiment of the method according to the invention, it can be provided that the signal transmission is initiated by sending a signal, such as an interrogation signal, from the communication module to the identification transmitter. The sending can e.g. B. take place when the communication module receives the activation signal from the vehicle. Based on the transmitted signal, the identification transmitter can, for. B. carry out the distance determination, for example. By evaluating a signal strength of this signal. To further simplify this type of signal transmission, the signal transmission can be unidirectional if necessary (i.e. only from the communication module to the ID transmitter)

Specifically, the signal transmission can be a first signal transmission of an interrogation signal from the identification transmitter to the communication module (or vice versa) and, as a reaction to the receipt of the interrogation signal by the communication module (or the ID transmitter), a second signal transmission of a response signal from the communication module to the identification transmitter ( or vice versa). This signal exchange enables a Distance determination as the security feature. For this purpose, for example, a signal transit time and / or (also additionally) the signal strength can be measured. The ID transmitter can, for example, to determine the distance, compare a transmission time of the interrogation signal with a reception time of the response signal in order to obtain information about the distance. This makes it possible to carry out a security check by the ID transmitter, which indicates an attempt at manipulation. So it is e.g. B. in the case of a relay attack or other attacks, it is possible that the signal propagation time and thus the distance determined are increased.

It is also possible for the protection by a method according to the invention to take place in parallel to the authentication originally provided on the vehicle using a wake-up signal and authentication signal (e.g. via LF and HF radio) in order to additionally (e.g. via UWB radio) provide a security mechanism. This can make it possible to detect and avoid attempts at manipulation such as a relay attack. The method according to the invention can be provided by a security system according to the invention in the sense of a retrofit solution for the access system. The access system can originally be used without the protection, i. H. especially relay attack detection. For the retrofitting, it may be necessary that an inventive identification transmitter is used as a new ID transmitter (e.g. with UWB technology in addition to the existing LF and HF technology for authentication) in the access system Provide functionality of the protection.

• - Aussenden des Aktivierungssignals von dem Zugangssystem des Fahrzeuges, wobei vorzugsweise das Aktivierungssignal als ein Wecksignal über Funk durch das Fahrzeug ausgesendet wird,
• - Empfangen des (zuvor durch das Fahrzeug ausgesendeten) Aktivierungssignals durch das Kommunikationsmodul, um das Kommunikationsmodul für die Signalübertragung zu aktivieren, sodass vorzugsweise das Kommunikationsmodul aus einem Energiesparmodus geweckt wird,
• - Empfangen des (zuvor durch das Fahrzeug ausgesendeten) Aktivierungssignals durch den Identifikationsgeber, um den Identifikationsgeber für die Signalübertragung zu aktivieren, sodass vorzugsweise der Identifikationsgeber aus einem Energiesparmodus geweckt wird,
• - Initiieren der Signalübertragung durch den Identifikationsgeber, wenn der Identifikationsgeber für die Signalübertragung (durch den Empfang des Aktivierungssignals) aktiviert wird, wobei vorzugsweise hierzu ein Abfragesignal von dem Identifikationsgeber an das Kommunikationsmodul übertragen wird, und als Reaktion darauf das Kommunikationsmodul ein Antwortsignal an den Identifikationsgeber überträgt, um anhand dieser Übertragung das Sicherheitsmerkmal zu bestimmen.

It is also advantageous if at least one of the following steps is carried out to initiate the signal transmission:

• - Sending the activation signal from the access system of the vehicle, wherein the activation signal is preferably sent as a wake-up signal via radio by the vehicle,
• - Receipt of the activation signal (previously transmitted by the vehicle) by the communication module in order to activate the communication module for the signal transmission, so that the communication module is preferably woken up from an energy-saving mode,
• - Receipt of the activation signal (previously transmitted by the vehicle) by the identification transmitter in order to activate the identification transmitter for the signal transmission, so that the identification transmitter is preferably woken up from an energy-saving mode,
• - Initiation of the signal transmission by the identification transmitter when the identification transmitter is activated for the signal transmission (by receiving the activation signal), preferably for this purpose a query signal is transmitted from the identification transmitter to the communication module, and in response to this the communication module transmits a response signal to the identification transmitter to determine the security feature based on this transmission.

As an alternative, last step, it is also conceivable that the signal transmission is initiated by the communication module when the communication module is activated for the signal transmission, and for this purpose, if necessary, transmits the query signal to the ID transmitter. In both cases, the signal transmission can enable a distance determination to be carried out on the basis of the signal transmission. For this purpose, specific parameters of the signal transmission can be evaluated for the distance, such as a signal transit time and / or a signal strength. In this way, the security feature can be provided reliably in order to carry out the authentication with higher security.

In the context of this invention, a wake-up signal can be understood to mean that the wake-up signal initiates a “wake-up” of an ID transmitter and / or communication module, e.g. B. each by changing from an energy-saving mode to a normal (ready-to-receive) operating mode. In normal operating mode (or active mode), unlike in energy-saving mode, e.g. B. the signal transmission (between ID transmitter and communication module) and especially the reception via UWB be possible. This makes it possible to activate the signal transmission (especially via UWB), which requires higher energy consumption, only when required. Receiving the wake-up signal, however, can be, B. can be done via LF and thus energy-saving in energy-saving mode.

In a further possibility it can be provided that the identification transmitter as a retrofit identification transmitter replaces an original identification transmitter for the access system, with the access system preferably sending out the activation signal in order to initiate the authentication by the original identification transmitter (in particular directly), with the retrofitting being preferred Identifier determines the security feature as an additional function to the original identification transmitter in order to carry out the authentication only if the security feature corresponds to a predetermined feature. It may be possible that the determination of the security feature the signal transmission (between communication module and thus on the vehicle side and ID transmitter) via a A type of communication such as UWB is required, which is not provided for with the original ID transmitter. It is also possible that the vehicle does not originally support this type of communication. In order to retrofit the signal transmission between a component on the vehicle and the ID transmitter, the at least one communication module can be attached to the vehicle and used with the ID transmitter according to the invention.

It is also advantageous if the communication module functionally supplements the access system as a retrofit communication module for subsequent attachment to the vehicle (in particular as a fully assembled vehicle), with the access system preferably sending out the activation signal (preferably originally only) for the identification transmitter in order to initiate authentication by the identification transmitter (in particular directly), the retrofit communication module preferably using the activation signal as an additional function in order to provide the signal transmission in a retrofittable and / or self-sufficient manner to the access system for determining the security feature, in particular thereby determining the distance between the vehicle and provide identification transmitters as an additional function. E.g. the authentication is originally carried out by the ID transmitter without the security feature being determined and evaluated. By using the signal transmission, an additional security mechanism can be provided. To simplify retrofitting, the communication module can be designed to be self-sufficient, i. H. have no fixed signal connection to the vehicle. It is also conceivable that the respective communication module has its own energy source and is thus not only functionally designed but also self-sufficient in terms of energy supply to the vehicle. Such an energy source is, for example, a (possibly also rechargeable) battery.

• - Bestimmen eines (räumlichen) Abstands zwischen dem Identifikationsgeber und dem Kommunikationsmodul als das Sicherheitsmerkmal durch eine Abstandsermittlung anhand der Signalübertragung,

wobei vorzugsweise das Initiieren und/oder Unterdrücken der Authentifizierung dadurch in Abhängigkeit von dem Sicherheitsmerkmal erfolgt, dass ein Authentifizierungssignal zur Authentifizierung nur dann an das Fahrzeug ausgesendet wird, und andernfalls unterdrückt wird, wenn das Sicherheitsmerkmal einem vorgegebenen Merkmal entspricht, insbesondere wenn der ermittelte Abstand geringer ist als ein vordefinierter Höchstabstand, wobei dieser vordefinierte Höchstabstand dann das vorgegebene Merkmal ist. Der Höchstabstand ist bspw. derart festgelegt, dass innerhalb des Höchstabstands ein Manipulationsversuch ausgeschlossen werden kann.In addition, it is conceivable within the scope of the invention that the determination of the security feature includes the following step:

• - Determination of a (spatial) distance between the identification transmitter and the communication module as the security feature by determining the distance based on the signal transmission,

The initiation and / or suppression of the authentication is preferably carried out as a function of the security feature in that an authentication signal for authentication is only sent to the vehicle and is otherwise suppressed if the security feature corresponds to a predetermined feature, in particular if the determined distance is less is as a predefined maximum distance, this predefined maximum distance then being the specified feature. The maximum distance is determined, for example, in such a way that an attempt at manipulation can be excluded within the maximum distance.

Furthermore, it is conceivable that, on the basis of the signal transmission, a distance measurement is carried out by means of a time-of-flight analysis and / or by means of an evaluation of the signal strength during the signal transmission. This enables the distance to be reliably determined.

Furthermore, it is optionally possible within the scope of the invention for the at least one communication module to be designed as a module that can be retrofitted to the vehicle and / or a module that is self-sufficient for the vehicle, information being exchanged between the communication module and the vehicle preferably exclusively via the activation signal. In this way, subsequent installation on the vehicle can be significantly simplified. This also makes it possible to retrofit a vehicle in a simple manner with an improved safety standard.

• - Durchführen einer Authentifizierung des Kommunikationsmoduls beim Identifikationsgeber und/oder umgekehrt, welche sich von der Authentifizierung durch den Identifikationsgeber bei dem Fahrzeug unterscheidet.

Optionally, the signal transmission and / or the determination of the security feature to increase security can further include the following step:

• - Carrying out an authentication of the communication module at the identification transmitter and / or vice versa, which differs from the authentication by the identification transmitter in the vehicle.

In this way it can be ensured that the communication module is an authorized communication module. This may require that the identification transmitter has been trained in the communication module and / or vice versa, and thus can carry out the authentication on the basis of pre-stored information.

• - Automatisches Aussenden des Aktivierungssignals in der Form eines Wecksignals durch das Zugangssystem, insbesondere wenn eine Annäherung des Identifikationsgebers an das Fahrzeug (z. B. durch einen Annäherungssensor) detektiert wird,

wobei vorzugsweise durch ein Empfangen von wenigstens einem Signal über die Signalübertragung durch den Identifikationsgeber und/oder durch ein Empfangen des Wecksignals durch den Identifikationsgeber automatisch Schritt a) und/oder b) und/oder c) initiiert wird, um die Authentifizierung in Abhängigkeit von dem Sicherheitsmerkmal durchzuführen. Die Detektion der Annäherung kann bspw. mittels wenigstens eines Annäherungssensors am Fahrzeug durchgeführt werden, um bei positiver Detektion das Wecksignal auszusenden. Wenn das (wenigstens eine) Kommunikationsmodul zum Empfangen des Wecksignals ausgeführt ist, hat dies den Vorteil, dass auf eine eigenständige Annäherungsdetektion durch das Kommunikationsmodul verzichtet werden kann.It is optionally conceivable that the following step is carried out before step a) to provide the access system as a passive access system:

• - Automatic transmission of the activation signal in the form of a wake-up signal by the access system, in particular if an approach of the identification transmitter to the vehicle is detected (e.g. by a proximity sensor),

preferably by receiving at least one signal via the signal transmission by the identification transmitter and / or by receiving the wake-up signal by the Identification transmitter automatically step a) and / or b) and / or c) is initiated in order to carry out the authentication as a function of the security feature. The proximity can be detected, for example, by means of at least one proximity sensor on the vehicle in order to transmit the wake-up signal in the event of a positive detection. If the (at least one) communication module is designed to receive the wake-up signal, this has the advantage that the communication module can dispense with an independent proximity detection.

• - ein elektrisches Signal über eine elektrische Leitung vom Zugangssystem, bevorzugt eines Annäherungssensors des Fahrzeuges, und/oder
• - als ein Bussignal eines Bussystems, insbesondere CAN- (Controller Area Network) oder LIN-Bussystem (LIN steht für Local Interconnect Network), des Fahrzeuges, und/oder
• - als Funksignal, vorzugsweise LF-Funksignal, vom Zugangssystem und/oder vom Identifikationsgeber empfangen wird.

Furthermore, it can be provided that the activation signal as a

• - An electrical signal via an electrical line from the access system, preferably a proximity sensor of the vehicle, and / or
• - As a bus signal of a bus system, in particular CAN (Controller Area Network) or LIN bus system (LIN stands for Local Interconnect Network), of the vehicle, and / or
• - Is received as a radio signal, preferably LF radio signal, from the access system and / or from the identification transmitter.

When the electrical line is used to receive the activation signal, the assembly effort may be increased, but in favor of a reliable signal connection. In particular, the LIN bus system can be used to advantage if the communication module is installed in the door handle. It can also be possible that different types of transmission paths (such as via wire or radio) are provided for the activation signal for different communication modules at different positions in the vehicle. Furthermore, the activation signal can always be transmitted to the ID transmitter by radio.

It can be provided within the scope of the invention that the signal transmission is carried out as a cryptographically secured and / or encrypted data transmission. An RSA cryptosystem can offer particularly reliable protection against manipulation. B. is used to encrypt and / or sign the data transmitted by means of the signal transmission.

In addition, it is conceivable within the scope of the invention that the at least one communication module comprises several communication modules, all of the communication modules each receiving the activation signal and, in particular, initiating the signal transmission or being activated for signal transmission, in particular for receiving an interrogation signal, when the activation signal is received, wherein the activation signal is preferably designed as a radio signal which is identical to a wake-up signal for the identification transmitter and is sent out by the vehicle to the identification transmitter to initiate authentication. It is possible here for the communication module to change from an energy-saving mode to a ready-to-receive mode when the respective communication module receives the activation signal. This change can possibly be limited in time so that the readiness to receive is terminated after a predetermined period of time. The readiness to receive can z. B. provided by activating a communication unit such as a UWB radio interface. In the energy-saving mode, this communication unit can be deactivated in order to reduce energy consumption. In contrast, in the ready-to-receive mode, the communication unit can be activated in order to receive and / or transmit an interrogation signal, and thus the signal transmission via z. B. to provide UWB with the ID transmitter.

• - Initiieren der Authentifizierung durch ein Aussenden eines Authentifizierungssignals über eine erste Kommunikationsschnittstelle, insbesondere wenn der Höchstabstand durch den gemessenen Abstand unterschritten wird,
• - Unterdrücken des Aussendens des Authentifizierungssignals zur Authentifizierung, insbesondere wenn der Höchstabstand durch den gemessenen Abstand überschritten wird.

Advantageously, it can be provided within the scope of the invention that the identification transmitter performs one of the following actions as a function of the security feature, in particular a comparison with a maximum distance in a distance measurement:

• - Initiation of the authentication by sending out an authentication signal via a first communication interface, in particular if the maximum distance is not reached by the measured distance,
• - Suppression of the transmission of the authentication signal for authentication, in particular if the maximum distance is exceeded by the measured distance.

In this way - based on the comparison with the maximum distance - a manipulation attempt and thus z. B. a relay station attack can be detected. As ways of suppressing the transmission of the authentication signal, for. B. signal transmission to the vehicle can be completely suspended or possibly another signal (such as a modified authentication signal) can be transmitted to the access system, which the possible manipulation attempt (such as the possible relay station attack) z. B. notifies based on a flag of the transmitted telegram.

It is also conceivable within the scope of the invention that the signal transmission is implemented as a contactless short-range signal transmission, preferably data transmission, preferably as UWB (ie ultra broadband) communication. This is the signal transmission between the ID transmitter and communication module, which on this way, it can be made particularly tamper-proof. The communication for the transmission of the activation signal or wake-up signal, on the other hand, can be implemented as LF communication and thus be provided in a particularly energy-saving manner. The communication for the transmission of the authentication signal is z. B. RF communication.

• - wenigstens eine erste (insbesondere elektronische) Kommunikationsschnittstelle zur Kommunikation mit wenigstens einer (insbesondere elektronischen) Authentifizierungsschnittstelle des Zugangssystems, um die Authentifizierung des Identifikationsgebers bei dem Zugangssystem durchzuführen, und eine Aktivierung einer sicherheitsrelevanten Fahrzeugfunktion in Abhängigkeit von der Authentifizierung zu initiieren,
• - eine zweite (insbesondere elektronische) Kommunikationsschnittstelle zur Kommunikation mit wenigstens einem Kommunikationsmodul am Fahrzeug, um eine Signalübertragung zwischen dem Kommunikationsmodul und dem Identifikationsgeber bereitzustellen, und anhand der Signalübertragung ein Sicherheitsmerkmal zur Absicherung der Authentifizierung bereitzustellen.

The invention also relates to an identification transmitter (in the form of an electronic key) for authentication in an access system of a vehicle (particularly mobile and therefore portable with regard to the vehicle). It is provided that the identification transmitter has the following components:

• - At least one first (in particular electronic) communication interface for communication with at least one (in particular electronic) authentication interface of the access system in order to carry out the authentication of the identification transmitter in the access system, and to initiate activation of a security-relevant vehicle function as a function of the authentication,
• - A second (in particular electronic) communication interface for communication with at least one communication module on the vehicle in order to provide a signal transmission between the communication module and the identification transmitter, and to provide a security feature for securing the authentication based on the signal transmission.

The identification transmitter according to the invention thus has the same advantages as have been described in detail with reference to a method according to the invention. In addition, the identification transmitter can be suitable to be operated by a method according to the invention. Preferably, it can also be provided that an identification transmitter according to the invention is designed to carry out the signal transmission according to a method according to the invention. The safety-relevant vehicle function is z. B. unlocking the vehicle and / or enabling an engine start and / or opening a flap of the vehicle (such as a front or tailgate). The protection relates in particular to the detection of a manipulation attempt during authentication, such as a relay station attack. The respective communication interface is designed, for example, as at least one radio interface. It can also be possible for the identification transmitter to have an energy source in order to operate the components mentioned. The first communication interface can differ from the second communication interface with regard to the (at least one used) communication technology. Operation of the first communication interface preferably requires less energy consumption than operation of the second communication interface.

According to a further advantage, it can be provided that the identification transmitter has an evaluation component (such as a microcontroller) in order to determine the distance to the communication module based on the signal transmission, and preferably to determine the security feature based on a comparison of the determined distance with a maximum limit, and / or in To carry out the authentication of the identification transmitter in the access system as a function of the security feature. It is thus conceivable that the first communication interface for authentication is only activated when the security feature corresponds to a specification (for example, the distance falls below a predefined maximum distance).

It can be advantageous if, within the scope of the invention, the identification transmitter is designed as a retrofit component to replace an original identification transmitter of the access system, the identification transmitter preferably having an adaptation interface for this purpose in order to be adapted and / or programmed to the access system. E.g. It is necessary for the identification transmitter to be able to transmit predetermined codes for authentication to the access system, which codes can be stored in the identification transmitter as part of the adaptation or programming. The adaptation interface is, for example, a radio or cable interface, preferably a Bluetooth or NFC interface.

Optionally, it can be provided that the identification transmitter has an identification feature for the at least one communication module in order to authenticate itself in addition to authentication with the access system of the vehicle via the signal transmission in the communication module, and / or that the at least one communication module has an identification feature for the identification transmitter in order to authenticate itself with the identification transmitter, wherein the identification transmitter preferably has at least one further identification feature (such as a code) for authentication with the access system. Since it can be a retrofit system, it makes sense to check the authorization of the ID transmitter or the communication module to carry out the signal transmission to provide the security feature in this way.

In addition, it can be advantageous within the scope of the invention that the Identification transmitter has an LF (low frequency) and an HF (high frequency) interface as the at least one first communication interface, and / or has a UWB (ultra broadband) interface as the second communication interface, preferably the LF interface for receiving an activation signal from the access system and / or the HF interface for sending an authentication signal to the access system and / or the UWB interface for sending and / or receiving signals via the signal transmission to secure the authentication. In this way, the authentication can be provided through the first communication interface and the securing of the authentication can be provided using the second communication interface. The first communication interface is preferably used for communication with the vehicle and the second communication interface (preferably exclusively) for communication with the communication module.

• - wenigstens ein Kommunikationsmodul, vorzugsweise mindestens drei Kommunikationsmodule, jeweils zur Anordnung am Fahrzeug,
• - wenigstens eine Kommunikationseinheit des jeweiligen Kommunikationsmoduls zur Bereitstellung einer Signalübertragung zu dem mobilen Identifikationsgeber,
• - wenigstens eine Aktivierungseinheit des jeweiligen Kommunikationsmoduls zum Empfang eines Aktivierungssignals,

wobei vorzugsweise die Kommunikationseinheit dazu ausgeführt ist, in Abhängigkeit vom Empfang des Aktivierungssignals die Signalübertragung bereitzustellen, um anhand der Signalübertragung ein Sicherheitsmerkmal zur Absicherung der Authentifizierung bereitzustellen. Bspw. ist hierzu die Kommunikationseinheit mit einer Elektronik (wie einer elektronischen Schaltanordnung und/oder einen integrierten Schaltkreis) des Kommunikationsmoduls verschaltet, wobei die Elektronik bei Empfang des Aktivierungssignals die Kommunikationseinheit in einen empfangsbereiten Zustand überführt und damit aktiviert. Ansonsten kann die Kommunikationseinheit ggf. deaktiviert und/oder in einem energiesparsamen Modus überführt sein. Die Aktivierung der Kommunikationseinheit kann den Empfang von Signalen von dem Identifikationsgeber ermöglichen, damit die Signalübertragung bereitstellen und somit die Bestimmung des Sicherheitsmerkmals durch den Identifikationsgeber ermöglichen. Vorteilhafterweise weist die Kommunikationseinheit hierzu eine UWB-Funkschnittstelle auf.The invention also relates to a security system, in particular in the form of a retrofit system, for an access system of a vehicle in order to secure an authentication of a mobile identification transmitter in the vehicle, comprising:

• - At least one communication module, preferably at least three communication modules, each for arrangement on the vehicle,
• - At least one communication unit of the respective communication module for providing signal transmission to the mobile identification transmitter,
• - At least one activation unit of the respective communication module for receiving an activation signal,

wherein the communication unit is preferably designed to provide the signal transmission as a function of the receipt of the activation signal in order to provide a security feature for securing the authentication on the basis of the signal transmission. E.g. For this purpose, the communication unit is connected to electronics (such as an electronic circuit arrangement and / or an integrated circuit) of the communication module, the electronics transferring the communication unit to a ready-to-receive state and thus activating it upon receipt of the activation signal. Otherwise, the communication unit can, if necessary, be deactivated and / or switched to an energy-saving mode. Activation of the communication unit can enable signals to be received from the identification transmitter, thus providing the signal transmission and thus enabling the identification transmitter to determine the security feature. For this purpose, the communication unit advantageously has a UWB radio interface.

It can advantageously be provided within the scope of the invention that the access system is designed as a passive access system. Furthermore, it can be possible that the security system can be operated according to a method according to the invention and / or has the identification transmitter, which is designed as an identification transmitter according to the invention. The security system according to the invention thus has the same advantages as have been described in detail with reference to a method according to the invention and / or an ID transmitter according to the invention.

In the security system according to the invention, it is advantageously possible for the communication unit to be designed to provide the signal transmission by changing from an energy-saving mode to a ready-to-receive mode when the activation signal is received, in order to receive an interrogation signal from the identification transmitter, and a response signal to this to send out the identification transmitter in order to provide the security feature for securing the authentication (in particular by the identification transmitter) on the basis of this signal transmission.

According to a further possibility, it can be provided that the security system is designed as a retrofit system for the vehicle in order to subsequently provide the security feature for the access system, the at least one communication module preferably being designed to be subsequently and / or individually manageable on the vehicle to be installed and operated independently of the access system. E.g. For assembly and retrofitting, the respective communication module can only be connected to the vehicle mechanically and therefore not electrically. To provide the security feature, the ID transmitter can also be part of the security system if necessary.

It may also be possible that the respective communication module is designed for short-range radio communication in order to provide the signal transmission only in a close-up area of the vehicle, in particular only when the identification transmitter is a maximum of 2 m or a maximum of 4 m or a maximum of 6 m or a maximum of 10 m from the communication module and / or is removed from the vehicle and / or has a clear line of sight to the communication module. Alternatively or additionally, it is possible that the maximum distance in a distance determination (distance measurement) for a determination of the security feature is a maximum of 2 m or a maximum of 4 m or a maximum of 6 m or a maximum of 10 m.

According to a further advantage, it can be provided that the respective communication module is designed as an ultra-broadband communication module for ultra-broadband communication in order to provide the signal transmission via ultra-broadband radio. This enables a particularly safe and reliable determination of the security feature, e.g. B. by determining the distance.

Furthermore, it can be provided within the scope of the invention that the respective communication module, in particular via the respective communication unit, is designed to provide the signal transmission in such a way that the security feature is designed as information about a distance and / or a line of sight between the respective communication module and the identification transmitter , preferably in that upon receipt of an interrogation signal via the communication unit (by the communication module) from the identification transmitter, a response signal (by the communication module) can be transmitted via the communication unit (to the identification transmitter). In other words, the signal transmission can be used as bidirectional communication in order to determine the security feature in the identification transmitter.

Furthermore, it is conceivable that the at least one communication module is arranged in an area of the vehicle immediately adjacent to the surroundings of the vehicle in order to provide a line of sight between the communication module and the identification transmitter (especially during authentication) for signal transmission. In this way, attempts at manipulation can be detected very reliably through the use of the security feature.

It is also advantageous if the at least one communication module is arranged in an area of the vehicle adjacent to the surroundings of the vehicle in order to provide the signal transmission via radio communication (especially during authentication), with the radio communication preferably being a direct, obstacle-free radio transmission path between the communication module and requires the identification transmitter. This ensures that signal transmission is only possible via a line of sight.

According to a further possibility it can be provided that the at least one communication module comprises at least or exactly three communication modules for different positions on the vehicle in order to provide a distance measurement based on the different positions via the signal transmission, preferably via triangulation. This increases the reliability for establishing communication with the ID transmitter, even for different positions of the ID transmitter.

• - an einem Stoßfänger,
• - an einem Türgriff,
• - an einem Türschweller,
• - an einem Annäherungs- und/oder optischen Sensor,
• - an einer Antenne,
• - an einem Fenster,
• - an einem Dach, vorzugsweise einer Dachreling,
• - an einem Außenspiegel,
• - an einem Scheinwerfer,
• - an einer B-Säule,
• - an einem Rücklicht.

For example, it can be provided that the vehicle is part of the security system, the at least one communication module having at least or exactly three communication modules which are arranged in different of the following positions on the vehicle:

• - on a bumper,
• - on a door handle,
• - on a door sill,
• - on a proximity and / or optical sensor,
• - on an antenna,
• - at a window,
• - on a roof, preferably a roof rail,
• - on an outside mirror,
• - on a headlight,
• - on a B-pillar,
• - on a taillight.

This enables a particularly space-saving arrangement and in particular ensures a line of sight to the ID transmitter.

• 1 eine schematische Seitenansicht eines Fahrzeuges mit einem erfindungsgemäßen Sicherheitssystem,
• 2 eine schematische Draufsicht auf ein Fahrzeug mit einem erfindungsgemäßen Sicherheitssystem,
• 3 eine weitere schematische Draufsicht auf ein Fahrzeug mit einem erfindungsgemäßen Sicherheitssystem,
• 4 eine schematische Darstellung von Verfahrensschritten eines erfindungsgemäßen Verfahrens.

Further advantages, features and details of the invention emerge from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination. Show it:

• 1 a schematic side view of a vehicle with a security system according to the invention,
• 2 a schematic top view of a vehicle with a security system according to the invention,
• 3 a further schematic plan view of a vehicle with a security system according to the invention,
• 4th a schematic representation of process steps of a process according to the invention.

In the following figures, the same reference numerals are used for the same technical features from different exemplary embodiments.

In the 1 to 3 is one vehicle each 1 with a security system according to the invention 100 shown. A security system designed in this way 100 is particularly suitable as a retrofit system to add an additional safety mechanism to the vehicle 1 provide. This security mechanism is used for an access system 2 of the vehicle 1 an authentication of a mobile identification transmitter 200 at the vehicle 1 secure. The security system 100 at least one communication module 110 have which (each) on the vehicle 1 is arranged. In 2 is an example of a first communication module 110a and a second communication module 110b on a roof rail 1.7 , and a third communication module 110c in the front of the vehicle 1 arranged.

There is also at least one communication unit 110.1 of the respective communication module 110 to provide a signal transmission D to the mobile identification transmitter 200 intended. As in 1 is shown, the signal transmission D can be a transmission of an interrogation signal D.1 from the identification transmitter 200 to the communication module 110 (or to the communication unit 110.1 ) and in response to this a transmission of a response signal D.2 from the communication module 110 (or from the communication unit 110.1 ) to the ID transmitter 200 include. Alternative configurations of the signal transmission D such as unidirectional data transmission are conceivable, especially if z. B. a time-of-flight analysis is dispensed with. The signal transmission D is preferably a UWB transmission.

In order to enable the signal transmission D, the communication unit must be activated 110.1 required. For this purpose, there is at least one activation unit 110.2 of the respective communication module 110 provided for receiving an activation signal S.1. The activation signal S.1 can be used in the same way to activate the identification transmitter 200 serve when the ID transmitter 200 a first communication interface 210 to receive the activation signal S.1. It can also have a further first communication interface 210 of the ID transmitter 200 be provided by the transmission of an authentication signal S.2 to the vehicle 1 authentication on the vehicle 1 perform.

The communication unit 110.1 can be designed to provide the signal transmission D as a function of the receipt of the activation signal S.1 in order to provide a security feature M for securing the authentication on the basis of the signal transmission D. The communication unit is for this purpose 110.1 For example, designed to provide the signal transmission D upon receipt of the activation signal S.1 by changing from an energy-saving mode to a ready-to-receive mode in order to receive the interrogation signal D.1 from the identification transmitter 200 to receive, and in response to this, the response signal D.2 to the identification transmitter 200 sent out in order to provide the security feature M for securing the authentication on the basis of this signal transmission D. This is done, for example, by the communication module 110 when the activation signal S.1 is received via the activation unit 110.2 initiates the change from the energy-saving mode to the ready-to-receive mode. Only in the ready-to-receive mode is z. B. UWB communication with the ID transmitter 200 possible.

The ID transmitter 200 can for authentication with the access system 2 of the vehicle 1 be formed, and for this purpose the at least one first communication interface 210 for communication with at least one authentication interface 300 of the access system 2 have to authenticate the identifier 200 at the access system 2 perform, and to initiate activation of a security-relevant vehicle function depending on the authentication. In addition, a second communication interface 220 for communication with the at least one communication module 110 at the vehicle 1 be provided to the signal transmission D between the communication module 110 and the ID transmitter 200 provide, and using the signal transmission D to provide the security feature M to secure the authentication. Furthermore, the identification transmitter 200 an evaluation component 240 have to use the signal transmission D to determine the distance to the communication module 110 perform, and based on a comparison of the determined distance with a maximum limit to determine the security feature, and depending on the security feature, the authentication of the identification transmitter 200 at the access system 2 perform.

The ID transmitter 200 is designed in particular as a retrofit component to an original identification transmitter of the access system 2 to replace, the identification transmitter 200 an adaptation interface for this purpose 230 has to connect to the access system 2 to be customized and / or programmed.

The ID transmitter 200 can be used as the at least one first communication interface 210 have an LF and an HF interface, and as the second communication interface 210 have a UWB interface (i.e. ultra broadband interface).

As in 2 is shown, the respective communication module 110 be designed to provide the signal transmission D such that the security feature M as information about a distance A and a line of sight of the respective communication module 110 to the identification transmitter 200 is executed. So is in 3 an obstacle 400 shown, which prevents the line of sight and thus the signal transmission D. In such a case, authentication is required by the identification transmitter 200 suppressed.

As in the 1 to 3 is shown, the at least one communication module 110 each on one area of the vehicle 1 directly adjacent to the surroundings of the vehicle 1 be arranged to have a line of sight of the communication module during the authentication for the signal transmission D 110 to the identification transmitter 200 provide. This is at least one communication module 110 each on one area of the vehicle 1 adjacent to the surroundings of the vehicle 1 arranged to provide the signal transmission D via a radio communication during the authentication, the radio communication being a direct, obstacle-free radio transmission path between the communication module 110 and the ID transmitter 200 presupposes.

Corresponding 1 to 3 are possible locations of the vehicle 1 for the at least one communication module 110 a bumper 1.12 , a door handle 1.1 , a door sill 1.2 , a proximity and / or optical sensor 1.3 , an antenna 1.4 , a window 1.5 , a roof 1.6 , preferably a roof rail 1.7 , an outside mirror 1.8 , a headlight 1.9 , a B-pillar 1.11 and a taillight 1.10 . The proximity sensor 1.3 can e.g. B. be designed as an optical sensor, and if an approach is detected, possibly cause the activation signal S.1 to be transmitted. Another possible arrangement of a proximity sensor 1.3 is z. B. in a door handle 1.1 or a bumper 1.12 . The proximity sensor 1.3 can optionally also be designed as a capacitive sensor.

It is also possible that the at least one communication module 110 in each case the activation signal S.1 as an electrical signal via an electrical line 330 from the access system 2 , preferably a proximity sensor 310 of the vehicle 1 , and / or as a bus signal of a bus system 320 , in particular the CAN or LIN bus system of the vehicle 1 , and / or as a radio signal, preferably an LF radio signal, from the access system 2 and / or from the ID transmitter 200 Will be received.

• - Aussenden des Aktivierungssignals S.1 von dem Zugangssystem 2 des Fahrzeuges 1, wobei das Aktivierungssignal S.1 als ein Wecksignal S.1 über Funk durch das Fahrzeug 1 ausgesendet wird,
• - Empfangen des Aktivierungssignals S.1 durch das Kommunikationsmodul 110, um das Kommunikationsmodul 110 für die Signalübertragung D zu aktivieren, sodass vorzugsweise das Kommunikationsmodul 110 aus einem Energiesparmodus geweckt wird,
• - Empfangen des Aktivierungssignals S.1 durch den Identifikationsgeber 200, um den Identifikationsgeber 200 für die Signalübertragung D zu aktivieren, sodass vorzugsweise der Identifikationsgeber 200 aus einem Energiesparmodus geweckt wird,
• - Initiieren der Signalübertragung D durch den Identifikationsgeber 200, wenn der Identifikationsgeber 200 für die Signalübertragung D aktiviert wird, wobei hierzu ein Abfragesignal D.1 von dem Identifikationsgeber 200 an das Kommunikationsmodul 110 übertragen wird, und als Reaktion darauf das Kommunikationsmodul 110 ein Antwortsignal D.2 an den Identifikationsgeber 200 überträgt, um anhand dieser Übertragung das Sicherheitsmerkmal M zu bestimmen.

In 4th is a method according to the invention for securing an authentication of a mobile identification transmitter 200 with an access system 2 of a vehicle 1 visualized schematically. According to a first process step 500a a signal transmission D is initiated between at least one communication module 110 at the vehicle 1 and the ID transmitter 200 . This is followed by a second process step 500b a determination of a security feature M by the identification transmitter 200 using the signal transmission D. Furthermore, according to a third method step 500c an initiation and / or suppression of the authentication by the identification transmitter 200 carried out depending on the security feature. It is possible that for the first process step 500a , so the initiation of the signal transmission D, the following steps are carried out, as well as based 1 is visualized:

• - Sending the activation signal S.1 from the access system 2 of the vehicle 1 , the activation signal S.1 as a wake-up signal S.1 via radio by the vehicle 1 is sent out,
• - Receipt of the activation signal S.1 by the communication module 110 to the communication module 110 to activate the signal transmission D, so that preferably the communication module 110 is awakened from an energy-saving mode,
• - Receipt of the activation signal S.1 by the identification transmitter 200 to the ID transmitter 200 to activate the signal transmission D, so that preferably the identification transmitter 200 is awakened from an energy-saving mode,
• - Initiation of the signal transmission D by the identification transmitter 200 if the ID transmitter 200 for signal transmission D is activated, for this purpose a query signal D.1 from the identification transmitter 200 to the communication module 110 is transmitted, and in response the communication module 110 a response signal D.2 to the identification transmitter 200 transmits in order to determine the security feature M on the basis of this transmission.

The security feature M is determined, for example, by determining a distance A between the identification transmitter 200 and the communication module 110 (as the security feature M) by determining the distance using the signal transmission D. In 2 is a first communication module for the visualization of this distance determination 110a shown. The initiation and / or suppression of the authentication can then take place as a function of the security feature M in that an authentication signal S.2 for authentication is only sent from the ID transmitter to the vehicle 1 is sent out when the security feature M corresponds to a predetermined feature, in particular when the determined distance A is less than a predefined maximum distance than the predetermined feature.

The above explanation of the embodiments describes the present invention exclusively in the context of examples. Of course, individual features of the embodiments can be freely combined with one another, provided that they are technically sensible, without departing from the scope of the present invention.

List of reference symbols

1

vehicle

1.1

Door handle

1.10

Taillight

1.11

B-pillar

1.12

Bumper

1.2

Door sill

1.3

sensor

1.4

antenna

1.5

window

1.6

top, roof

1.7

Roof rails

1.8

Exterior mirrors

1.9

Headlights

2

Access system

100

security system

110

Communication module

110.1

Communication unit

110.2

Activation unit

110a

first communication module

110b

second communication module

110c

third communication module

200

ID transmitter

210

first communication interface

220

second communication interface

230

Customization interface

240

Evaluation component

300

Authentication interface

310

Proximity sensor

320

Bus system

330

management

400

obstacle

500a

first procedural step

500b

second process step

500c

third process step

A.

distance

D.

Signal transmission

D.1

Query signal

D.2

Response signal

M.

Security feature

P.1

Activation signal, alarm signal

P.2

Authentication signal

Claims (30)

Method for securing authentication of a mobile identification transmitter (200) in an access system (2) of a vehicle (1), preferably for detecting a relay attack, the following steps being carried out: a) initiating a signal transmission (D) between at least one communication module (110) on the vehicle (1) and the identification transmitter (200) as a function of an activation signal (S.1), b) Determination of a security feature (M) by the identification transmitter (200) on the basis of the signal transmission (D), c) suppressing the authentication by the identification transmitter (200) as a function of the security feature (M). Method according to the preceding claim, characterized in that the following steps are carried out to initiate the signal transmission (D): - Sending the activation signal (S.1) from the access system (2) of the vehicle (1), wherein preferably the activation signal (S .1) is sent as a wake-up signal (S.1) by radio by the vehicle (1), - Receipt of the activation signal (S.1) by the communication module (110) in order to enable the communication module (110) for the signal transmission (D) to activate, so that the communication module (110) is preferably woken up from an energy-saving mode, - Receipt of the activation signal (S.1) by the identification transmitter (200) in order to activate the identification transmitter (200) for the signal transmission (D), so that preferably the Identification transmitter (200) is awakened from an energy-saving mode, initiation of the signal transmission (D) by the identification transmitter (200) when the identification transmitter (200) for the Signa transmission (D) is activated, for this purpose a query signal (D.1) from the identification transmitter (200) to the communication module (110) is transmitted, and in response to this, the communication module (110) transmits a response signal (D.2) to the identification transmitter (200) in order to determine the security feature (M) on the basis of this transmission. Method according to one of the preceding claims, characterized in that the identification transmitter (200) as a retrofit identification transmitter replaces an original identification transmitter for the access system (2), the access system (2) sending out the activation signal (S.1) for authentication initiated by the original identification transmitter, the retrofit identification transmitter determining the security feature (M) as an additional function to the original identification transmitter in order to carry out the authentication only if the security feature (M) corresponds to a predetermined feature. Method according to one of the preceding claims, characterized in that the communication module (110) functionally supplements the access system (2) as a retrofit communication module for retrofitting to the vehicle (1), the access system (2) sending the activation signal (S.1 ) for the identification transmitter (200) to initiate the authentication by the identification transmitter, the retrofit communication module using the activation signal (S.1) as an additional function in order to be retrofittable and / or self-sufficient to the access system (2) for the determination of the security feature (M) to provide the signal transmission (D), in particular thereby to provide a distance determination between the vehicle (1) and the identification transmitter (200) as an additional function. Method according to one of the preceding claims, characterized in that the determination of the security feature (M) comprises the following step: - determining a distance (A) between the identification transmitter (200) and the communication module (110) as the security feature (M) by a Distance determination on the basis of the signal transmission (D), the suppression and / or initiation of the authentication taking place as a function of the security feature (M) in that an authentication signal (S.2) for authentication is only sent to the vehicle (1), if the security feature (M) corresponds to a predetermined feature, in particular if the determined distance (A) is less than a predefined maximum distance. Method according to one of the preceding claims, characterized in that a distance measurement is carried out using the signal transmission (D) by means of a time-of-flight analysis and / or by means of an evaluation of the signal strength during the signal transmission (D). Method according to one of the preceding claims, characterized in that the at least one communication module (110) is designed as a module that can be retrofitted to the vehicle (1) and / or a module that is self-sufficient for the vehicle (1), with preferably an exchange of information between the communication module (110) and the vehicle (1) takes place exclusively via the activation signal (S.1). Method according to one of the preceding claims, characterized in that the following step is carried out in order to provide the access system (2) as a passive access system before step a): Automatic transmission of the activation signal (S.1) in the form of a wake-up signal by the access system (2), in particular when an approach of the identification transmitter (200) to the vehicle (1) is detected, preferably by receiving signals via the signal transmission (D) by the identification transmitter (200) and / or by receiving the wake-up signal ( S.1) step a) and / or b) and / or c) is automatically initiated by the identification transmitter (200) in order to carry out the authentication as a function of the security feature (M). Method according to one of the preceding claims, characterized in that the at least one communication module (110) in each case sends the activation signal (S.1) as - an electrical signal via an electrical line (330) from the access system (2), preferably a proximity sensor (310 ) of the vehicle (1), and / or - as a bus signal of a bus system (320), in particular a CAN or LIN bus system, of the vehicle (1), and / or - as a radio signal, preferably LF radio signal, from the access system (2 ) and / or is received by the identification transmitter (200). Method according to one of the preceding claims, characterized in that the signal transmission (D) is carried out as a cryptographically secured and / or encrypted data transmission (D). Method according to one of the preceding claims, characterized in that the at least one communication module (110) comprises several communication modules (110), all of the communication modules (110) each receiving the activation signal (S.1) and upon receipt of the activation signal (S. 1) each initiate the signal transmission (D) or to Signal transmission (D), in particular to receive an interrogation signal (D.1), can be activated, the activation signal (S.1) preferably being designed as a radio signal which is identical to a wake-up signal (S.1) for the identification transmitter (200 ), and is sent out by the vehicle (1) to initiate the authentication to the identification transmitter (200). Method according to one of the preceding claims, characterized in that the identification transmitter (200) performs one of the following actions as a function of the security feature (M), in particular a comparison with a maximum distance in a distance measurement: initiation of the authentication by sending out a Authentication signal (S.2) via a first communication interface (210), in particular if the maximum distance is not reached by the measured distance (A), suppression of the transmission of the authentication signal (S.2) for authentication, in particular if the maximum distance is exceeded by the measured distance (A) is exceeded. Method according to one of the preceding claims, characterized in that the signal transmission (D) is implemented as a contactless short-range signal transmission, preferably data transmission, preferably as UWB communication. Identification transmitter (200) for authentication in an access system (2) of a vehicle (1), comprising: - At least one first communication interface (210) for communication with at least one authentication interface (300) of the access system (2) in order to carry out the authentication of the identification transmitter (200) in the access system (2), and activation of a safety-relevant vehicle function as a function of the authentication to initiate, - A second communication interface (220) for communication with at least one communication module (110) on the vehicle (1) in order to provide a signal transmission (D) between the communication module (110) and the identification transmitter (200), and based on the signal transmission (D) Provide security feature (M) to secure the authentication. Identification transmitter (200) according to one of the preceding claims, characterized in that the identification transmitter (200) has an evaluation component (240) in order to determine the distance to the communication module (110) based on the signal transmission (D), preferably a time-of-flight analysis and to determine the security feature based on a comparison of the determined distance with a maximum limit, and to authenticate the identification transmitter (200) in the access system (2) as a function of the security feature. Identification transmitter (200) according to one of the preceding claims, characterized in that the identification transmitter (200) is designed as a retrofit component to replace an original identification transmitter of the access system (2), the identification transmitter (200) preferably having an adaptation interface (230) for this purpose , to be adapted to the access system (2) and / or programmed. Identification transmitter (200) according to one of the preceding claims, characterized in that the identification transmitter (200) has an LF and an HF interface as the at least one first communication interface (210), and a UWB interface as the second communication interface (210) has, wherein the LF interface for receiving an activation signal (S.1) from the access system (2) and the HF interface for sending an authentication signal (S.2) to the access system (2) and the UWB interface for sending and / or receiving signals via the signal transmission (D) is designed to secure the authentication. Identification transmitter (200) according to one of the preceding claims, characterized in that the identification transmitter (200) is designed to carry out the signal transmission according to a method according to one of the preceding claims. Security system (100), in particular in the form of a retrofit system, for an access system (2) of a vehicle (1) in order to secure authentication of a mobile identification transmitter (200) in the vehicle (1), comprising: - At least one communication module (110), preferably at least three communication modules (110), for arrangement on the vehicle (1), - At least one communication unit (110.1) of the respective communication module (110) for providing a signal transmission (D) to the mobile identification transmitter (200), - At least one activation unit (110.2) of the respective communication module (110) for receiving an activation signal (S.1), the communication unit (110.1) being designed to provide the signal transmission (D) as a function of the receipt of the activation signal (S.1) in order to provide a security feature (M) to secure the authentication based on the signal transmission (D). Security system (100) according to one of the preceding claims, characterized in that the communication unit (110.1) is designed to provide the signal transmission (D) by changing from an energy-saving mode to a ready-to-receive mode upon receipt of the activation signal (S.1) in order to to receive an interrogation signal (D.1) from the identification transmitter (200), and in response to this, a response signal (D.2) to be sent to the identification transmitter (200) in order to use this signal transmission (D) to use the security feature (M) to protect the Provide authentication. Security system (100) according to one of the preceding claims, characterized in that the security system (100) is designed as a retrofit system for the vehicle (1) in order to subsequently provide the security feature (M) for the access system (2) the at least one communication module (110) is designed to be mounted subsequently and / or individually manageable on the vehicle and to be operated independently of the access system (2). Security system (100) according to one of the preceding claims, characterized in that the respective communication module (110) is designed for short-range radio communication in order to provide the signal transmission (D) only in a close-up area of the vehicle (1), in particular only when the identification transmitter ( 200) is a maximum of 2 m or a maximum of 4 m or a maximum of 6 m or a maximum of 10 m from the communication module (110) and / or has a clear line of sight to the communication module (110). Security system (100) according to one of the preceding claims, characterized in that the respective communication module (110) is designed as an ultra-broadband communication module (110) for ultra-broadband communication in order to provide the signal transmission (D) via ultra-broadband radio. Security system (100) according to one of the preceding claims, characterized in that the respective communication module (110), in particular via the respective communication unit (110.1), is designed to provide the signal transmission (D) in such a way that the security feature (M) as a Information about a distance (A) and / or a line of sight between the respective communication module (110) and the identification transmitter (200) is carried out, preferably in that upon receipt of a query signal (D.1) via the communication unit (110.1) from the identification transmitter (200 ) a response signal (D.2) can be transmitted via the communication unit (110.1). Safety system (100) according to one of the preceding claims, characterized in that the at least one communication module (110) is arranged in each case on an area of the vehicle (1) immediately adjacent to the surroundings of the vehicle (1) in order to provide a Provide line of sight between the communication module (110) and the identification transmitter (200). Safety system (100) according to one of the preceding claims, characterized in that the at least one communication module (110) is arranged in each case on an area of the vehicle (1) adjacent to the surroundings of the vehicle (1) in order to enable the signal transmission (D) via radio communication to provide, wherein the radio communication requires a direct, obstacle-free radio transmission path between the communication module (110) and the identification transmitter (200). Safety system (100) according to one of the preceding claims, characterized in that the at least one communication module (110) comprises at least or exactly three communication modules (110a, 110b, 110c) for different positions on the vehicle (1) in order to use the different positions to find out about the Signal transmission (D) to provide a distance measurement, preferably via triangulation. Security system (100) according to one of the preceding claims, characterized in that the security system (100) has the vehicle (1), the at least one communication module (110) having at least or exactly three communication modules (110a, 110b, 110c) which are connected to different of the following positions are arranged on the vehicle (1): - on a bumper (1.12), - on a door handle (1.1), - on a door sill (1.2), - on a proximity and / or optical sensor (1.3), - on an antenna (1.4), - on a window (1.5), - on a roof (1.6), preferably a roof rail (1.7), - on an outside mirror (1.8), - on a headlight (1.9), - on a B-pillar (1.11), - on a rear light (1.10). Security system (100) according to one of the preceding claims, characterized in that the access system is designed as a passive access system. Security system (100) according to one of the preceding claims, characterized in that the security system (100) can be operated according to a method according to one of the preceding claims and / or has the identification transmitter (200) which is designed as an identification transmitter according to one of the preceding claims .

Images