Identity verification method and device

Abstract

The invention provides an identity verification method and device, and the method comprises the steps: carrying out the interaction with a target terminal when the identity verification of the target terminal is determined, and obtaining the detection feature information; when it is determined that the channel reciprocity meets the condition according to the detection feature information, the detection feature information is reserved, and the process of interaction with the target terminal is repeated until a preset number of detection feature information meeting the condition is obtained; determining radio frequency fingerprint information of the target terminal based on the detection feature information meeting the conditions; and performing identity verification on the target terminal by using the radio frequency fingerprint information. The extracted radio frequency fingerprint information still retains the fingerprint information of the device while removing the channel characteristics, thereby ensuring the high discrimination of the characteristics. Due to the fact that the influence of channel characteristics is removed, the method can more effectively resist interference caused by multipath fading and channel noise, and therefore the accuracy and reliability of identity verification are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of communication signal and radio frequency fingerprint extraction, and in particular to an identity authentication method and device. Background Art

[0002] Radio Frequency Fingerprint (RFF) comes from differences in transmitter circuit design and manufacturing tolerances of hardware circuits during production. Device parameters in different production batches or even the same production batch vary slightly. In addition, due to differences in component type, component layout, and PCB routing, the differences between transmitters designed by different manufacturers are even more significant.

[0003] RF fingerprints are unique and difficult to clone. This feature can be used to identify wireless transmitters and authenticate the identity of transmitters to protect communication security. RF fingerprints are a tiny signal distortion parasitic on the transmitted signal. Its generation mechanism is very complex. There is no RF fingerprint extraction method in the relevant technology that can resist the influence of multipath fading and channel noise. Summary of the invention

[0004] The present invention provides an identity authentication method and device, which are used to solve the problem in the related art that there is a lack of a radio frequency fingerprint extraction method capable of resisting the influence of multipath fading and channel noise.

[0005] The present invention provides an identity authentication method, comprising the following steps.

[0006] When determining to initiate identity authentication for a target terminal, interact with the target terminal and obtain detection feature information; If it is determined according to the detection feature information that the channel reciprocity satisfies the condition, retain the detection feature information, and repeat the process of interacting with the target terminal until a preset number of detection feature information satisfying the condition is obtained; Determine the radio frequency fingerprint information of the target terminal based on the detection feature information that meets the conditions; wherein the detection feature information includes the first channel state information and the second channel state information The radio frequency fingerprint information is used to authenticate the identity of the target terminal.

[0007] Optionally, when determining to initiate identity authentication for a target terminal, interacting with the target terminal and acquiring detection feature information includes: In response to an identity authentication request for the target terminal, interact with the target terminal, wherein during the interaction, a first signal is sent to the target terminal, and a second signal sent by the target terminal is received; Determine first channel state information according to a first received signal, and receive second channel state information; wherein the second channel state information is determined by the target terminal according to the second received signal, the first received signal is obtained based on the second signal, and the second received signal is obtained based on the first signal.

[0008] Optionally, judging whether the channel reciprocity satisfies a condition is performed in the following manner, including: determining a channel reciprocity value based on the first channel state information and the second channel state information; If the channel reciprocity value exceeds the threshold, the channel reciprocity meets the condition; otherwise, the channel reciprocity does not meet the condition.

[0009] Optionally, the determining the radio frequency fingerprint information of the target terminal based on each detection feature information that meets the conditions includes: Determine the weight of each detection feature information that meets the conditions; The radio frequency fingerprint information is determined by the following formula according to the weight of each detection feature information that meets the conditions, the first channel state information, and the second channel state information: in, is the radio frequency fingerprint information, is the number of groups of detection feature information that meet the conditions, To detect the group of characteristic information, For the The weight of the detection feature information that meets the conditions, is the first channel state information, is the second channel state information.

[0010] Optionally, the weight of the detection feature information is determined in the following manner: in, Represents the conjugate transpose operation.

[0011] Optionally, the detection feature information further includes a signal-to-noise ratio; and the weight of the detection feature information is determined in the following manner: in, represents the conjugate transpose operation, SNR A is the signal-to-noise ratio.

[0012] In a second aspect, the present invention further provides an identity authentication device, comprising the following modules: An interaction module, used to determine when to initiate identity authentication for a target terminal, interact with the target terminal, and obtain detection feature information; A judgment module, configured to retain the detection feature information if it is determined that the channel reciprocity satisfies the condition according to the detection feature information, and repeat the process of interacting with the target terminal until a preset number of detection feature information satisfying the condition is obtained; A calculation module, used to determine the radio frequency fingerprint information of the target terminal based on the detection feature information that meets the conditions; The verification module is used to use the radio frequency fingerprint information to authenticate the identity of the target terminal.

[0013] In a third aspect, the present invention further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the identity authentication method as described above when executing the program.

[0014] In a fourth aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which implements the identity authentication method as described above when executed by a processor.

[0015] In a fifth aspect, the present invention also provides a computer program product, including a computer program, which implements the identity authentication method as described above when executed by a processor.

[0016] The identity authentication method provided by the present invention first obtains a series of detection feature information by communicating and interacting with the target terminal in the identity authentication process. Subsequently, based on these feature information, it is evaluated whether the channel reciprocity meets the conditions. Channel reciprocity means that the transmission characteristics of the channel are the same between the uplink and the downlink. Through this evaluation process, the signals with sudden changes in the uplink and downlink channels can be removed. Next, multiple interactions are performed with the target terminal until a sufficient amount of detection feature information that meets the conditions is obtained. After that, these information are fused. The fusion processing process can extract more stable and reliable radio frequency fingerprint features, which show stronger robustness to changes in channel characteristics, that is, they are not easily interfered and affected by fluctuations in channel characteristics. The extracted fingerprint features retain the fingerprint information of the device itself while removing the channel characteristics, ensuring high discrimination of the features. Since the influence of the channel characteristics has been removed, the method can more effectively resist the interference caused by multipath fading and channel noise, thereby improving the accuracy and reliability of identity authentication. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is one of the flow charts of an identity authentication method provided by the present invention; Figure 2 A schematic diagram of a frequency domain waveform principle of a transfer function provided by the present invention; Figure 3 A schematic diagram of the frequency domain amplitude principle of channel state information provided by the present invention; Figure 4 A schematic diagram of the principle of radio frequency fingerprint amplitude provided by the present invention; Figure 5 A schematic diagram of the amplitude residual principle between a radio frequency fingerprint and an ideal fingerprint provided for the invention; Figure 6 A schematic diagram of the phase residual principle between a radio frequency fingerprint and an ideal fingerprint provided for the invention; Figure 7 A schematic diagram of the comparison of amplitude residuals between a radio frequency fingerprint and an ideal fingerprint provided for the invention; Figure 8 This is the second flow chart of an identity authentication method provided by the present invention; Fig. 9 It is a structural schematic diagram of an identity authentication device provided by the present invention; Fig.10 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Radio Frequency Fingerprint (RFF) comes from differences in transmitter circuit design and manufacturing tolerances of hardware circuits during production. Device parameters in different production batches or even the same production batch vary slightly. In addition, due to differences in component type, component layout, and PCB routing, the differences between transmitters designed by different manufacturers are even more significant.

[0021] RF fingerprints are unique and difficult to clone. This feature can be used to identify wireless transmitters and authenticate the identity of transmitters to protect communication security. RF fingerprints are a tiny signal distortion parasitic on the transmitted signal. Its generation mechanism is very complex and difficult to accurately model and characterize through mathematical models. Therefore, it is also difficult to find the theoretically optimal RF fingerprint extraction method.

[0022] Since wireless transmission signals usually reach the receiver through wireless multipath channels, the transmission signal is in a convolution relationship with the multipath effect, and the RF fingerprint is also in a convolution relationship with the transmission signal to a certain extent. Removing the multipath channel will inevitably damage the RF fingerprint. Therefore, the multipath effect greatly limits the accurate extraction of the RF fingerprint.

[0023] Therefore, an identity authentication method is urgently needed to solve the above problems.

[0024] Combine the following Figure 1-Figure 9 The identity authentication method and device of the present invention are described.

[0025] Figure 1 It is one of the flow charts of the identity authentication method provided by the present invention, such as Figure 1 As shown, the method includes the following: S101. When determining to initiate identity authentication for a target terminal, interact with the target terminal and obtain detection feature information.

[0026] When the target terminal needs to be authenticated, the authentication requester (hereinafter referred to as the first terminal) first establishes a communication connection with the target terminal and initiates an authentication request. During the authentication process, multiple interactions are performed with the target terminal to obtain detection feature information for analysis. Afterwards, the first terminal sends an authentication request to the target terminal. The first terminal may be, for example, a base station, a server, or a device with authentication function.

[0027] Specifically, the detection characteristic information includes the first channel state information and the second channel state information. The two communicating parties in the wireless network, namely the first terminal and the target terminal, interact once, and the first terminal and the target terminal respectively estimate the received signal to obtain the first channel state information. and second channel state information The first channel state information and the second channel state information are channel state information of the first terminal and the target terminal respectively.

[0028] S102: if it is determined according to the detection feature information that channel reciprocity satisfies a condition, retain the detection feature information, and repeat the process of interacting with the target terminal until a preset number of detection feature information satisfying the condition is obtained.

[0029] Based on the acquired detection feature information, determine whether the current channel meets the reciprocity condition. Channel reciprocity means that when the uplink and downlink are transmitted in different time slots of the same frequency resource, the channel fading experienced by the transmission signals of the uplink and downlink in a relatively short period of time is the same. Each interaction with the target terminal will obtain the corresponding detection feature information. Based on the detection feature information, determine whether the channel reciprocity meets the condition. If the channel reciprocity meets the condition, retain the detection feature information; otherwise, discard the detection feature information. Repeat the above step S101 interaction process with the target terminal to obtain new detection feature information, and repeat the process of determining whether the channel reciprocity meets the condition in the above step S102 based on the new detection feature information until a preset number of detection feature information that meets the condition is obtained. The purpose of this step is to ensure that subsequent processing can eliminate the impact of multipath channels.

[0030] S103: Determine the radio frequency fingerprint information of the target terminal based on each detection feature information that meets the conditions.

[0031] For the detection feature information that meets the conditions, further processing and analysis are performed to determine the RF fingerprint information of the target terminal.

[0032] S104: Authentication of the target terminal is performed using the radio frequency fingerprint information.

[0033] The determined RF fingerprint information is compared with the pre-stored RF fingerprint information to verify the identity of the target terminal. If the match is successful, the identity authentication is passed; otherwise, the identity authentication fails.

[0034] The identity authentication method provided by the present invention first obtains a series of detection feature information by communicating and interacting with the target terminal in the identity authentication process. Subsequently, based on these feature information, it is evaluated whether the channel reciprocity is satisfied. Channel reciprocity means that the transmission characteristics of the channel are the same between the uplink and the downlink. Through this evaluation process, those signals with sudden changes in the uplink and downlink channels can be removed. Next, multiple interactions are performed with the target terminal until a sufficient number of detection feature information that meets the conditions is obtained. After that, these information are fused. The fusion processing process can extract more stable and reliable radio frequency fingerprint features, which show stronger robustness to changes in channel characteristics, that is, they are not easily disturbed and affected by fluctuations in channel characteristics. The extracted fingerprint features retain the fingerprint information of the device itself while removing the channel characteristics, ensuring high discrimination of the features. Since the influence of the channel characteristics has been removed, the method can more effectively resist the interference caused by multipath fading and channel noise, thereby improving the accuracy and reliability of identity authentication. The method can be widely used in fingerprint extraction and identity authentication of radio frequency devices. Since RF devices will show unique fingerprint characteristics during the communication process, this method can be used to identify different RF devices and authenticate them.

[0035] Moreover, this method does not require third-party signal collection. The radio frequency fingerprint can be obtained through a small amount of interaction and calculation between the communicating parties (i.e., the first terminal and the target terminal). There is no computing performance requirement for the authentication terminal (i.e., the target terminal) and it is not restricted by the signal format. Fingerprints can be extracted for different types of transmission signals in the communication system.

[0036] Optionally, the first channel state information and the second channel state information are channel state information of the first terminal and the target terminal respectively. When determining to initiate identity authentication for the target terminal in step S101, interacting with the target terminal and acquiring detection feature information includes: S1011. In response to an identity authentication request for the target terminal, interact with the target terminal, wherein during the interaction, a first signal is sent to the target terminal, and a second signal sent by the target terminal is received; S1012. Determine first channel state information based on a first received signal, and receive second channel state information; wherein the second channel state information is determined by the target terminal based on a second received signal, the first received signal is obtained based on the second signal, and the second received signal is obtained based on the first signal.

[0037] When the target terminal needs to be authenticated, the first terminal sends an authentication request to the target terminal. In response to the request, the first terminal and the target terminal start to interact. During the interaction, the first terminal sends a first signal to the target terminal. This signal can be a specific detection signal for obtaining channel state information. The target terminal sends a second signal in response.

[0038] The first terminal determines the first channel state information using a channel estimation technique according to the first received signal (the signal after the second signal is processed by the target terminal and transmitted through the channel). This information reflects the characteristics of the channel from the target terminal to the first terminal.

[0039] Similarly, the target terminal may determine the second channel state information according to the second received signal (the signal after the first signal is processed by the first terminal and transmitted through the channel). This information reflects the channel characteristics from the first terminal to the target terminal. The target terminal sends the second channel state information The signal is transmitted back to the first terminal without distortion.

[0040] At the same time, the first terminal and the target terminal estimate the signal-to-noise ratio of their received signals respectively, where the signal-to-noise ratio corresponding to the first received signal is , the signal-to-noise ratio corresponding to the second received signal is .

[0041] Through the above process, the first terminal obtains two sets of channel state information: the first channel state information and second channel state information . Comprehensive signal-to-noise ratio , the first terminal obtains a single detection feature set ,These three sets of information together constitute the detection feature information used for ,identification.

[0042] The present invention uses channel state information as detection feature information to capture the physical layer hardware characteristics of the target terminal during the communication process. This characteristic is difficult to forge, so it helps to improve the accuracy of identity authentication. The estimated channel state information contains device characteristics and channel characteristics. By analyzing and processing this information, the channel influence can be effectively removed, and stable device characteristics can be extracted for identity authentication, thereby enhancing the system's robustness to multipath fading and channel noise. The acquisition and processing of channel state information is usually relatively fast, so using it for identity authentication can support fast response and real-time verification requirements. Moreover, compared with traditional key- or password-based authentication methods, using channel state information for identity authentication does not require pre-sharing of keys or passwords, thereby simplifying the identity authentication process.

[0043] The first signal and the second signal may be the same or may be different, which is not limited in the embodiment of the present invention. To illustrate, the spectrum corresponding to this signal is This fixed signal is hereinafter referred to as a transmission signal.

[0044] In this embodiment, the received signal of the target terminal To send a signal The transfer function is The first terminal transmitter, the transfer function is The channel transfer function is The target terminal receiver and spectrum are The received signal of the first terminal is obtained after the noise To send a signal The transfer function is The target terminal transmitter, the transfer function is The channel transfer function is The first terminal receiver and the spectrum are The four transfer functions of the first terminal and the target terminal transceiver are obtained after the noise is removed. , , , like Figure 2 As shown, it can be seen that the value of the transfer function varies slightly around 1.

[0045] Among them, the spectrum of the signal received by the target terminal satisfies: , In the frequency domain, the spectrum of the received signal is used Divide by the spectrum of the known signal (the transmitted signal above) , get the channel state information estimated by the target terminal: , The spectrum of the signal received by the first terminal satisfies: , In the frequency domain, the spectrum of the received signal is used Divide by the spectrum of the known signal (the transmitted signal above) , obtain the channel state information estimated by the first terminal: , Paired channel state information obtained by one interactive estimation between the first terminal and the target terminal at a 30dB signal-to-noise ratio like Figure 3 shown.

[0046] In a channel with good reciprocity, the transmission signals of the uplink (from the target terminal to the first terminal) link and the downlink (from the first terminal to the target terminal) link will experience the same channel fading. The present invention uses this point, and the first terminal can send a known signal to the target terminal and require the target terminal to return the same signal (or a signal that has been specially processed). By comparing the received signal with the transmitted signal, that is, using the spectrum of the received signal as mentioned above Divide by the spectrum of the transmitted signal , remove the channel influence from the received signal to obtain the first channel state information and the second channel state information. The fingerprint feature extracted based on the information removes the channel characteristics, thereby highlighting the device fingerprint feature. This makes the fingerprint features of different devices easier to distinguish after removing the channel characteristics, and the feature differentiation is high.

[0047] Optionally, judging whether the channel reciprocity satisfies a condition is performed in the following manner, including: determining a channel reciprocity value based on the first channel state information and the second channel state information; If the channel reciprocity value exceeds the threshold, the channel reciprocity meets the condition; otherwise, the channel reciprocity does not meet the condition.

[0048] In this embodiment, the four transfer functions of the first terminal and the target terminal transceiver are , , , All are fixed values. Figure 2 and Figure 3 It can be seen that the transfer function of the transceiver is relatively weak compared to the channel transfer function, and the pairwise channel state information can be calculated. The channel transfer function is approximated by the similarity of The similarity of the channel reciprocity is used to determine whether the channel reciprocity meets the conditions. One or more thresholds are set, which are determined according to system requirements, channel characteristics, noise levels and other factors. The calculated channel reciprocity value is compared with the set threshold. If the channel reciprocity value exceeds the threshold, it is considered that the channel reciprocity meets the conditions; otherwise, it is considered that the channel reciprocity does not meet the conditions and the detection feature information is discarded.

[0049] In this embodiment, cosine similarity is used as the similarity calculation method, and the threshold is set to When the cosine similarity value exceeds 0.98, the detection feature information is considered to be valid, otherwise the detection information is discarded.

[0050] Optionally, the first terminal extracts the features of the fingerprint information of the target terminal in the frequency domain according to the multiple detection feature information, that is, the above-mentioned radio frequency fingerprint information The above step S103 of determining the radio frequency fingerprint information of the target terminal based on the detection feature information that meets the conditions includes: S1031. Determine the weight of each detection feature information that meets the conditions.

[0051] S1032: Determine radio frequency fingerprint information according to weights corresponding to each detection feature information that meets the conditions, the first channel state information, and the second channel state information.

[0052] For each type of channel state information (the first channel state information and second channel state information ), weighted sum each channel state information according to the previously determined weight, thereby obtaining the first feature information and the second feature information. Finally, the ratio of the first feature information to the second feature information is calculated. This ratio reflects the device RF fingerprint characteristics, has a high degree of device specificity, and can be used for device identification or authentication.

[0053] In this embodiment, the RF fingerprint information including the fingerprint feature For both ends N The quotient of the weighted sum of the secondary channel state information: in, is the number of groups of detection feature information that meet the conditions, To detect the group of characteristic information, For the The weight of the detection feature information that meets the conditions for the first time, that is, The weight corresponding to the effective detection information.

[0054] RF fingerprint information It is calculated by calculating the channel state information at both ends (i.e. the first channel state information and second channel state information ) is the ratio of the weighted sum. Channel noise is the random interference that the signal receives during transmission. Similarly, due to It is obtained by calculating the ratio of weighted sums through multiple interactions, so the impact of channel noise will also be averaged over multiple interactions. The impact will be further reduced.

[0055] The present invention can more effectively extract the unique radio frequency characteristics of the device by comprehensively considering multiple detection feature information and weighting them according to their importance, thereby improving the accuracy of recognition. Using the ratio as radio frequency fingerprint information can reduce the impact of environmental changes (such as changes in channel conditions) on the recognition results and enhance the robustness of the system. This method does not rely on specific hardware or protocols and can be applied to a variety of wireless communication systems, including Wi-Fi, Bluetooth, Zigbee, etc., and has a wide range of applicability.

[0056] The above weight There are three selection methods: When the channel and signal-to-noise ratio remain unchanged, use the accumulation division method directly: .

[0057] When the signal-to-noise ratio is basically stable, choose the least squares method: , Represents the conjugate transpose operation.

[0058] When both the channel and the signal-to-noise ratio vary, choose the weighted least squares method: ,in, Represents the conjugate transpose operation.

[0059] The above signal-to-noise ratio It reflects the relative strength between the received signal and the noise when the first terminal receives the second information. By taking the signal-to-noise ratio as one of the detection feature information and taking it into account in the weight determination process, the change of the channel state can be more accurately reflected, thereby improving the accuracy of the channel estimation. Noise is an inevitable factor in wireless communication systems, which will interfere with the transmission and reception of signals. By using the signal-to-noise ratio to determine the weight of the detection feature information, the system can handle the influence of noise more intelligently, compensate for or suppress the noise, thereby enhancing the system's robustness to noise. By comprehensively considering the second channel state information and signal-to-noise ratio By determining the weights, the channel quality and noise level of different terminals can be more accurately evaluated, thereby making more reasonable resource allocation decisions. The optimization of the weight determination process not only improves the accuracy of channel estimation, but also enhances the system's robustness to noise, helping to resist channel noise.

[0060] Of course, the selection of the above three calculation methods can also be appropriately adjusted according to usage.

[0061] The following is a detailed description of the three selection methods.

[0062] When the weight is When the radio frequency fingerprint information is obtained The result obtained by the equivalent least squares method. At this time, the 10 effective detection information sets with SNR = 20dB are weighted and accumulated and then divided. The result is as follows Figure 4 , Figure 5 and Figure 6 As shown in the figure, the characteristic stability of the extracted RF fingerprint is further improved compared with the direct accumulation and division, and the amplitude and phase fluctuations are reduced to within ±0.1.

[0063] When the weight is When the radio frequency fingerprint information is obtained The result obtained by equivalent weighted least squares method. Compared with the least squares method, this method is completely equivalent when the signal-to-noise ratio (SNR) remains unchanged. However, in practical applications, the signal-to-noise ratio usually fluctuates. If the target terminal is a mobile device, the signal-to-noise ratio fluctuates widely. In this case, the least squares method does not take into account the change of noise variance, so the estimation result is biased, while the weighted least squares method can solve this problem well.

[0064] In this embodiment, for a signal with SNR=10-40dB, the performance when three different weights are adopted is further compared, such as Figure 7 As shown in the figure, when the signal-to-noise ratio fluctuates, the fingerprint fluctuation is relatively large and the robustness is insufficient because both the direct accumulation division and the least squares method consider the impact of the signal-to-noise ratio on the fingerprint. However, the weighted least squares method fully considers the impact of the signal-to-noise ratio on fingerprint extraction in the weight, and the fingerprint deviation is reduced by nearly an order of magnitude compared with the first two methods. It is highly robust and practical.

[0065] Under ideal conditions, when the channel is completely reciprocal and noise-free, the three methods are equivalent, and the extracted RF fingerprint information containing the fingerprint information of the target terminal device is expressed as: In view of the defects of the prior art RF fingerprint extraction method that obtains the amplitude quotient as the RF fingerprint through one interaction between the two communicating parties and a small amount of calculation, without considering the impact of noise on the amplitude quotient or the impact of multipath fading on the fingerprint, the identity authentication method of the present invention obtains multiple sets of channel state information by interacting with the target terminal multiple times. This helps to average out the random effects of channel characteristics and noise and improve the stability of RF fingerprints. When , the weighted sum ratio method is adopted. By reasonably selecting the weights , which can further reduce the impact of channel noise and multipath fading on RF fingerprints.

[0066] This method uses the principle of channel reciprocity, that is, the transmission characteristics of the channel are the same in the uplink and downlink. By judging the channel reciprocity, the feature information that is less affected by the channel can be screened out, thereby further improving the accuracy and stability of the RF fingerprint. After obtaining a sufficient number of detection feature information that meets the conditions, the method fuses this information. The fusion process can extract more stable and reliable RF fingerprint features, which are more robust to changes in channel characteristics. Due to the use of multiple interactions and weighted processing, as well as the use of channel reciprocity, this method can better resist the influence of multipath fading and channel noise. Weighted processing can further reduce the interference of noise, while the use of channel reciprocity helps to eliminate random changes in channel characteristics.

[0067] Compared with the existing technology, this method has higher stability and accuracy. Through multiple interactions and weighted processing, as well as the use of channel reciprocity, this method can extract more stable and reliable RF fingerprint features, thereby improving the accuracy and reliability of identity authentication. This method is not limited by the signal format and does not require the participation of third-party high-cost acquisition equipment, so it has a wider application prospect and lower cost.

[0068] The identity authentication method provided by the present invention can be used to identify different radio frequency devices and authenticate them. The following is an example of a first terminal (hereinafter referred to as terminal A) authenticating the target terminal (hereinafter referred to as terminal B). Figure 8 As shown, the specific steps include: S1. Feature detection: The two communicating parties A and B in the wireless network interact with each other and estimate the signal-to-noise ratio of the received signal. , and channel state information , ; S2. Feature feedback: The B end transmits the channel status information The data is transmitted back to the A side without distortion, and the A side obtains a single detection feature set. , that is, detecting characteristic information; S3. Channel reciprocity judgment: End A calculates paired channel state information If the similarity exceeds the threshold T, it is determined that the channel reciprocity meets the conditions, otherwise the invalid detection information is discarded; S4. Repeat: Repeat steps S1-S3 several times until K channel reciprocity conditions are met. ; S5. Feature extraction: End A extracts the RF feature information containing the fingerprint information of End B’s device in the frequency domain based on K detection feature information. . It is the quotient of the weighted sum of the K-times channel state information at both ends.

[0069] The identity authentication device provided by the present invention is described below. The identity authentication device described below and the identity authentication method described above can be referenced to each other.

[0070] like Fig. 9 As shown, the present invention provides an identity authentication device, comprising the following modules: The interaction module 201 is used to determine that when initiating identity authentication for a target terminal, interact with the target terminal and obtain detection feature information; The judgment module 202 is used to retain the detection feature information if it is determined that the channel reciprocity meets the condition according to the detection feature information, and repeat the process of interacting with the target terminal until a preset number of detection feature information meeting the condition is obtained; The calculation module 203 is used to determine the RF fingerprint information of the target terminal based on the detection feature information that meets the conditions. The verification module 204 is used to perform identity verification on the target terminal using the radio frequency fingerprint information.

[0071] Fig.10 An example of a physical structure diagram of an electronic device is shown in FIG. Fig.10 As shown, the electronic device may include: a processor 310, a communications interface 320, a memory 330 and a communication bus 340, wherein the processor 310, the communications interface 320 and the memory 330 communicate with each other through the communication bus 340. The processor 310 may call the logic instructions in the memory 330 to execute the identity authentication method.

[0072] In addition, the logic instructions in the above-mentioned memory 330 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0073] On the other hand, the present invention also provides a computer program product, the computer program product includes a computer program, the computer program can be stored on a non-transitory computer-readable storage medium, and when the computer program is executed by a processor, the computer can execute the identity authentication method provided by the above methods. On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the computer program is executed by a processor to perform the identity authentication method provided by the above-mentioned methods.

[0074] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, i.e., they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative effort.

[0075] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, and these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An identity authentication method, characterized in that: The method comprises: When determining to initiate identity authentication for a target terminal, interact with the target terminal and obtain detection feature information; If it is determined according to the detection feature information that the channel reciprocity satisfies the condition, retain the detection feature information, and repeat the process of interacting with the target terminal until a preset number of detection feature information satisfying the condition is obtained; Determine the radio frequency fingerprint information of the target terminal based on each detection feature information that meets the conditions; wherein the detection feature information includes first channel state information and second channel state information; The radio frequency fingerprint information is used to authenticate the identity of the target terminal.

2. The identity authentication method according to claim 1, characterized in that: When determining to initiate identity authentication for the target terminal, interacting with the target terminal and acquiring detection feature information includes: In response to an identity authentication request for the target terminal, interact with the target terminal, wherein during the interaction, a first signal is sent to the target terminal, and a second signal sent by the target terminal is received; Determine first channel state information based on a first received signal, and receive second channel state information; wherein the second channel state information is determined by the target terminal based on the second received signal, the first received signal is obtained based on the second signal, and the second received signal is obtained based on the first signal.

3. The identity authentication method according to claim 1, characterized in that: Whether the channel reciprocity meets the conditions is determined by the following methods, including: determining a channel reciprocity value based on the first channel state information and the second channel state information; If the channel reciprocity value exceeds the threshold, the channel reciprocity meets the condition; otherwise, the channel reciprocity does not meet the condition.

4. The identity authentication method according to claim 1, characterized in that: The determining the radio frequency fingerprint information of the target terminal based on each detection feature information that meets the conditions includes: Determine the weight of each detection feature information that meets the conditions; The radio frequency fingerprint information is determined by the following formula according to the weight of each detection feature information that meets the conditions, the first channel state information, and the second channel state information: in, is the radio frequency fingerprint information, is the number of groups of detection feature information that meet the conditions, To detect the group of characteristic information, For the The weight of the detection feature information that meets the conditions, is the first channel state information, is the second channel state information.

5. The identity authentication method according to claim 4, characterized in that: The weight of the detection feature information is determined in the following manner: in, Represents the conjugate transpose operation.

6. The identity authentication method according to claim 4, characterized in that: The detection feature information also includes a signal-to-noise ratio; the weight of the detection feature information is determined in the following manner: in, represents the conjugate transpose operation, SNR A is the signal-to-noise ratio.

7. An identity verification device, characterized in that: include: An interaction module, used to determine when to initiate identity authentication for a target terminal, interact with the target terminal, and obtain detection feature information; A judgment module, configured to retain the detection feature information if it is determined that the channel reciprocity satisfies the condition according to the detection feature information, and repeat the process of interacting with the target terminal until a preset number of detection feature information satisfying the condition is obtained; A calculation module, configured to determine the radio frequency fingerprint information of the target terminal based on each detection feature information that meets the conditions; wherein the detection feature information includes first channel state information and second channel state information; The verification module is used to perform identity verification on the target terminal using the radio frequency fingerprint information.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the identity authentication method according to any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the identity authentication method according to any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the identity authentication method according to any one of claims 1 to 6 is implemented.

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