Intelligent key system and intelligent lock based on low-power-consumption Bluetooth channel detection

Abstract

The invention relates to an intelligent key system and an intelligent lock based on low-power-consumption Bluetooth channel detection, the system comprises a key terminal and a controlled device, the key terminal comprises a first BLE communication module, and the controlled device comprises a second BLE communication module, a distance calculation and judgment module, a channel detection distance measurement module and an execution module; the first BLE communication module is used for broadcasting regularly; the second BLE communication module is used for acquiring broadcast data; the distance calculation and judgment module is used for sending a distance measurement request; the channel detection distance measurement module is used for carrying out detection signal exchange on a plurality of BLE channels to obtain a detection result; the distance calculation and judgment module is also used for calculating the distance between the key terminal and the controlled equipment; and the execution module is used for determining an execution action according to the authentication result of the key terminal. According to the invention, high-precision distance measurement and security authentication can be realized through a low-power-consumption Bluetooth channel detection technology, and the convenience and security of equipment unlocking are remarkably improved.

Description

Technical Field

[0001] This disclosure relates to the field of smart key technology, and in particular to a smart key system and smart lock based on low-power Bluetooth channel detection. Background Technology

[0002] With the widespread application of smart door locks, keyless vehicle entry systems, and smart access control, existing smart key solutions generally rely on Bluetooth Low Energy (BLE) or radio frequency communication to achieve contactless unlocking.

[0003] However, existing solutions still have many problems in practical applications. For example, distance judgment is inaccurate. Existing BLE unlocking solutions mostly rely on Received Signal Strength Indicator (RSSI) for distance estimation. RSSI is easily affected by environmental obstructions, multipath effects, and human posture, and cannot accurately reflect the true physical distance between the key and the controlled device. In addition, there are security issues. They are vulnerable to relay attacks. RSSI or simple near-field judgment cannot effectively defend against relay attacks, signal forwarding, and amplification attacks. Attackers can forge a "presence" condition even when the key is far away from the controlled device, causing serious security risks. Summary of the Invention

[0004] In view of this, this disclosure proposes a smart key system and smart lock based on Bluetooth Low Energy channel detection, which can achieve high-precision ranging and security authentication through Bluetooth Low Energy channel detection technology, significantly improving the convenience and security of device unlocking.

[0005] According to one aspect of this disclosure, a smart key system based on Bluetooth Low Energy (BLE) channel detection is provided. The system includes a key terminal and a controlled device. The key terminal includes a first BLE communication module, and the controlled device includes a second BLE communication module, a distance calculation and judgment module, a channel detection ranging module, and an execution module. The first BLE communication module is used for periodic broadcasting. The second BLE communication module is used for periodically acquiring first broadcast data, and upon acquiring the first broadcast data sent by the first BLE communication module, determining that the key terminal is within a preset communication range. The distance calculation and judgment module is used to determine that the key terminal is within a preset communication range when the key terminal is within the preset range. When the communication range is within range, a ranging request is sent to the channel detection ranging module; the channel detection ranging module is used to respond to the ranging request by exchanging detection signals with the key terminal on multiple BLE channels to obtain detection results; the distance calculation and judgment module is also used to calculate the actual distance between the key terminal and the controlled device based on the detection results, and to initiate authentication for the key terminal if the actual distance meets a preset distance condition; the execution module is used to determine the execution action based on the authentication result of the key terminal, the execution action including unlocking the controlled device or keeping the controlled device in a locked state.

[0006] In this way, the smart key system achieves high-precision ranging and secure authentication through low-power Bluetooth channel probing technology, significantly improving the convenience and security of device unlocking. This system employs a two-stage verification mechanism. First, it uses BLE broadcasting to initially determine if the key terminal is within the preset communication range. Then, it uses multi-channel probing signal exchange to accurately calculate the actual distance. Authentication is initiated only when the distance meets preset conditions, effectively preventing relay attacks. Compared to the fuzzy ranging of traditional Bluetooth keys that rely on signal strength, multi-channel probing technology significantly improves distance calculation accuracy, resulting in a significantly lower false positive rate. Finally, the execution module makes dynamic decisions based on the authentication results, supporting seamless unlocking to enhance the user experience while preventing accidental operations through distance threshold limits. This makes it highly suitable for security-sensitive scenarios such as automobiles and smart homes.

[0007] In one possible implementation, the first BLE communication module is further configured to periodically broadcast encrypted BLE broadcast data, so that the positioning terminal in the external positioning service platform uploads the received encrypted BLE broadcast data and its own location, the encrypted BLE broadcast data and its own location being used as the basis for determining the location of the key terminal.

[0008] Thus, the integrated unlocking and anti-loss smart key system provided in this embodiment of the present disclosure, under the same BLE architecture, can simultaneously achieve high-security, contactless unlocking capabilities and distributed anti-loss positioning capabilities, taking into account security, reliability, and low power consumption requirements. It has low hardware costs, a simple system, reduced power consumption, and a consistent user experience. Moreover, it can achieve wide-area anti-loss positioning in a low-power, small-size key form without the need for an additional communication module. It has a complete security strategy and is suitable for anti-loss needs in scenarios such as automobiles and smart homes.

[0009] In one possible implementation, the key terminal further includes a channel sounding response module; the channel sounding ranging module is further configured to, in response to the ranging request, control the second BLE communication module to send sounding signals to the first BLE communication module on different BLE channels; the channel sounding response module is configured to control the first BLE communication module to receive sounding signals from different BLE channels and forward the sounding signals to the second BLE communication module; the channel sounding ranging module is further configured to control the second BLE communication module to receive the forwarded sounding signals from different BLE channels and determine the sounding results corresponding to different BLE channels.

[0010] In this way, by adding a channel detection and response module to the key terminal, a two-way multi-channel signal interaction mechanism is constructed, significantly improving ranging accuracy and anti-attack capability. After the channel detection and ranging module controls the second BLE module to send detection signals on different channels, the channel detection and response module of the key terminal forwards the received signals along the original path, forming a closed-loop interaction of "send-receive-forward". Multi-channel detection can also eliminate single-frequency interference, improving ranging stability in complex environments such as shopping malls and parking garages, thus meeting the high-security requirements of scenarios such as keyless car entry and smart homes.

[0011] In one possible implementation, the detection result includes the phase difference corresponding to the detection signals of different BLE channels; the distance calculation and judgment module is further configured to calculate a first distance based on the phase difference corresponding to the detection signals of different BLE channels and a preset frequency difference, and use the first distance as the actual distance between the key terminal and the controlled device.

[0012] In this way, the phase difference ranging scheme provided by the smart key system can effectively eliminate the phase ambiguity problem caused by multipath interference under a single frequency by fusion calculation of multichannel frequency difference and phase difference, and by utilizing the frequency difference of multiple available BLE channels and measuring the phase offset of signals from different channels. This significantly improves ranging accuracy compared to the traditional RSSI method.

[0013] In one possible implementation, the detection results include the transmission time, first reception time, forwarding time, and second reception time corresponding to the detection signals of different BLE channels. The transmission time refers to the time when the second BLE communication module sends the detection signal, the first reception time refers to the time when the first BLE communication module receives the detection signal, the forwarding time refers to the time when the first BLE communication module forwards the received detection signal to the second BLE communication module, and the second reception time refers to the time when the second BLE communication module receives the detection signal forwarded by the first BLE communication module. The distance calculation and judgment module is further configured to calculate a first time difference based on the corresponding transmission time and second reception time for each BLE channel, calculate a second time difference based on the corresponding first reception time and forwarding time, calculate a second sub-distance for the corresponding BLE channel based on a preset wave velocity, the first time difference, and the second time difference, determine a second distance based on the second sub-distances corresponding to all BLE channels, and use the second distance as the actual distance between the key terminal and the controlled device.

[0014] In this way, the time information ranging scheme provided by the smart key system uses four-timestamp closed-loop calculation and multi-channel fusion, and performs parallel ranging on multiple BLE channels, which significantly improves the ranging accuracy compared to the traditional RSSI method.

[0015] In one possible implementation, the detection results include the phase difference corresponding to the detection signals of different BLE channels, the transmission time corresponding to the detection signals of different BLE channels, the first reception time, the forwarding time, and the second reception time. The transmission time refers to the time when the second BLE communication module sends the detection signal, the first reception time refers to the time when the first BLE communication module receives the detection signal, the forwarding time refers to the time when the first BLE communication module forwards the received detection signal to the second BLE communication module, and the second reception time refers to the time when the second BLE communication module receives the detection signal forwarded by the first BLE communication module. The distance calculation and judgment module is further configured to calculate a third distance based on a preset first weight, a first distance, a preset second weight, and a second distance, and use the third distance as the actual distance between the key terminal and the controlled device. The first distance is determined based on the phase difference corresponding to the detection signals of different BLE channels, and the second distance is determined based on the transmission time, the first reception time, the forwarding time, and the second reception time corresponding to the detection signals of different BLE channels.

[0016] In this way, the fusion ranging scheme provided by the smart key system can improve the accuracy of distance calculation by weighted fusion of phase difference and time information. The smart key system can better cope with various complex electromagnetic environments and perfectly adapt to scenarios that are sensitive to both accuracy and safety by using multi-channel frequency difference to eliminate phase ambiguity for the first distance and using four timestamps to eliminate processing delay for the second distance, combined with dynamic weight fusion to form the third distance.

[0017] In one possible implementation, the distance calculation and judgment module is further configured to compare the actual distance with a preset safety threshold, and if the actual distance is less than the preset safety threshold, determine that the actual distance meets the preset distance condition; if the actual distance is equal to or greater than the safety threshold, determine that the actual distance does not meet the preset distance condition.

[0018] In this way, the security threshold comparison mechanism provided by the smart key system achieves layered security protection through dynamic distance determination, significantly improving the system's ability to resist relay attacks. When the actual distance is less than the preset threshold, the system determines that the user has actually approached and initiates authentication; otherwise, it maintains the locked state. This design upgrades the traditional coarse logic of unlocking within communication range to dual protection of precise spatial determination and identity authentication, significantly reducing the success rate of relay attacks.

[0019] In one possible implementation, the key terminal further includes a security key module, and the controlled device further includes a security authentication control module; the distance calculation and judgment module is further configured to send an authentication request to the security authentication control module when it is determined that the actual distance meets a preset distance condition; the security authentication control module is configured to send a key provision request to the security key module in response to the authentication request; the security key module is configured to send a pre-stored first key to the security key module in response to the key provision request; the security authentication control module is further configured to verify the first key to obtain the authentication result of the key terminal, the authentication result including pass or fail.

[0020] In this way, the security authentication mechanism provided by the smart key system constructs a two-factor protection system of distance determination and key verification, significantly reducing the risk of relay attacks. The security authentication control module only triggers the key verification process when the actual distance meets the security threshold. It sends a request to the key terminal's security key module to obtain the pre-stored first key for verification, ensuring that the controlled device is securely protected.

[0021] In one possible implementation, the security authentication control module is further configured to determine whether the first key matches the pre-stored second key; if the first key matches the second key, the authentication result is determined to be successful; if the first key does not match the second key, the authentication result is determined to be unsuccessful.

[0022] In this way, the key matching and verification mechanism provided by the smart key system constructs a hardware-level identity authentication barrier through bidirectional comparison of pre-stored keys, reducing the success rate of unauthorized device forgery. The security authentication control module can compare the received first key with the locally pre-stored second key bit by bit. If a match is found, authentication is successful; otherwise, it is directly rejected, ensuring that the controlled device is securely protected.

[0023] According to another aspect of this disclosure, a smart lock is provided, the smart lock including the smart key system.

[0024] Other features and aspects of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0025] The accompanying drawings, which are included in and form part of this specification, illustrate exemplary embodiments, features, and aspects of this disclosure together with the specification and serve to explain the principles of this disclosure.

[0026] Figure 1 A block diagram of a smart key system based on Bluetooth Low Energy channel detection provided in an embodiment of this disclosure is shown. Detailed Implementation

[0027] Various exemplary embodiments, features, and aspects of this disclosure will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0028] As used herein, the terms “comprising,” “including,” “having,” or variations thereof are open-ended and include one or more of the stated features, integrals, elements, steps, components, or functions, but do not exclude the presence or addition of one or more other features, integrals, elements, steps, components, functions, or groups thereof.

[0029] When an element is referred to as “connected,” “coupled,” “responding,” or a variation thereof relative to another element, it may be directly connected, coupled, or responding to another element, or there may be an intermediate element present.

[0030] Although the terms first, second, third, etc., may be used herein to describe various elements / operations, these elements / operations should not be limited by these terms. These terms are only used to distinguish one element / operation from another. Therefore, without departing from the teachings of the inventive concept, a first element / operation in some embodiments may be referred to as a second element / operation in other embodiments.

[0031] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0032] Furthermore, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that this disclosure can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art have not been described in detail in order to highlight the main points of this disclosure.

[0033] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, data stored, data displayed, etc.) and signals involved in this application are all authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant regions.

[0034] To facilitate understanding of the technical solutions provided by the embodiments of this disclosure by those skilled in the art, the technical environment for implementing the technical solutions will be described below.

[0035] BLE technology, due to its low power consumption, low cost, and mature ecosystem, is widely used in smart keys, wearable devices, and IoT terminals. Currently, typical BLE keyless unlocking solutions primarily involve the key periodically sending BLE broadcasts, followed by the controlled device measuring the RSSI (Real-Time Stability Indicator). When the RSSI exceeds a threshold, a BLE connection is established, and finally, identity verification and unlocking are performed. This solution estimates distance using RSSI, but RSSI is not a true physical distance measurement, resulting in significant measurement errors and a high rate of false unlocking attempts. Furthermore, the lack of reliable physical distance verification makes it vulnerable to relay attacks. In addition to inaccurate distance assessment and insufficient security, traditional BLE solutions also suffer from a disconnect between unlocking and anti-loss functions. In current key solutions, unlocking and anti-loss positioning functions are typically handled by different systems or devices, leading to high hardware costs, system complexity, increased power consumption, and inconsistent user experience. Moreover, anti-loss capabilities are limited to short-range applications or require additional communication modules. Traditional anti-loss solutions rely on buzzers, short-range scanning, or cellular communication modules, making it difficult to achieve wide-area anti-loss positioning in a low-power, small-size key form factor, and lacking a complete security strategy.

[0036] To address the aforementioned technical challenges, this disclosure provides a smart key system based on Bluetooth Low Energy Channel Sounding (BLE Channel Sounding). Through a high-precision physical distance verification mechanism based on BLE Channel Sounding, it enables secure key interaction and seamless unlocking within a trusted distance. Furthermore, it provides wide-area anti-loss positioning capabilities without a cellular module, achieving an integrated design of unlocking and anti-loss functions within the same key terminal. This ensures high security while achieving low power consumption, low cost, and a superior user experience.

[0037] The smart key system provided in this disclosure can be applied to smart home scenarios, such as smart door locks, and also to smart car scenarios, such as smart car locks.

[0038] Now combined Figure 1 This disclosure provides an illustrative description of a smart key system based on low-power Bluetooth channel detection, as provided in the embodiments of this disclosure. Figure 1 As shown, a smart key system may include a key terminal and a controlled device. In a smart door lock scenario, the key terminal may be an electronic key, and the controlled device may be a door lock or access control system. In a smart car lock scenario, the key terminal may be an electronic key, and the controlled device may be a vehicle.

[0039] The key terminal may include a first Bluetooth Low Energy (BLE) communication module. The controlled device may include a second BLE communication module, a distance calculation and judgment module, a channel sounding ranging module, and an execution module.

[0040] The first BLE communication module is the core hardware component of BLE wireless communication, integrating components such as an RF transceiver, baseband processor, and controller. It can transmit data in the 2.4GHz band with microwatt-level power consumption. The first BLE communication module can be used for periodic broadcasts. The first broadcast data sent out by the first BLE communication module can be broadcast data set according to the matching relationship between the key terminal and the controlled device.

[0041] The second BLE communication module can be used to periodically acquire first broadcast data, and upon acquiring the first broadcast data sent by the first BLE communication module, determine that the key terminal is within a preset communication range. For example, the second BLE communication module acquires broadcast data every 100ms. When the second BLE communication module acquires the first broadcast data, it can determine that the key terminal has entered the communication range of the controlled device, and can send first information to the distance calculation and judgment module to indicate that the key terminal has entered the communication range of the controlled device.

[0042] The distance calculation and judgment module can be used to send a ranging request to the channel detection ranging module when the key terminal is within a preset communication range. The preset communication range can be set to a specific size according to actual needs.

[0043] The channel sounding and ranging module can be used to exchange sounding signals with the key terminal on multiple BLE channels in response to ranging requests, obtain sounding results, and send the results to the distance calculation and judgment module for distance calculation and judgment. The sounding results may include the phase difference and / or time information corresponding to the sounding signals of different BLE channels. The time information includes the time when the receiver and transmitter received and transmitted signals respectively. A BLE channel refers to a wireless communication channel allocated in the 2.4GHz ISM band. Specifically, BLE can divide the 2.400MHz-2483.5MHz band into 40 channels with a width of 1MHz.

[0044] The distance calculation and judgment module can also be used to calculate the actual distance between the key terminal and the controlled device based on the detection results, and initiate authentication for the key terminal if the actual distance meets the preset distance conditions. The authentication result can be either pass or fail. Pass indicates that the key terminal and the controlled device are compatible. Fail indicates that the key terminal and the controlled device are not compatible.

[0045] The execution module can be used to determine the action to be performed based on the authentication result of the key terminal. The action to be performed includes unlocking the controlled device or keeping the controlled device in a locked state. For example, the execution module may include a door lock unit and a control unit. The control unit controls the state of the door lock unit according to the authentication result. For example, if the authentication result is successful, the control unit controls the door lock unit to unlock to unlock the controlled device; if the authentication result is unsuccessful, the control unit controls the door lock unit to keep the controlled device in a locked state.

[0046] In this way, the smart key system achieves high-precision ranging and secure authentication through low-power Bluetooth channel probing technology, significantly improving the convenience and security of device unlocking. This system employs a two-stage verification mechanism. First, it uses BLE broadcasting to initially determine if the key terminal is within the preset communication range. Then, it uses multi-channel probing signal exchange to accurately calculate the actual distance. Authentication is initiated only when the distance meets preset conditions, effectively preventing relay attacks. Compared to the fuzzy ranging of traditional Bluetooth keys that rely on signal strength, multi-channel probing technology significantly improves distance calculation accuracy, resulting in a significantly lower false positive rate. Finally, the execution module makes dynamic decisions based on the authentication results, supporting seamless unlocking to enhance the user experience while preventing accidental operations through distance threshold limits. This makes it highly suitable for security-sensitive scenarios such as automobiles and smart homes.

[0047] Considering the increasing maturity of distributed positioning networks based on BLE broadcasting (such as Find My technology), the smart key system also sends encrypted BLE broadcast data to the external environment through the first BLE communication module to further enhance its anti-loss functionality. The encrypted BLE broadcast data can be generated by the anti-loss BLE broadcasting and identification generation unit of the key terminal, and it features dynamic encryption, does not contain plaintext device identity, and adaptively adjusts the broadcast interval.

[0048] Specifically, the first BLE communication module can also periodically broadcast encrypted BLE broadcast data, enabling positioning terminals in the external positioning service platform to upload the received encrypted BLE broadcast data and their own location. The encrypted BLE broadcast data and the user's location are used as the basis for determining the key terminal's location. All positioning terminals (e.g., mobile phones, tablets) in the positioning service platform near the key terminal can receive the encrypted BLE broadcast data and upload it along with their own location to the cloud. The positioning service platform then parses the data to determine the owner and location of the key terminal, storing the location under the corresponding account of the owner. This way, when a user loses their key terminal, they can query its location through the corresponding positioning service platform. Thus, through a network composed of numerous mobile terminals, passive sensing and location feedback are achieved for the key terminal sending the encrypted BLE broadcast, realizing low-power, wide-coverage anti-loss positioning capabilities.

[0049] Thus, the integrated unlocking and anti-loss smart key system provided in this embodiment of the present disclosure, under the same BLE architecture, can simultaneously achieve high-security, contactless unlocking capabilities and distributed anti-loss positioning capabilities, taking into account security, reliability, and low power consumption requirements. It has low hardware costs, a simple system, reduced power consumption, and a consistent user experience. Moreover, it can achieve wide-area anti-loss positioning in a low-power, small-size key form without the need for an additional communication module. It has a complete security strategy and is suitable for anti-loss needs in scenarios such as automobiles and smart homes.

[0050] The smart key system provides a high-precision physical distance verification mechanism based on BLE Channel Sounding to achieve high-precision calculation of the actual distance between the key terminal and the controlled device.

[0051] Specifically, the key terminal may also include a channel sounding response module. The channel sounding response module can work in conjunction with the channel sounding ranging module of the controlled device to achieve ranging.

[0052] The channel sounding and ranging module can also be used to control the second BLE communication module to send sounding signals to the first BLE communication module on different BLE channels in response to the ranging request sent by the distance calculation and judgment module.

[0053] The channel sounding response module can be used to control the first BLE communication module to receive sounding signals from different BLE channels and forward the sounding signals to the second BLE communication module. When forwarding / returning sounding signals, the channel sounding response module can send the time when the first BLE communication module receives the sounding signal and the time when it forwards the sounding signal to the second BLE communication module, so that the subsequent distance calculation and judgment module can perform distance calculations based on these times.

[0054] The channel sounding and ranging module is also used to control the second BLE communication module to receive the forwarded sounding signals from different BLE channels and determine the sounding results corresponding to different BLE channels.

[0055] In this way, by adding a channel detection and response module to the key terminal, a two-way multi-channel signal interaction mechanism is constructed, significantly improving ranging accuracy and anti-attack capability. After the channel detection and ranging module controls the second BLE module to send detection signals on different channels, the channel detection and response module of the key terminal forwards the received signals along the original path, forming a closed-loop interaction of "send-receive-forward". Multi-channel detection can also eliminate single-frequency interference, improving ranging stability in complex environments such as shopping malls and parking garages, thus meeting the high-security requirements of scenarios such as keyless car entry and smart homes.

[0056] The smart key system offers three calculation methods to determine the actual distance between the key terminal and the controlled device.

[0057] The first calculation method is distance calculation based on phase difference. In this case, the detection result may include the phase difference corresponding to the detection signals of different BLE channels. The distance calculation and judgment module can also be used to calculate a first distance based on the phase difference corresponding to the detection signals of different BLE channels and a preset frequency difference, and use the first distance as the actual distance between the key terminal and the controlled device.

[0058] For example, assuming the controlled device is the transmitter and the key terminal is the reflector, a signal interaction can be completed through two frequency switches. During the first transmission, the controlled device transmits a probe signal via BLE channel 1 at frequency f1. The key terminal receives the probe signal, records phase p1, and sends back the probe signal with the same phase. The controlled device then measures phase Pf1. During the second transmission, the controlled device switches to frequency f2 and transmits a probe signal via BLE channel 2. The key terminal receives the probe signal, records phase p2, and sends it back to the controlled device. The controlled device then measures phase Pf2. Specifically, the controlled device can receive and transmit the probe signal through the channel sounding ranging module, and the key terminal can receive and transmit the probe signal through the channel sounding response module. The controlled device can send the detection results Pf1 and Pf2 to the distance calculation and judgment module through the channel sounding ranging module. The distance calculation and judgment module calculates the first sub-distance between the key terminal and the controlled device based on the phase difference between the two frequencies. Specifically, through... -Pf1 calculates the phase difference between the two receptions. ,pass -f1 calculates the frequency difference ,pass Calculate the first sub-distance ,in It is the speed of light. Due to the phase difference... The range of values ​​is In actual calculations, multiple frequency pairs are needed to eliminate ambiguity and ensure a unique distance solution. That is, the controlled device and the key terminal use multiple BLE channels to perform multiple signal interactions according to the above process to calculate multiple first sub-distances. Then, the average of all the first sub-distances can be calculated to obtain the first distance D1, which is then used as the actual distance between the key terminal and the controlled device.

[0059] In this way, the phase difference ranging scheme provided by the smart key system calculates by fusing the frequency difference and phase difference of multiple channels. By utilizing the frequency difference of available BLE channels in the 2.4GHz ISM band and measuring the phase offset of signals from different channels, it can effectively eliminate the phase ambiguity problem caused by multipath interference at a single frequency, and significantly improve the ranging accuracy compared to the traditional RSSI method.

[0060] The second calculation method is distance calculation based on time information. In this case, the detection results may include the transmission time, first reception time, forwarding time, and second reception time corresponding to the detection signals of different BLE channels. The transmission time refers to the time when the second BLE communication module sends the detection signal. The first reception time refers to the time when the first BLE communication module receives the detection signal. The forwarding time refers to the time when the first BLE communication module forwards the received detection signal to the second BLE communication module. The second reception time refers to the time when the second BLE communication module receives the detection signal forwarded by the first BLE communication module. The distance calculation and judgment module can also be used to calculate a first time difference based on the corresponding transmission time and second reception time for each BLE channel, calculate a second time difference based on the corresponding first reception time and forwarding time, calculate a second sub-distance for the corresponding BLE channel based on the preset beam velocity, the first time difference, and the second time difference, determine the second distance based on the second sub-distances corresponding to all BLE channels, and use the second distance as the actual distance between the key terminal and the controlled device.

[0061] For example, it is still assumed that the controlled device is the transmitter and the key terminal is the reflector. The controlled device transmits a probe signal through BLE channel 1 and records the transmission time. After receiving the detection signal, the key terminal confirms the first reception time. Then it transmits the detection signal back and sends the first reception time and forwarding time. The controlled device receives the detection signal and records the second reception time. Specifically, it can be achieved through... Calculate the round trip time ,in, Indicates the first time difference. , Indicates the second time difference. Then it can be accessed through Calculate the second sub-distance ,in The preset wave velocity is the speed of light. Specifically, the controlled device receives and transmits detection signals via a channel sounding ranging module, while the key terminal receives and transmits detection signals via a channel sounding response module. The controlled device and the key terminal interact multiple times using multiple BLE channels according to the above process. The second sub-distance corresponding to each BLE channel can be calculated. Then, all second sub-distances are averaged to obtain the second distance D2, which is used as the actual distance between the key terminal and the controlled device.

[0062] In this way, the time information ranging scheme provided by the smart key system uses four-timestamp closed-loop calculation and multi-channel fusion, and performs parallel ranging on multiple BLE channels, which significantly improves the ranging accuracy compared to the traditional RSSI method.

[0063] The third calculation method is distance calculation based on phase difference and time information. In this case, the detection results may include the phase difference corresponding to the detection signals of different BLE channels, the transmission time corresponding to the detection signals of different BLE channels, the first reception time, the forwarding time, and the second reception time. The distance calculation and judgment module can also be used to calculate a third distance based on a preset first weight, a first distance, a preset second weight, and a second distance, and use the third distance as the actual distance between the key terminal and the controlled device.

[0064] The first distance is determined based on the phase difference corresponding to the probe signals of different BLE channels. The process of determining the first distance by the distance calculation and judgment module can be found in the determination process of D1 above, and will not be repeated here for the sake of brevity.

[0065] The second distance is determined based on the transmission time, first reception time, forwarding time, and second reception time of the probe signals for different BLE channels. The process of determining the second distance by the distance calculation and judgment module can be found in the determination process of D2 mentioned above, and will not be repeated here for the sake of brevity.

[0066] For example, after determining the first distance D1 and the second distance D2, the distance calculation and judgment module can calculate the third distance D3 using D3 = a1*D1 + a2*D2, and use the third distance as the actual distance between the key terminal and the controlled device. Here, a1 represents the first weight corresponding to the time ranging scheme, a represents the second weight corresponding to the phase ranging scheme, and a1 + a2 = 1. The first and second weights can be dynamically set to specific values ​​according to the actual situation. For example, in an open scene, the time ranging scheme can be emphasized, and the second weight can be set to 0.7 and the first weight to 0.3. Similarly, in a multipath scenario, the phase ranging scheme can be emphasized, and the first weight can be set to 0.7 and the second weight to 0.3.

[0067] In this way, the fusion ranging scheme provided by the smart key system can improve the accuracy of distance calculation by weighted fusion of phase difference and time information. The smart key system can better cope with various complex electromagnetic environments and perfectly adapt to scenarios that are sensitive to both accuracy and safety by using multi-channel frequency difference to eliminate phase ambiguity for the first distance and using four timestamps to eliminate processing delay for the second distance, combined with dynamic weight fusion to form the third distance.

[0068] The Channel Sounding unlocking capability of the smart key system disclosed herein can be used for high-security authentication at close range, and the BLE distributed positioning capability can be used for mid-to-long-range anti-loss retrieval. Unlocking and positioning share the BLE hardware and security key system, but are independent of each other in terms of protocol and triggering conditions, thereby enabling seamless unlocking against relay attacks at close range and low-power, wide-coverage anti-loss positioning at long range.

[0069] After calculating the actual distance between the key terminal and the controlled device, the distance calculation and judgment module can also be used to compare the actual distance with a preset safety threshold. Specifically, the distance calculation and judgment module can be used to determine that the actual distance meets the preset distance condition if the actual distance is less than the preset safety threshold. The distance calculation and judgment module can also be used to determine that the actual distance does not meet the preset distance condition if the actual distance is equal to or greater than the safety threshold. The safety threshold can be flexibly set according to the actual application scenario, such as 1.5 meters for automotive scenarios and 0.5 meters for smart homes.

[0070] In this way, the security threshold comparison mechanism provided by the smart key system achieves layered security protection through dynamic distance determination, significantly improving the system's ability to resist relay attacks. When the actual distance is less than the preset threshold, the system determines that the user has actually approached and initiates authentication; otherwise, it maintains the locked state. This design upgrades the traditional coarse logic of unlocking within communication range to dual protection of precise spatial determination and identity authentication, significantly reducing the success rate of relay attacks.

[0071] The key terminal may also include a security key module. The controlled device also includes a security authentication control module. The distance calculation and judgment module can also be used to send an authentication request to the security authentication control module to initiate the authentication process for the key terminal when it is determined that the actual distance meets a preset distance condition. In response to the authentication request, the security authentication control module can send a key provision request to the security key module. In response to the key provision request, the security key module can send a pre-stored first key to the security key module. The security authentication control module can also verify the first key to obtain the authentication result of the key terminal, which includes pass or fail.

[0072] In this way, the security authentication mechanism provided by the smart key system constructs a two-factor protection system of distance determination and key verification, significantly reducing the risk of relay attacks. The security authentication control module only triggers the key verification process when the actual distance meets the security threshold. It sends a request to the key terminal's security key module to obtain the pre-stored first key for verification, ensuring that the controlled device is securely protected.

[0073] Specifically, the security authentication control module can also be used to determine whether the first key matches the pre-stored second key in order to verify the first key. If the first key matches the second key, the authentication result is determined to be successful; if the first key does not match the second key, the authentication result is determined to be unsuccessful.

[0074] In this way, the key matching and verification mechanism provided by the smart key system constructs a hardware-level identity authentication barrier through bidirectional comparison of pre-stored keys, reducing the success rate of unauthorized device forgery. The security authentication control module can compare the received first key with the locally pre-stored second key bit by bit. If a match is found, authentication is successful; otherwise, it is directly rejected, ensuring that the controlled device is securely protected.

[0075] The key terminal may also include a power management and low-power control module, which can be used to issue a power reminder message when the key terminal has low power to remind the user to charge the key terminal; it can also be used to enable or disable the low-power mode of the key terminal.

[0076] The smart key system disclosed herein introduces Channel Sounding technology under the BLE architecture, providing a physical distance verification mechanism based on BLE Channel Sounding, a strongly coupled unlocking process of distance verification and security authentication, a binding mechanism between anti-loss broadcast data and key security keys, and an integrated system architecture design of unlocking and anti-loss capabilities. This achieves high-precision verification of the real physical distance to the key terminal, effectively defending against relay attacks and signal spoofing at the physical layer, significantly improving the security and reliability of the unlocking system. Simultaneously, this disclosure utilizes a BLE distributed positioning network to achieve wide-area anti-loss capabilities, enabling low-power positioning without the need for a cellular communication module, and unifies the design with the unlocking system, reducing system complexity and hardware costs, thus possessing good practicality and promotional value.

[0077] This disclosure also provides a smart lock, which includes the smart key system described above. In some embodiments, the specific implementation of the smart lock provided in this disclosure can be referred to the description of the smart key system embodiment above, and for the sake of brevity, it will not be repeated here.

[0078] This disclosure also provides a smart key method applied to a controlled device. The controlled device includes a second BLE communication module, a distance calculation and judgment module, a channel detection and ranging module, and an execution module. The method includes: periodically acquiring first broadcast data sent by a key terminal; and determining that the key terminal is within a preset communication range when first broadcast data sent by a first low-power Bluetooth BLE communication module is acquired, wherein the key terminal includes the first BLE communication module; generating a ranging request when the key terminal is within the preset communication range; exchanging detection signals with the key terminal on multiple BLE channels in response to the generation of the ranging request to obtain detection results; calculating the actual distance between the key terminal and the controlled device based on the detection results; and initiating authentication for the key terminal when the actual distance meets a preset distance condition; and determining an execution action based on the authentication result of the key terminal, wherein the execution action includes unlocking the controlled device or keeping the controlled device in a locked state.

[0079] In one possible implementation, the key terminal further includes a channel sounding response module; the method further includes: in response to the ranging request, controlling the second BLE communication module to send probes to the first BLE communication module on different BLE channels; the channel sounding ranging module is further configured to control the second BLE communication module to receive the probe signals forwarded by the key terminal through different BLE channels, and determine the probe results corresponding to different BLE channels.

[0080] In one possible implementation, the detection result includes the phase difference corresponding to the detection signals of different BLE channels; the method further includes: calculating a first distance based on the phase difference corresponding to the detection signals of different BLE channels and a preset frequency difference, and using the first distance as the actual distance between the key terminal and the controlled device.

[0081] In one possible implementation, the detection results include the transmission time, first reception time, forwarding time, and second reception time corresponding to the detection signals of different BLE channels. The transmission time refers to the time when the second BLE communication module sends the detection signal, the first reception time refers to the time when the first BLE communication module receives the detection signal, the forwarding time refers to the time when the first BLE communication module forwards the received detection signal to the second BLE communication module, and the second reception time refers to the time when the second BLE communication module receives the detection signal forwarded by the first BLE communication module. The method further includes: for each BLE channel, calculating a first time difference based on the corresponding transmission time and second reception time, calculating a second time difference based on the corresponding first reception time and forwarding time, calculating a second sub-distance for the corresponding BLE channel based on a preset wave velocity, the first time difference, and the second time difference, determining a second distance based on the second sub-distances corresponding to all BLE channels, and using the second distance as the actual distance between the key terminal and the controlled device.

[0082] In one possible implementation, the detection results include the phase difference corresponding to the detection signals of different BLE channels, the transmission time corresponding to the detection signals of different BLE channels, the first reception time, the forwarding time, and the second reception time. The transmission time refers to the time when the second BLE communication module sends the detection signal, the first reception time refers to the time when the first BLE communication module receives the detection signal, the forwarding time refers to the time when the first BLE communication module forwards the received detection signal to the second BLE communication module, and the second reception time refers to the time when the second BLE communication module receives the detection signal forwarded by the first BLE communication module. The method further includes: calculating a third distance based on a preset first weight, a first distance, a preset second weight, and a second distance, and using the third distance as the actual distance between the key terminal and the controlled device; wherein the first distance is determined based on the phase difference corresponding to the detection signals of different BLE channels, and the second distance is determined based on the transmission time, the first reception time, the forwarding time, and the second reception time corresponding to the detection signals of different BLE channels.

[0083] In one possible implementation, the method further includes: comparing the actual distance with a preset safety threshold; if the actual distance is less than the preset safety threshold, determining that the actual distance meets the preset distance condition; if the actual distance is equal to or greater than the safety threshold, determining that the actual distance does not meet the preset distance condition.

[0084] In one possible implementation, the key terminal further includes a security key module; the method further includes: sending an authentication request when it is determined that the actual distance meets a preset distance condition; in response to the authentication request, sending a key provision request to the security key module; verifying the first key returned by the security key module to obtain the authentication result of the key terminal, the authentication result including pass or fail.

[0085] In one possible implementation, the method further includes: determining whether the first key matches a pre-stored second key; if the first key matches the second key, determining that the authentication result is passed; if the first key does not match the second key, determining that the authentication result is failed.

[0086] In some embodiments, the specific implementation of the method provided in this disclosure can be referred to the description of the system embodiments above, and for the sake of brevity, it will not be repeated here.

[0087] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0088] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A smart key system based on low-power Bluetooth channel detection, characterized in that, The system includes a key terminal and a controlled device. The key terminal includes a first low-power Bluetooth BLE communication module, and the controlled device includes a second BLE communication module, a distance calculation and judgment module, a channel detection and ranging module, and an execution module. The first BLE communication module is used for periodic broadcasting; The second BLE communication module is used to periodically acquire first broadcast data, and upon acquiring the first broadcast data sent by the first BLE communication module, determine that the key terminal is within a preset communication range; The distance calculation and judgment module is used to send a ranging request to the channel detection ranging module when the key terminal is within a preset communication range. The channel detection and ranging module is used to respond to the ranging request by exchanging detection signals with the key terminal on multiple BLE channels to obtain detection results; The distance calculation and judgment module is also used to calculate the actual distance between the key terminal and the controlled device based on the detection results, and to initiate authentication for the key terminal when it is determined that the actual distance meets the preset distance conditions; The execution module is used to determine the execution action based on the authentication result of the key terminal. The execution action includes unlocking the controlled device or keeping the controlled device in a locked state.

2. The system according to claim 1, characterized in that, The first BLE communication module is also used to periodically broadcast encrypted BLE broadcast data so that the positioning terminal in the external positioning service platform can upload the received encrypted BLE broadcast data and its own location. The encrypted BLE broadcast data and its own location are used as the basis for determining the location of the key terminal.

3. The system according to claim 1 or 2, characterized in that, The key terminal also includes a channel detection and response module; The channel detection and ranging module is also used to respond to the ranging request by controlling the second BLE communication module to send detection signals to the first BLE communication module on different BLE channels; The channel detection response module is used to control the first BLE communication module to receive detection signals from different BLE channels and forward the detection signals to the second BLE communication module; The channel detection and ranging module is also used to control the second BLE communication module to receive the forwarded detection signals of different BLE channels and determine the detection results corresponding to different BLE channels.

4. The system according to claim 3, characterized in that, The detection results include the phase difference corresponding to the detection signals of different BLE channels; The distance calculation and judgment module is also used to calculate a first distance based on the phase difference and preset frequency difference corresponding to the detection signals of different BLE channels, and to use the first distance as the actual distance between the key terminal and the controlled device.

5. The system according to claim 3, characterized in that, The detection results include the transmission time, first reception time, forwarding time, and second reception time corresponding to the detection signals of different BLE channels. The transmission time refers to the time when the second BLE communication module sends the detection signal, the first reception time refers to the time when the first BLE communication module receives the detection signal, the forwarding time refers to the time when the first BLE communication module forwards the received detection signal to the second BLE communication module, and the second reception time refers to the time when the second BLE communication module receives the detection signal forwarded by the first BLE communication module. The distance calculation and judgment module is further configured to, for each BLE channel, calculate a first time difference based on the corresponding transmission time and second reception time, calculate a second time difference based on the corresponding first reception time and forwarding time, calculate a second sub-distance for the corresponding BLE channel based on the preset wave velocity, the first time difference, and the second time difference, determine a second distance based on the second sub-distances corresponding to all BLE channels, and use the second distance as the actual distance between the key terminal and the controlled device.

6. The system according to claim 3, characterized in that, The detection results include the phase difference corresponding to the detection signals of different BLE channels, the transmission time corresponding to the detection signals of different BLE channels, the first reception time, the forwarding time, and the second reception time. The transmission time refers to the time when the second BLE communication module sends the detection signal, the first reception time refers to the time when the first BLE communication module receives the detection signal, the forwarding time refers to the time when the first BLE communication module forwards the received detection signal to the second BLE communication module, and the second reception time refers to the time when the second BLE communication module receives the detection signal forwarded by the first BLE communication module. The distance calculation and judgment module is also used to calculate a third distance based on a preset first weight, a first distance, a preset second weight, and a second distance, and to use the third distance as the actual distance between the key terminal and the controlled device; The first distance is determined based on the phase difference of the probe signals of different BLE channels, and the second distance is determined based on the transmission time, first reception time, forwarding time and second reception time of the probe signals of different BLE channels.

7. The system according to claim 1 or 2, characterized in that, The distance calculation and judgment module is also used to compare the actual distance with a preset safety threshold. If the actual distance is less than a preset safety threshold, it is determined that the actual distance meets the preset distance condition. If the actual distance is equal to or greater than the safety threshold, it is determined that the actual distance does not meet the preset distance condition.

8. The system according to claim 1 or 2, characterized in that, The key terminal also includes a security key module, and the controlled device also includes a security authentication control module; The distance calculation and judgment module is also used to send an authentication request to the security authentication control module when it is determined that the actual distance meets the preset distance conditions; The security authentication control module is used to send a key provision request to the security key module in response to the authentication request; The security key module is used to send a pre-stored first key to the security key module in response to the key provision request; The security authentication control module is also used to verify the authentication result of the key terminal obtained by the first key, and the authentication result includes pass or fail.

9. The system according to claim 8, characterized in that, The security authentication control module is also used to determine whether the first key matches the pre-stored second key. If it is determined that the first key matches the second key, the authentication result is determined to be successful; If it is determined that the first key and the second key do not match, the authentication result is determined to be unsuccessful.

10. A smart lock, characterized in that, The smart lock includes the smart key system according to any one of claims 1 to 9.

Images