Three-dimensional signal secure transmission method and device based on index modulation

Abstract

The invention discloses a three-dimensional signal secure transmission method and device based on index modulation. The method comprises the following steps: generating four-dimensional chaotic sequences X, Y, Z and U from a key initial value through a chaotic model; performing XOR operation on the original data by using an encrypted sequence generated by X and U in the four-dimensional chaotic sequence to obtain encrypted data; performing binary conversion on the key initial value to obtain a binary key initial value consisting of N four bits; dividing the encrypted data into N groups, each group having 15 subcarriers, determining a to-be-inserted silent position of each group of subcarriers according to a binary key initial value, performing three-dimensional mapping after the silent subcarriers are inserted, and setting the silent subcarriers at an original point position to obtain a three-dimensional constellation diagram; performing constellation masking on the three-dimensional constellation diagram by using Y and Z in the four-dimensional chaos sequence; carrying out IFFT (Inverse Fast Fourier Transform) on the three-dimensional constellation diagram after constellation masking, adding a suffix, and carrying out parallel-serial conversion to obtain transmission data; and transmitting the transmission data to a receiving end through an optical fiber channel.

Description

Technical Field

[0001] The present application belongs to the field of optical communication technology, and specifically relates to a method and device for secure transmission of three-dimensional signals based on index modulation. Background Art

[0002] With the continuous improvement of network infrastructure and the rapid development of modern Internet technology, including the rapid development of emerging scientific and technological applications such as virtual reality, cloud computing, artificial intelligence, and data backup, users have increasingly higher demands for efficient and secure data information transmission. As a basic bandwidth-bearing technology, optical communication has become particularly important in the face of a new round of technological evolution and innovation to improve the efficiency of spectrum resource utilization and ensure the security of information transmission. At present, there are two main ways to improve the efficiency of spectrum resource utilization in optical communication networks. One is to use spectrum redistribution and other methods at a macro level, mainly by adjusting and allocating the spectrum resources of the entire optical communication network to reduce the waste of spectrum resources; the other is to use spectrum reuse and spectrum compression technologies at each use of the spectrum at a micro level, mainly to enable multiple users to share the same spectrum resources or reduce the spectrum bandwidth occupied by the signal through compression each time the optical communication network transmits information, thereby improving spectrum utilization.

[0003] In optical communication networks, as the technology to solve the problem of spectrum resource utilization efficiency is continuously optimized, the efficiency of spectrum resource utilization can be further optimized by combining multiple technologies. People have proposed combining index modulation technology with orthogonal frequency division multiplexing technology (OFDM). Index modulation orthogonal frequency division multiplexing (SIM-OFDM) technology has the advantages of improving data transmission efficiency, enhancing signal stability, reducing complexity, and increasing system capacity. SIM-OFDM technology introduces index information into OFDM symbols, and the data signal is encoded as index information and transmission data. It can represent more information through information bits and index bits without adding additional bits.

[0004] At present, communication encryption schemes mainly include encryption at the network layer and physical layer. Among them, the upper layer schemes of optical networks, such as the use of various security protocols, have certain security risks, and with the increase in the number of users, key management has become difficult. Physical layer encryption technologies, such as quantum key distribution, are more secure, but due to the slow key generation, the transmission cost and technical application of this technology are still limited, and there is still room for development in practical applications. Therefore, digital domain encryption technology based on chaotic systems has been proposed, which has been widely used due to its high sensitivity to initial values, randomness of chaotic systems, and large key space. However, most of the current chaotic encryption schemes assume that the receiving end knows the key by default. In such schemes, the key is usually the initial value of the chaotic system and is also fixed. Such schemes cannot respond in time when receiving illegal brute force cracking, resulting in continuous losses. In order to further improve the security of the system, it is necessary to realize dynamic keys and their transmission, which poses a challenge to how to transmit the key together with the data signal without being directly deciphered by illegal eavesdroppers. Summary of the invention

[0005] Purpose: In view of at least one of the above technical problems, the present application provides a three-dimensional signal security transmission method and device based on index modulation, which maps the initial value of the chaotic key into the position of the silent subcarrier, and then sets the position of the silent subcarrier inside the three-dimensional constellation diagram to realize the key synchronization transmission of the encryption system. Improve the efficiency of spectrum resource utilization and signal security.

[0006] The technical solution adopted in this application is:

[0007] In a first aspect, the present application provides a method for secure transmission of three-dimensional signals based on index modulation, comprising:

[0008] Get the initial key value and the original data to be sent;

[0009] The initial value of the key is used to generate a four-dimensional chaotic sequence X, Y, Z, U through a chaotic model;

[0010] The encryption sequence R generated by X and U in the four-dimensional chaotic sequence is used to perform XOR operation on the original data in binary form to obtain the encrypted data;

[0011] The initial key value is converted into a binary value to obtain a binary initial key value consisting of N four bits;

[0012] Divide the encrypted data into N groups, each group has 15 subcarriers, and determine the silent position to be inserted of each group of subcarriers according to the initial value of the binary key, and insert the silent subcarrier at the silent position, so that each group becomes 16 subcarriers, and then perform three-dimensional mapping and set the silent subcarrier at the origin position to obtain a three-dimensional constellation diagram;

[0013] Using Y and Z in the four-dimensional chaotic sequence to perform constellation masking on the three-dimensional constellation diagram, a three-dimensional constellation diagram after constellation masking is obtained;

[0014] Perform IFFT on the three-dimensional constellation diagram after constellation masking, add a suffix, and perform parallel-to-serial conversion to obtain transmission data;

[0015] The transmission data is transmitted to a receiving end via an optical fiber channel.

[0016] In a second aspect, the present application provides a three-dimensional signal security transmission device based on index modulation, including a processor and a storage medium;

[0017] The storage medium is used to store instructions;

[0018] The processor is configured to operate according to the instructions to execute the method according to the first aspect.

[0019] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the method described in the first aspect when executed by a processor.

[0020] Beneficial effects: The three-dimensional signal security transmission method and device based on index modulation provided by the present application have the following advantages: adopting the three-dimensional subcarrier index modulation method, mapping the initial value of the chaotic key into the subcarrier silent position, and setting its silent position in the three-dimensional constellation point, and encrypting and transmitting simultaneously with the three-dimensional constellation diagram. It can realize the transmission of more information without increasing the transmission power of the transmitter and under limited spectrum conditions, so as to improve the spectrum efficiency of the transmission system, and at the same time, it can realize the mapping of the chaotic key into the subcarrier silent position, hide the initial value of the chaotic key in the information of the subcarrier silent position, and improve the signal transmission security. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of a flow chart of a method for secure transmission of three-dimensional signals based on index modulation according to an embodiment of the present application;

[0022] Figure 2 is a schematic diagram of a phase diagram of a 4D Zhang Model according to an embodiment of the present application;

[0023] Figure 3 A schematic diagram of binary conversion mapping processing of a key initial value according to an embodiment of the present application;

[0024] Figure 4 A schematic diagram of subcarrier muting in three-dimensional index modulation according to an embodiment of the present application;

[0025] Figure 5 A schematic diagram of a three-dimensional constellation diagram of a regular tetrahedron according to an embodiment of the present application;

[0026] Figure 6 A schematic diagram of a three-dimensional constellation diagram with subcarrier silent positions according to an embodiment of the present application;

[0027] Figure 7 A schematic diagram of a key recovery bit error rate curve according to an embodiment of the present application;

[0028] Figure 8 The figure is a schematic diagram of bit error rate curves of an illegal receiving end and a legal receiving end according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] The present application is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and cannot be used to limit the protection scope of the present application.

[0030] In the description of this application, "several" means more than one, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0031] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0032] The term "and / or" is only a description of the association relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " generally indicates that the related objects are in an "or" relationship.

[0033] Embodiment 1: This embodiment provides a three-dimensional signal security transmission method based on index modulation, such as Figure 1 As shown, including:

[0034] S1. Obtain the initial value of the key and the original data to be sent;

[0035] S2, generating a four-dimensional chaotic sequence X, Y, Z, U by using the initial key value through a chaotic model;

[0036] S3, using the encryption sequence R generated by X and U in the four-dimensional chaotic sequence to perform an XOR operation on the original data in binary form to obtain encrypted data;

[0037] S4, converting the initial key value into a binary value to obtain a binary initial key value consisting of N four bits;

[0038] S5. Divide the encrypted data into N groups, each group having 15 subcarriers, and determine the silent position to be inserted of each group of subcarriers according to the initial value of the binary key, and insert the silent subcarrier at the silent position, so that each group becomes 16 subcarriers, and then perform three-dimensional mapping and set the silent subcarrier at the origin position to obtain a three-dimensional constellation diagram;

[0039] S6, using Y and Z in the four-dimensional chaotic sequence to perform constellation masking on the three-dimensional constellation diagram to obtain the three-dimensional constellation diagram after constellation masking;

[0040] S7, performing IFFT on the three-dimensional constellation diagram after constellation masking, adding a suffix, and performing parallel-to-serial conversion to obtain transmission data;

[0041] S8. Transmit the transmission data to a receiving end via an optical fiber channel.

[0042] In some embodiments, S2, generating a four-dimensional chaotic sequence from the initial key value through a chaotic model, comprising:

[0043] The chaos model adopts 4D Zhang model, which is expressed as:

[0044]

[0045] Among them, X, Y, Z, and U are state variables. are the derivatives of X, Y, Z, U with respect to time t respectively, and a, b, c, d, e are system parameters.

[0046] When a=3.04, b=1.02, c=9.02, d=1, e=2.02, the system has two positive Lyapunov exponents, proving that the system is a hyperchaotic system.

[0047] In this embodiment, the initial values ​​of the keys X0, Y0, Z0, and U0 of the chaotic model are 0.34978641, 1.25812974, 0.80056479, and 0.10078942, respectively. The partial differential equation of the chaotic model can be solved by the fourth-order Runge-Kutta method. The phase diagram of the chaotic model is shown in FIG. Figure 2 In this embodiment, from Figure 2It can be found that the value ranges of the four four-dimensional chaotic sequences of the 4DZhang Model are (-9,10), (-10,12), (-4,9), and (-7,7) respectively.

[0048] In some embodiments, step S3, performing an XOR operation on the original data in binary form using the encryption sequence R generated by X and U in the four-dimensional chaotic sequence to obtain encrypted data, includes:

[0049] S31, using X and U in the binary four-dimensional chaotic sequence to generate an encryption sequence R;

[0050] In step S31, in this embodiment, two columns X and U in the four-dimensional chaotic sequence are taken, each column is half the length of the original data T in binary form, and multiplied by 10. 4 , to increase the randomness of the encryption sequence. Replacing it with a different number may change the encryption order, but a similar encryption effect can still be achieved. Then take the remainder of 2 and get a sequence of 0 and 1 from the chaotic distribution. X1 and U1 are the processed sequences of X and U in the chaotic sequence respectively;

[0051] X1=mod(floor(X·10 4 ),2)

[0052] U1=mod(floor(U·10 4 ),2)

[0053] Connect X1 and U1 in series to obtain the encrypted sequence R;

[0054] S32. Use the encryption sequence R to perform an XOR operation on the original data T in binary form to obtain encrypted data.

[0055]

[0056] Among them, T' is the encrypted data, and T is the original data in binary form.

[0057] In this embodiment, the initial key values ​​X0 and Y0 of the chaotic model are converted into binary representation, such as Figure 3 As shown, X0=0.34978641 and Y0=1.25812974 are converted into binary respectively. After the binary conversion, the initial key value will be used in the subsequent subcarrier silent position mapping process.

[0058] The schematic diagram of 3D index modulation subcarrier silence is as follows Figure 4As shown, the encrypted data is first divided into N groups, each group has 15 subcarriers, and the silent position to be inserted of each group of subcarriers is determined according to the initial value of the binary key, and the silent subcarrier is inserted at the silent position, so that each group becomes 16 subcarriers containing index information and original data information, and then three-dimensional mapping is performed and the silent subcarrier is set at the origin position to obtain a three-dimensional constellation diagram.

[0059] In some embodiments, in step S5, determining the silent position to be inserted for each group of subcarriers according to the binary initial key value includes:

[0060] For the nth group of subcarriers, according to the value F represented by the nth four bits of the binary key initial value, the silent position to be inserted in the group of subcarriers is obtained as between the Fth subcarrier and the F+1th subcarrier.

[0061] Figure 5 This is an example of a three-dimensional constellation diagram of a normal regular tetrahedron. Figure 6 This is an example of a three-dimensional constellation diagram of a multi-dimensional signal security transmission method based on index modulation. By comparison, it can be seen that the three-dimensional constellation diagram after three-dimensional index modulation has one more point at the origin in the middle of the constellation diagram than the normal three-dimensional constellation diagram of a regular tetrahedron. The specific idea of ​​setting the constellation diagram of the three-dimensional signal security transmission method based on index modulation is: after mapping the initial value of the binary chaotic key to the subcarrier silent position information, the subcarrier silent position is set at the origin of the three-dimensional constellation diagram, that is, Figure 4 As shown, the three-dimensional subcarrier silent position is represented as 0, and the specific three-dimensional constellation point is Figure 5 The inside of the red dotted circle.

[0062] In some embodiments, step S6, using Y and Z in the four-dimensional chaotic sequence to perform constellation masking on the three-dimensional constellation diagram to obtain the constellation-masked three-dimensional constellation diagram, includes:

[0063] S61, using Y and Z in the four-dimensional chaotic sequence to generate a first scrambled sequence and a second scrambled sequence respectively;

[0064] First, the chaotic sequences Y and Z are sorted in ascending order and then the inverse is used to generate a matrix. Then, they are multiplied with the original chaotic sequence matrices Y and Z to generate a scrambled square matrix. The orders are the number of subcarriers and the number of symbols, respectively. There is a 1 in each row and column of the square matrix, and the remaining elements are all marked as 0. The positions of 1 in the scrambled matrices Y1 and Z1 generated by Y and Z are extracted respectively to generate the first scrambled sequence and the second scrambled sequence.

[0065]

[0066]

[0067] Among them, Y1 and Z1 are the scrambled matrices generated by Y and Z respectively, and sort(-) is the ascending sorting function.

[0068] S62: Use the first scrambling sequence and the second scrambling sequence to scramble the subcarriers and symbols of the three-dimensional constellation diagram respectively to obtain the three-dimensional constellation diagram after constellation masking.

[0069] Furthermore, in some embodiments, the method further includes: after the receiving end receives the transmission data, performing the following steps:

[0070] Perform serial-to-parallel conversion, remove suffixes, and perform FFT on the received transmission data to obtain a three-dimensional constellation diagram;

[0071] Demodulating the silent position information of the three-dimensional constellation diagram to obtain an initial value of a key;

[0072] Generate a four-dimensional chaotic sequence using the initial key value through a chaotic model;

[0073] The four-dimensional chaotic sequence is used to perform masking recovery and XOR recovery on the three-dimensional constellation diagram to obtain received data.

[0074] The bit error rate performance of key recovery is an extremely critical step for the key transmission scheme. If it cannot be accurately extracted at the receiving end, then due to the sensitivity of the key initial value of the chaotic system, the wrong key initial value will generate a completely different chaotic sequence, and decryption cannot be completed, which will cause a large bit error rate of the data. As explained in the above steps, the present invention samples the key 15 times in a loop, compares the key information after extracting it, and uses the information with the most occurrences of each bit in the 15 times as the final key, which can effectively ensure the accuracy of the key. Figure 7 As shown, the bit error rate performance of the key recovery of the method proposed by the present invention at the receiving end shows that even when the signal-to-noise ratio is poor, the accuracy of the key of the present application can still be maintained at 0. In actual transmission, under the action of the forward error correction threshold, the key of the present application can be guaranteed to be accurately recovered, which shows that the present invention can accurately transmit the key to the receiving end synchronously with the information.

[0075] Under the condition of ensuring the key is accurate, the application performs the final decryption on the decrypted data. The initial signal is serialized and then QPSK demapped and compared with the original generated bit information, such as Figure 8 The following are comparison diagrams of the bit error rate curves of the illegal receiving end and the legal receiving end after demodulation. It can be seen that the illegal receiving end cannot obtain the key information, so its bit error rate always remains at around 0.5, while the legal receiving end can accurately extract the key information for demodulation. As the signal-to-noise ratio increases, the bit error rate continues to decrease, and a better transmission effect is achieved.

[0076] Embodiment 2: Based on Embodiment 1, this embodiment provides a three-dimensional signal secure transmission device based on index modulation, including a processor and a storage medium;

[0077] The storage medium is used to store instructions;

[0078] The processor is used to operate according to the instruction to execute the method according to embodiment 1.

[0079] Embodiment 3: Based on Embodiment 1, this embodiment provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method described in Embodiment 1 is implemented.

[0080] Embodiment 4: Based on Embodiment 1, this embodiment provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the method described in Embodiment 1 when executing the computer program.

[0081] Embodiment 5: Based on Embodiment 1, this embodiment provides a computer program product, including a computer program, which implements the method described in Embodiment 1 when executed by a processor.

[0082] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0083] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram and the combination of the processes and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0084] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0085] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0086] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A three-dimensional signal secure transmission method based on index modulation, characterized in that: include: Get the initial key value and the original data to be sent; The initial value of the key is used to generate a four-dimensional chaotic sequence X, Y, Z, U through a chaotic model; The encryption sequence R generated by X and U in the four-dimensional chaotic sequence is used to perform XOR operation on the original data in binary form to obtain the encrypted data; The initial key value is converted into a binary value to obtain a binary initial key value consisting of N four bits; Divide the encrypted data into N groups, each group has 15 subcarriers, and determine the silent position to be inserted of each group of subcarriers according to the initial value of the binary key, and insert the silent subcarrier at the silent position, so that each group becomes 16 subcarriers, and then perform three-dimensional mapping and set the silent subcarrier at the origin position to obtain a three-dimensional constellation diagram; Using Y and Z in the four-dimensional chaotic sequence to perform constellation masking on the three-dimensional constellation diagram, a three-dimensional constellation diagram after constellation masking is obtained; Perform IFFT on the three-dimensional constellation diagram after constellation masking, add suffixes, and perform parallel-to-serial conversion to obtain transmission data; The transmission data is transmitted to a receiving end via an optical fiber channel.

2. The method according to claim 1, characterized in that The initial key value is used to generate a four-dimensional chaotic sequence through a chaotic model, including: The chaos model adopts 4D Zhang model, which is expressed as: Among them, X, Y, Z, and U are state variables. are the derivatives of X, Y, Z, U with respect to time t respectively, and a, b, c, d, e are system parameters.

3. The method according to claim 2, characterized in that The initial key values ​​X0, Y0, Z0, and U0 of the chaotic model are 0.34978641, 1.25812974, 0.80056479, and 0.10078942, respectively.

4. The method according to claim 2, characterized in that: The value ranges of the four four-dimensional chaotic sequences of the 4D Zhang Model are (-9,10), (-10,12), (-4,9), and (-7,7).

5. The method according to claim 1, characterized in that The encryption sequence R generated by X and U in the four-dimensional chaotic sequence is used to perform XOR operation on the original data in binary form to obtain encrypted data, including: Generate an encryption sequence R by using X and U in a binary four-dimensional chaotic sequence; perform an XOR operation on original data in binary form by using the encryption sequence R to obtain encrypted data; wherein generating the encryption sequence R by using X and U in a binary four-dimensional chaotic sequence includes: X1=mod(floor(X·10 4 ),2) U1=mod(floor(U·10 4 ),2) Connect X1 and U1 in series to obtain the encrypted sequence R.

6. The method according to claim 1, characterized in that And the silent position to be inserted of each group of subcarriers is determined according to the binary key initial value, including: For the nth group of subcarriers, according to the value F represented by the nth four bits of the binary key initial value, the position of silence to be inserted in the group of subcarriers is obtained as between the Fth subcarrier and the F+1th subcarrier.

7. The method according to claim 1, characterized in that The three-dimensional constellation diagram is constellation-masked using Y and Z in the four-dimensional chaotic sequence to obtain the three-dimensional constellation diagram after constellation masking, including: Using Y and Z in the four-dimensional chaotic sequence to generate a first scrambled sequence and a second scrambled sequence respectively; The subcarriers and symbols of the three-dimensional constellation diagram are scrambled by using the first scrambling sequence and the second scrambling sequence respectively to obtain the three-dimensional constellation diagram after constellation masking.

8. The method according to claim 7, characterized in that Using Y and Z in the four-dimensional chaotic sequence to generate a first scrambled sequence and a second scrambled sequence respectively, including: Sort Y in ascending order and then perform the inverse operation to generate a matrix, and then multiply it with Y to generate the first scrambled matrix Y1; Sort Z in ascending order and perform the inverse operation to generate a matrix, and then multiply it with Z to generate the second scrambled matrix Z1; Among them, sort(-) is the ascending sorting function; The positions of 1 in the first scrambled matrix Y1 and the second scrambled matrix Z1 are extracted respectively to generate a first scrambled sequence and a second scrambled sequence.

9. A three-dimensional signal secure transmission device based on index modulation, characterized in that: including processor and storage medium; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to execute the method according to any one of claims 1 to 8.

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

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