Satellite communication encryption method capable of resisting channel interference

Abstract

The invention relates to a satellite communication encryption method resistant to channel interference. According to the method, satellite orbit parameters are dynamically mapped into a chaos spread spectrum sequence, an anti-interference pseudo-random sequence and a dynamically decoupled encryption key are synchronously generated based on the chaos sequence, a spread spectrum code and the key are completely isolated mathematically, chaos parameters and a channel state are hidden and embedded into a physical layer signal, and therefore the anti-interference pseudo-random sequence and the dynamically decoupled encryption key are obtained. According to the method, deep cooperation of anti-interference and encryption is achieved, the concealment and the anti-interception capability of signals in a complex channel are enhanced through chaos spread spectrum, the synchronization precision of a decryption end is guaranteed through real-time binding of a dynamic key and channel parameters, and finally synchronous improvement of the anti-interference capability and the information security is achieved in a satellite communication high-dynamic environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of satellite communication, and particularly relates to a satellite communication encryption method for anti-channel interference. Background Art

[0002] In the field of satellite communication, anti-interference and information security have always been core technical challenges. Traditional satellite communication systems usually adopt spread spectrum technology to improve anti-interference ability, and at the same time combine encryption algorithms to ensure data transmission security. However, these two types of technologies are often designed independently, resulting in potential security vulnerabilities. For example, there may be a hidden correlation between the generation logic of the spread spectrum pseudo-random sequence and the mathematical structure of the encryption key. Attackers can reverse-derive some key information by analyzing the statistical characteristics of the spread spectrum code, reducing the overall security of the system.

[0003] In addition, in the prior art, the encrypted signal needs to transmit synchronization parameters through a pilot, but the existence of the pilot signal is likely to expose communication characteristics. Attackers can use the pilot to locate the communication link and implement targeted interference.

[0004] On the other hand, it is difficult to coordinate the key update mechanism and the physical layer anti-interference ability in a dynamic channel environment. The key synchronization error in a high-dynamic scenario may lead to a significant increase in the decryption failure rate, while a complex error correction mechanism will increase communication delay and resource overhead.

[0005] Therefore, how to achieve deep coupling of anti-interference and encryption technologies, while improving the signal concealment and ensuring the reliability of key dynamic synchronization, is still an urgent problem to be solved in the field of satellite communication. Summary of the Invention

[0006] Based on this, it is necessary to provide a satellite communication encryption method for anti-channel interference in view of the above technical problems.

[0007] In a first aspect, the present application provides a satellite communication encryption method for anti-channel interference, including:

[0008] S1: Generating a chaotic spread spectrum sequence based on satellite orbit parameters;

[0009] S2: Generating an anti-interference pseudo-random sequence and an encryption key according to the chaotic spread spectrum sequence; wherein, the encryption key and the anti-interference pseudo-random sequence are decoupled through chaotic mapping;

[0010] S3: Performing joint spread spectrum encryption processing on the original data to generate a baseband signal; the joint spread spectrum encryption processing includes: encrypting the original data with the encryption key to generate a ciphertext, and performing spread spectrum modulation on the ciphertext and the anti-interference pseudo-random sequence;

[0011] S4: Embedding chaotic parameters and channel state identifiers in the baseband signal to generate a final transmitted signal; wherein, the chaotic parameters include the initial seed for generating the chaotic spread spectrum sequence;

[0012] S5: Transmit the final transmission signal and complete the decryption of the final transmission signal through satellite-ground synchronization.

[0013] In a second aspect, the present application also provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements an anti-channel interference satellite communication encryption method as described in the first aspect.

[0014] In a third aspect, the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements an anti-channel interference satellite communication encryption method as described in the first aspect.

[0015] The above anti-channel interference satellite communication encryption method maps satellite orbit parameters dynamically to chaotic spread-spectrum sequences, and based on chaotic sequence synchronization, generates anti-interference pseudo-random sequences and dynamically decoupled encryption keys, making the spread-spectrum codes and keys completely isolated mathematically. At the same time, chaotic parameters and channel states are covertly embedded in the physical layer signals to achieve deep coordination of anti-interference and encryption. It not only enhances the concealment and anti-interception ability of signals in complex channels through chaotic spread-spectrum, but also ensures the synchronization accuracy of the decryption end by real-time binding of dynamic keys and channel parameters, ultimately achieving synchronous improvement of anti-interference ability and information security in the high-dynamic environment of satellite communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Figure 1 It is a flowchart of an anti-channel interference satellite communication encryption method provided by the present invention;

[0018] Figure 2 It is a flowchart of generating an encryption key in an optional embodiment of the present invention;

[0019] Figure 3 It is a flowchart of generating the final transmission signal in an optional embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] To make the objectives, technical solutions, and advantages of this application clearer and more understandable, the following further elaborates on this application in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely used to explain this application and not to limit it.

[0021] Reference Figure 1 , which shows a schematic flowchart of a satellite communication encryption method for anti-channel interference provided by this application. The method includes the following steps:

[0022] S1: Generate a chaotic spread spectrum sequence based on satellite orbit parameters.

[0023] Specifically, in satellite communication, satellite orbit parameters (such as orbital altitude, inclination, right ascension of the ascending node, mean anomaly, etc.) have uniqueness and dynamic change characteristics. The present invention uses these parameters as the initial seeds of the chaotic system to generate a spread spectrum sequence with pseudo-random characteristics. The chaotic system can adopt the Logistic map. Its core idea is to utilize the sensitivity of the initial conditions of chaos theory, where even very small changes will lead to completely different results, thus ensuring the uniqueness of the spread spectrum sequence generated each time a communication link is established.

[0024] In specific implementation, the satellite orbit parameters are converted into the initial seeds of the chaotic system through a specific mapping function. The design of this mapping function takes into account the dynamic change range of the parameters and the input requirements of the chaotic system to ensure that the generated initial seeds can make full use of the characteristics of the orbit parameters. The generation process of the chaotic spread spectrum sequence is completed through iterative calculations. Each iteration generates the next state value based on the current state and chaotic parameters, ultimately forming a pseudo-random sequence.

[0025] To adapt to the dynamic channel environment, the chaotic parameters can be adjusted according to the real-time channel state (such as signal-to-noise ratio). This dynamic adjustment mechanism ensures that the spread spectrum sequence can adapt to channel changes in real time and enhances the anti-interference ability.

[0026] S2: Generate an anti-interference pseudo-random sequence and an encryption key according to the chaotic spread spectrum sequence; among them, the encryption key and the anti-interference pseudo-random sequence are decoupled through chaotic mapping.

[0027] Specifically, after generating the chaotic spread spectrum sequence, two independent sequences are extracted through the non-linear transformation of chaotic mapping: the anti-interference pseudo-random sequence and the encryption key seed. The anti-interference pseudo-random sequence is used for subsequent spread spectrum modulation, while the encryption key seed is used to generate the encryption key.

[0028] The extraction of anti-interference pseudo-random sequences can be accomplished through the high-dimensional projection of a chaotic system. This method can ensure that the sequences have excellent autocorrelation characteristics, thereby providing better anti-interference performance in spread-spectrum modulation. The extraction of the encryption key seed can be achieved through low-dimensional projection and then extended in combination with a quantum random number generator to generate the final encryption key. This design ensures that there is no mathematical correlation between the encryption key and the anti-interference pseudo-random sequence, thus enhancing security.

[0029] The key synchronization verification mechanism ensures synchronization accuracy by comparing the locally generated key and the received key. After the ground station receives the signal, it reconstructs the local chaotic sequence according to the embedded chaotic parameters and generates the local key. By comparing the local key and the received key, the synchronization accuracy can be verified to ensure the reliability of decryption.

[0030] S3: Perform joint spread-spectrum encryption processing on the original data to generate a baseband signal; the joint spread-spectrum encryption processing includes: encrypting the original data with the encryption key to generate ciphertext, and performing spread-spectrum modulation on the ciphertext and the anti-interference pseudo-random sequence.

[0031] Specifically, the original data can first be encrypted with the encryption key through the Advanced Encryption Standard (AES-256-GCM) algorithm to generate ciphertext. The encryption algorithm provides high-intensity security to ensure the confidentiality of data during transmission.

[0032] The encrypted ciphertext is subjected to spread-spectrum modulation with the anti-interference pseudo-random sequence. The process of spread-spectrum modulation is to perform a bitwise exclusive OR operation on the ciphertext and the pseudo-random sequence, thereby spreading the signal to a wider frequency band. This spread-spectrum technology can not only improve the anti-interference ability of the signal but also increase the concealment of the signal, making it difficult for attackers to locate and interfere with the communication link.

[0033] To further improve the reliability and anti-interference ability of the signal, the spread-spectrum signal can be error-corrected encoded through a Low-Density Parity-Check (LDPC) code. The coding technology can provide powerful error-correction ability while maintaining a high coding efficiency, thereby reducing the bit error rate.

[0034] S4: Embed chaotic parameters and channel state identifiers in the baseband signal to generate the final transmitted signal; among them, the chaotic parameters include the initial seeds for generating chaotic spread-spectrum sequences.

[0035] Specifically, embedding chaotic parameters and channel state identifiers in the baseband signal is a key step to ensure that the receiving end can accurately decrypt and adapt to the dynamic channel. The embedding process can be completed through frequency-domain embedding technology, which can embed auxiliary data (such as chaotic parameters and channel state identifiers) into the signal without affecting the quality of the main signal.

[0036] The embedded chaotic parameters include the initial seed for generating the chaotic spread-spectrum sequence and the number of iterations, which are crucial for the receiver to reconstruct the local chaotic sequence. The channel state identification includes information such as the real-time signal-to-noise ratio and Doppler shift, which helps the receiver dynamically adjust the demodulation and decryption strategies to adapt to channel changes.

[0037] The selection of the embedding position is optimized, and the low-energy subbands in the frequency domain are preferentially selected to reduce interference to the main signal. At the same time, by using a specific embedding algorithm (such as the Zadoff-Chu sequence), the robustness and extractability of the embedded data can be ensured.

[0038] S5: Transmit the final transmitted signal and complete the decryption of the final transmitted signal through satellite-ground synchronization.

[0039] Specifically, the final transmitted signal is sent to the ground station through the satellite link. After receiving the signal, the ground station first extracts the embedded chaotic parameters and channel state identification through the blind source separation algorithm. These parameters are used to reconstruct the local chaotic spread-spectrum sequence and the encryption key.

[0040] The reconstructed local key and the received ciphertext are decrypted. The decryption algorithm is consistent with the encryption end to ensure that the data can be accurately restored. The dynamic key update mechanism ensures that the key can be updated in real time to adapt to the communication requirements in high-dynamic scenarios while maintaining high synchronization accuracy.

[0041] Through this satellite-ground synchronization decryption mechanism, not only can the confidentiality and integrity of the data be ensured, but also it can dynamically adapt to channel changes, improving the overall performance and reliability of the system.

[0042] The above satellite communication encryption method against channel interference maps the satellite orbit parameters dynamically to a chaotic spread-spectrum sequence, and based on the chaotic sequence synchronization, generates an anti-interference pseudo-random sequence and a dynamically decoupled encryption key, making the spread-spectrum code and the key completely isolated mathematically. At the same time, the chaotic parameters and channel state are covertly embedded in the physical layer signal to achieve deep coordination between anti-interference and encryption. It not only enhances the concealment and anti-interception ability of the signal in complex channels through chaotic spread-spectrum, but also ensures the synchronization accuracy of the decryption end by the real-time binding of the dynamic key and channel parameters, ultimately achieving the synchronous improvement of anti-interference ability and information security in the high-dynamic environment of satellite communication.

[0043] In an alternative embodiment, S1 includes the following steps:

[0044] S11: Calculate the Doppler shift according to the satellite's instantaneous elevation angle. The calculation formula for the Doppler shift is:

[0045]

[0046] where f dLet \(f_d\) be the Doppler frequency shift, \(\theta\) be the instantaneous elevation angle of the satellite, \(c\) be the speed of light, and \(v\) be the component of the satellite velocity vector in the communication direction.

[0047] Specifically, in satellite communication, the Doppler frequency shift is the frequency change caused by the relative motion between the satellite and the ground station. In specific implementation, the instantaneous elevation angle of the satellite and the component of the satellite velocity vector in the communication direction are the key parameters for calculating the Doppler frequency shift.

[0048] The instantaneous elevation angle of the satellite is the elevation angle of the satellite relative to the ground station, reflecting the position of the satellite in the sky. The component of the satellite velocity vector in the communication direction reflects the motion speed of the satellite relative to the ground station. By combining these parameters, the frequency change caused by the satellite motion, i.e., the Doppler frequency shift, can be calculated.

[0049] S12: Calculate the chaotic initial seed according to the instantaneous elevation angle of the satellite and the Doppler frequency shift. The calculation formula for the chaotic initial seed is:

[0050]

[0051] where \(x_0\) is the chaotic initial seed and \(K\) is a preset normalization constant.

[0052] Specifically, the chaotic initial seed is the starting value for the chaotic system to generate a pseudo-random sequence. In specific implementation, the instantaneous elevation angle of the satellite and the Doppler frequency shift are used as input parameters, and a chaotic initial seed is generated through a specific mathematical model.

[0053] The combination of the instantaneous elevation angle of the satellite and the Doppler frequency shift ensures the randomness and uniqueness of the initial seed. Through modulo operation and normalization processing, the initial seed is mapped to the input range of the chaotic system. This design ensures the uniqueness of the chaotic sequence generated each time a communication link is established, thereby enhancing the security and anti-interference ability of the system.

[0054] S!3: Generate a chaotic sequence through chaotic mapping according to the chaotic initial seed. The generation formula for the chaotic sequence is:

[0055] x n+1 =\(\mu x\) n (1 - x n );

[0056] where \(\mu\) is the chaotic parameter.

[0057] Specifically, the chaotic sequence is a pseudo-random sequence generated through chaotic mapping. In specific implementation, the chaotic initial seed is used as the starting value of the chaotic mapping, and a chaotic sequence is generated through iterative calculation.

[0058] A chaotic map is a non - linear dynamics model. Its core idea is to generate a sequence with pseudo - random characteristics by using the sensitivity of the initial conditions. Each iteration generates the next state value based on the current state and chaotic parameters, ultimately forming a pseudo - random sequence. The generation process of the chaotic sequence makes full use of the characteristics of chaos theory to ensure the uniqueness of the sequence generated each time a communication link is established.

[0059] S14: Normalize the chaotic sequence to generate a normalized chaotic sequence as the chaotic spread - spectrum sequence.

[0060] Specifically, the purpose of normalization is to map the chaotic sequence to a specific range to generate a normalized chaotic sequence as the chaotic spread - spectrum sequence. In specific implementation, the chaotic sequence is linearly normalized to map its values to the range [0, 1] to ensure the uniform distribution of the sequence.

[0061] The normalized chaotic sequence is further converted into a pseudo - random binary sequence for subsequent spread - spectrum modulation. This kind of processing ensures that the chaotic sequence has excellent autocorrelation characteristics and anti - interference ability in spread - spectrum modulation, while enhancing the concealment of the signal.

[0062] In an alternative embodiment, generating an anti - interference pseudo - random sequence according to the normalized chaotic sequence in step S2 includes the following steps:

[0063] S211: Intercept at least two sub - segments of the normalized chaotic sequence and use them as the initial states of the linear feedback shift register respectively.

[0064] Specifically, intercept at least two non - overlapping sub - segments from the normalized chaotic sequence. These sub - segments will be used as the initial states of the linear feedback shift register (LFSR). The normalized chaotic sequence has good randomness and uniform distribution characteristics and is suitable as the seed for generating pseudo - random sequences. By intercepting multiple sub - segments, it can be ensured that the generated pseudo - random sequence has higher complexity and anti - predictability. In specific implementation, intercept two or more sub - segments from the normalized chaotic sequence. The length of each sub - segment can be 32 bits or 64 bits, and the specific length is determined according to requirements. Then, set the intercepted sub - segments as the initial states of multiple linear feedback shift registers respectively. The initial state of each register is determined by a sub - segment, ensuring the independence and randomness of the initial state of each register.

[0065] S212: Configure the generating polynomial of the linear feedback shift register to generate a pseudo - random sequence with a predetermined code length as the anti - interference pseudo - random sequence.

[0066] Specifically, after setting the initial state of the linear feedback shift register, configure the generating polynomial to generate a pseudo-random sequence with a predetermined code length. The generating polynomial of the linear feedback shift register determines the period and statistical characteristics of the pseudo-random sequence. Selecting an appropriate generating polynomial can ensure that the generated sequence has good autocorrelation characteristics and anti-interference ability. In specific implementation, an appropriate generating polynomial can be selected according to specific requirements. For example, for a 32-bit linear feedback shift register, a primitive polynomial can be selected to ensure the maximum period. Through the iterative operation of the linear feedback shift register, a pseudo-random sequence with a predetermined code length is generated, and the predetermined code length can be determined according to the requirements of the communication system, such as 1024 bits or 2048 bits.

[0067] The complexity of the pseudo-random sequence is enhanced. By intercepting multiple sub-segments as the initial state, it is ensured that the generated pseudo-random sequence has higher complexity and anti-predictability. The generated pseudo-random sequence has good autocorrelation characteristics and anti-interference ability, and can effectively resist channel interference. By selecting different generating polynomials, the period and statistical characteristics of the pseudo-random sequence can be flexibly adjusted to adapt to different communication requirements.

[0068] Reference Figure 2 , in an alternative embodiment, generating the encryption key according to the normalized chaotic sequence in step S2 includes the following steps:

[0069] S221: Extract at least one sub-segment of the normalized chaotic sequence and perform bitwise operation with the random entropy source to generate an intermediate entropy source.

[0070] Specifically, extract at least one sub-segment from the normalized chaotic sequence and perform bitwise operation with the random entropy source to generate an intermediate entropy source. The random entropy source can come from a quantum random number generator or other high-entropy sources to ensure that the generated intermediate entropy source has sufficient randomness and unpredictability. The bitwise operation can adopt the XOR operation, which can effectively mix the entropy of the two input sources, thereby enhancing the randomness of the final key.

[0071] S222: Concatenate the intermediate entropy source with the time stamp and input it into the quantum-resistant hash algorithm to generate the master key.

[0072] Specifically, concatenate the generated intermediate entropy source with the time stamp. The introduction of the time stamp provides an additional dynamic factor for the key generation process, so that even under the same chaotic sequence and random entropy source, the keys generated at different times are unique. The concatenated data is input into the quantum-resistant hash algorithm to generate the master key. The quantum-resistant hash algorithm can select the SHA-3 algorithm to ensure the security of the master key.

[0073] S223: Dynamically truncate the master key according to the channel quality to generate the encryption key.

[0074] Specifically, the master key is dynamically truncated according to the real-time monitored channel quality to generate the final encryption key. Channel quality assessment can be achieved by monitoring indicators such as bit error rate and signal strength. Based on these indicators, the system can judge the security and reliability of the current channel and adjust the length of the key accordingly. When the channel quality is poor, a longer key can be intercepted to enhance security; while when the channel quality is good, the key length can be appropriately shortened to balance security and efficiency.

[0075] The key generation process combines chaotic sequences, random entropy sources, and timestamps to ensure the high randomness and unpredictability of the key. The application of anti-quantum hash algorithms safeguards the key's resistance to quantum computing attacks. Dynamically adjusting the key length according to the channel quality enables the system to flexibly adapt to different communication environments and security requirements while ensuring security.

[0076] In an alternative embodiment, S223 includes the following steps:

[0077] S2231: If the channel quality indicator is higher than the preset threshold, truncate the first half of the master key as the encryption key.

[0078] S2232: If the channel quality indicator is lower than the preset threshold, use the full length of the master key as the encryption key.

[0079] S2233: Perform integrity verification on the encryption key.

[0080] Specifically, channel quality assessment can judge the security and reliability of the current channel by monitoring indicators such as bit error rate and signal strength. According to the results of channel quality assessment, dynamically adjust the length of the encryption key to adapt to different communication environments and security requirements.

[0081] When the channel quality indicator is higher than the preset threshold, it indicates that the current channel has high stability and security. In this case, truncate the first half of the master key as the encryption key. This truncation strategy can not only ensure the randomness and security of the key, but also reduce the key length, thereby improving the efficiency of encryption and decryption.

[0082] On the contrary, when the channel quality indicator is lower than the preset threshold, it indicates that there may be interference or security risks in the current channel. In this case, use the full length of the master key as the encryption key. This strategy can ensure that when the channel quality is poor, the encryption key has sufficient length and complexity, thus providing higher security.

[0083] To ensure the integrity and validity of the encryption key, integrity verification can also be performed on the generated encryption key. Integrity verification can be achieved through a hash algorithm or other verification mechanisms to ensure that the key has not been tampered with or damaged during generation and transmission. Through integrity verification, the system can promptly detect and handle abnormal situations of the key, thereby ensuring the security of communication.

[0084] The above strategy of dynamically adjusting the key length can adjust the key length in real time according to the channel quality, ensuring appropriate security in different environments; through integrity verification, the reliability of the key and the security of the system can be further enhanced. This strategy can flexibly adapt to different communication requirements and provides an efficient and secure encryption solution for satellite communication.

[0085] Reference Figure 3 , in an optional embodiment, S4 includes the following steps:

[0086] S41: Divide the baseband signal into multiple orthogonal frequency division multiplexing (OFDM) subcarriers, where the OFDM subcarriers include data subcarriers and pilot subcarriers.

[0087] Specifically, divide the baseband signal into multiple orthogonal frequency division multiplexing (OFDM) subcarriers, including data subcarriers and pilot subcarriers. The data subcarriers are used to transmit the encrypted ciphertext data, while the pilot subcarriers are used to transmit control information such as the initial seed and channel state identifier. This division method can effectively improve the spectrum utilization rate and provide an independent transmission channel for the pilot signal to ensure the reliable transmission of control information.

[0088] The division of OFDM subcarriers is achieved through fast Fourier transform (FFT). After converting the baseband signal to the frequency domain, it is divided into multiple subcarriers. The number of data subcarriers and the number of pilot subcarriers are optimized according to the system design and channel characteristics to balance the data transmission efficiency and the reliability of control information.

[0089] S42: Encode the initial seed and the channel state identifier into a binary pilot data stream.

[0090] Specifically, the initial seed and the channel state identifier are encoded into a binary pilot data stream. This encoding method ensures the compactness and efficiency of the pilot data. By encoding these key parameters into a binary stream, it can be more easily mapped to the pilot subcarriers during the subsequent modulation process. During the encoding process, the initial seed and the channel state identifier are converted into binary format and their anti-interference ability is enhanced through specific encoding algorithms (such as convolutional coding or Turbo coding).

[0091] S43: By performing quadrature phase shift keying (QPSK) modulation on the binary pilot data stream, map the binary pilot data stream to the pilot subcarriers to generate a pilot signal.

[0092] Specifically, perform QPSK modulation on the binary pilot data stream. QPSK modulation is a commonly used digital modulation method that represents digital information by changing the phase of the carrier wave. QPSK modulation combines every two bits into a symbol and represents four possible symbol values by changing the phase of the carrier wave (0°, 90°, 180°, 270°). This modulation method can not only improve the reliability of data transmission but also ensure the stability of the pilot signal in a complex channel environment. The modulated pilot data stream is mapped to the pilot subcarriers to generate a pilot signal.

[0093] S44: Superimpose the pilot signal on the data subcarriers and adjust the transmit power of the pilot subcarriers to a preset ratio of the transmit power of the data subcarriers to obtain the final transmit signal.

[0094] Specifically, superimpose the pilot signal on the data subcarriers to form the final transmit signal. In this process, the transmit power of the pilot subcarriers is adjusted to a preset ratio of the transmit power of the data subcarriers. This power adjustment strategy ensures that the pilot signal can provide sufficient strength for channel estimation and synchronization at the receiving end without significantly affecting the data transmission efficiency. The preset ratio can be optimized according to the communication system design and channel characteristics to balance the reliability of control information transmission and the efficiency of data transmission.

[0095] OFDM technology can effectively resist multipath fading and frequency selective fading and improve the transmission quality of signals. By generating a pilot signal through QPSK modulation, the stability and reliability of the pilot signal are ensured. By adjusting the transmit power of the pilot subcarriers, the overall performance of the system can be optimized while ensuring the transmission quality of control information. In addition, this method can also dynamically adapt to different channel conditions and further improve the flexibility and adaptability of the system by adjusting the number and power ratio of the pilot subcarriers.

[0096] The above satellite communication encryption method against channel interference generates a chaotic spread spectrum sequence by fusing satellite orbit parameters in real time, and drives the collaborative generation of anti-interference pseudo-random sequences and dynamic encryption keys based on this. It uses chaotic mapping to cut off the mathematical correlation between the spread spectrum code and the key, and at the same time covertly embeds chaotic parameters and channel state identifiers in the physical layer signal. Combining with the quantum entropy source to enhance the unpredictability of the key, it realizes the deep coupling of spread spectrum anti-interference and dynamic encryption. It not only improves the anti-interception and anti-interference capabilities of the signal in complex channels through chaotic spread spectrum and pilot concealment, but also ensures the real-time nature of key distribution and decryption reliability in a high-dynamic environment through the dynamic binding of keys and channel parameters and the satellite-ground chaotic synchronization mechanism. Finally, it synchronously achieves the dual goals of strengthening the anti-interference ability of the physical layer and ensuring end-to-end information security in satellite communication.

[0097] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are sequentially shown according to the indication of the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same moment, but can be executed at different moments. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0098] An embodiment of the present application also provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the steps in the above-described method embodiments.

[0099] An embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the steps in the above-described method embodiments.

[0100] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can refer to the partial description of the method embodiments. The device embodiments described above are only illustrative. The components described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the present disclosure solution. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0101] The above-described embodiments merely represent several implementation manners of the embodiments of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent for the embodiments of the application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the embodiments of the present application, several variations and improvements can still be made, and these all fall within the protection scope of the embodiments of the present application.

Claims

1. A satellite communication encryption method against channel interference, characterized in that The method includes: S1: Generating a chaotic spread spectrum sequence based on satellite orbit parameters; S2: Generating an anti-jamming pseudo-random sequence and an encryption key according to the chaotic spread spectrum sequence; wherein, the encryption key and the anti-jamming pseudo-random sequence are decoupled through chaotic mapping; S3: Performing joint spread spectrum encryption processing on the original data to generate a baseband signal; the joint spread spectrum encryption processing includes: encrypting the original data through the encryption key to generate ciphertext, and performing spread spectrum modulation on the ciphertext and the anti-jamming pseudo-random sequence; S4: Embedding chaotic parameters and channel state identifiers in the baseband signal to generate a final transmitted signal; wherein, the chaotic parameters include the initial seed for generating the chaotic spread spectrum sequence; S5: Transmitting the final transmitted signal and decrypting the final transmitted signal through satellite-ground synchronization.

2. The method according to claim 1, wherein The S1 includes: S11: Calculating the Doppler frequency shift according to the satellite instantaneous elevation angle, and the calculation formula of the Doppler frequency shift is: Among them, f d is the Doppler frequency shift, θ is the instantaneous elevation angle of the satellite, c is the speed of light, and v is the component of the satellite velocity vector in the communication direction; S12: Calculating the chaotic initial seed according to the satellite instantaneous elevation angle and the Doppler frequency shift, and the calculation formula of the chaotic initial seed is: wherein, x0 is the chaotic initial seed, and K is a preset normalization constant; S13: Generating a chaotic sequence through chaotic mapping according to the chaotic initial seed, and the generation formula of the chaotic sequence is: x n+1 = μx n (1 - x n ); wherein, μ is a chaotic parameter; S14: Performing normalization processing on the chaotic sequence to generate a normalized chaotic sequence as the chaotic spread spectrum sequence.

3. The method according to claim 2, characterized in that In the S2, generating the anti-jamming pseudo-random sequence according to the normalized chaotic sequence includes: S211: Intercepting at least two sub-segments of the normalized chaotic sequence and respectively using them as the initial states of a linear feedback shift register; S212: Configuring the generating polynomial of the linear feedback shift register to generate a pseudo-random sequence with a predetermined code length as the anti-jamming pseudo-random sequence.

4. The method according to claim 2, wherein In the S2, generating the encryption key according to the normalized chaotic sequence includes: S221: Extracting at least one sub-segment of the normalized chaotic sequence and performing bitwise operation with a random entropy source to generate an intermediate entropy source; S222: Concatenating the intermediate entropy source with a timestamp and inputting it into an anti-quantum hash algorithm to generate a master key; S223: Dynamically truncating the master key according to the channel quality to generate the encryption key.

5. The method according to claim 4, wherein The S223 includes: S2231: If the channel quality index is higher than a preset threshold, truncating the first half of the master key as the encryption key; S2232: If the channel quality index is lower than a preset threshold, using the full length of the master key as the encryption key; S2233: Performing integrity verification on the encryption key.

6. The method according to any one of claims 1 to 5, characterized in that, The S4 includes: S41: Dividing the baseband signal into multiple orthogonal frequency division multiplexing sub-carriers, and the orthogonal frequency division multiplexing sub-carriers include data sub-carriers and pilot sub-carriers; S42: Encoding the initial seed and the channel state identifier into a binary pilot data stream; S43: Mapping the binary pilot data stream to the pilot sub-carriers by performing quadrature phase shift keying modulation on the binary pilot data stream to generate a pilot signal; S44: Superimpose the pilot signal on the data subcarriers, and adjust the transmission power of the pilot subcarriers to a preset ratio of the transmission power of the data subcarriers to obtain the final transmission signal.

7. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, the method according to any one of claims 1 to 6 is implemented.

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

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