Physical layer secure transmission method and system for high-speed rail wireless communication system

Abstract

The invention belongs to the technical field of high-speed rail wireless communication, and discloses a physical layer secure transmission method and system for a high-speed rail wireless communication system. The method comprises the following steps: acquiring a high-speed rail wireless communication baseband signal to be sent and channel state information; generating an encrypted baseband signal through orthogonal transformation, nonlinear reversible encryption and adaptive disturbance based on channel state information; the receiving end obtains the intention signal after decryption; acquiring an inversion baseband signal based on potential wireless eavesdropping channel monitoring, and performing adversarial optimization to obtain an eavesdropping intention signal; and constructing and optimizing a wireless physical layer security loss function according to the intention signal and the eavesdropping intention signal until convergence. According to the method, physical layer key synchronization is realized by utilizing wireless channel reciprocity, and the physical layer security of a high-speed rail wireless communication system is effectively improved by matching channel change in a high-speed moving scene through adaptive disturbance.

Description

Technical Field

[0001] This invention belongs to the field of high-speed rail wireless communication technology, specifically relating to a physical layer secure transmission method and system for high-speed rail wireless communication systems, which is particularly suitable for enhancing wireless channel security in high-speed mobile scenarios. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Security research on high-speed rail wireless communication systems is a prerequisite for maintaining the reliable and autonomous operation of the entire high-speed rail system. With the application of 5G-R and future 6G in high-speed rail scenarios, high-speed rail wireless communication systems face challenges such as rapid channel changes, severe Doppler shift, and frequent handovers caused by high-speed movement. Semantic communication, as a new communication paradigm, can directly transmit semantic features of information instead of bit streams, effectively mitigating the performance degradation caused by channel estimation errors and inter-carrier interference in high-speed mobile environments, providing a new approach for intelligent transportation systems on high-speed rail. However, semantic communication also introduces new security challenges during wireless channel transmission, especially the defense against physical layer inversion attacks, necessitating the development of dedicated security mechanisms.

[0004] Currently, there are three main approaches to addressing inversion attacks in wireless communication: covert communication, application-layer encryption, and cryptographic encryption. Covert communication reduces the probability of detection by methods such as power control, thus hiding the communication itself. Application-layer encryption, from a system design and network security perspective, achieves protection through cross-layer encryption and adversarial training. Cryptographic encryption follows and expands upon classical cryptographic systems, encrypting data after source encoding to achieve end-to-end content confidentiality.

[0005] While existing inversion attack defense technologies have made significant progress, their direct application in high-speed rail wireless communication scenarios still faces considerable limitations. Especially under the frequent network switching and rapid channel changes caused by high-speed train movement, existing technologies are prone to security-utility imbalances. Furthermore, current methods fail to fully utilize the inherent characteristics of high-speed rail wireless channels, such as channel reciprocity, fading characteristics, and the Doppler effect, to enhance physical layer security. Therefore, researching physical layer secure transmission technologies suitable for high-speed rail wireless communication systems is particularly important. Summary of the Invention

[0006] To address the aforementioned issues, this invention proposes a physical layer secure transmission method and system for high-speed rail wireless communication systems. It maps baseband signals to a normed linear space through orthogonal transformation, removing inter-dimensional correlations and increasing the difficulty of statistical information-assisted inversion. A nonlinear reversible encryption operator is employed to enhance signal inversion difficulty through nonlinear reversible transformation, while embedding reversibility constraints to ensure that legitimate receivers can accurately reconstruct the intended signal. Utilizing the reciprocity of the wireless channel at both ends, an adaptive perturbation encryption module based on channel state information is used to internalize channel characteristics as the physical layer key, resolving the security-utility imbalance problem. The algorithm is embedded in the wireless communication physical layer, and an adversarial training algorithm is designed under the assumption of an attacker, internalizing the security-utility balance.

[0007] According to some embodiments, the first aspect of the present invention provides a physical layer secure transmission method for a high-speed rail wireless communication system, employing the following technical solution: A physical layer secure transmission method for a high-speed rail wireless communication system includes: The original high-speed rail wireless communication baseband signal to be transmitted is acquired, and the channel state information of the current wireless channel is measured, wherein the channel state information is the signal-to-noise ratio; The original high-speed rail wireless communication baseband signal is orthogonally transformed to obtain a rotating baseband signal; the obtained rotating baseband signal is nonlinearly reversibly encrypted in a normed linear space to obtain a confused baseband signal; based on the confused baseband signal and the adaptive perturbation generated according to the channel state information, an encrypted baseband signal suitable for wireless channel transmission is constructed. The received encrypted baseband signal is decrypted to obtain the decrypted baseband signal; The decrypted baseband signal is reconstructed to obtain the intended signal of the high-speed rail wireless communication baseband signal; Based on the monitoring of the transmission process of the original high-speed rail wireless communication baseband signal using potential wireless eavesdropping channels, the inverted baseband signal is obtained; The eavesdropping intent signal is obtained by inverting the baseband signal. Construct a wireless physical layer security loss function based on the obtained intent signal and eavesdropping intent signal; The constructed wireless physical layer security loss function is optimized until it converges, thus obtaining the optimal wireless transmission parameters and completing the physical layer security transmission of the high-speed rail wireless communication system.

[0008] As a further technical limitation, the process of generating adaptive perturbation based on channel state information is as follows: based on the measured signal-to-noise ratio, a deterministic perturbation seed is generated through a hash function; based on the deterministic perturbation seed, a perturbation vector bound to the channel state is generated to complete the adaptive perturbation of signal state information; when the channel conditions are good, the perturbation is increased to enhance security, and when the channel conditions are poor, the perturbation intensity is reduced to ensure communication effectiveness.

[0009] As a further technical limitation, the process of decrypting the received encrypted baseband signal is as follows: performing inverse adaptive perturbation on the encrypted baseband signal to obtain a decrypted obfuscated baseband signal; performing inverse nonlinear reversible decryption on the decrypted obfuscated baseband signal to obtain a decrypted rotated baseband signal; performing inverse orthogonal transformation on the decrypted rotated baseband signal to obtain a decrypted baseband signal; and iterating the decrypted baseband signal sequence to obtain the intention signal.

[0010] As a further technical limitation, the constructed wireless physical layer security loss function is: ; ; in, Indicates the source signal; Signals indicating intent to eavesdrop; Indicates intent signal; , , , These represent the baseband coding modules on the legitimate link, respectively. Encryption module Decryption module Decoding module Parameters; Indicates a potential eavesdropping module on a potential eavesdropping link. Parameters; This represents the security loss function of the eavesdropping link; Describes the loss function of security utility on legitimate links; This represents the balance coefficient between the utility loss of the legitimate link and the security loss of the eavesdropping link during the training process of the legitimate link. This indicates the operation of taking the average value; Represents the 2-norm; This represents the balance parameter between transmission loss and reconstruction loss; The encoded signal representing the source signal; Encoded signals that indicate the intent to eavesdrop.

[0011] As a further technical limitation, the encryption shared key in the encryption process and the decryption shared key in the decryption process can be generated synchronously based on the reciprocity of the wireless channel. By utilizing the symmetry of the uplink and downlink channels in time-division duplex mode, the physical layer key can be extracted from the channel impulse response.

[0012] As a further technical limitation, the method also includes: dynamically adjusting the feedback period of channel state information according to the terminal's moving speed; when the terminal speed exceeds the speed threshold (generally set to 300km / h), enabling a high-speed mobile dedicated transmission mode, including shortening the transmission time interval and increasing the pilot density.

[0013] According to some embodiments, the second aspect of the present invention provides a physical layer secure transmission system for a high-speed rail wireless communication system, employing the following technical solution: A physical layer secure transmission system for high-speed rail wireless communication systems includes: The baseband coding module is configured to acquire the original high-speed rail wireless communication baseband signal to be transmitted and measure the channel state information of the current wireless channel, wherein the channel state information is the signal-to-noise ratio. An encryption module is configured to perform an orthogonal transformation on the acquired original high-speed rail wireless communication baseband signal to obtain a rotated baseband signal; to perform nonlinear reversible encryption on the obtained rotated baseband signal in a normed linear space to obtain a confused baseband signal; and to construct an encrypted baseband signal suitable for wireless channel transmission based on the confused baseband signal and an adaptive perturbation generated according to channel state information. The decryption module is configured to decrypt the received encrypted baseband signal to obtain the decrypted baseband signal; The decoding module is configured to reconstruct the decrypted baseband signal to obtain the intention signal of the high-speed rail wireless communication baseband signal; A potential eavesdropping module is configured to monitor the transmission process of the original high-speed rail wireless communication baseband signal based on a potential wireless eavesdropping channel to obtain an inverted baseband signal; and to invert the inverted baseband signal to obtain an eavesdropping intent signal. The defense module is configured to construct a wireless physical layer security loss function based on the obtained intent signal and eavesdropping intent signal; optimize the constructed wireless physical layer security loss function until the loss function converges, obtain the optimal wireless transmission parameters, and complete the physical layer security transmission of the high-speed rail wireless communication system.

[0014] According to some embodiments, a third aspect of the present invention provides a computer-readable storage medium, employing the following technical solution: A computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps of the physical layer secure transmission method for a high-speed rail wireless communication system as described in the first aspect of the present invention.

[0015] According to some embodiments, the fourth aspect of the present invention provides an electronic device, which adopts the following technical solution: An electronic device includes a memory, a processor, and a program stored in the memory and running on the processor. When the processor executes the program, it implements the steps in the physical layer secure transmission method for a high-speed rail wireless communication system as described in the first aspect of the present invention.

[0016] According to some embodiments, the fifth aspect of the present invention provides a computer program product, which adopts the following technical solution: A computer program product includes software code, wherein the program in the software code performs the steps of the physical layer secure transmission method for a high-speed rail wireless communication system as described in the first aspect of the present invention.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention addresses the security-utility imbalance problem that easily arises when existing inversion attack defense technologies are applied to high-speed rail wireless communication scenarios. It proposes a physical layer secure transmission method and system for high-speed rail wireless communication systems. This invention utilizes the reciprocity and fading characteristics of high-speed rail wireless channels, mapping the baseband signal to a normed linear space through orthogonal transformation, removing inter-dimensional correlations, and increasing the difficulty of using statistical information to assist in inversion. A nonlinear reversible encryption operator is designed, using nonlinear reversible transformations to enhance the difficulty of signal inversion, while embedding reversibility constraints to ensure that legitimate receivers can accurately reconstruct the signal. Utilizing the channel reciprocity at both the transmitting and receiving ends, an adaptive perturbation encryption module based on channel state information is designed, internalizing channel characteristics as the physical layer key to solve the security-utility imbalance problem. The algorithm is embedded in the wireless communication physical layer, and an adversarial training algorithm is designed under the assumption of an attacker, internalizing the security-utility balance. This invention can effectively adapt to high-speed mobile scenarios above 300 km / h, maximizing physical layer security capacity while ensuring the communication quality of legitimate links. Attached Figure Description

[0018] The accompanying drawings, which form part of this embodiment, are used to provide a further understanding of this embodiment. The illustrative embodiments and their descriptions are used to explain this embodiment and do not constitute an improper limitation of this embodiment.

[0019] Figure 1 This is a flowchart of the physical layer secure transmission method for a high-speed rail wireless communication system according to Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the overall architecture of physical layer secure transmission in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the affine coupling structure in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the communication link after the embedding algorithm in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram illustrating the decryption error at different SNR values ​​in Embodiment 1 of the present invention; Figure 6 This is a schematic diagram illustrating the change in decryption error with the number of guesses for K1 in Embodiment 1 of the present invention; Figure 7 This is a schematic diagram illustrating the change in decryption error with the number of K2 guesses in Embodiment 1 of the present invention; Figure 8 This is a schematic diagram illustrating the change of decryption error with signal-to-noise ratio estimation error in Embodiment 1 of the present invention; Figure 9 This is a structural block diagram of the physical layer secure transmission system for high-speed rail wireless communication system in Embodiment 2 of the present invention. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] In this invention, terms such as "upper," "lower," "left," "right," "front," "back," "vertical," "horizontal," "side," and "bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only to facilitate the description of the structural relationships of the various components or elements of this invention and do not specifically refer to any component or element in this invention. They should not be construed as limiting the invention.

[0024] In this invention, terms such as "fixed connection," "connected," and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can determine the specific meaning of these terms in this invention based on the specific circumstances, and they should not be construed as limitations on the invention.

[0025] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0026] Example 1 Embodiment 1 of the present invention introduces a physical layer secure transmission method for a high-speed rail wireless communication system.

[0027] like Figure 1 The physical layer secure transmission method for a high-speed rail wireless communication system, as shown, includes: The original high-speed rail wireless communication baseband signal to be transmitted is acquired, and the channel state information of the current wireless channel is measured, wherein the channel state information is the signal-to-noise ratio; The acquired original high-speed rail wireless communication baseband signal is orthogonally transformed to obtain a rotated baseband signal; the obtained rotated baseband signal is then nonlinearly reversibly encrypted in a normed linear space to obtain a confused baseband signal; based on the confused baseband signal and an adaptive perturbation generated according to channel state information, an encrypted baseband signal suitable for wireless channel transmission is constructed. The received encrypted baseband signal is decrypted to obtain the decrypted baseband signal; The decrypted baseband signal is reconstructed to obtain the intended signal of the high-speed rail wireless communication baseband signal; Based on the monitoring of the transmission process of the original high-speed rail wireless communication baseband signal using potential wireless eavesdropping channels, the inverted baseband signal is obtained; The eavesdropping intent signal is obtained by inverting the baseband signal. Construct a wireless physical layer security loss function based on the obtained intent signal and eavesdropping intent signal; The constructed wireless physical layer security loss function is optimized until it converges, thus obtaining the optimal wireless transmission parameters and completing the physical layer security transmission of the high-speed rail wireless communication system.

[0028] The high-speed rail wireless communication physical layer secure transmission method in this embodiment adopts the following... Figure 2 The overall architecture shown is as follows: At the transmitting end, the baseband signal is extracted from the source signal by the baseband encoding module, and then the baseband signal is encrypted by the encryption module to obtain the encrypted baseband signal. After the encrypted baseband signal is transmitted through the wireless channel, it is received at the receiving end. The decryption module is responsible for decrypting the received signal into a decrypted baseband signal, which is then passed to the decoding module to obtain the intention signal.

[0029] In the encryption module, the baseband signal is first orthogonally transformed to destroy the interdimensional correlation and obtain a rotated baseband signal. The rotated baseband signal is then encrypted nonlinearly to obtain a confused baseband signal. An adaptive perturbation is then added to the confused baseband signal to obtain an encrypted baseband signal.

[0030] In the decryption module, the received signal first undergoes adaptive perturbation decryption to obtain a decrypted obfuscated baseband signal, then undergoes nonlinear reversible encryption decryption to obtain a decrypted rotated baseband signal, and finally undergoes inverse orthogonal transformation to obtain the decrypted baseband signal. Potential eavesdroppers can intercept the inverted baseband signal from the wireless channel and then obtain the eavesdropping intent signal through the potential eavesdropping module. The entire encryption process is used to defend against eavesdropping attacks and ensure security, while the decryption process ensures the effectiveness of the security method. Both the encryption and decryption processes are deeply integrated with the characteristics of the wireless channel.

[0031] In this embodiment, the sending end and the receiving end have two shared keys. and Shared key Responsible for disrupting the correlation between dimensions of the original baseband signal, sharing the key. This process introduces nonlinear confusion; firstly, an orthogonal transformation is performed on the input baseband signal, projecting the baseband signal onto a normed linear space to obtain a rotated baseband signal. Next, the rotating baseband signal... Perform nonlinear reversible encryption to obtain a confused baseband signal. Finally, an adaptive perturbation is generated based on the real-time measured channel state information to confuse the baseband signal. It is deeply bound to the current physical channel. For the receiver on a legitimate link, a shared key is used. Based on channel reciprocity synchronization, all transformations are known and reversible. For the eavesdropping end of a potential wireless eavesdropping link, a shared key is required. Unknown or known shared key However, when the channels are not interchangeable, it is impossible to effectively reconstruct the signal of the eavesdropping intent.

[0032] As one or more implementation methods, the original high-speed rail wireless communication baseband signal The baseband signal exhibits complex internal correlations and specific statistical patterns. To increase the difficulty for eavesdroppers to directly infer the original baseband signal from statistical regularities or characteristic correlations, a "format reconstruction" of the baseband signal is required. In this embodiment, the orthogonal transformation module utilizes a shared key between the transmitting and receiving ends. The baseband signal is mapped to a space composed of a set of orthogonal bases, achieving decorrelation while ensuring reversible signal recovery. A deterministic orthogonal matrix is ​​generated using a deterministic orthogonal matrix generation algorithm. To represent the dimension of the baseband signal, first use a fixed random seed. Generate a random square matrix that follows a standard normal distribution. The Gram-Schmidt orthogonalization method is used to perform orthogonalization, resulting in a deterministic orthogonal matrix. .

[0033] Damaging the original high-speed rail wireless communication baseband signal Dimensional correlation to obtain rotating baseband signal Right now .

[0034] because To decrypt the orthogonal transformation, the Gram-Schmidt orthogonalization method is first used to generate identical orthogonal matrices. ,use Decryption is performed to obtain the decrypted baseband signal. ;in, To decrypt the rotating baseband signal.

[0035] Although orthogonal transformations can break the internal coordinate structure of the original semantics, they are essentially linear operations and may retain higher-order statistical features. This embodiment designs a nonlinear reversible encryption module to achieve encryption of rotating baseband signals. The "deep obfuscation" is used. The non-linear reversible encryption module consists of... It consists of a component of an affine coupling layer and a displacement layer (the last component removes the displacement layer). The larger the value, the stronger the encryption, and the more difficult it is to reconstruct effectively. The parameters of the affine coupling layer are determined by the shared key. The parameters of the generation and permutation layers are obtained through training; the specific affine coupling structure is as follows: Figure 3 As shown, the input to the first affine coupling structure is a rotating baseband signal. For each affine coupling structure, the input features are first... Divide into two equal parts, with the first part used as the operation value. The latter part serves as the condition value. .

[0036] For operands and condition values Process to obtain the operation output value of the current layer. and conditional output values ,Right now

[0037] in, It represents the Hadamah accumulation. It is an exponential function, used to scale functions. The output is mapped to The interval is further enhanced to increase nonlinearity. It is a scaling function. It is a translation function.

[0038] Final operation output value and conditional output values Coupling to obtain the output of the current layer .

[0039] The permutation layer contains a learnable... Convolution is used in subsequent coupling layers, where the operation value has the opportunity to be used as a condition, and the condition has the opportunity to be operated on, ensuring that information from different dimensions can be fully mixed. The key to the effect of the permutation layer lies in the permutation method learned by the network.

[0040] Output features of the last encryption layer That is, confusing the baseband signal .

[0041] It is important to note that the decryption structure of a nonlinear reversible encryption process is symmetrical to the encryption process.

[0042] The decryption parameters of the permutation layer are learned through a joint training process and stored at the receiving end. The decryption process only requires loading the parameters for calculation. Because the key... The parameters of the shared, decryption-side affine coupling layer can be generated using the same algorithm. The input to the first inverse affine coupling structure is... For each inverse affine coupling structure, the decryption output calculation process involves partitioning the input to obtain the operation value. and condition values .

[0043] Calculate the decryption operation value respectively and decryption condition value ,Right now

[0044] Finally, the decryption operation value and decryption condition value Coupling obtains the output of the current layer as the input feature of the next layer. .

[0045] Output features of the last decryption layer That is, decrypting the rotating baseband signal .

[0046] The core contradiction of "security-utility imbalance" in wireless communication security in high-speed mobile scenarios refers to the following: when the channel is good, insufficient protection leads to low security redundancy and difficulty in resisting inversion attacks; when the channel is bad, excessive protection seriously damages decoding utility and may even cause communication interruption.

[0047] To address this issue, this embodiment designs an adaptive perturbation module based on channel state information. By utilizing the channel reciprocity between the transceiver and receiver, both parties can synchronously obtain the real-time "fingerprint" of the current wireless channel and dynamically adjust the perturbation intensity accordingly, allowing the security mechanism to intelligently "change with the channel".

[0048] Signal-to-noise ratio (SNR) is a metric for measuring signal quality in wireless communication systems, reflecting the receiver's ability to clearly extract the signal from noise. A higher SNR indicates better channel conditions and higher communication efficiency. Conversely, a lower SNR indicates poorer channel conditions, with the signal being severely overwhelmed by noise, making communication prone to errors or even interruptions. This embodiment uses SNR to adaptively encrypt and perturb the baseband signal.

[0049] The SHA-256 algorithm is used to obtain a 256-bit hash value. The first 8 bytes are truncated and converted into a 32-bit integer as the seed output. ;in, This indicates a splicing operation. This represents the modulo operation. This is the SHA-256 function, used to call the SHA-256 algorithm to generate a deterministic random seed. SNR represents the signal-to-noise ratio. This indicates scrambling of the baseband signal. Characteristic functions for obfuscating baseband signals.

[0050] This embodiment is based on deterministic perturbation seed generation. The standard normal distribution vector is given, and adaptive intensity scaling is added to obtain the adaptive perturbation vector. ,Right now ; in, It is a 2-norm. This represents a random number generation function. Represents the adaptive intensity function , The minimum threshold representing the intensity of the disturbance. This represents the maximum threshold for the intensity of the disturbance.

[0051] Mixing baseband signals Added adaptive perturbation vector The encrypted baseband signal is obtained. ,Right now ; The decryption process of adaptive perturbation encryption relies on solving fixed-point equations. ,in, In order to receive signals, This represents a random number generation function. Represents the adaptive intensity function. This indicates a splicing operation. This represents the modulo operation. For SHA-256 functions, SNR represents the signal-to-noise ratio. This indicates the decryption of the obfuscated baseband signal. To decrypt the characteristic functions of the confused baseband signal, It is a 2-norm.

[0052] The fixed-point equations are solved using an iterative method to receive the signal. For the initial estimate, at the th In this iteration, the feature values ​​of the currently estimated decrypted confused baseband signal are first extracted. Then, the current adaptive perturbation is reconstructed based on the current signal-to-noise ratio. Subsequently, from the last decryption of the confused baseband signal Subtract the current adaptive perturbation from the current signal to obtain the updated current decrypted and confused baseband signal. .

[0053] In this embodiment, the fixed-point equation solving algorithm is input to the receiving end receiving signal. Current signal-to-noise ratio (SNR), maximum number of iterations Convergence tolerance Minimum threshold for disturbance intensity and the maximum threshold of disturbance intensity Output decrypted and obfuscated baseband signal Specifically: (1) Initialization: The decrypted and confused baseband signal is obtained in the 0th iteration. ,Right now ; (2) Iterative solution: For the The next iteration ( ); 1) Calculate the eigenvalues ​​of the currently estimated decrypted confused baseband signal. ,Right now ; 2) Calculate the current adaptive perturbation ,Right now ; 3) Update the estimate to obtain the current decrypted and scrambled baseband signal. ,Right now ; 4) Convergence judgment: Repeat steps 1-3 until... The iteration terminates, and the output is given. .

[0054] Output: Outputs the current decrypted and obfuscated baseband signal. As a decryption and obfuscation baseband signal To ensure the safety of the internalization method, this embodiment proposes the following: Figure 4 The algorithm shown is embedded in the communication link. It assumes the presence of an attacker, eavesdrops on signals from the wireless channel, and attempts to obtain the eavesdropping intent signal through a potential eavesdropping module. It uses an adversarial training method for adaptive learning.

[0055] To minimize the difference between the source signal and the signal intended for eavesdropping in a potential eavesdropping link, a security loss function for the eavesdropping link is defined. ,Right now ; in, Indicates the source signal. Signals indicating intent to eavesdrop , These represent the baseband coding modules on the legitimate link, respectively. Encryption module , Indicates a potential eavesdropping module on a potential eavesdropping link. The parameters, To perform the averaging operation, It is a 2-norm. This is a balance parameter between transmission loss and reconstruction loss.

[0056] The legitimate link minimizes the difference between the source signal and the intent signal, while maximizing the difference between the source signal and the eavesdropping intent signal. A legitimate link security utility loss function is defined. ,Right now ; in, Indicates the source signal. Signals indicating intent to eavesdrop Indicates intent signal, , , , These represent the baseband coding modules on the legitimate link, respectively. Encryption module Decryption module Decoding module parameter, Indicates a potential eavesdropping module on a potential eavesdropping link. The parameters, This is a balance coefficient between the security utility loss of the legitimate link and the security loss of the eavesdropping link during the training process of the legitimate link. To perform the averaging operation, It is a 2-norm. This is a balance parameter between transmission loss and reconstruction loss.

[0057] The adversarial approach involves alternately optimizing legitimate and eavesdropping links to achieve system equilibrium during dynamic training, employing an adversarial training algorithm. The system parameters are randomly initialized, and the goal is to minimize the security loss function of the eavesdropping links. To achieve this goal, a communication model for the eavesdropping link is trained to learn the parameters of the eavesdropping link. Obtain the optimal parameters of potential eavesdropping modules. Fixed potential eavesdropping module parameters To minimize To achieve this, train a legitimate link communication model and learn the legitimate link parameters. Fixed baseband encoding module parameters and encryption module parameters To minimize the security loss function of the eavesdropping link To achieve this goal, a communication model for the eavesdropping link is trained to learn the parameters of potential eavesdropping modules. Alternately train the eavesdropping link communication model and the legitimate link communication model until the defined eavesdropping link security loss function is obtained. and legitimate link security utility loss function All converge.

[0058] Combination Figure 5 The different ones shown As can be seen from the decryption error at the given value, the decryption error increases with the signal-to-noise ratio. The variation is stable, with an error between 0.004 and 0.008. This is under poor channel conditions. At lower levels, the decryption error is... The lower the disturbance intensity, the more important it is to prioritize ensuring communication effectiveness. This is especially true when channel conditions are good. At higher levels, the decryption error... The larger the disturbance, the stronger the disturbance, which makes it necessary to ensure the security of the communication link under the condition of ensuring communication.

[0059] Combination Figure 6 The decryption error shown varies with The change in the number of guesses indicates that the attacker, unaware of... In this case, the average decryption error is 0.01, which is much higher than... Figure 5 The decryption error of the legitimate recipient is due to the fact that no matter how many guesses are made, the content cannot be reversed.

[0060] Combination Figure 7 The decryption error shown varies with The change in the number of guesses indicates that the attacker is unknown. Similarly, the attacker was unaware In this case, the average decryption error is 0.01, which is much higher than... Figure 5 The decryption error of the legitimate recipient is due to the fact that no matter how many guesses are made, the content cannot be reversed.

[0061] Combination Figure 8As shown in the diagram, the decryption error varies with the signal-to-noise ratio (SNR) estimation error. When the estimation accuracy error is 0, the lowest decryption error can be achieved. As the SNR estimation error increases, the decryption error also increases significantly. Attackers, due to different communication links, find it difficult to accurately estimate the SNR, and their estimation will be more difficult than that of legitimate receivers.

[0062] To address the security-utility imbalance problem that often arises when existing inversion attack defense technologies are applied to high-speed rail wireless communication scenarios, this embodiment maps the signal to a normed linear space through orthogonal transformation, removing inter-dimensional correlations and increasing the difficulty of using statistical information to assist in inversion. A nonlinear reversible encryption operator is designed to enhance the difficulty of signal inversion through nonlinear reversible transformation, while embedding reversibility constraints to ensure that legitimate receivers can accurately reconstruct the content. Utilizing the channel reciprocity at the transmitting and receiving ends, an adaptive perturbation encryption module based on channel state information is designed, internalizing channel characteristics as the physical layer key to solve the security-utility imbalance problem. The algorithm is embedded in the wireless communication physical layer, and an adversarial training algorithm is designed under the assumption of an attacker to internalize the security-utility balance.

[0063] Example 2 Embodiment 2 of the present invention introduces a physical layer secure transmission system for high-speed rail wireless communication systems.

[0064] like Figure 9 The physical layer secure transmission system for high-speed rail wireless communication systems shown includes: The baseband coding module is configured to acquire the original high-speed rail wireless communication baseband signal to be transmitted and measure the channel state information of the current wireless channel, wherein the channel state information is the signal-to-noise ratio. An encryption module is configured to perform an orthogonal transformation on the acquired original high-speed rail wireless communication baseband signal to obtain a rotated baseband signal; to perform nonlinear reversible encryption on the obtained rotated baseband signal in a normed linear space to obtain a confused baseband signal; and to construct an encrypted baseband signal suitable for wireless channel transmission based on the confused baseband signal and an adaptive perturbation generated according to channel state information. The decryption module is configured to decrypt the received encrypted baseband signal to obtain the decrypted baseband signal; The decoding module is configured to reconstruct the decrypted baseband signal to obtain the intention signal of the high-speed rail wireless communication baseband signal; A potential eavesdropping module is configured to monitor the transmission process of the original high-speed rail wireless communication baseband signal based on a potential wireless eavesdropping channel to obtain an inverted baseband signal; and to invert the inverted baseband signal to obtain an eavesdropping intent signal. The defense module is configured to construct a wireless physical layer security loss function based on the obtained intent signal and eavesdropping intent signal; optimize the constructed wireless physical layer security loss function until the loss function converges, obtain the optimal wireless transmission parameters, and complete the physical layer security transmission of the high-speed rail wireless communication system.

[0065] The detailed steps are the same as those of the physical layer secure transmission method for high-speed rail wireless communication system provided in Example 1, and will not be repeated here.

[0066] Example 3 Embodiment 3 of the present invention provides a computer-readable storage medium.

[0067] A computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps of the physical layer secure transmission method for a high-speed rail wireless communication system as described in Embodiment 1 of the present invention.

[0068] The detailed steps are the same as those of the physical layer secure transmission method for high-speed rail wireless communication system provided in Example 1, and will not be repeated here.

[0069] Example 4 Embodiment 4 of the present invention provides an electronic device.

[0070] An electronic device includes a memory, a processor, and a program stored in the memory and running on the processor. When the processor executes the program, it implements the steps in the physical layer secure transmission method for a high-speed rail wireless communication system as described in Embodiment 1 of the present invention.

[0071] The detailed steps are the same as those in the physical layer secure transmission method for high-speed rail wireless communication systems provided in Example 1. They will not be repeated here.

[0072] Example 5 Embodiment 5 of the present invention provides a computer program product.

[0073] A computer program product includes software code, wherein the program in the software code performs the steps of the physical layer secure transmission method for a high-speed rail wireless communication system as described in Embodiment 1 of the present invention.

[0074] The detailed steps are the same as those in the physical layer secure transmission method for high-speed rail wireless communication systems provided in Embodiment 1, and will not be repeated here.

[0075] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0076] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0077] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0078] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0079] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0080] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

[0081] The above description is merely a preferred embodiment of this practice and is not intended to limit the scope of this practice. Various modifications and variations can be made to this practice by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this practice should be included within the protection scope of this practice.

Claims

1. A physical layer secure transmission method for a high-speed rail wireless communication system, characterized in that, include: The original high-speed rail wireless communication baseband signal to be transmitted is acquired, and the channel state information of the current wireless channel is measured, wherein the channel state information is the signal-to-noise ratio; The original high-speed rail wireless communication baseband signal is orthogonally transformed to obtain a rotated baseband signal; the obtained rotated baseband signal is then nonlinearly reversibly encrypted in a normed linear space to obtain a confused baseband signal. Based on the obfuscated baseband signal and the adaptive perturbation generated according to the channel state information, an encrypted baseband signal suitable for wireless channel transmission is constructed. The received encrypted baseband signal is decrypted to obtain the decrypted baseband signal; The decrypted baseband signal is reconstructed to obtain the intended signal of the high-speed rail wireless communication baseband signal; Based on the monitoring of the transmission process of the original high-speed rail wireless communication baseband signal using potential wireless eavesdropping channels, the inverted baseband signal is obtained; The eavesdropping intent signal is obtained by inverting the baseband signal. Construct a wireless physical layer security loss function based on the obtained intent signal and eavesdropping intent signal; The constructed wireless physical layer security loss function is optimized until it converges, thus obtaining the optimal wireless transmission parameters and completing the physical layer security transmission of the high-speed rail wireless communication system.

2. The physical layer secure transmission method for a high-speed rail wireless communication system as described in claim 1, characterized in that, The process of generating adaptive perturbation based on channel state information is as follows: based on the measured signal-to-noise ratio, a deterministic perturbation seed is generated through a hash function, and a perturbation vector bound to the channel state is generated based on the deterministic perturbation seed to complete the adaptive perturbation of signal state information.

3. The physical layer secure transmission method for a high-speed rail wireless communication system as described in claim 1, characterized in that, The process of decrypting the received encrypted baseband signal is as follows: the encrypted baseband signal is subjected to inverse adaptive perturbation to obtain a decrypted confused baseband signal; the decrypted confused baseband signal is subjected to inverse nonlinear reversible decryption to obtain a decrypted rotated baseband signal. Perform an inverse orthogonal transform on the decrypted rotating baseband signal to obtain the decrypted baseband signal; The intent signal is obtained by iterating through the decrypted baseband signal sequence.

4. The physical layer secure transmission method for a high-speed rail wireless communication system as described in claim 1, characterized in that, The constructed wireless physical layer security loss function is: ； ； in, Indicates the source signal; Signals indicating intent to eavesdrop; Indicates intent signal; , , , These represent the baseband coding modules on the legitimate link, respectively. Encryption module Decryption module Decoding module Parameters; Indicates a potential eavesdropping module on a potential eavesdropping link. Parameters; This represents the security loss function of the eavesdropping link; Describes the loss function for the security utility of legitimate links; This represents the balance coefficient between the utility loss of the legitimate link and the security loss of the eavesdropping link during the training process of the legitimate link. This indicates the operation of taking the average value; Represents the 2-norm; This represents the balance parameter between transmission loss and reconstruction loss; The encoded signal representing the source signal; Encoded signals that indicate the intent to eavesdrop.

5. The physical layer secure transmission method for a high-speed rail wireless communication system as described in claim 1, characterized in that, The encryption shared key during the encryption process and the decryption shared key during the decryption process can be generated synchronously based on the reciprocity of the wireless channel. By utilizing the symmetry of the uplink and downlink channels in time-division duplex mode, the physical layer key can be extracted from the channel impulse response.

6. The physical layer secure transmission method for a high-speed rail wireless communication system as described in claim 1, characterized in that, The method further includes: dynamically adjusting the feedback period of channel state information according to the terminal's moving speed; when the terminal speed exceeds the speed threshold, enabling a high-speed mobile dedicated transmission mode, including shortening the transmission time interval and increasing the pilot density.

7. A physical layer secure transmission system for high-speed rail wireless communication systems, characterized in that, include: The baseband coding module is configured to acquire the original high-speed rail wireless communication baseband signal to be transmitted and measure the channel state information of the current wireless channel, wherein the channel state information is the signal-to-noise ratio. The encryption module is configured to perform an orthogonal transformation on the acquired original high-speed rail wireless communication baseband signal to obtain a rotated baseband signal; and to perform nonlinear reversible encryption on the obtained rotated baseband signal in a normed linear space to obtain a confused baseband signal. Based on the obfuscated baseband signal and the adaptive perturbation generated according to the channel state information, an encrypted baseband signal suitable for wireless channel transmission is constructed. The decryption module is configured to decrypt the received encrypted baseband signal to obtain the decrypted baseband signal; The decoding module is configured to reconstruct the decrypted baseband signal to obtain the intention signal of the high-speed rail wireless communication baseband signal; A potential eavesdropping module is configured to monitor the transmission process of the original high-speed rail wireless communication baseband signal based on a potential wireless eavesdropping channel, and obtain the inverted baseband signal. The eavesdropping intent signal is obtained by inverting the baseband signal. The defense module is configured to construct a wireless physical layer security loss function based on the obtained intent signal and eavesdropping intent signal; optimize the constructed wireless physical layer security loss function until the loss function converges, obtain the optimal wireless transmission parameters, and complete the physical layer security transmission of the high-speed rail wireless communication system.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps of the physical layer secure transmission method for a high-speed rail wireless communication system as described in any one of claims 1-6.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the program, it implements the steps of the physical layer secure transmission method for a high-speed rail wireless communication system as described in any one of claims 1-6.

10. A computer program product, comprising software code, characterized in that, The program in the software code executes the steps of the physical layer secure transmission method for a high-speed rail wireless communication system as described in any one of claims 1-6.

Images