A signal encryption transmission method, apparatus, medium, and device based on sparse matrix perturbation

Abstract

This invention discloses a signal encryption transmission method, apparatus, medium, and device based on sparse matrix perturbation, belonging to the field of communication encryption technology. The method includes: acquiring a signal to be transmitted; encoding the signal to be transmitted using SCMA technology to obtain an encoded signal; perturbing the encoded signal with a sparse matrix using chaotic sequence values ​​generated by a four-dimensional hyperchaotic model to obtain an encrypted signal; and transmitting the encrypted signal to achieve encrypted signal transmission. This invention can improve the transmission capacity and security of communication systems.

Description

Technical Field

[0001] This invention relates to a signal encryption transmission method, apparatus, medium, and device based on sparse matrix perturbation, belonging to the field of communication encryption technology. Background Technology

[0002] With the advent of the 5G era, new services such as metaverse, digital twins, and the industrial internet are emerging, leading to a surge in global data traffic. This data will ultimately be transmitted via access networks and integrated into optical fibers. Passive Optical Networks (PONs) have gained widespread attention due to their advantages such as low loss, high bandwidth, and low cost. From Time Division Multiplexing Passive Optical Networks (TDM-PON) and Wavelength Division Multiplexing Passive Optical Networks (WDM-PON) to Orthogonal Frequency Division Multiplexing Passive Optical Networks (OFDM-PON), their continuous system upgrades have struggled to meet the ever-increasing capacity demands. OFDM essentially refers to different users occupying different subcarriers, requiring strict orthogonality between different subcarriers; it remains a form of orthogonal multiple access (OMA). Unlike non-orthogonal multiple access (NOMA) technologies, traditional orthogonal multiple access technologies allocate each mutually orthogonal resource block to a single user, such as Time Division Multiple Access (TDMA) and Orthogonal Frequency Division Multiple Access (OFDM). However, while OMA access schemes offer good resistance to interference and fading, their spectrum utilization is extremely inefficient. Compared to orthogonal transmission, in NOMA, the same resource block is shared by multiple users, significantly improving the system's spectrum efficiency and accessibility.

[0003] Non-orthogonal multiple access (NOMA) is one of the key technologies in 5G systems. Sparse code division multiple access (SCMA) based on the code domain is a traditional NOMA method. It loads different codewords allocated to different users onto the same resource to improve spectral efficiency. Since the number of non-orthogonal superimposed codewords can be much greater than the number of orthogonal resource units, SCMA can serve more users within the same resource range. SCMA effectively increases system capacity and can provide access for more users. However, because different users occupy the same resource block in SCMA, in addition to attacks on unauthorized receivers, there is also the problem of information theft by users on the same resource block. Currently, physical layer encryption mainly uses optical domain signal encryption based on chaotic lasers, but this method is limited by signal bandwidth and cannot meet the needs of high-capacity transmission. Summary of the Invention

[0004] The purpose of this invention is to provide a signal encryption transmission method, apparatus, medium, and device based on sparse matrix perturbation, which solves the problems of user eavesdropping and low transmission capacity in the prior art.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] In a first aspect, the present invention provides a signal encryption transmission method based on sparse matrix perturbation, comprising:

[0007] Acquire the signal to be transmitted;

[0008] The signal to be transmitted is encoded using SCMA technology to obtain the encoded signal;

[0009] The encrypted signal is obtained by perturbing the coded signal with a sparse matrix using chaotic sequence values ​​generated by a four-dimensional hyperchaotic model.

[0010] Encrypted signals are transmitted to achieve encrypted signal transmission.

[0011] In conjunction with the first aspect, further, the encoding of the signal to be transmitted using SCMA technology to obtain an encoded signal includes:

[0012] After the signal to be transmitted is encoded by the SCMA encoder, the encoded signal is represented by a sparse matrix. The expression of the sparse matrix is ​​as follows:

[0013] F = [diag(V1V1)] T ),diag(V2V2 T )…diag(V J V J T )]

[0014] Where F is a sparse matrix, V1, V2…V J These are the mapping matrices for the 1st, 2nd...Jth users, respectively. T represents the transpose operation, and diag() is the diag function.

[0015] The expression for the SCMA encoder is:

[0016]

[0017] Where f represents the SCMA encoder, A is the signal to be transmitted, M is the number of codewords in each codebook, and X is the user codebook, X∈B. K B is the mother codebook, K is the number of resources, x is the complex field codeword, and f(a) is the function that maps a binary vector to a complex vector.

[0018] The mapping representation of the mother codebook is as follows:

[0019] g:A log M →B, b=g(a)

[0020] Where g represents the mapping of the mother codebook, b is an N-dimensional constellation point in the mother codebook, and g(a) is the binary vector mapped to the multi-dimensional constellation point set domain;

[0021] The N-dimensional constellation points are mapped to K-dimensional sparse codewords using a binary mapping matrix. In this process, the SCMA encoder is redefined as f = Vg, where V is the mapping matrix.

[0022] In conjunction with the first aspect, the expression for the four-dimensional hyperchaotic model is further as follows:

[0023]

[0024] Where a, b, c, d, and r are preset parameters, and x, y, z, and w are variables. and It is the derivative of variables x, y, z, and w with respect to time t.

[0025] In conjunction with the first aspect, the chaotic sequence value is further obtained by the following method:

[0026] The four-dimensional hyperchaotic model is solved using the Runge-Kutta method to obtain four-dimensional random chaotic sequence values.

[0027] In conjunction with the first aspect, furthermore, the sparse matrix perturbation of the encoded signal using chaotic sequence values ​​is achieved through the following formula:

[0028] masking_i1=floor(mod(i×x i ×10 5 ,10))

[0029]

[0030] Where, x i Here, i is the value of the chaotic sequence, i is the i-th column of the sparse matrix, i1 is the first element of the i-th column of the sparse matrix, mod() is the modulo function, floor() is the floor function, masking_i1 means to use the chaotic sequence to perturb and encrypt the first element of the i-th column of the sparse matrix, and direction i1 means to make a judgment on the first element of the i-th column after perturbation and encryption.

[0031] Secondly, the present invention also provides a signal encryption transmission device based on sparse matrix perturbation, comprising:

[0032] The signal acquisition module is used to: acquire the signal to be transmitted;

[0033] The signal encoding module is used to encode the signal to be transmitted using SCMA technology to obtain an encoded signal.

[0034] The signal encryption module is used to: perform sparse matrix perturbation on the encoded signal using chaotic sequence values ​​generated by a four-dimensional hyperchaotic model to obtain an encrypted signal;

[0035] The signal transmission module is used to transmit encrypted signals, thereby achieving encrypted signal transmission.

[0036] Furthermore, in conjunction with the second aspect, the signal encryption module utilizes chaotic sequence values ​​to perform sparse matrix perturbation on the encoded signal, achieved through the following formula:

[0037] masking_i1=floor(mod(i×x i ×10 5 ,10))

[0038]

[0039] Where, x i Here, i is the value of the chaotic sequence, i is the i-th column of the sparse matrix, i1 is the first element of the i-th column of the sparse matrix, mod() is the modulo function, floor() is the floor function, masking_i1 means to use the chaotic sequence to perturb and encrypt the first element of the i-th column of the sparse matrix, and direction i1 means to make a judgment on the first element of the i-th column after perturbation and encryption.

[0040] Thirdly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the signal encryption transmission method based on sparse matrix perturbation as described in any of the first aspects.

[0041] Fourthly, the present invention also provides an apparatus comprising:

[0042] Memory, used to store instructions;

[0043] A processor is configured to execute the instructions, causing the device to perform a signal encryption transmission method based on sparse matrix perturbation as described in any of the first aspects.

[0044] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0045] This invention provides a signal encryption transmission method, apparatus, medium, and device based on sparse matrix perturbation. It utilizes the spreading characteristics of SCMA sparse codes to encode the user's bit data (the signal to be transmitted), thereby improving the transmission capacity of the communication system. It uses chaotic sequence values ​​generated by a four-dimensional hyperchaotic model to perform multi-dimensional perturbation on the encoded signal, achieving synchronous encryption of the codebook and subcarriers without introducing additional noise. This solves the problems of attacks from illegal receivers and eavesdropping on the same resource block introduced by SCMA, thereby improving the security performance of the communication system. Attached Figure Description

[0046] Figure 1 This is one of the flowcharts of a signal encryption transmission method based on sparse matrix perturbation provided in the embodiments of the present invention;

[0047] Figure 2 This is the second flowchart of a signal encryption transmission method based on sparse matrix perturbation provided in this embodiment of the invention;

[0048] Figure 3 This is a schematic diagram of 6 users reusing 4 units of resources provided in an embodiment of the present invention;

[0049] Figure 4 This is a schematic diagram of 6 users reusing 4 units of resource factor provided in an embodiment of the present invention;

[0050] Figure 5 This is the phase diagram of the four-dimensional hyperchaotic model provided in this embodiment of the invention;

[0051] Figure 6 This is an example diagram of sparse matrix perturbation provided in an embodiment of the present invention;

[0052] Figure 7 This is a schematic diagram of a communication system using the method of the present invention in a seven-core optical fiber provided in an embodiment of the present invention. Detailed Implementation

[0053] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0054] Example 1

[0055] Digital signals are encrypted using a chaotic model. This encryption method has advantages such as simplicity, high sensitivity, and flexible initial value setting.

[0056] Therefore, in this patent, we propose a signal encryption transmission method based on sparse matrix perturbation. Considering that the capacity of single-mode fiber is approaching the Shannon limit, spatial division multiplexing (SDM) is a very promising solution to further improve system capacity. In a seven-core fiber, we use a four-dimensional hyperchaotic model to generate four chaotic sequence values ​​for multi-dimensional perturbation encryption of the sparse matrix.

[0057] like Figure 1 As shown, this invention provides a signal encryption transmission method based on sparse matrix perturbation, comprising the following steps:

[0058] S1. Obtain the signal to be transmitted.

[0059] like Figure 2As shown, the signal to be transmitted (Data) is obtained at the transmitting end of the communication system. in).

[0060] S2. Encode the signal to be transmitted using SCMA technology to obtain the encoded signal.

[0061] SCMA enables different users to occupy some of the overlapping time and frequency resources through sparse multiplexing of code domains, and can realize the access of massive numbers of users by using SCMA technology.

[0062] An SCMA encoder can be defined as:

[0063]

[0064] Where f represents the SCMA encoder, A is the signal to be transmitted (binary set), M is the number of codewords in each codebook, and X is the user codebook with codebook specification |X| = M, X ∈ B. K B is the mother codebook (a set of complex numbers), K is the number of resources, also known as the dimension. Each K-dimensional codeword contains KN (N < K) zero elements. x is a complex field codeword, which contains a sparse vector with N non-zero elements. f(a) is a function that maps a binary vector to a complex vector.

[0065] The mapping process of SCMA codes refers to the following: the bit information sent by the user is mapped to an N-dimensional constellation point b (b∈B) in the constellation set B. The constellation set B composed of this constellation point is called the mother codebook, and B∈B N The mapping of the mother codebook can be represented as:

[0066] g:A log M →B, b=g(a) (2)

[0067] Where g represents the mapping of the mother codebook, b is an N-dimensional constellation point in the mother codebook, and g(a) is the binary vector mapped to the multi-dimensional constellation point set domain;

[0068] The N-dimensional constellation points are mapped to K-dimensional sparse codewords using a binary mapping matrix. During this process, the SCMA encoder is redefined as f = Vg, where V is the mapping matrix. The time-frequency resources occupied by the codewords sent by user j can be determined by their corresponding mapping matrix V. j To choose. The coding structure of SCMA can be represented by a sparse matrix F with K rows and J columns, which can be expressed as:

[0069] F = [diag(V1V1)] T ),diag(V2V2 T )…diag(V J V J T(3)

[0070] Where F is a sparse matrix, V1, V2…V J These are the mapping matrices for the 1st, 2nd...Jth users, respectively. T represents the transpose operation, and diag() is the diag function.

[0071] This embodiment uses a codebook with K=4 and J=6 as an example. The specific encoding process is as follows: Figure 3 As shown, each of the six users has its own code table, and each code table has four codewords, each corresponding one-to-one with the input bitstream. Furthermore, each codeword occupies four subcarriers, but only two are non-empty, reflecting the sparsity of the codewords. In the specific encoding process, the binary sequence is first mapped according to the codebook. If user 1 inputs (1,1), the fourth codeword in code table 1 is selected; if user 2 inputs (1,0), the third codeword in code table 2 is selected, and so on. If user 6 inputs (1,1), the fourth codeword in code table 6 is selected. Then, the codewords obtained by each user are directly added together to obtain the encoded data. Since only two carriers in each code table are non-empty, the data from three users will be mixed together on each carrier. Although these three users share the frequency resources of the subcarriers, they can be distinguished from each other using different codebooks. By using SCMA coding, data from six users can be transmitted using only four subcarriers, increasing the number of access users to 1.5 times the original, thus improving system capacity; the corresponding sparse matrix F is:

[0072]

[0073] The corresponding factor diagram is as follows Figure 4 As shown in the figure, circles represent users, and squares represent resource factors, i.e., the number of subcarriers. It can be seen that each user only uses two resources, and each resource has the data of three users superimposed.

[0074] S3. Use the chaotic sequence values ​​generated by the four-dimensional hyperchaotic model to perform sparse matrix perturbation on the encoded signal to obtain the encrypted signal.

[0075] While SCMA coding improves the transmission capacity of communication systems, it also faces the problem of information theft by users on the same resource block. Based on this, this patent proposes a four-dimensional hyperchaotic model to encrypt the coded signal. The specific four-dimensional hyperchaotic model is expressed as follows:

[0076]

[0077] Where a, b, c, d, and r are preset parameters, and x, y, z, and w are variables. and It represents the derivatives of variables x, y, z, and w with respect to time t; the initial key is set to (35, 3, 12, 7, 0.5, 3, -1, 4, 2), and the four-dimensional random chaotic sequence values ​​(x, y, z, w) can be obtained using the Runge-Kutta method. The phase diagram is shown below. Figure 5 As shown, this model exhibits highly complex chaotic characteristics, and encryption systems based on this chaotic model possess strong security performance.

[0078] The chaotic sequence value x generated by the 4D hyperchaotic model i The perturbation of the first element of each column of a sparse matrix can be expressed as follows:

[0079] masking_i1=floor(mod(i×x i ×10 5 ,10))

[0080]

[0081] Where, x i Here, xi is a chaotic sequence value, i is the i-th column of the sparse matrix, i1 is the first element of the i-th column of the sparse matrix, mod() is the modulo function, floor() is the floor function. The generated random sequence value xi is multiplied by the corresponding multiple and then the remainder is taken by 10. After taking the remainder, the floor function is taken. The floor function then judges the result. masking_i1 means that the first element of the i-th column of the sparse matrix is ​​perturbed and encrypted using the chaotic sequence, and direction i1 means the judgment of the first element of the i-th column after perturbing and encryption.

[0082] Taking a 6-user, 4-unit SCMA codebook as an example, the corresponding 4x6 sparse matrix consists of 0 and 1 elements. Each row has 3 elements (1 and 0), and each column is unique. The sum of all elements in each row represents a subcarrier. For perturbation encryption of the sparse matrix, we first fix the first element of the first column as 1. We treat the remaining three rows of elements in the first column as a whole, with three possible arrangements. We apply perturbation to these three rows, using a random sequence y generated by a four-dimensional hyperchaotic model to generate the perturbation vector for these three rows. The generated sequence values ​​correspond to the three changes in these three rows. After perturbing the first column of the sparse matrix, we continue to perturb the first element of the second column, using the generated random sequence x to generate the perturbation vector for this position. This process continues to perturb the elements in rows 2, 3, and 4 of the second column, until we reach the elements in rows 2, 3, and 4 of the sixth column of the sparse matrix, at which point the perturbation of the sparse matrix is ​​complete. During the perturbation process, it's necessary to ensure that each subsequent column is distinct from all preceding columns, and that each row contains 0 and 1 elements that appear 3 times. This scrambles the sparse matrix and the corresponding SCMA codebook, thus encrypting the codebook. Simultaneously, the scrambling of elements in each row of the sparse matrix also scrambles the order of the superimposed subcarriers, encrypting the subcarriers and ultimately improving the system's security performance.

[0083] The specific sparse matrix perturbation process is as follows:

[0084] Step 1: First, fix the first element of the first column as 1. Then, continue to perturb the elements in rows 2, 3, and 4 of the first column. There are three possible outcomes: Formula 7 is as follows:

[0085] mask_1 = floor(mod(y1×10)) 7 ,3))+1 (7)

[0086] Formula 7 yields a sequence value of 1, therefore the elements in rows 2, 3, and 4 are... If the sequence value is 2, then the elements in rows 2, 3, and 4 are: If the sequence value is 3, then the elements in rows 2, 3, and 4 are:

[0087] Where mask_ means to perform perturbation encryption on all elements from the first element of the first column to the last element of the sixth column.

[0088] Step 2: Perturb the first element of the second column using Equation 6, resulting in two cases: 0 and 1. If the sequence value of Equation 6 is 1, then the elements in rows 2, 3, and 4 of the second column have two possible cases. Excluding the cases identical to those in the first column, continue perturbing the elements in rows 2, 3, and 4 of the second column, as shown in Formula 8 below:

[0089] mask_2 = floor(mod(y2×10)) 9 ,2))+1 (8)

[0090] When formula 8 yields a sequence value of 1, one of two cases is considered; when the sequence value is 2, the other of the two cases is considered. For example, if the elements in rows 2, 3, and 4 of the first column are... When the sequence value of formula 8 is 1, take the elements of rows 2, 3, and 4 of the second column as... When the sequence value of formula 8 is 2, take the elements of rows 2, 3, and 4 of the second column as...

[0091] If the sequence value of equation 6 is 0, then the elements in rows 2, 3, and 4 of the second column have three possible outcomes: The perturbation formula 9 is as follows:

[0092] mask_3 = floor(mod(y3×10)) 11 ,3))+1 (9)

[0093] When formula 9 yields a sequence value of 1, the elements in rows 2, 3, and 4 of the second column are: When the sequence value is 2, the elements in rows 2, 3, and 4 of the second column are: When the sequence value is 3, the elements in rows 2, 3, and 4 of the second column are:

[0094] Step 3: When the first element of the second column in Step 2 is 1, use Formula 6 to perturb the first element of the third column. When the sequence value is 1, meaning the first element of the third column is 1, continue perturbing the elements in rows 2, 3, and 4 of the third column. At this point, there is only one possible case, excluding cases that are the same as those in the first and second columns. For example, if the elements in rows 2, 3, and 4 of the first column are... The elements in rows 2, 3, and 4 of the second column are: Then the elements in rows 2, 3, and 4 of the third column can only be... Conversely, when the first element of the third column is 0, the elements in rows 2, 3, and 4 of the third column are perturbed. There are three possible outcomes: Formula 10 is as follows:

[0095] mask_4 = floor(mod(z1×10)) 11 ,3))+1 (10)

[0096] When the sequence value of formula 10 is 1, the elements in rows 2, 3, and 4 of the third column are defined as follows: When the sequence value of formula 10 is 2, the elements in rows 2, 3, and 4 of the third column are defined as follows: When the sequence value of formula 10 is 3, the elements in rows 2, 3, and 4 of the third column are defined as follows:

[0097] When the first element of the second column in step 2 is 0, use formula 6 to perturb the first element of the third column. When the sequence value is 1, that is, the first element of the third column is 1, continue to perturb the elements of the second, third, and fourth rows of the third column. Formula 11 is as follows:

[0098] mask_5 = floor(mod(z2×10)) 11 ,2))+1 (11)

[0099] At this point, the elements in rows 2, 3, and 4 of the third column have only two possibilities. Excluding cases identical to those in the first column, when the sequence value obtained by formula 11 is 1, one of the two possibilities is taken; when the sequence value obtained by formula 11 is 2, the other of the two possibilities is taken. For example, when the elements in rows 2, 3, and 4 of the first column are... When the sequence value of formula 11 is 1, the elements in rows 2, 3, and 4 of the third column are defined as follows: When the sequence value of formula 11 is 2, the elements in rows 2, 3, and 4 of the third column are defined as follows:

[0100] When the first element of the second column in step 2 is 0, use formula 6 to perturb the first element of the third column. When the sequence value is 0, that is, the first element of the third column is 0, continue to perturb the elements of rows 2, 3, and 4 of the third column. Formula 12 is as follows:

[0101] mask_6 = floor(mod(z3×10)) 12 ,2))+1 (12)

[0102] At this point, the elements in rows 2, 3, and 4 of the third column also have only two possibilities. Excluding the cases identical to those in the second column, when the sequence value obtained by formula 12 is 1, one of the two possibilities is taken; when the sequence value obtained by formula 12 is 2, the other of the two possibilities is taken. For example, when the elements in rows 2, 3, and 4 of the second column are... When the sequence value of formula 12 is 1, the elements in rows 2, 3, and 4 of the third column are defined as follows: When the sequence value of formula 12 is 2, the elements in rows 2, 3, and 4 of the third column are defined as follows:

[0103] Step 4: Perturb the fourth, fifth, and sixth columns.

[0104] ① When the first element of the second and third columns is 1, the first element of the fourth, fifth, and sixth columns can only be 0. In this case, the elements in rows 2, 3, and 4 of the fourth column are perturbed, as shown in Formula 13 below:

[0105] mask_7 = floor(mod(z4×10)) 12,3))+1 (13)

[0106] When the sequence value of formula 13 is 1, the elements in rows 2, 3, and 4 of the fourth column are: When the sequence value of formula 13 is 2, the elements in rows 2, 3, and 4 of the fourth column are: When the sequence value of formula 13 is 3, the elements in rows 2, 3, and 4 of the fourth column are: After perturbing the elements in the fourth column, continue perturbing the elements in rows 2, 3, and 4 of the fifth column, as shown in Formula 14:

[0107] mask_8 = floor(mod(z5×10)) 13 ,2))+1 (14)

[0108] The elements in rows 2, 3, and 4 of the fifth column have two possibilities, unlike the fixed fourth column. When the sequence value of formula 14 is 1, one of the two possibilities is taken; when the sequence value of formula 14 is 2, the other of the two possibilities is taken. For example, when the elements in rows 2, 3, and 4 of the fourth column are determined to be... The sequence value of Formula 14 is 1, and the elements in rows 2, 3, and 4 of the fifth column are defined as follows: The sequence value of Formula 14 is 2, and the elements in rows 2, 3, and 4 of the fifth column are defined as follows: The elements in the last six columns, rows 2, 3, and 4, have only one possible case, unlike the fourth and fifth columns.

[0109] ② When the first element of the second column is 1 and the first element of the third column is 0, use formula 6 to perturb the first element of the fourth column. If the sequence value is 1, then the elements in rows 2, 3, and 4 of the fourth column will only have one possible value, unlike the first and second columns. The first elements of the fifth and sixth columns can also all be 0. Continue to perturb the elements in rows 2, 3, and 4 of the fifth column, as shown in formula 15 below:

[0110] mask_9 = floor(mod(w1×10)) 13 ,2))+1 (15)

[0111] Unlike the third column, there are two cases. When the sequence value of Formula 15 is 1, one of the two cases is taken; when the sequence value of Formula 15 is 2, the other case is taken. For example, when the elements of rows 2, 3, and 4 of the third column are determined to be... The sequence value of Formula 15 is 1, and the elements in rows 2, 3, and 4 of the fifth column are defined as follows: The sequence value of Formula 15 is 2, and the elements in rows 2, 3, and 4 of the fifth column are defined as follows: So, the perturbation was achieved in the first 5 columns, and the elements in rows 2, 3, and 4 of the sixth column only have one case, unlike the third and fifth columns.

[0112] ③ When the first element of the second column is 0 and the first element of the third column is 1, use formula 6 to perturb the first element of the fourth column. If the sequence value is 1, then the elements in rows 2, 3, and 4 of the fourth column will only have one possible case, unlike the first and third columns. Similarly, the first elements of the fifth and sixth columns are all 0, so continue to perturb the elements in rows 2, 3, and 4 of the fifth column, as shown in formula 16 below:

[0113] mask_10 = floor(mod(w2×10)) 13 ,2))+1 (16)

[0114] Excluding cases identical to those in the second column, the elements in rows 2, 3, and 4 of the fifth column have two possibilities. When the sequence value of formula 16 is 1, one of the two possibilities is taken; when the sequence value of formula 16 is 2, the other possibility is taken. For example, when the elements in rows 2, 3, and 4 of the second column are... The sequence value of Formula 16 is 1, and the elements in rows 2, 3, and 4 of the fifth column are defined as follows: The sequence value of formula 16 is 2, and the elements in rows 2, 3, and 4 of the fifth column are defined as follows: So, the perturbation was achieved in the first 5 columns, and the elements in rows 2, 3, and 4 of the sixth column have only one case, which is different from the second and fifth columns.

[0115] ④ When the first element of both the second and third columns is 0, use formula 6 to perturb the first element of the fourth column. If the sequence value is 0, then the elements in rows 2, 3, and 4 of the fourth column will only have one possible value, unlike the second and third columns. The first elements of the fifth and sixth columns are also determined, all being 1. Continue to perturb the elements in rows 2, 3, and 4 of the fifth column, as shown in formula 17 below:

[0116] mask_11 = floor(mod(w3×10)) 14 ,2))+1 (17)

[0117] Excluding cases identical to those in the first column, the elements in rows 2, 3, and 4 of the fifth column have two possibilities. When the sequence value of formula 17 is 1, one of the two possibilities is taken; when the sequence value of formula 17 is 2, the other possibility is taken. For example, when the elements in rows 2, 3, and 4 of the first column are determined to be... The sequence value of Formula 17 is 1, so the elements in rows 2, 3, and 4 of the fifth column are defined as follows: The sequence value of Formula 17 is 2, so the elements in rows 2, 3, and 4 of the fifth column are defined as follows: Therefore, the first 5 columns of the sparse matrix are perturbed, and the elements in the 2nd, 3rd, and 4th rows of the sixth column have only one case, unlike the first and fifth columns.

[0118] When the first element of the second and third columns is 0, use formula 6 to perturb the first element of the fourth column. If the sequence value is 1, then the first element of the fourth column is 1. Continue to perturb the elements in rows 2, 3, and 4 of the fourth column, as shown in formula 18 below:

[0119] mask_12 = floor(mod(w4×10)) 15 ,2))+1 (18)

[0120] Excluding cases identical to those in the first column, the elements in rows 2, 3, and 4 of the fourth column have two possibilities. When the sequence value of formula 18 is 1, one of the two possibilities is taken; when the sequence value of formula 18 is 2, the other possibility is taken. For example, when the elements in rows 2, 3, and 4 of the first column are determined to be... The sequence value of Formula 18 is 1, so the elements in rows 2, 3, and 4 of the fourth column are defined as follows: The sequence value of formula 18 is 2, so the elements in rows 2, 3, and 4 of the fourth column are defined as follows: Next, we perturb the first element of the fifth column. Using formula 6, if the resulting sequence value is 1, then the first element of the fifth column is 1, and the elements in rows 2, 3, and 4 of the fifth column will be uniquely determined, and will be different from the first and fourth columns. At the same time, the first element of the sixth column will be determined to be 0, and the elements in rows 2, 3, and 4 of the sixth column will also be uniquely determined, and will be different from the second and third columns. If the resulting sequence value is 0, then the first element of the fifth column is 0, and the elements in rows 2, 3, and 4 of the fifth column will be uniquely determined, and will be different from the second and third columns. At the same time, the first element of the sixth column will be determined to be 1, and the elements in rows 2, 3, and 4 of the sixth column will also be uniquely determined, and will be different from the first and fourth columns.

[0121] Examples of sparse matrix perturbations Figure 6 As shown, through this sparse matrix perturbation method, all SCMA codebooks are encrypted, and the subcarriers are also encrypted in tandem. The encrypted signal undergoes inverse fast Fourier transform (IFFT), cyclic prefix addition (CP), and serial-to-parallel conversion before entering the channel for transmission.

[0122] S4. Transmit the encrypted signal to achieve encrypted signal transmission.

[0123] Encrypt the signal in, for example Figure 7 Transmission is performed in the communication system shown.

[0124] like Figure 7As shown, the entire transmission process from the transmitter to the receiver includes: In the optical line terminal (OLT), a 1550nm continuous wave laser (CW) is used to transmit the signal to a Mach-Zehnder modulator (MZM). The original user's data bits are encrypted, and the encrypted signal is fed into a 20GSa / s arbitrary waveform generator for digital-to-analog conversion (DAC) and amplified by an electrical amplifier (EA). It is then injected into the MZM for electro-optic modulation. After amplification by an erbium-doped fiber amplifier (EDFA), it is split into seven parts by a power splitter, passed through delay lines (DL) of different lengths, and then fan-in to achieve seven-core fiber coupling transmission. After 2km of transmission through the seven-core fiber, the seven-core fiber is decoupled by a fan-out device. After being split by a coupler, the signals enter different optical network units (ONUs). In each ONU, a variable optical attenuator is used to adjust the optical power, and a photodiode is used to achieve photoelectric conversion. The received signal is finally acquired by a mixed-signal oscilloscope and then demodulated offline to recover the original data.

[0125] In summary, this invention addresses the low spectral efficiency of traditional OMA technology through the superposition of power or code domains. Code domain-based SCMA, as a traditional NOMA technology, effectively increases system capacity, provides access for more users, and enables the reuse of limited spectrum resources. However, SCMA faces not only the problem of unauthorized receiver attacks common to PON, but also the issue of eavesdropping by users sharing the same resource block. To solve this problem, this patent, under the premise of system security and fairness among users, proposes multi-dimensional perturbation of the sparse matrix to achieve collaborative encryption of the user codebook and multiple carriers, addressing both unauthorized receiver attacks and eavesdropping by users sharing the same resource block.

[0126] Example 2

[0127] This invention also provides a signal encryption transmission device based on sparse matrix perturbation, comprising:

[0128] The signal acquisition module is used to: acquire the signal to be transmitted;

[0129] The signal encoding module is used to encode the signal to be transmitted using SCMA technology to obtain an encoded signal.

[0130] The signal encryption module is used to: perform sparse matrix perturbation on the encoded signal using chaotic sequence values ​​generated by a four-dimensional hyperchaotic model to obtain an encrypted signal;

[0131] The signal transmission module is used to transmit encrypted signals, thereby achieving encrypted signal transmission.

[0132] The signal encryption module uses chaotic sequence values ​​to perform sparse matrix perturbation on the encoded signal, which is achieved through the following formula:

[0133] masking_i1=floor(mod(i×x i ×10 5 ,10))

[0134]

[0135] Where, x i Here, i is the value of the chaotic sequence, i is the i-th column of the sparse matrix, i1 is the first element of the i-th column of the sparse matrix, mod() is the modulo function, floor() is the floor function, masking_i1 means to use the chaotic sequence to perturb and encrypt the first element of the i-th column of the sparse matrix, and direction i1 means to make a judgment on the first element of the i-th column after perturbation and encryption.

[0136] Example 3

[0137] This invention also provides a computer-readable storage medium storing a computer program thereon. When executed by a processor, the computer program implements the signal encryption transmission method based on sparse matrix perturbation as provided in Embodiment 1.

[0138] Acquire the signal to be transmitted;

[0139] The signal to be transmitted is encoded using SCMA technology to obtain the encoded signal;

[0140] The encrypted signal is obtained by perturbing the coded signal with a sparse matrix using chaotic sequence values ​​generated by a four-dimensional hyperchaotic model.

[0141] Encrypted signals are transmitted to achieve encrypted signal transmission.

[0142] Example 4

[0143] This invention also provides a device comprising:

[0144] Memory, used to store instructions;

[0145] The processor is configured to execute the instructions, causing the device to perform the signal encryption transmission method based on sparse matrix perturbation as provided in Embodiment 1:

[0146] Acquire the signal to be transmitted;

[0147] The signal to be transmitted is encoded using SCMA technology to obtain the encoded signal;

[0148] The encrypted signal is obtained by perturbing the coded signal with a sparse matrix using chaotic sequence values ​​generated by a four-dimensional hyperchaotic model.

[0149] Encrypted signals are transmitted to achieve encrypted signal transmission.

[0150] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied 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.

[0151] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. 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... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0152] 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.

[0153] 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.

[0154] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A signal encryption transmission method based on sparse matrix perturbation, characterized by, The method comprises the following steps: acquiring a signal to be transmitted; encoding the signal to be transmitted by using SCMA technology to obtain an encoded signal; performing sparse matrix perturbation on the encoded signal by using chaotic sequence values generated by a four-dimensional hyperchaotic model to obtain an encrypted signal; transmitting the encrypted signal to achieve signal encrypted transmission; an expression of the four-dimensional hyperchaotic model is: wherein a, b, c, d and r are preset parameters, and x, y, z and w are variables, and are the differentials of the variables x, y, z and w with respect to time t; the chaotic sequence values are obtained by using the Runge-Kutta method to solve four-dimensional random chaotic sequence values, and the chaotic sequence values include x, y, z, and w; the sparse matrix perturbation on the encoded signal by using chaotic sequence values generated by the four-dimensional hyperchaotic model comprises: the sparse matrix perturbation on the sparse matrix by using chaotic sequence values generated by the four-dimensional hyperchaotic model comprises: first, fix the first element of the first column of the sparse matrix, and take the remaining elements of the first column as a first whole, the first whole has three arrangement modes, and the variable y in the chaotic sequence values is used to perform perturbation on the first whole to generate sequence values corresponding to the three arrangement modes of the first whole; for the columns of the sparse matrix other than the first column, perturbation is performed according to the following rules: first, the variable x in the chaotic sequence values is used to perform perturbation on the first element, and then the variable x in the chaotic sequence values is used to perform perturbation on the remaining elements; and in each perturbation process, the following column is kept different from all the previous columns, and the number of times of occurrence of the element 0 and the element 1 in each row is consistent with that before the perturbation; wherein the perturbation of the first element of each column of the sparse matrix by using the chaotic sequence values is performed through the following formula: masking_i1 = floor(mod(i x x i ×10 5 , 10)) where x i is a chaotic sequence value, i is the i-th column of the sparse matrix, i1 is the first element of the i-th column of the sparse matrix, mod() is a modulo function, floor() is an integer function, masking_i1 indicates that the first element of the i-th column of the sparse matrix is perturbed and encrypted using a chaotic sequence value, and direction_i1 indicates a decision on the perturbed and encrypted first element of the i-th column.

2. The signal encryption transmission method based on sparse matrix perturbation according to claim 1, characterized in that, the encoding of the signal to be transmitted by using SCMA technology to obtain the encoded signal comprises: after the signal to be transmitted is encoded by the SCMA encoder, the encoded signal is represented by a sparse matrix, and an expression of the sparse matrix is: F = [diag(V1V1 T ), diag(V2V2 T )... diag(V J V J T )] wherein F is a sparse matrix, V1, V2…V J are mapping matrices of the 1st, 2nd…Jth users, respectively, T represents a transposition operation, and diag() is a diag function. an expression of the SCMA encoder is: Wherein, f represents the SCMA encoder, A is the signal to be transmitted, M is the number of code words contained in each codebook, X is the user codebook, X∈B K , B is the mother codebook, K is the number of resources, x is the complex number field code word, f(a) is the binary vector mapped to a complex vector; a mapping of the mother codebook is represented as: g: A log M → B, b = g(a) wherein g represents the mapping of the mother codebook, b is an N-dimensional constellation point in the mother codebook, and g(a) is the mapping of a binary vector to a multi-dimensional constellation point set domain; the N-dimensional constellation point is mapped to a K-dimensional sparse code word by using a binary mapping matrix, and in this process, the SCMA encoder is redefined as f=Vg, and V is a mapping matrix.

3. A device for signal encryption transmission based on sparse matrix perturbation based on the method of any one of claims 1 to 2, characterized in that, The method comprises the following steps: a signal acquisition module is configured to acquire a signal to be transmitted; a signal encoding module is configured to encode the signal to be transmitted by using SCMA technology to obtain an encoded signal; a signal encryption module is configured to perform sparse matrix perturbation on the encoded signal by using chaotic sequence values generated by a four-dimensional hyperchaotic model to obtain an encrypted signal; a signal transmission module is configured to transmit the encrypted signal to achieve signal encrypted transmission.

4. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by a processor to implement the signal encrypted transmission method based on sparse matrix perturbation according to any one of claims 1-2.

5. An apparatus, comprising: The device comprises a memory and a processor. The memory is configured to store instructions. The processor is configured to execute the instructions to enable the device to implement the signal encrypted transmission method based on sparse matrix perturbation according to any one of claims 1-2.

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