Authentication system for authenticating a key with respect to the vehicle, and associated method
Patent Information
- Application Number
- EP2023751626
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-09-22
- Filing Date
- 2023-08-02
- Publication Date
- 2025-01-22
AI Technical Summary
Existing keyless entry systems, particularly those using ultra-wideband (UWB) and Bluetooth Low Energy (BLE) communication, require a significant amount of energy, making it impractical to integrate an ID transmitter into a conventional key or smart fob without frequent charging or replacement.
The authentication system employs a key with a first UWB transceiver for UWB communication and a first BLE transceiver designed as an advertiser, minimizing energy consumption by optimizing UWB frames and using time-offset communication to reduce simultaneous processing of UWB and BLE signals, allowing for extended battery life without the need for frequent charging.
This approach enables energy-efficient authentication, extending the battery life of the key and preventing relay station attacks by determining the key's distance from the vehicle using time-of-flight methods, ensuring secure and reliable vehicle function release.
Smart Images
Figure 1.1
Abstract
Description
[0001] Authentication system for authenticating a key to the vehicle and associated method
[0002] Description:
[0003] The invention relates to an authentication system with which a particularly portable, but alternatively also stationary, key can be authenticated to the vehicle in order to enable vehicle functions for an operator who, for example, carries the key, operates it, or approaches it. Furthermore, the invention relates to a method for operating such an authentication system of a vehicle for authenticating a particularly portable key.
[0004] A wide variety of keyless entry systems are known from the state of the art, which can use both low-frequency (LF) and high-frequency (HF) radio waves. Combinations using LF / HF systems are also known from the state of the art.
[0005] In radio-based authorization systems, security is of crucial importance, especially against compromise of the radio communication. When enabling a vehicle function using portable keys or ID transmitters, the determination of a position, a distance, or a similar value, for example, to verify the plausibility of the bidirectional communication, is well known from the state of the art. In general, it is increasingly common to determine the distance using ultra-wideband (UWB) communication.
[0006] For example, DE 10 2017 109 293 A1 and US 11,277,742 B2, which comes from the same patent family, teach a method and an associated system in which radio communication takes place successively between the ID transmitter and various UWB antennas and the signal propagation time is evaluated in a central control unit.
[0007] At the time of registration, a standard widely used in the automotive industry provides for distance determination using both UWB communication and Bluetooth Low Energy (BLE) communication, using a mobile phone as an ID transmitter.
[0008] The problem, however, is that UWB communication and BLE communication require a comparatively large amount of energy, so that the ID transmitter function cannot be integrated into a conventional key or a "smart fob", as its internal energy storage would otherwise have to be replaced or charged very frequently.
[0009] It is therefore an object of the present invention to overcome the aforementioned disadvantages and to provide an authentication system and an associated method which enable integration into an ID transmitter which is not designed as a mobile phone or the like and is preferably designed as a key.
[0010] The object is achieved according to the invention by an authentication system having the features of patent claim 1 and by a method having the features of the independent patent claim.
[0011] According to the invention, an authentication system of a vehicle is therefore proposed for authenticating a particularly portable key to the vehicle in order to enable vehicle functions for an operator who, in particular, carries the key with them. For this purpose, the key has a first UWB transceiver for UWB communication with the vehicle and a first BLE transceiver for BLE communication with the vehicle. Analogously, the vehicle also has a second UWB transceiver for UWB communication with the key and a second BLE transceiver for BLE communication with the key. Deviating from the prior art, the first BLE transceiver is designed to exclusively assume an advertising role in BLE communication, so that it does not have to assume the energy-intensive scanner role. Accordingly, the second BLE transceiver is designed to assume a scanning role in BLE communication.
[0012] By operating the first BLE transceiver as an advertiser and, if necessary, the additional measures explained below, the energy consumption in or on the key can be reduced, thus increasing the battery life of a battery that provides the energy in or on the key.
[0013] In addition to the energy savings achieved by using the key-side, i.e., first BLE, transceiver as an advertiser, the invention further provides for energy savings by embodying the first UWB transceiver to be configured to generate UWB frames as messages for UWB communication, which are, in particular, poll, response, final, and / or final data messages optimized to consume as little energy as possible, particularly during transmission but also during reception at the first UWB transceiver. Accordingly, the UWB frames are configured to consume minimal energy during UWB communication, i.e., during transmission and reception of UWB signals at the first UWB transceiver, through a minimal message length and / or a minimal signal amplitude.
[0014] At the time of registration, the UWB frames or frame types to be sent within the messages are defined. The frame types are, in particular, Pre-Poll, Poll, Response Final, and Final Data. These frame types, in turn, sometimes contain different sections or data sections, which result in different frame structures.
[0015] The UWB signals themselves or the UWB communication can initially be optimized or the energy consumption minimized by completely eliminating the UWB frame pre-poll in the context of UWB communication.
[0016] The data sections can include, in particular, the STS (Scrambled Timestamp Sequence) and PHY header (also known as PHR or Physical Layer Header) sections.
[0017] To minimize energy consumption, the UWB Poll, Response, and Final frames can contain a shorter STS. Furthermore, the PHY header in Finaldata can be omitted.
[0018] In addition, with the transmission of final data, only time differences or delta timestamps are transmitted, instead of the otherwise usually absolute timestamps. Since simultaneous processing, receiving, or transmission of both UWB signals in UWB communication and BLE signals in BLE communication is energy-intensive, another variant provides for the first UWB transceiver and the first BLE transceiver and / or the second UWB transceiver and the second BLE transceiver to be configured for synchronization and time-shifted or time-parallel communication, so that the BLE communication and the UWB communication can be executed or are executed offset in time from one another and not overlapping in time or in parallel. This configuration can be implemented, for example, by a corresponding method or by software and / or hardware locks.
[0019] As explained at the beginning, the ID transmitter embodied as a key is preferably not a mobile phone or the like, but rather a device designed for a specific application. Accordingly, the key can be a "smart key" or a "smart fob." Alternatively, the key can also be integrated into a charging station or other stationary structure, such as a garage.
[0020] In particular, if the key is integrated into a charging station, it can be used to enable a charging function.
[0021] Furthermore, the key can be characterized by the fact that it has an internal energy source, such as a battery or accumulator, but at least no pluggable charging port for charging the energy source via a physical connection.
[0022] Preferably, the second UWB transceiver and the second BLE transceiver are integrated into or connected to a module of the vehicle for determining the distance of the key from the vehicle. The module is configured to determine the distance of the key from the vehicle from UWB signals transmitted during UWB communication. Furthermore, information transmitted via BLE communication can be used to determine the distance. In addition to simply determining the distance, the module or a control unit integrated therein can be configured to control the second UWB transceiver and / or the second BLE transceiver.
[0023] The module or the arrangement consisting of the module, the second UWB transceiver and the second BLE transceiver can also be referred to as an authentication arrangement.
[0024] The distance is determined primarily by calculating the signal propagation time of a UWB signal transmitted between the first and second UWB transceivers during UWB communication. Using the signal propagation time to determine the distance is also known as the "time-of-flight" method, for which the module is designed accordingly.
[0025] For more precise, fail-safe, and compromise-proof distance determination, the vehicle can also have a plurality of second UWB transceivers that can communicate sequentially with the first UWB transceiver. The second UWB transceivers can be provided at different positions on the vehicle. They can communicate with the second BLE transceiver, for example, via the vehicle's control unit, so that information exchanged or requested via BLE communication can be made available to each of the UWB transceivers and, for example, indirectly via the control unit.
[0026] A further aspect of the invention relates to a method for operating an authentication system according to the invention. The method comprises at least the following steps, in particular in the stated order:
[0027] A) Establishment of a BLE communication between the first BLE transceiver and the second BLE transceiver;
[0028] B) transmitting distance determination information by means of BLE communication from the first BLE transceiver to the second BLE transceiver;
[0029] C) Request to initiate the distance determination from the second BLE transceiver to the first BLE transceiver via BLE communication;
[0030] D) Confirmation of the request from the first BLE transceiver to the second BLE transceiver via BLE communication;
[0031] E) controlling the first UWB transceiver to initiate the UWB communication between the first UWB transceiver and the second UWB transceiver for distance determination, wherein the information transmitted by the BLE communication is preferably provided to the second UWB transceiver to establish the UWB communication.
[0032] Although the stated sequence of steps A to E may correspond to the actual order of the steps of the method, each of steps B) to D) can optionally be skipped or performed in a different order. For example, in the method, step A can be followed directly by step E. Alternatively, the steps could also be performed in the order A), C), E).
[0033] If the vehicle has several or a plurality of second UWB transceivers, step E) can further be repeated multiple times. Each time step E) is performed, a different second UWB transceiver and / or a different combination of second UWB transceivers can be activated to establish or initiate UWB communication.
[0034] Preferably, it is provided that the first UWB transceiver, the first BLE transceiver, the second UWB transceiver and the second BLE transceiver communicate with each other at a time offset, and the UWB communication and the BLE communication are carried out at a time offset and do not overlap in time, which leads to energy savings, since in particular the key-side, ie first, transceivers neither have to receive signals at the same time nor have to receive and process signals at the same time.
[0035] It is further advantageous if the information for determining the distance is a processing time of a UWB signal in the key and / or settings of the first UWB transceiver and / or information about the first UWB transceiver relevant for determining the distance.
[0036] The BLE time slot (connection interval), i.e. the time slot in which BLE data is sent, can be optimized by selecting the BLE time slot to match the ranging cycle, i.e. a cycle for which the distance is to be determined.
[0037] Although 42 ms is often defined for this, in this case a BLE time slot of between 300 and 400 ms and preferably approximately 360 ms is preferably used.
[0038] The features disclosed above can be combined as desired, as long as this is technically possible and they do not contradict each other.
[0039] Other advantageous developments of the invention are characterized in the subclaims or are presented in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. They show:
[0040] Fig. 1 an authentication system;
[0041] Fig. 2 shows a procedure for operating the authentication system.
[0042] The figures are schematic examples. Identical reference numerals in the figures indicate identical functional and / or structural features.
[0043] Figure 1 shows an authentication system 1 of a vehicle 20 for authenticating a portable key 10 to the vehicle 20 to enable vehicle functions for an operator 2 carrying the portable key 10. The key 10 has a first UWB transceiver 11 for UWB communication with the vehicle 20 and a first BLE transceiver 12 for BLE communication with the vehicle 20. Accordingly, the vehicle 20 has a second UWB transceiver 21 for UWB communication with the key 10, or more precisely, for UWB communication with the first UWB transceiver 11 of the key 10, and a second BLE transceiver 22 for BLE communication with the key 10, or more precisely, for BLE communication with the first BLE transceiver 12 of the key 10.
[0044] Systems are already known in the state of the art which use a mobile phone or smartphone instead of a key 10, since the high energy consumption resulting from UWB and BLE communication can be compensated by regularly charging the mobile phone.
[0045] In order to redesign the authentication system 1 and the associated method so that it can also be implemented in or with a key 10 through a significantly reduced energy consumption, at least one, but preferably several, complementary measures are provided.
[0046] Accordingly, the first BLE transceiver 12 is configured to assume an advertising role exclusively during BLE communication and not a scanning role, since the advertising role (i.e., sending advertising messages) consumes less energy than the constant or frequent scanning for advertising messages in the scanning role. Accordingly, the second BLE transceiver 22 must be configured to assume a scanning role during BLE communication.
[0047] Such an authentication system 1 is also intended to determine, in particular, the distance of the key 10 from the vehicle 20 in order to thereby rule out relay station attacks. For this purpose, the time-of-flight method is used, in which the signal propagation times of UWB signals sent as part of the UWB communication are determined. Accordingly, the second UWB transceiver 21 and the second BLE transceiver 22 are integrated into a module 24 of the vehicle 20 for determining the distance. For this purpose, the distance determination module 24 can have further control means or control units which control the second UWB transceiver 21 and the second BLE transceiver 22 to carry out the method and can determine the distance between the key 10 and the vehicle 20 based on the UWB communication and the BLE communication.Furthermore, such control units, such as the illustrated control unit 23, can also be provided outside the module 24. In general, the second UWB transceiver 21, the second BLE transceiver 22, and the control unit 23 do not have to be arranged in a single module 24, but can be integrated into different systems of the vehicle 20 and merely coupled to one another in terms of signaling. Figure 2 shows, in particular, the communication sequence according to its temporal progression t between the various components of the authentication system 1, wherein the first UWB transceiver 11 and the first BLE transceiver 12 of the key 10 are shown together, whereas the UWB transceiver 21, the BLE transceiver 22, and the vehicle-side control unit 23 of the vehicle 20 controlling the method are shown separately from one another.
[0048] The process can essentially be divided into at least four phases I to IV, which can also be considered independently of each other, so that the individual phases could be preceded or followed by other or different phases.
[0049] The phases are essentially:
[0050] I Temporal synchronization of the control unit 23 with the second UWB transceiver 21 and the second BLE transceiver 22 or temporal synchronization of these with each other.
[0051] II Defining or determining the information required for distance determination;
[0052] III Requesting distance determination;
[0053] IV Transmission of signals for distance determination or distance determination.
[0054] During these phases, signals or commands are transmitted, which can also be referred to as messages. The signals between the key 10 and the second UWB transceiver 21 are always UWB signals, and the signals between the key 10 and the second BLE transceiver 22 are always BLE signals.
[0055] Commands between the components of the vehicle 20 are preferably transmitted via cable and, in particular, via CAN bus. To illustrate the BLE connection intervals (s), these are shown as examples.
[0056] Instead of a single UWB transceiver 21, several UWB transceivers 21 can be provided on or in the vehicle 20, which can also be interconnected to form a UWB module.
[0057] The transmitted signals or commands are the following: a "SYNC" signal for the temporal synchronization of control unit 23, second BLE transceiver 22 and second UWB transceiver 21; b "FUP" signal for the temporal synchronization of control unit 23, second BLE transceiver 22 and second UWB transceiver 21; c request for the information required by key 10 for distance determination (Ranging Definition Request); d request for the information required by key 10 for distance determination (Ranging Definition Request); e confirmation that information has been requested; f internal provision of the information (Transfer Ranging Settings), which in particular corresponds to IEEE 802.15.4z HRP taking into account the deviations according to the invention; g transmission of the information (Ranging Definition Response); h transmission of the information with a timestamp (Ranging Definition Response incl.Time Stamp); i Transmission of information for establishing UWB communication (ranging keys); j Confirmation; k Request or announcement of UWB communication (setup and.
[0058] Start), whereby the time (time stamp) is transmitted at which the UWB communication is to take place on the part of key 10;
[0059] I Confirmation; m Request for UWB communication (Setup and Start), where the
[0060] Time stamp is transmitted at which the UWB communication is to take place on the part of the key 10; n request for UWB communication (setup and start), whereby the time stamp is transmitted at which the UWB communication is to take place on the part of the key 10; o confirmation (ranging start response); p confirmation (ranging start response including time stamp); q UWB communication, according to its chronological order consisting of the messages or UWB frames: poll, response, final, final data. With several second UWB transceivers 21, the UWB communication can take place multiple times and one after the other, so that the key-side first UWB transceiver 11 communicates one after the other with different second UWB transceivers; r transmission of the signal propagation times between the first and second UWB transceivers 11, 21 and / or the distance between the key 10 and the vehicle 20.
Claims
Patent claims 1 . Authentication system (1) of a vehicle (20) for authenticating a particularly portable key (10) to the vehicle (20) for enabling vehicle functions for an operator (2) who in particular carries the key (10), wherein the key (10) has a first UWB transceiver (11) for UWB communication with the vehicle (20) and a first BLE transceiver (12) for BLE communication with the vehicle (20), wherein the vehicle (20) has a second UWB transceiver (21) for UWB communication with the key (10) and a second BLE transceiver (22) for BLE communication with the key (10), wherein the first BLE transceiver (12) is designed to assume exclusively an advertising role in the BLE communication, and the second BLE transceiver (22) is designed to assume a scanning role in the BLE communication, wherein the first UWB transceiver (11 ),to generate UWB frames as messages for UWB communication, and wherein the UWB frames are designed to consume minimal energy during UWB communication at the first UWB transceiver (11) by means of a minimal message length and / or a minimal signal amplitude.
2. Authentication system according to claim 1 , wherein the messages for UWB communication are Poll, response, final and / or final data messages.
3. Authentication system according to claim 1 or 2, wherein the first UWB transceiver (11) and the first BLE transceiver (12) and / or the second UWB transceiver (21) and the second BLE transceiver (22) are designed for synchronization and time-shifted or parallel communication, so that the BLE communication and the UWB communication are carried out offset in time from one another or in time in parallel. Authentication system according to one of the preceding claims, wherein the key (20) is designed as a smart key or smart fob. Authentication system according to one of the preceding claims, wherein the second UWB transceiver (21) and the second BLE transceiver (22) are integrated into or connected to a module (24) of the vehicle (20) for determining a distance of the key (10) from the vehicle (20), wherein the module (24) is designed to determine the distance of the key (10) from the vehicle (20) from UWB signals transmitted during the UWB communication.Authentication system according to one of the preceding claims, wherein a plurality of second UWB transceivers (21) are provided, which are designed to communicate sequentially with the first UWB transceiver (11). A method for operating an authentication system (1) of a vehicle (20) for authenticating a key (10), in particular a portable key, to the vehicle (20) for enabling vehicle functions for an operator (2), who in particular carries the key (10), according to one of the preceding claims, wherein the method comprises at least the following steps: A) Establishing a BLE communication between the first BLE transceiver (12) and the second BLE transceiver (22); E) controlling the first UWB transceiver (11) to initiate the UWB communication between the first UWB transceiver (11 ) and the second UWB transceiver (21 ) for distance determination.
8. Method according to the preceding claim, further comprising at least one of the steps A) and E) executable steps: B) transmitting information for distance determination by means of the BLE communication from the first BLE transceiver (12) to the second BLE transceiver (22); C) Request to initiate the distance determination from the second BLE transceiver (22) to the first BLE transceiver (12) via BLE communication; D) Confirmation of the request from the first BLE transceiver (12) to the second BLE transceiver (22) via BLE communication.
9. Method according to one of the two preceding claims, wherein the vehicle (20) has a plurality of second UWB transceivers (21 ) and step E) is repeated several times, wherein in each case different and / or a mutually different combination of second UWB transceivers (21 ) is controlled to establish the UWB communication.
10. The method according to any one of the preceding claims 7 to 9, wherein the first UWB transceiver (11), the first BLE Transceiver (12), the second UWB transceiver (21), and the second BLE transceiver (22) communicate with each other at a time offset, and the UWB communication and the BLE communication are carried out at a time offset and without overlapping each other.
11. Method according to the preceding claim, wherein the information for determining the distance is a processing time of a UWB signal in the key (10) and / or settings of the first UWB transceiver (11) and / or information relevant to determining the distance relating to the first UWB transceiver (11).