A wireless key generation method, system and device based on time slot correlation

Abstract

This invention discloses a wireless key generation method, system, and device based on time slot correlation, specifically relating to the field of communication key generation technology. The key points are as follows: In each communication terminal, the correlation value between the t-th channel time slot feature and the previous P-1 historical channel time slot features within its channel feature sequence is calculated. Based on the correlation value, the previous P-1 historical channel time slot features are fused to obtain the memory enhancement feature corresponding to the t-th channel time slot feature. The adaptive quantization rule is adjusted based on the feature distribution information of the memory enhancement feature. Quantization is performed using the adjusted adaptive quantization rule to obtain the quantized initial key bit sequence. The reliability of the initial key bit sequence is screened based on the observation residual to obtain the final key bit sequence. The two communication terminals exchange bit position index information in their respective key bit sequences and retain key bits at the same position according to the other party's bit position index information to obtain a shared wireless key.

Description

Technical Field

[0001] This invention relates to the field of communication key generation technology, and specifically to a wireless key generation method, system, and device based on time slot correlation. Background Technology

[0002] With the rapid development of wireless communication technology, information security issues in open wireless channels are becoming increasingly prominent. Traditional key distribution methods based on high-level encryption algorithms typically rely on pre-shared keys, trusted third parties, or complex key management mechanisms. In application scenarios with limited resources, dynamically changing network topologies, or large-scale terminal access, these methods suffer from high deployment costs, complex management, and insufficient flexibility. Physical layer key generation technology, which utilizes the randomness, reciprocity, and time-varying nature of wireless channels, provides a new solution for both communicating parties to directly extract consistent random characteristics from the shared wireless channel and generate symmetric keys. Therefore, it has high application value in scenarios such as the Internet of Things (IoT), vehicle-to-everything (V2X) communication, edge communication, and low-power wireless access.

[0003] Most existing wireless physical layer key generation methods are based on physical characteristics such as received signal strength, channel amplitude, phase, or channel state information. They generate shared keys through channel probing, feature extraction, quantization, information negotiation, and privacy amplification. While these methods can leverage the inherent randomness of wireless channels to achieve secure key generation to some extent, most rely primarily on single-moment or single-slot channel observations, failing to adequately utilize the temporal correlations and historical evolution patterns existing between consecutive time slots. Furthermore, many methods employ fixed quantization thresholds or empirical quantization intervals, which can easily lead to quantization bit bias, reduced effective bit rate, and key inconsistencies between communicating parties when channel statistical distribution, noise levels, and fading intensity change. Especially in low signal-to-noise ratio, fast fading, or complex dynamic environments, instantaneous channel fluctuations further amplify quantization errors, impacting key generation performance.

[0004] Therefore, how to fully exploit the relevant information between multiple time slot observations in a time-varying wireless channel environment, establish a memory modeling mechanism that can reflect the historical evolution characteristics of the channel, and dynamically adjust the quantization threshold and quantization strategy according to the changing state of the channel, thereby improving the key generation rate, key consistency rate and system adaptability, has become a technical problem that urgently needs to be solved in the field of wireless physical layer key generation.

[0005] Based on this, the present invention aims to propose a wireless key generation method, system, and device based on time slot correlation to solve the aforementioned related problems. Summary of the Invention

[0006] The technical problem this invention aims to solve is that existing technologies struggle to fully exploit the relevant information between multiple time-slot observations in time-varying wireless channel environments and establish a memory modeling mechanism that reflects the historical evolution characteristics of the channel. The goal is to provide a wireless key generation method, system, and device based on time-slot correlation. This invention analyzes and calculates the correlation between each channel time-slot feature and its preceding historical channel time-slot features to construct a memory enhancement feature corresponding to each channel time-slot feature. Furthermore, it introduces this memory enhancement feature into the wireless physical layer key generation process, enabling more full utilization of the correlation and shared randomness of the wireless channel in the time dimension. Compared to existing methods that rely solely on single-slot observation results... There are methods that can significantly improve the stability of random feature extraction. Furthermore, this invention introduces an adaptive quantization mechanism that dynamically adjusts the quantization threshold and decision interval based on the statistical characteristics under different channel conditions. It also utilizes adaptive quantization rules to adaptively quantize memory-enhanced features, thereby reducing the quantization mismatch problem that easily occurs in fixed-threshold methods under low signal-to-noise ratio, fast fading, and complex dynamic environments. Simultaneously, through the collaborative design of reliability screening, information negotiation, and privacy amplification, this invention can effectively reduce the key inconsistency rate between communicating parties, improve the key generation rate, key consistency rate, and final key security, demonstrating strong environmental adaptability and engineering application value.

[0007] This invention is achieved through the following technical solution:

[0008] A wireless key generation method based on time slot correlation, used for wireless key generation between two communication terminals in wireless communication, the method includes:

[0009] Two communication terminals respectively collect wireless channel state information from multiple consecutive time slots and construct their respective channel feature sequences; wherein, the channel feature sequence includes multiple channel time slot features, and each channel time slot feature is used to characterize the channel state features in different time slots;

[0010] In each communication terminal, the correlation value between the t-th channel time slot feature in its channel feature sequence and the previous P-1 historical channel time slot features is calculated. Based on the correlation value, the previous P-1 historical channel time slot features are fused to obtain the memory enhancement feature corresponding to the t-th channel time slot feature. Here, P represents the number of features participating in the correlation calculation of the t-th channel time slot feature, t represents the channel time slot feature index in the channel feature sequence, and t and P are both integers greater than 1.

[0011] The feature distribution information of all memory-enhanced features is obtained, and the adaptive quantization rule is adjusted based on the feature distribution information. The memory-enhanced features are quantized using the adjusted adaptive quantization rule to obtain the quantized initial key bit sequence. The reliability of the initial key bit sequence is screened based on the observation residual between the channel slot features and the corresponding memory-enhanced features to obtain the key bit sequence.

[0012] Two communication terminals exchange bit position index information in their respective key bit sequences through a public channel, and retain key bits with the same position according to the other party's bit position index information to obtain a shared wireless key.

[0013] Furthermore, the characteristics of the first P-1 historical channel slots are fused based on the correlation values, specifically as follows:

[0014] The weighting coefficients of the first P-1 historical channel time slot features relative to the t-th channel time slot feature are determined based on the correlation value; the weighting coefficients are then used to fuse the first P-1 historical channel time slot features.

[0015] Furthermore, the two communication terminals respectively collect wireless channel state information from multiple consecutive time slots and construct their respective channel feature sequences, specifically as follows:

[0016] Two communication terminals respectively collect wireless channel state information from multiple consecutive time slots to construct their respective initial channel feature sequences;

[0017] The two communication ends each preprocess their respective initial channel feature sequences to obtain preprocessed channel feature sequences;

[0018] The preprocessing includes noise removal, time slot synchronization, amplitude normalization, and reciprocity calibration.

[0019] Furthermore, the feature distribution information of all memory enhancement features is obtained, and the adaptive quantization rule is adjusted based on the feature distribution information, specifically as follows:

[0020] The average deviation between the memory enhancement feature and the corresponding channel slot feature is obtained, and the quantization adjustment coefficient of each memory enhancement feature is generated using the average deviation.

[0021] Obtain the mean and standard deviation of each memory enhancement feature, and adjust the adaptive quantization rule of each memory enhancement feature using the quantization adjustment coefficient, mean, and standard deviation.

[0022] Furthermore, the initial key bit sequence is subjected to reliability screening based on the observation residuals between the channel time slot characteristics and the corresponding memory enhancement characteristics, resulting in the following key bit sequence:

[0023] For each memory enhancement feature, the minimum value between each memory enhancement feature value and the quantization threshold value is obtained as the quantization margin of each memory enhancement feature value;

[0024] The prediction deviation between each memory enhancement feature value in the memory enhancement feature and the corresponding time slot feature value in the channel time slot feature is obtained as the prediction deviation of each memory enhancement feature value.

[0025] A reliability index for each memory-enhanced feature value is constructed using prediction bias and quantization margin.

[0026] In the initial key bit sequence, the reliability index is used to filter the bits corresponding to each memory enhancement feature value to obtain the final key bit sequence.

[0027] Furthermore, reliability screening is performed on the bits corresponding to each memory enhancement feature value using reliability metrics, specifically:

[0028] If the reliability index of the memory-enhanced feature value is not less than the preset index threshold, the corresponding bit is retained; otherwise, the corresponding bit is discarded.

[0029] Furthermore, after obtaining the shared wireless key, the method also includes:

[0030] The shared wireless key is subjected to privacy amplification processing to generate the final shared wireless key.

[0031] Furthermore, the method also includes:

[0032] Based on the correlation values ​​between the t-th channel time slot feature and the previous P-1 historical channel time slot features, calculate the average correlation of the t-th channel time slot feature;

[0033] The number of features involved in the correlation calculation of the (t+1)th channel time slot is updated by combining the average correlation of the t-th channel time slot feature with a preset average correlation decision threshold.

[0034] The present invention also provides a wireless key generation system based on time slot correlation, which is used in the wireless key generation method based on time slot correlation described in any one of the above claims, the system comprising:

[0035] The feature sequence construction module is used by two communication ends to collect wireless channel state information from multiple consecutive time slots and construct their respective channel feature sequences. The channel feature sequence includes multiple channel time slot features, and each channel time slot feature is used to characterize the channel state features in different time slots.

[0036] The correlation fusion module is used in each communication terminal to calculate the correlation value between the t-th channel time slot feature in its channel feature sequence and the previous P-1 historical channel time slot features, and to fuse the previous P-1 historical channel time slot features based on the correlation value to obtain the memory enhancement feature corresponding to the t-th channel time slot feature; where P represents the number of features participating in the correlation calculation of the t-th channel time slot feature, t represents the channel time slot feature index in the channel feature sequence, and t and P are both integers greater than 1;

[0037] The key bit quantization module is used to acquire the feature distribution information of all memory enhancement features in each communication end, and adjust the adaptive quantization rule based on the feature distribution information; quantize the memory enhancement features using the adjusted adaptive quantization rule to obtain the quantized initial key bit sequence; and perform reliability screening on the initial key bit sequence based on the observation residual between the channel time slot features and the corresponding memory enhancement features to obtain the final key bit sequence.

[0038] The wireless key generation module is used by two communication terminals to exchange bit position index information in their respective key bit sequences through a public channel, and to retain key bits with the same position according to the other party's bit position index information to obtain a shared wireless key.

[0039] The present invention also provides a computer device, including a system memory and a processor, wherein the system memory stores a computer program, and the processor executes the computer program to implement the steps of any of the methods described above.

[0040] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0041] In this invention, the correlation between each channel time slot feature and its preceding historical channel time slot features is analyzed and calculated to construct a memory enhancement feature corresponding to each channel time slot feature. This memory enhancement feature is then introduced into the wireless physical layer key generation process, enabling more full utilization of the correlation and shared randomness of the wireless channel in the time dimension. Compared to existing methods that rely solely on single time slot observations, this significantly improves the stability of random feature extraction. Furthermore, by introducing an adaptive quantization mechanism, the invention dynamically adjusts the quantization threshold and decision interval based on the statistical characteristics under different channel conditions, and uses adaptive quantization rules to adaptively quantize the memory enhancement feature, thereby reducing the quantization mismatch problem that easily occurs in fixed-threshold methods under low signal-to-noise ratio, fast fading, and complex dynamic environments. Simultaneously, through the collaborative design of reliability screening, information negotiation, and privacy amplification, this invention effectively reduces the key inconsistency rate between communicating parties, improves the key generation rate, key consistency rate, and final key security, demonstrating strong environmental adaptability and engineering application value. Attached Figure Description

[0042] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0043] Figure 1 This is a flowchart illustrating a wireless key generation method based on time slot correlation in this embodiment.

[0044] Figure 2 This is a schematic diagram of the module connections of a wireless key generation system based on time slot correlation in this embodiment;

[0045] Figure 3 This is a schematic diagram of the structure of a computer device in this embodiment. Detailed Implementation

[0046] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0047] In this disclosure, unless otherwise stated, the use of terms such as "first," "second," etc., to describe various elements is not intended to limit the positional, temporal, or importance relationships of these elements; such terms are merely used to distinguish one element from another. In some examples, the first element and the second element may refer to the same instance of that element, while in other cases, based on the context, they may refer to different instances.

[0048] The terminology used in the description of the various examples in this disclosure is for the purpose of describing particular examples only and is not intended to be limiting. Unless the context explicitly indicates otherwise, an element may be one or more unless the number of elements is specifically limited. Furthermore, the term "and / or" as used in this disclosure covers any one of the listed items and all possible combinations thereof.

[0049] Example 1

[0050] See Figure 1 , Figure 1A flowchart illustrating a wireless key generation method based on time slot correlation is shown. This method is used for wireless key generation between two communication endpoints in wireless communication, and includes the following steps:

[0051] S1: The two communication terminals respectively collect wireless channel state information from multiple consecutive time slots and construct their respective channel feature sequences; wherein, the channel feature sequence includes multiple channel time slot features, and each channel time slot feature is used to characterize the channel state features in different time slots;

[0052] First, it should be noted that in this embodiment, both communication ends can act as both receivers and transmitters, without any specific restrictions on them; at the same time, in this embodiment, the two communication ends are named Alice end and Bob end, respectively, and they acquire wireless channel state information in continuous time slots through bidirectional pilot detection.

[0053] Secondly, it should be noted that in this embodiment, the wireless channel state information can be one or more of the following: subcarrier channel response, received signal strength, channel amplitude information, channel phase information, or channel impulse response tap value in an orthogonal frequency division multiplexing system; for ease of explanation, this embodiment uses extraction per time slot. The channel amplitude characteristics are described in a way that is dimensional; at the same time, the pilot detection period can be set to 5ms to 20ms, and the interval between adjacent time slots should not be greater than the channel coherence time, so as to ensure that the channel characteristics observed by both parties in adjacent time slots still have strong reciprocity and timing correlation; and for OFDM communication scenarios, channel amplitude characteristics can be extracted from multiple stable subcarriers for subsequent key generation.

[0054] Finally, it should be noted that in this embodiment, the channel feature sequence constructed by Alice is as follows: ,in, Indicates that Alice's end is at the 1st Channel time slot features acquired from each time slot, i.e., channel feature sequence The Middle Channel slot characteristics, This represents the channel slot feature index within the channel feature sequence, where t is an integer greater than 1. ,in, Indicates that Alice's end is at the 1st The first time slot obtained 3D channel eigenvalues Similarly, the channel feature sequence constructed by Bob is ,in, This indicates that Bob's end is at the 1st Channel time slot features acquired from each time slot, i.e., channel feature sequence The Middle Channel slot characteristics, ,in, This indicates that Bob's end is at the 1st The first time slot obtained 3D channel eigenvalues.

[0055] Specifically, in this embodiment, the two communication terminals respectively collect wireless channel state information from multiple consecutive time slots to construct their respective initial channel feature sequences; the two communication terminals respectively preprocess their respective initial channel feature sequences to obtain preprocessed channel feature sequences; wherein, the preprocessing includes noise interference elimination, time slot synchronization, amplitude normalization processing and reciprocity calibration.

[0056] Specifically, after both communication ends have constructed their respective initial channel feature sequences, they need to preprocess the initial channel feature sequences. This involves filtering, denoising, and smoothing the initial channel feature sequences to suppress thermal noise, burst interference, and random spikes. Specifically, this includes processing the initial channel feature sequences of the first... The first channel slot feature The dimensional channel eigenvalues ​​use a length of The sliding window is smoothed, and the smoothed first... 3D channel eigenvalues In the formula, Indicates either of the two communication ends. Indicates the smooth window half-width. This represents the channel characteristic values ​​within adjacent time slot windows;

[0057] Next, the denoised channel feature sequence undergoes time slot synchronization and amplitude normalization to eliminate differences in sampling time and amplitude scale between the two sides. Specifically, the smoothed channel time slot features are normalized using a standardization method. 3D channel eigenvalues In the formula, Indicates the first The mean of all channel feature values ​​within a channel time slot feature. Indicates the first The standard deviation of all channel feature values ​​within a single channel time slot feature. This represents a very small positive number that prevents the denominator from being zero;

[0058] The normalized channel features are then subjected to reciprocity compensation and outlier removal to obtain a preprocessed channel feature sequence. Specifically, this involves matching the statistical features of the two communication ends within the overlapping time window to reduce non-ideal errors caused by RF front-end gain drift and local oscillator instability. For outliers exceeding the preset statistical range, mean replacement, median replacement, or neighborhood interpolation can be used for correction, ultimately yielding the channel feature sequence. , In the formula, Indicates the first after preprocessing Channel slot characteristics, Indicates the first after preprocessing The first of the channel time slot characteristics 3D channel eigenvalues.

[0059] S2: In each communication terminal, calculate the correlation value between the t-th channel time slot feature in its channel feature sequence and the previous P-1 historical channel time slot features, and fuse the previous P-1 historical channel time slot features based on the correlation value to obtain the memory enhancement feature corresponding to the t-th channel time slot feature;

[0060] It should be noted that, in this embodiment, when calculating the correlation between the historical channel time slot feature and the t-th channel time slot feature, the t-th channel time slot feature and its preceding P-1 historical channel time slot features are combined to form a correlation calculation sequence. ,in, Let P represent the correlation calculation sequence corresponding to the t-th channel time slot feature, and let P represent the number of features involved in the correlation calculation of the t-th channel time slot feature. P includes the t-th channel time slot feature itself and the previous P-1 historical channel time slot features. P is an integer greater than 1. Among them, the historical channel time slot features refer to the P-1 channel time slot features located between the t-th channel time slot features in the channel feature sequence.

[0061] Furthermore, to ensure that the correlation calculation and memory enhancement processing can be stably performed at the beginning stage of the channel feature sequence, when the number of available historical channel time slot features before the t-th channel time slot feature is less than a preset number P-1, the actual available historical channel time slot features can be used in the calculation. Specifically, when t-1 is greater than or equal to P-1, P-1 historical channel time slot features before the t-th channel time slot feature are selected for correlation calculation; when t-1 is less than P-1, all available historical channel time slot features before the t-th channel time slot feature are selected for correlation calculation. In this case, the actual number of features involved in the correlation calculation for the t-th channel time slot feature can be expressed as: ,in, This includes the t-th channel time slot feature itself. Through this method, the present invention can employ a variable-length historical window in the initial stage of the sequence, and switch to a fixed-length window after the number of historical features meets the condition, thereby enhancing the completeness and engineering applicability of the method.

[0062] Specifically, in this embodiment, in each communication terminal, the correlation value between the t-th channel time slot feature in its channel feature sequence and the previous P-1 historical channel time slot features is calculated; the weight coefficients of the previous P-1 historical channel time slot features relative to the t-th channel time slot feature are determined based on the correlation values; the previous P-1 historical channel time slot features are fused using the weight coefficients to obtain the memory enhancement feature corresponding to the t-th channel time slot feature.

[0063] Specifically, in each communication terminal, the correlation value between the t-th channel time slot feature and the previous P-1 historical channel time slot features is first calculated using a correlation calculation function. The correlation value of the historical channel slot features is In the formula, Indicates the first The characteristics of the first channel slot and the first The correlation values ​​between historical channel slot characteristics Indicates the number after preprocessing. The mean of all channel feature values ​​within a channel time slot feature. Indicates the number after preprocessing. The mean of all channel feature values ​​within a given historical channel time slot feature. ;

[0064] Then, based on the calculated correlation values, determine the weight coefficients for the first P-1 historical channel slot features. The weight coefficients for each historical channel slot feature are expressed as follows: ,in, Indicates relative to the first The characteristics of the first channel slot, the first The weighting coefficients of the historical channel slot characteristics; and relative to the first historical channel slot feature. The weighting coefficients of the first P-1 historical channel slot features of each channel slot feature satisfy the following... ;

[0065] Then, the weighting coefficients are used to fuse the features of the first P-1 historical channel slots to obtain the memory enhancement feature corresponding to the t-th channel slot feature, specifically: ,in, , Indicates the first The first of the memory enhancement features Dimensional memory enhancement feature value.

[0066] S3: Obtain the feature distribution information of all memory enhancement features and adjust the adaptive quantization rule based on the feature distribution information; quantize the memory enhancement features using the adjusted adaptive quantization rule to obtain the quantized initial key bit sequence; perform reliability screening on the initial key bit sequence based on the observation residual between the channel slot features and the corresponding memory enhancement features to obtain the key bit sequence.

[0067] It should be noted that, in this embodiment, the feature distribution information of the memory enhancement feature includes statistical distribution, fluctuation intensity, and multi-slot correlation. In other embodiments, other feature information may also be used, and no further restrictions are imposed here.

[0068] Specifically, in this embodiment, the average deviation between the memory enhancement feature and the corresponding channel slot feature is obtained, and the quantization adjustment coefficient for each memory enhancement feature is generated using the average deviation; the mean and standard deviation of each memory enhancement feature are obtained, and the adaptive quantization rule for each memory enhancement feature is adjusted using the quantization adjustment coefficient, mean, and standard deviation; the memory enhancement feature is quantized using the adjusted adaptive quantization rule to obtain the quantized initial key bit sequence; for each memory enhancement feature, the minimum value between each memory enhancement feature value and the quantization threshold value is obtained as the quantization margin for each memory enhancement feature value; the prediction deviation between each memory enhancement feature value and the corresponding slot feature value in the channel slot feature is obtained as the prediction deviation for each memory enhancement feature value; the reliability index for each memory enhancement feature value is constructed using the prediction deviation and the quantization margin; in the initial key bit sequence, when the reliability index of the memory enhancement feature value is not less than a preset index threshold... If the condition is met, the corresponding bit is retained; otherwise, the corresponding bit is discarded; thus, the final key bit sequence is obtained through filtering.

[0069] Specifically, the average deviation between the memory enhancement feature and the corresponding channel time slot feature is first obtained, and then the average deviation between the memory enhancement feature and the corresponding channel time slot feature is defined as a fluctuation intensity index, specifically: In the formula, Indicates the first The average bias of each memory enhancement feature;

[0070] Then, the average bias is used to generate the quantization adjustment coefficient for each memory enhancement feature, specifically: In the formula, Indicates the first The quantization adjustment coefficient corresponding to each memory enhancement feature Represents the basic quantization coefficient. This represents the fluctuation intensity adjustment factor. It should also be noted that the quantization adjustment coefficient in this invention can be determined using a combination of "current time slot statistical feature generation" and "cross-time slot feedback update." Specifically, candidate quantization adjustment coefficients for the current time slot can be generated first based on the average deviation between the current memory enhancement feature and the corresponding channel time slot feature. This reflects the quantization sensitivity under the current channel fluctuation state; that is, the quantization adjustment coefficient for each memory enhancement feature is generated using the average deviation, as described above. Then, the quantization adjustment coefficient from the previous time slot is combined with this. Key inconsistency rate corresponding to the previous time slot and key generation rate The candidate quantization adjustment coefficients for the current time slot are updated smoothly. , and These represent the inconsistency rate update step size and the generation rate update step size, respectively. This represents the target inconsistency rate. This represents the target key generation rate; thus, the final quantization adjustment coefficient used for adjusting the quantization threshold in the current time slot is obtained. This method enables adaptive adjustment by utilizing the statistical distribution characteristics of the current time slot, and also uses historical performance feedback to suppress drastic fluctuations in the quantization threshold between consecutive time slots, improving the stability and environmental adaptability of the quantization process.

[0071] Next, obtain the mean and standard deviation of each memory enhancement feature, specifically: , In the formula, Indicates the first The mean of each memory-enhancing feature, Indicates the first The standard deviation of each memory enhancement feature;

[0072] Then, using the quantization adjustment coefficient, mean, and standard deviation, the adaptive quantization rule for each memory enhancement feature is adjusted. Specifically, the upper and lower quantization thresholds in the adaptive quantization rule are adjusted as follows: , In the formula, , They represent the first The upquantization threshold and downquantization threshold in the adaptive quantization rule of a memory-enhancing feature;

[0073] The memory-enhanced features are quantized using the adjusted adaptive quantization rule to obtain the quantized initial key bit sequence, where the adjusted bit sequence is... The adaptive quantization rule for each memory-enhancing feature is: ,in, Indicates to Quantized feature values ​​after quantization express Features falling into the unreliable decision interval are discarded; each memory enhancement feature is quantized using this adaptive quantization rule to obtain the quantized initial key bit sequence. ;

[0074] For each memory enhancement feature, the minimum value between each memory enhancement feature value and the upper or lower quantization threshold is obtained as the quantization margin for each memory enhancement feature value, specifically: In the formula, Indicates the first The first of the memory enhancement features The quantization margin of the dimensional memory-enhanced eigenvalue, i.e., the 1st dimension... The first of the memory enhancement features The minimum distance between the dimensionality-enhanced eigenvalue and the two quantization thresholds;

[0075] Next, the prediction deviation between each memory enhancement feature value in the memory enhancement features and the corresponding time slot feature value in the channel time slot features is obtained, and this deviation is used as the prediction deviation for each memory enhancement feature value. Specifically: In the formula, Indicates the first The first of the memory enhancement features Prediction bias of dimensional memory-enhanced eigenvalues;

[0076] Based on the quantification margin and prediction bias, a reliability index is constructed, specifically: In the formula, Indicates the first The first of the memory enhancement features Reliability index of 3D memory-enhanced eigenvalues This represents a very small positive number that prevents the denominator from being zero;

[0077] Finally, low-reliability bits are filtered out based on reliability indicators, and the position index of the retained bits is recorded; in this embodiment, when At that time, retain the corresponding quantized bits and record their feature index. ;when When the corresponding quantized bits are removed, the final key bit sequence is obtained by filtering.

[0078] S4: The two communication ends exchange bit position index information in their respective key bit sequences through a public channel, and retain key bits with the same position according to the other party's bit position index information to obtain a shared wireless key.

[0079] Specifically, Alice and Bob each send their respective sets of reserved bit position indices to each other via a public channel, and then take the intersection of their index sets. Subsequently, they only retain the key bits corresponding to the intersection indices, i.e., the key bits with the same positions, thus obtaining a set of length [value missing]. And a fully aligned shared wireless key and ;

[0080] Meanwhile, both Alice's and Bob's ends are based on the aligned shared wireless key. and Information negotiation and error correction consistency processing are performed through a public channel to correct bit differences between the two parties. Specifically, let the aligned shared wireless keys of Alice and Bob be as follows: Then Alice calculates the comprehensive verification information: ,in, This represents the comprehensive verification information generated by the Alice client. This represents the preset check matrix. Indicates modulo 2 operation;

[0081] The Bob terminal calculates based on its shared wireless key: ,in, This represents the comprehensive checksum information generated by Bob; then, error correction decoding is performed based on the comprehensive checksum difference: ,in, This represents the overall verification difference. This represents the XOR operation; then the error vector is obtained through decoding. Then, the candidate key sequence on Bob's end is corrected: ,in, This indicates the shared wireless key obtained by Bob after error correction. This represents the error vector obtained from error correction decoding.

[0082] Correspondingly, the shared wireless key after consistency on the Alice side is In an ideal situation, there is .

[0083] It should also be noted that, in this embodiment, the key inconsistency rate... The inconsistency rate is equivalently estimated using the error vector obtained during error correction decoding in step S4. Therefore, the inconsistency rate of the original key is defined as follows: In the formula, Indicates the first The original key inconsistency rate for each time slot. This represents the error vector obtained from error correction decoding. Hamming weight (i.e., the total number of error bits corrected). Indicates the first The length of the shared wireless key obtained by aligning the index intersection of the time slots;

[0084] Define the key generation rate as: In the formula, Indicates the first Key generation rate per time slot, Indicates the first The length of the candidate key obtained after filtering each time slot This represents the time interval between two consecutive key generation processes.

[0085] As one possible implementation, after obtaining the shared wireless key, the method further includes:

[0086] The shared wireless key is subjected to privacy amplification processing to generate the final shared wireless key.

[0087] Specifically, this embodiment uses the Toeplitz matrix hashing method to compress and map the unified shared wireless key. Specifically, the length of the unified shared wireless key is set to... The final key length is ,in The final shared key is represented as: ,in, Indicates the final shared key. Indicates dimension as Toeplitz privacy amplification matrix, This represents the unified shared wireless key. This indicates a modulo-2 operation.

[0088] In this embodiment, the same Toeplitz privacy amplification matrix is ​​used on both the Alice and Bob ends. After compressing and mapping the unified shared wireless key, a consistent final shared key can be obtained. By performing privacy amplification processing on the unified shared wireless key, the information leakage that may occur during the information negotiation process is reduced, and the final shared key is generated.

[0089] As one possible implementation, the method further includes:

[0090] Based on the correlation values ​​between the t-th channel time slot feature and the previous P-1 historical channel time slot features, the average correlation of the t-th channel time slot feature is calculated, specifically as follows: In the formula, This represents the average correlation within the t-th channel time slot feature. This represents the number of features participating in the correlation calculation of the t-th channel time slot feature. The number of features participating in the correlation calculation of the (t+1)-th channel time slot feature is updated using the average correlation of the t-th channel time slot feature combined with a preset average correlation decision threshold. , This represents the number of features involved in the correlation calculation of the (t+1)th channel slot features. This indicates the number of features involved. This represents the minimum number of features involved. This represents the preset average relevance decision threshold. In some implementations, it refers to the number of features involved. The minimum number of features involved can be set to an integer greater than 4, preferably 5 to 12, depending on the historical time slot utilization requirements; It can be set to an integer not less than 2, preferably 2 to 4; preset average correlation decision threshold It can be set between 0 and 1, preferably between 0.4 and 0.8. The above parameters can be adjusted according to the channel change rate, sampling period, and target key generation rate.

[0091] Specifically, in this embodiment, the present invention constructs a memory enhancement feature corresponding to each channel time slot feature by analyzing and calculating the correlation between each channel time slot feature and its previous multiple historical channel time slot features. This memory enhancement feature is then introduced into the wireless physical layer key generation process, enabling more full utilization of the correlation and shared randomness of the wireless channel in the time dimension. Compared to existing methods that rely solely on single time slot observation results, this significantly improves the stability of random feature extraction. Furthermore, the present invention introduces an adaptive quantization mechanism, which dynamically adjusts the quantization threshold and decision interval according to the statistical characteristics under different channel conditions. Adaptive quantization rules are used to adaptively quantize the memory enhancement feature, thereby reducing the quantization mismatch problem that easily occurs in fixed-threshold methods under low signal-to-noise ratio, fast fading, and complex dynamic environments. Simultaneously, through the collaborative design of reliability screening, information negotiation, and privacy amplification, the present invention effectively reduces the key inconsistency rate between communicating parties, improves the key generation rate, key consistency rate, and final key security, demonstrating strong environmental adaptability and engineering application value.

[0092] Example 2

[0093] The present invention also provides a wireless key generation system based on time slot correlation, which is used in the wireless key generation method based on time slot correlation described in any one of the above claims, the system comprising:

[0094] The feature sequence construction module 100 is used for two communication ends to collect wireless channel state information from multiple consecutive time slots and construct their respective channel feature sequences; wherein, the channel feature sequence includes multiple channel time slot features, and each channel time slot feature is used to characterize the state features of the channel in different time slots;

[0095] The correlation fusion module 200 is used in each communication terminal to calculate the correlation value between the t-th channel time slot feature in its channel feature sequence and the previous P-1 historical channel time slot features, and to fuse the previous P-1 historical channel time slot features based on the correlation value to obtain the memory enhancement feature corresponding to the t-th channel time slot feature; where P represents the number of features participating in the correlation calculation of the t-th channel time slot feature, t represents the channel time slot feature index in the channel feature sequence, and t and P are both integers greater than 1;

[0096] The key bit quantization module 300 is used to acquire the feature distribution information of all memory enhancement features in each communication end, and adjust the adaptive quantization rule based on the feature distribution information; quantize the memory enhancement features using the adjusted adaptive quantization rule to obtain the quantized initial key bit sequence; and perform reliability screening on the initial key bit sequence based on the observation residual between the channel time slot features and the corresponding memory enhancement features to obtain the key bit sequence.

[0097] The wireless key generation module 400 is used for two communication terminals to exchange bit position index information in their respective key bit sequences through a public channel, and to retain key bits with the same position according to the other party's bit position index information to obtain a shared wireless key.

[0098] It should be noted that the modules in the system of Embodiment 2 correspond to the steps in the method of Embodiment 1. The steps in the method of Embodiment 1 have been described in detail in Embodiment 1, and the module content in the system will not be described in detail in this Embodiment 2.

[0099] Example 3

[0100] This embodiment also provides a computer device, including a system memory 1005 and a processor 1001. The system memory 1005 stores a computer program, and the processor 1001 executes the computer program to implement the steps of any of the methods described above.

[0101] It should be noted that the processor 1001 is used to execute the steps in the above method embodiments according to the instructions in the program code. Alternatively, when the processor 1001 executes the computer program, it implements the functions of each module / unit in the above system / device embodiments.

[0102] Specifically, in this embodiment, the computer program can be divided into one or more modules / units, which are stored in the system memory 1005 and executed by the processor 1001 to complete this application. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program in the terminal device.

[0103] The terminal device can be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor 1001 and a system memory 1005. Those skilled in the art will understand that this does not constitute a limitation on the terminal device; it may include more or fewer components than shown in the figures, or a combination of certain components, or different components. For example, the terminal device may also include an input / output device 1003, a network access device 1002, a bus 1006, etc.

[0104] The processor 1001 can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0105] System memory 1005 can be an internal storage unit of the terminal device, such as a hard drive or RAM. System memory 1005 can also be a storage device 1004 of the terminal device, such as an external hard drive, SmartMedia Card (SMC), Secure Digital (SD) card, or FlashCard. Furthermore, system memory 1005 can include both internal storage units and storage device 1004. System memory 1005 is used to store computer programs and other programs and data required by the terminal device. System memory 1005 can also be used to temporarily store data that has been output or will be output.

[0106] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0107] Example 4

[0108] This embodiment provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the methods described above.

[0109] The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), registers, hard disks, optical fibers, compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof, or any other form of computer-readable storage medium in the art.

[0110] An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside within an application-specific integrated circuit (ASIC). In embodiments of the invention, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device.

[0111] Example 5

[0112] This embodiment also provides a computer program product containing instructions that, when executed by a cluster of computer devices, cause the cluster of computer devices to perform the method described in Embodiment 1.

[0113] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A wireless key generation method based on time slot correlation, characterized in that, This method is used for generating wireless keys between two communication terminals in wireless communication, and the method includes: Two communication terminals respectively collect wireless channel state information from multiple consecutive time slots and construct their respective channel feature sequences; wherein, the channel feature sequence includes multiple channel time slot features, and each channel time slot feature is used to characterize the channel state features in different time slots; In each communication terminal, the correlation value between the t-th channel time slot feature in its channel feature sequence and the previous P-1 historical channel time slot features is calculated. Based on the correlation value, the previous P-1 historical channel time slot features are fused to obtain the memory enhancement feature corresponding to the t-th channel time slot feature. Here, P represents the number of features participating in the correlation calculation of the t-th channel time slot feature, t represents the channel time slot feature index in the channel feature sequence, and t and P are both integers greater than 1. The feature distribution information of all memory-enhanced features is obtained, and the adaptive quantization rule is adjusted based on the feature distribution information. The memory-enhanced features are quantized using the adjusted adaptive quantization rule to obtain the quantized initial key bit sequence. The reliability of the initial key bit sequence is screened based on the observation residual between the channel slot features and the corresponding memory-enhanced features to obtain the key bit sequence. Two communication terminals exchange bit position index information in their respective key bit sequences through a public channel, and retain key bits with the same position according to the other party's bit position index information to obtain a shared wireless key.

2. The wireless key generation method based on time slot correlation according to claim 1, characterized in that, The features of the first P-1 historical channel slots are fused based on the correlation value, specifically as follows: The weighting coefficients of the first P-1 historical channel time slot features relative to the t-th channel time slot feature are determined based on the correlation value; the weighting coefficients are then used to fuse the first P-1 historical channel time slot features.

3. The wireless key generation method based on time slot correlation according to claim 1, characterized in that, Two communication terminals respectively collect wireless channel state information from multiple consecutive time slots and construct their respective channel feature sequences, specifically: Two communication terminals respectively collect wireless channel state information from multiple consecutive time slots to construct their respective initial channel feature sequences; The two communication ends each preprocess their respective initial channel feature sequences to obtain preprocessed channel feature sequences; The preprocessing includes noise removal, time slot synchronization, amplitude normalization, and reciprocity calibration.

4. The wireless key generation method based on time slot correlation according to claim 1, characterized in that, Obtain the feature distribution information of all memory-enhancing features, and adjust the adaptive quantization rule based on the feature distribution information, specifically as follows: The average deviation between the memory enhancement feature and the corresponding channel slot feature is obtained, and the quantization adjustment coefficient of each memory enhancement feature is generated using the average deviation. Obtain the mean and standard deviation of each memory enhancement feature, and adjust the adaptive quantization rule of each memory enhancement feature using the quantization adjustment coefficient, mean, and standard deviation.

5. The wireless key generation method based on time slot correlation according to claim 1, characterized in that, The reliability of the initial key bit sequence is screened based on the observation residuals between the channel time slot characteristics and the corresponding memory enhancement characteristics, resulting in the following key bit sequence: For each memory enhancement feature, the minimum value between each memory enhancement feature value and the quantization threshold value is obtained as the quantization margin of each memory enhancement feature value; The prediction deviation between each memory enhancement feature value in the memory enhancement feature and the corresponding time slot feature value in the channel time slot feature is obtained as the prediction deviation of each memory enhancement feature value. A reliability index for each memory-enhanced feature value is constructed using prediction bias and quantization margin. In the initial key bit sequence, the reliability index is used to filter the bits corresponding to each memory enhancement feature value to obtain the final key bit sequence.

6. The wireless key generation method based on time slot correlation according to claim 5, characterized in that, The reliability of the bits corresponding to each memory-enhancing feature value is screened using reliability metrics, specifically as follows: If the reliability index of the memory-enhanced feature value is not less than the preset index threshold, the corresponding bit is retained; otherwise, the corresponding bit is discarded.

7. The wireless key generation method based on time slot correlation according to claim 1, characterized in that, After obtaining the shared wireless key, the method also includes: The shared wireless key is subjected to privacy amplification processing to generate the final shared wireless key.

8. The wireless key generation method based on time slot correlation according to claim 1, characterized in that, The method also includes: Based on the correlation values ​​between the t-th channel time slot feature and the previous P-1 historical channel time slot features, calculate the average correlation of the t-th channel time slot feature; The number of features involved in the correlation calculation of the (t+1)th channel time slot is updated by combining the average correlation of the t-th channel time slot feature with a preset average correlation decision threshold.

9. A wireless key generation system based on time slot correlation, characterized in that, The system is used in a wireless key generation method based on time slot correlation as described in any one of claims 1-8, the system comprising: The feature sequence construction module is used by two communication ends to collect wireless channel state information from multiple consecutive time slots and construct their respective channel feature sequences. The channel feature sequence includes multiple channel time slot features, and each channel time slot feature is used to characterize the channel state features in different time slots. The correlation fusion module is used in each communication terminal to calculate the correlation value between the t-th channel time slot feature in its channel feature sequence and the previous P-1 historical channel time slot features, and to fuse the previous P-1 historical channel time slot features based on the correlation value to obtain the memory enhancement feature corresponding to the t-th channel time slot feature; where P represents the number of features participating in the correlation calculation of the t-th channel time slot feature, t represents the channel time slot feature index in the channel feature sequence, and t and P are both integers greater than 1; The key bit quantization module is used to acquire the feature distribution information of all memory enhancement features in each communication end, and adjust the adaptive quantization rule based on the feature distribution information; quantize the memory enhancement features using the adjusted adaptive quantization rule to obtain the quantized initial key bit sequence; and perform reliability screening on the initial key bit sequence based on the observation residual between the channel time slot features and the corresponding memory enhancement features to obtain the final key bit sequence. The wireless key generation module is used by two communication terminals to exchange bit position index information in their respective key bit sequences through a public channel, and to retain key bits with the same position according to the other party's bit position index information to obtain a shared wireless key.

10. A computer device comprising a system memory and a processor, wherein the system memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 8.

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