An Encryption Transmission Method in Satellite Communication

Abstract

The present invention discloses an encryption transmission method in satellite communication, belonging to the field of encryption technology. First, the satellite communication data is divided into blocks, and each data block is split according to odd and even bits to respectively construct odd-bit and even-bit encryption keys. After encrypting the corresponding data sub-blocks, they are restored to the initial encrypted data blocks. Then, a shift number is generated based on the encrypted sub-blocks, and the initial encrypted data blocks are subjected to a shift process. Finally, the satellite transmission signal is obtained through quadrature amplitude modulation. Through this multi-step and multi-dimensional encryption method, the encryption intensity of satellite communication data is significantly improved, and the security of data transmission is enhanced.

Description

Technical Field

[0001] The present invention relates to the field of encryption technology, and particularly to an encryption transmission method in satellite communication. Background Art

[0002] Satellite communication data is transmitted in space, with a wide signal propagation range, and is easily illegally received and monitored. Malicious organizations or individuals can use highly sensitive receiving devices to intercept satellite communication data within the signal coverage area and obtain the sensitive information contained therein. In addition to information interception, satellite communication also faces the threat of data tampering. An attacker can modify the data during signal transmission, resulting in the receiving party receiving incorrect information, thereby affecting the correctness of decision-making and even causing serious consequences.

[0003] Existing communication encryption methods use random codes to encrypt communication signals, which can protect communication content to a certain extent, but their encryption strength is limited. For example, some malicious attackers can crack the keys generated by existing encryption algorithms through large-scale cluster computing within a short time, thereby obtaining the original communication signals. Summary of the Invention

[0004] Aiming at the above deficiencies in the prior art, an encryption transmission method in satellite communication provided by the present invention solves the problem of low encryption strength existing in the prior art.

[0005] In order to achieve the above invention purpose, the technical solution adopted by the present invention is: an encryption transmission method in satellite communication, including:

[0006] Performing block processing on satellite communication data to obtain a plurality of data blocks;

[0007] Splitting each data block according to odd and even bits to obtain an odd-bit data sub-block and an even-bit data sub-block;

[0008] Constructing an odd-bit encryption key based on the odd-bit data sub-blocks of each data block, encrypting the odd-bit data sub-blocks to obtain odd-bit encrypted data sub-blocks;

[0009] Constructing an even-bit encryption key based on the even-bit data sub-blocks of each data block, encrypting the even-bit data sub-blocks to obtain even-bit encrypted data sub-blocks;

[0010] Restoring the odd-bit encrypted data sub-blocks and the even-bit encrypted data sub-blocks according to odd and even bits to obtain an initial encrypted data block;

[0011] Generating a shift number based on the odd-bit encrypted data sub-blocks and the even-bit encrypted data sub-blocks, and performing a shift process on the initial encrypted data block to obtain a shift-encrypted data block;

[0012] Perform quadrature amplitude modulation on the shifted encrypted data block to obtain a satellite transmission signal.

[0013] Further, the process of splitting each data block by parity bits includes:

[0014] Number each byte in the data block in sequence;

[0015] Collect the bytes with odd numbers to form an odd-bit data sub-block;

[0016] Collect the bytes with even numbers to form an even-bit data sub-block.

[0017] Further, the processes of obtaining the odd-bit encrypted data sub-block and the even-bit encrypted data sub-block both include:

[0018] Arrange the data sub-blocks in sequence to obtain a data set;

[0019] In the data set, generate a first initial key for each data sub-block;

[0020] In the data set, generate a second initial key for each data sub-block according to the difference between adjacent data sub-blocks;

[0021] Perform bitwise exclusive OR on the first initial key and the corresponding data sub-block to obtain a first encrypted block;

[0022] Perform bitwise exclusive OR on the second initial key and the corresponding data sub-block to obtain a second encrypted block;

[0023] Perform hybrid encryption on the first encrypted block and the second encrypted block to obtain an encrypted data sub-block. Among them, when the data sub-block is an odd-bit data sub-block, the obtained encrypted data sub-block is an odd-bit encrypted data sub-block; when the data sub-block is an even-bit data sub-block, the obtained encrypted data sub-block is an even-bit encrypted data sub-block.

[0024] Further, the process of generating the first initial key includes:

[0025] In the data set, convert each byte in the data sub-block into a numerical value to obtain a numerical value sub-block;

[0026] In the data set, obtain the eigenvalue for each numerical value in the numerical value sub-block;

[0027] According to each numerical value in the numerical value sub-block, as well as the numerical value number and the eigenvalue, obtain the first initial numerical key, and form the first initial key by corresponding the binary numbers of the first initial numerical keys belonging to one numerical value sub-block.

[0028] Further, the specific process of obtaining the first initial numerical key includes: multiplying a numerical value, a numerical serial number, and a characteristic value, and performing a modulo operation on the multiplication result with 255 to obtain the first initial numerical key. The specific formula is: , where is the first initial numerical key corresponding to the j-th numerical value in the i-th numerical sub-block, x i,j is the j-th numerical value in the i-th numerical sub-block, j is the numerical serial number, i is a positive integer, c i is the characteristic value corresponding to the i-th numerical sub-block, and mod is the modulo operation.

[0029] Further, the process of generating the second initial key includes:

[0030] In the data set, subtracting the i-th data sub-block from the (i - 1)-th data sub-block bit by bit to obtain the first data difference sub-block of the i-th data sub-block, where i is a positive integer;

[0031] Subtracting the i-th data sub-block from the (i + 1)-th data sub-block bit by bit to obtain the second data difference sub-block of the i-th data sub-block;

[0032] Converting the bytes in the first data difference sub-block into numerical values, and extracting characteristic values for each numerical value corresponding to the first data difference sub-block;

[0033] Converting the bytes in the second data difference sub-block into numerical values, and extracting characteristic values for each numerical value corresponding to the second data difference sub-block;

[0034] According to the numerical values, numerical serial numbers, and characteristic values in the first data difference sub-block and the second data difference sub-block, obtaining the second initial numerical key, and forming the second initial key by corresponding binaries of each second initial numerical key belonging to the i-th data sub-block.

[0035] Further, the process of obtaining the second initial numerical key includes: multiplying the numerical value, numerical serial number, and the characteristic value corresponding to the first data difference sub-block of the data sub-block to obtain the first data characteristic quantity; multiplying the numerical value, numerical serial number, and the characteristic value corresponding to the second data difference sub-block of the data sub-block to obtain the second data characteristic quantity, adding the first data characteristic quantity and the second data characteristic quantity, and performing a modulo operation on the addition result with 255 to obtain the second initial numerical key.

[0036] Further, the process of obtaining the shifted encrypted data block includes:

[0037] Calculating the first randomness measure according to the probability of each encrypted byte in the odd-bit encrypted data sub-block appearing in the odd-bit encrypted data sub-block;

[0038] Calculate the second randomness metric according to the probability of each encrypted byte in the odd-bit encrypted data sub-block appearing in the initial encrypted data block;

[0039] Calculate the third randomness metric according to the probability of each encrypted byte in the even-bit encrypted data sub-block appearing in the even-bit encrypted data sub-block;

[0040] Calculate the fourth randomness metric according to the probability of each encrypted byte in the even-bit encrypted data sub-block appearing in the initial encrypted data block;

[0041] Obtain the shift number according to the four randomness metrics;

[0042] Perform a cyclic shift process on the initial encrypted data block according to the shift number to obtain the shifted encrypted data block.

[0043] Furthermore, the process of obtaining the shift number is as follows:

[0044] Sum the four randomness metrics to obtain the sum of randomness metrics. Take the product of the four randomness metrics as the amplification factor. Multiply the amplification factor by the sum of randomness metrics and round down to obtain the amplified amount. Take the remainder of the amplified amount divided by 128 to obtain the shift number. The specific formula is: , where K is the shift number, H1 is the first randomness metric, H2 is the second randomness metric, H3 is the third randomness metric, and H4 is the fourth randomness metric. is rounding down, and mod is the remainder operation.

[0045] Furthermore, shift each binary number in the initial encrypted data block to the left according to the shift number, and sequentially add the removed binary numbers to the right; or, shift each binary number in the initial encrypted data block to the right according to the shift number, and sequentially add the removed binary numbers to the left.

[0046] The beneficial effects of the present invention are:

[0047] 1. The present invention processes satellite communication data in blocks, realizes separate encryption processing for each data block, so that each data block has a different key. Then split each data block into odd-bit and even-bit parts to obtain an odd-bit data sub-block and an even-bit data sub-block, and generate encryption keys according to the odd-bit data sub-block and the even-bit data sub-block respectively, making the encryption key closely related to the original data, with strong dynamics and randomness, and improving the encryption intensity.

[0048] 2. The present invention restores the odd - numbered encrypted data sub - blocks and the even - numbered encrypted data sub - blocks according to odd and even positions, keeping the data length unchanged. Then, based on the odd - numbered encrypted data sub - blocks and the even - numbered encrypted data sub - blocks, a shift number is generated. The shift numbers of each data block may be different, which makes the encryption process have strong randomness and improves the encryption intensity. It is difficult for an attacker to find the shifting rule by analyzing multiple encrypted data blocks, thus effectively resisting cracking means such as statistical analysis. Description of the Drawings

[0049] Figure 1 It is a flowchart of an encryption transmission method in satellite communication. Detailed Embodiments

[0050] The following describes the detailed embodiments of the present invention to facilitate those skilled in the art of this technology to understand the present invention. However, it should be clear that the present invention is not limited to the scope of the detailed embodiments. For those of ordinary skill in the art of this technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions created using the concept of the present invention are within the scope of protection.

[0051] As Figure 1 shown, an encryption transmission method in satellite communication includes:

[0052] Perform block processing on satellite communication data to obtain multiple data blocks;

[0053] Split each data block according to odd and even positions to obtain an odd - numbered data sub - block and an even - numbered data sub - block;

[0054] Construct an odd - numbered encryption key according to the odd - numbered data sub - blocks of each data block, and encrypt the odd - numbered data sub - blocks to obtain odd - numbered encrypted data sub - blocks;

[0055] Construct an even - numbered encryption key according to the even - numbered data sub - blocks of each data block, and encrypt the even - numbered data sub - blocks to obtain even - numbered encrypted data sub - blocks;

[0056] Restore the odd - numbered encrypted data sub - blocks and the even - numbered encrypted data sub - blocks according to odd and even positions to obtain an initial encrypted data block, where the odd - numbered encrypted data sub - blocks and the even - numbered encrypted data sub - blocks are two encrypted data sub - blocks corresponding to the same data block;

[0057] Generate a shift number according to the odd - numbered encrypted data sub - blocks and the even - numbered encrypted data sub - blocks, and perform a shift process on the initial encrypted data block to obtain a shifted encrypted data block;

[0058] Perform quadrature amplitude modulation on the shifted encrypted data block to obtain a satellite transmission signal.

[0059] In this embodiment, the satellite communication data can be text, voice, image, etc. The length of the data block is 1024 bytes, and 1024 bytes is a commonly used unit for storage and transmission.

[0060] In this embodiment, the process of splitting each data block by parity bits includes:

[0061] Number each byte in the data block in sequence;

[0062] Collect the bytes with odd numbers to form an odd-bit data sub-block;

[0063] Collect the bytes with even numbers to form an even-bit data sub-block.

[0064] In this embodiment, the process of obtaining the odd-bit encrypted data sub-block and the even-bit encrypted data sub-block both includes:

[0065] Arrange the data sub-blocks in sequence to obtain a data set;

[0066] In the data set, generate a first initial key for each data sub-block;

[0067] In the data set, generate a second initial key for each data sub-block according to the difference between adjacent data sub-blocks;

[0068] Exclusive OR the first initial key with the corresponding data sub-block to obtain a first encrypted block;

[0069] Exclusive OR the second initial key with the corresponding data sub-block to obtain a second encrypted block;

[0070] Perform hybrid encryption on the first encrypted block and the second encrypted block to obtain an encrypted data sub-block. Among them, when the data sub-block is an odd-bit data sub-block, the obtained encrypted data sub-block is an odd-bit encrypted data sub-block. When the data sub-block is an even-bit data sub-block, the obtained encrypted data sub-block is an even-bit encrypted data sub-block. The odd-bit encryption key includes: the first initial key and the second initial key. The even-bit encryption key includes: the first initial key and the second initial key.

[0071] In this embodiment, the hybrid encryption is to add the first encrypted block and the second encrypted block bit by bit, and take half of the addition result to obtain the encrypted data sub-block.

[0072] The first initial key is generated separately for each data sub-block, while the second initial key is generated based on the differences between adjacent data sub-blocks. This complex key generation method makes the relationship between the key and the data sub-block itself as well as adjacent data sub-blocks closely connected. It is very difficult for an attacker to infer the key generation rule by analyzing part of the data. Even if part of the encrypted data is intercepted, it is difficult to obtain useful information from it, effectively resisting attack means based on statistical analysis and pattern recognition.

[0073] In this embodiment, the process of generating the first initial key includes:

[0074] In the data set, each byte in the data sub-block is converted into a numerical value to obtain a numerical sub-block;

[0075] In the data set, eigenvalues are obtained for the numerical values in each numerical sub-block;

[0076] According to each numerical value in the numerical sub-block, as well as the numerical number and the eigenvalue, a first initial numerical key is obtained, and the respective first initial numerical keys belonging to a numerical sub-block are corresponding binary to form the first initial key.

[0077] In this embodiment, the specific process of obtaining the first initial numerical key includes: multiplying the numerical value, the numerical number, and the eigenvalue, and performing a modulo operation on the multiplication result with 255 to obtain the first initial numerical key. The specific formula is: , where is the first initial numerical key corresponding to the j-th numerical value in the i-th numerical sub-block, x i,j is the j-th numerical value in the i-th numerical sub-block, j is the numerical number, i is a positive integer, c i is the eigenvalue corresponding to the i-th numerical sub-block, and mod is the modulo operation. It is equivalent to generating a numerical key for each byte to be encrypted to encrypt this byte.

[0078] The present invention first converts each byte of the data sub-block into a numerical value, and then generates the first initial numerical key based on the numerical value, the numerical number, and the eigenvalue. This makes the key generation closely bound to the original data sub-block, and the keys generated by different data sub-blocks are significantly different. It is difficult for an attacker to crack other data through a single key, effectively improving the encryption pertinence and security.

[0079] In the present invention, converting a byte into a numerical value means changing a binary number into a decimal number.

[0080] In the present invention, the eigenvalue is the standard deviation or variance of the numerical value.

[0081] In this embodiment, the process of generating the second initial key includes:

[0082] In the data set, subtract the i-th data sub-block from the (i - 1)-th data sub-block bit by bit to obtain the first data difference sub-block of the i-th data sub-block, where i is a positive integer;

[0083] Subtract the i-th data sub-block from the (i + 1)-th data sub-block bit by bit to obtain the second data difference sub-block of the i-th data sub-block;

[0084] Convert the bytes in the first data difference sub-block into numerical values, and extract feature values for each corresponding numerical value in the first data difference sub-block;

[0085] Convert the bytes in the second data difference sub-block into numerical values, and extract feature values for each corresponding numerical value in the second data difference sub-block;

[0086] According to the numerical values, numerical value numbers, and feature values in the first data difference sub-block and the second data difference sub-block, obtain the second initial numerical key, and form the second initial key by corresponding binary of each second initial numerical key belonging to the i-th data sub-block.

[0087] In this embodiment, the process of obtaining the second initial numerical key includes: multiplying the numerical value, numerical value number, and the corresponding feature value of the first data difference sub-block of the data sub-block to obtain the first data feature quantity; multiplying the numerical value, numerical value number, and the corresponding feature value of the second data difference sub-block of the data sub-block to obtain the second data feature quantity, adding the first data feature quantity and the second data feature quantity, and performing a modulo operation on the added result with 255 to obtain the second initial numerical key.

[0088] The formula for obtaining the second initial numerical key is: , where is the second initial numerical key corresponding to the j-th numerical value of the i-th data sub-block, y i,1,j is the j-th numerical value in the first data difference sub-block of the i-th data sub-block, r i,1 is the feature value of the first data difference sub-block of the i-th data sub-block, y i,2,j is the j-th numerical value in the second data difference sub-block of the i-th data sub-block, r i,2 is the feature value of the second data difference sub-block of the i-th data sub-block, j is the numerical value number, i is a positive integer, and mod is the modulo operation. It is equivalent to generating a numerical key for each byte to be encrypted for encrypting that byte.

[0089] In the present invention, each data sub-block is subtracted from the adjacent neighborhoods on both sides to obtain the first data difference sub-block and the second data difference sub-block. This way makes full use of the correlation between data sub-blocks, so that the generated key is not only related to a single data sub-block, but also related to the difference information of adjacent data sub-blocks.

[0090] Obtain the second initial numerical key according to the values, numerical numbers, and eigenvalue in the first data difference sub-block and the second data difference sub-block. This multi-factor combination method makes the generation of the key highly random. The position (numerical number) of each data sub-block, the difference (value) from the adjacent data sub-block, and the eigenvalue are all factors affecting the key generation, and different combinations of these factors will generate a unique key. Even if there are minor changes in some data in the data set, it will result in a completely different generated key, thus effectively resisting the risks of known plaintext attacks and brute-force cracking.

[0091] When the data sub-block is at the beginning or end of the data set, the missing data sub-block on one side is filled with 0.

[0092] In this embodiment, the specific process of restoring the odd-bit encrypted data sub-blocks and even-bit encrypted data sub-blocks according to odd and even bits is as follows: Fill the bytes in the odd-bit encrypted data sub-blocks into the positions with odd numbers in the initial encrypted data block in sequence, and at the same time fill the bytes in the even-bit encrypted data sub-blocks into the positions with even numbers in the initial encrypted data block in sequence, so as to complete the restoration. For example, the byte numbered 9 in the data block belongs to the odd-bit data sub-block with a serial number of 5. The encrypted byte with a serial number of 5 in the odd-bit encrypted data sub-block is returned to the position 9 in the data block.

[0093] In this embodiment, the process of obtaining the shifted encrypted data block includes:

[0094] Calculate the first randomness measure according to the probability of each encrypted byte in the odd-bit encrypted data sub-block appearing in the odd-bit encrypted data sub-block;

[0095] Calculate the second randomness measure according to the probability of each encrypted byte in the odd-bit encrypted data sub-block appearing in the initial encrypted data block;

[0096] Calculate the third randomness measure according to the probability of each encrypted byte in the even-bit encrypted data sub-block appearing in the even-bit encrypted data sub-block;

[0097] Calculate the fourth randomness measure according to the probability of each encrypted byte in the even-bit encrypted data sub-block appearing in the initial encrypted data block;

[0098] Obtain the shift number according to the four randomness measures;

[0099] Perform a cyclic shift process on the initial encrypted data block according to the shift number to obtain the shifted encrypted data block.

[0100] In this embodiment, the information entropy is used to calculate the randomness measure, and the specific formula is: , where H is the information entropy, P nis the probability of the nth encrypted byte, log is the logarithmic function, N is the number of encrypted bytes, and n is a positive integer.

[0101] The present invention calculates the probabilities of encrypted bytes appearing in different ranges in the encrypted data sub-blocks of odd and even bits, and uses the information entropy formula to obtain the randomness measure. Information entropy can measure the uncertainty of data. Based on this, the shift number is determined to closely associate the encryption process with the probability distribution of the data itself.

[0102] In this embodiment, the process of obtaining the shift number is as follows:

[0103] Sum the four randomness measures to obtain the sum of randomness measures. Take the product of the four randomness measures as the amplification factor. Multiply the amplification factor by the sum of randomness measures and round down to obtain the amplified amount. Perform a modulo operation on the amplified amount with 128 to obtain the shift number. The specific formula is: , where K is the shift number, H1 is the first randomness measure, H2 is the second randomness measure, H3 is the third randomness measure, and H4 is the fourth randomness measure. is rounding down, and mod is the modulo operation.

[0104] The present invention introduces multiplying the amplification factor (the product of the four randomness measures) by the sum of randomness measures, rounding down the result, and then performing a modulo operation with 128. The use of the amplification factor further amplifies the differences and combined effects between randomness measures, making the value range and variation of the shift number more abundant. Performing a modulo operation with 128 controls the shift number between 0 and 127.

[0105] In this embodiment, perform a left shift operation on each binary number in the initial encrypted data block according to the shift number, and sequentially add the removed binary numbers to the right; or, perform a right shift operation on each binary number in the initial encrypted data block according to the shift number, and sequentially add the removed binary numbers to the left.

[0106] Process the satellite communication data in blocks, splitting the originally continuous long signal into multiple independent data blocks. This enables each data block to be independently encrypted in subsequent operations. Even if an attacker intercepts some data blocks, it is difficult to obtain the complete communication information. Moreover, the encryption processes of different data blocks are independent of each other, increasing the difficulty for the attacker to analyze the encryption rules. For example, if the communication signal is a long text message, after block splitting, the attacker cannot infer the content and encryption method of other data blocks from one data block.

[0107] Each data block is split based on the parity bit, resulting in odd-bit and even-bit data sub-blocks. Odd-bit and even-bit encryption keys are then constructed for encryption. This splitting method increases encryption complexity, as an attacker must simultaneously crack both the odd-bit and even-bit encryption keys to obtain the complete data. Compared to traditional monolithic encryption, this splitting increases the encryption dimension, significantly increasing the difficulty of cracking. For example, while previously only requiring a single encryption key, an attacker now needs to crack two separate keys. These two keys are dynamically generated based on the parity bit of the data block, making them even more difficult to crack.

[0108] The odd- and even-bit encrypted data sub-blocks are restored based on their parity bits to obtain the initial encrypted data block. The initial encrypted data block is then shifted using a shift number generated based on the odd- and even-bit encrypted data sub-blocks. These two steps further obfuscate the structure and order of the encrypted data. Parity restoration makes it difficult for attackers to discern the original parity splitting information from the encrypted data, while the shifting disrupts the data's original order, increasing its randomness. An attacker must master both the parity restoration and shifting rules to attempt to restore the original data, making the cracking process more complex and difficult.

[0109] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for encrypted transmission in satellite communication, characterized in that, Including: Performing block processing on satellite communication data to obtain multiple data blocks; Splitting each data block by parity bits to obtain an odd-bit data sub-block and an even-bit data sub-block; Constructing an odd-bit encryption key based on the odd-bit data sub-blocks of each data block, encrypting the odd-bit data sub-blocks to obtain odd-bit encrypted data sub-blocks; Constructing an even-bit encryption key based on the even-bit data sub-blocks of each data block, encrypting the even-bit data sub-blocks to obtain even-bit encrypted data sub-blocks; Restoring the odd-bit encrypted data sub-blocks and the even-bit encrypted data sub-blocks by parity bits to obtain an initial encrypted data block; Generating a shift number based on the odd-bit encrypted data sub-blocks and the even-bit encrypted data sub-blocks, performing a shift process on the initial encrypted data block to obtain a shift-encrypted data block; Performing quadrature amplitude modulation on the shift-encrypted data block to obtain a satellite transmission signal; The processes of obtaining the odd-bit encrypted data sub-blocks and the even-bit encrypted data sub-blocks both include: Sequentially arranging the data sub-blocks to obtain a data set; Generating a first initial key for each data sub-block in the data set; Generating a second initial key for each data sub-block in the data set according to the difference between adjacent data sub-blocks; Performing bitwise exclusive OR on the first initial key and the corresponding data sub-block to obtain a first encrypted block; Performing bitwise exclusive OR on the second initial key and the corresponding data sub-block to obtain a second encrypted block; Performing hybrid encryption on the first encrypted block and the second encrypted block to obtain an encrypted data sub-block, where when the data sub-block is an odd-bit data sub-block, the obtained encrypted data sub-block is an odd-bit encrypted data sub-block, and when the data sub-block is an even-bit data sub-block, the obtained encrypted data sub-block is an even-bit encrypted data sub-block; The process of generating the first initial key includes: In the data set, converting each byte in the data sub-block into a numerical value to obtain a numerical value sub-block; Obtaining a characteristic value for each numerical value in the numerical value sub-block in the data set; Obtaining a first initial numerical key according to each numerical value in the numerical value sub-block, as well as the numerical value number and the characteristic value, and forming the first initial key by corresponding binary of each first initial numerical key belonging to a numerical value sub-block.

2. The encrypted transmission method in satellite communication according to claim 1, wherein The process of splitting each data block by parity bits includes: Sequentially numbering each byte in the data block; Collecting the bytes with odd numbers to form an odd-bit data sub-block; Collecting the bytes with even numbers to form an even-bit data sub-block.

3. The encrypted transmission method in satellite communication according to claim 1, wherein The specific process of obtaining the first initial numerical key includes: multiplying the numerical value, the numerical number, and the eigenvalue, and performing a modulo operation on the multiplication result with 255 to obtain the first initial numerical key. The specific formula is: , where is the first initial numerical key corresponding to the j-th numerical value in the i-th numerical sub-block, x i,j is the j-th numerical value in the i-th numerical sub-block, j is the numerical number, i is a positive integer, c i is the eigenvalue corresponding to the i-th numerical sub-block, and mod is the modulo operation.

4. The encryption transmission method in satellite communication according to claim 1, characterized in that, The process of generating the second initial key includes: In the data set, performing bitwise subtraction on the i-th data sub-block and the (i - 1)-th data sub-block to obtain a first data difference sub-block of the i-th data sub-block, where i is a positive integer; Performing bitwise subtraction on the i-th data sub-block and the (i + 1)-th data sub-block to obtain a second data difference sub-block of the i-th data sub-block; Converting the bytes in the first data difference sub-block into numerical values, and extracting characteristic values for each numerical value corresponding to the first data difference sub-block; Converting the bytes in the second data difference sub-block into numerical values, and extracting characteristic values for each numerical value corresponding to the second data difference sub-block; Obtain a second initial numerical key according to the values, value numbers, and eigenvalue in the first data difference sub-block and the second data difference sub-block, and form a second initial key by corresponding binary of each second initial numerical key belonging to the i-th data sub-block.

5. The encryption transmission method in satellite communication according to claim 4, wherein The process of obtaining the second initial numerical key includes: multiplying the value, value number, and the eigenvalue corresponding to the first data difference sub-block in the first data difference sub-block of the data sub-block to obtain a first data feature quantity; multiplying the value, value number, and the eigenvalue corresponding to the second data difference sub-block in the second data difference sub-block of the data sub-block to obtain a second data feature quantity, adding the first data feature quantity and the second data feature quantity, and performing a modulo operation on the added result with 255 to obtain the second initial numerical key.

6. The encrypted transmission method in satellite communication according to claim 1, wherein The process of obtaining the shifted encrypted data block includes: Calculate a first randomness measure according to the probability of each encrypted byte in the odd-bit encrypted data sub-block appearing in the odd-bit encrypted data sub-block; Calculate a second randomness measure according to the probability of each encrypted byte in the odd-bit encrypted data sub-block appearing in the initial encrypted data block; Calculate a third randomness measure according to the probability of each encrypted byte in the even-bit encrypted data sub-block appearing in the even-bit encrypted data sub-block; Calculate a fourth randomness measure according to the probability of each encrypted byte in the even-bit encrypted data sub-block appearing in the initial encrypted data block; Obtain a shift number according to the four randomness measures; Perform a circular shift process on the initial encrypted data block according to the shift number to obtain the shifted encrypted data block.

7. The encrypted transmission method in satellite communication according to claim 6, characterized in that, The process of obtaining the shift number is: Sum four randomness metrics to obtain the sum of randomness metrics. Take the product of the four randomness metrics as the amplification factor. Multiply the amplification factor by the sum of randomness metrics and round down to obtain the amplified quantity. Take the remainder of the amplified quantity divided by 128 to obtain the shift number. The specific formula is: , where K is the shift number, H1 is the first randomness metric, H2 is the second randomness metric, H3 is the third randomness metric, and H4 is the fourth randomness metric. is rounding down, and mod is the remainder operation.

8. The encryption transmission method in satellite communication according to claim 6, characterized in that, Perform a left shift process on each binary number in the initial encrypted data block according to the shift number, and sequentially add the removed binary numbers to the right; or, perform a right shift process on each binary number in the initial encrypted data block according to the shift number, and sequentially add the removed binary numbers to the left.

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