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

Abstract

The application discloses a three-dimensional signal security transmission method and device based on index modulation, which comprises the following steps: generating four-dimensional chaotic sequences X, Y, Z and U by a chaotic model from a key initial value; performing XOR operation on original data by an encryption sequence generated from X and U in the four-dimensional chaotic sequences to obtain encrypted data; converting the key initial value into a binary key initial value composed of N four-bit groups; dividing the encrypted data into N groups, each group having 15 subcarriers, and determining the to-be-inserted mute positions of each group of subcarriers according to the binary key initial value; performing three-dimensional mapping after inserting mute subcarriers, and setting the mute subcarriers at the original position to obtain a three-dimensional constellation diagram; performing constellation masking on the three-dimensional constellation diagram by Y and Z in the four-dimensional chaotic sequences; obtaining transmission data by performing IFFT, adding a suffix and converting the transmission data from parallel to serial; and transmitting the transmission data to a receiving end through an optical fiber channel.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of optical communication, and particularly relates to a three-dimensional signal security transmission method and device based on index modulation. BACKGROUND

[0002] With the continuous improvement of network infrastructure, modern Internet technology is developing rapidly, including the rapid development of emerging technologies such as virtual reality, cloud computing, artificial intelligence, and data backup. Users have increasingly high demands for efficient and secure data information transmission. As a basic bandwidth carrying technology, optical communication is particularly important in improving spectrum resource utilization efficiency and ensuring information transmission security in the face of a new round of technological evolution and innovation. Currently, the improvement of spectrum resource utilization efficiency in optical communication networks mainly falls into two categories. One is to use spectrum reallocation methods on a macro level, mainly by adjusting and allocating the overall spectrum resources of the optical communication network to reduce spectrum resource waste. The other is to use spectrum multiplexing and spectrum compression techniques at the micro level of each spectrum use, mainly to enable multiple users to share the same spectrum resource or to reduce the occupied spectrum bandwidth by compression during each optical communication network information transmission, thereby improving spectrum utilization.

[0003] In optical communication networks, as the technology for solving spectrum resource utilization efficiency is continuously optimized, the combination of multiple technologies can further optimize spectrum resource utilization efficiency. People have proposed the combination of index modulation technology and orthogonal frequency division multiplexing technology (OFDM). The SIM-OFDM technology has the advantages of improving data transmission efficiency, enhancing signal stability, reducing complexity, and improving system capacity. SIM-OFDM technology introduces index information into OFDM symbols. Data signals are encoded as index information and transmission data, which can represent more information through information bits and index bits without increasing additional bits.

[0004] Currently, the communication encryption schemes mainly include network upper layer encryption and physical layer encryption. The network upper layer encryption scheme, such as various security protocols, has certain security risks, and with the increase of the number of users, the key management is difficult. The physical layer encryption technology, such as quantum key distribution, is more secure, but the key generation is slow, the transmission cost and the application of the technology are still limited, and the actual application still needs to be developed. Therefore, a digital domain encryption technology based on a chaotic system is proposed, which is widely used due to the high sensitivity to initial value, randomness of the chaotic system, large key space and other advantages. However, most of the current research on chaotic encryption schemes are based on the assumption that the receiving end knows the key, and the key is usually the initial value of the chaotic system and is fixed. For such a scheme, when illegal brute force cracking is received, it cannot respond in time, thereby continuously causing losses. In order to further improve the security of the system, dynamic key and its transmission need to be realized, which poses a challenge to how to transmit the key together with the data signal without being directly decrypted by illegal eavesdroppers. SUMMARY

[0005] Object: 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 chaotic key initial value into the silent subcarrier position, and sets the silent subcarrier position in the three-dimensional constellation diagram to realize the key synchronous transmission of the encryption system. Improve the efficiency of spectrum resource utilization and signal security.

[0006] The technical scheme adopted by the present application is:

[0007] In a first aspect, the present application provides a three-dimensional signal security transmission method based on index modulation, comprising:

[0008] obtaining a key initial value and original data to be sent;

[0009] generating four-dimensional chaotic sequences X, Y, Z and U through a chaotic model from the key initial value;

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

[0011] obtaining a binary key initial value composed of N four-bit groups by binary conversion of the key initial value;

[0012] dividing the encrypted data into N groups, each group having 15 subcarriers, determining the silent position to be inserted for each group of subcarriers according to the binary key initial value, inserting a silent subcarrier at the silent position, changing each group to 16 subcarriers, and then performing three-dimensional mapping and setting the silent subcarrier at the origin position to obtain a three-dimensional constellation diagram;

[0013] The Y and Z in the four-dimensional chaotic sequence are used for constellation masking of a three-dimensional constellation diagram, to obtain a three-dimensional constellation diagram after constellation masking;

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

[0015] The transmission data is transmitted to a receiving end through a fiber channel.

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

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

[0018] The processor is configured to operate according to the instructions to perform 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 is executed by a processor to implement the method according to the first aspect.

[0020] Advantages: the three-dimensional signal secure transmission method and device based on index modulation provided by the present application have the following advantages: a three-dimensional subcarrier index modulation method is adopted, a chaotic key initial value is mapped into a subcarrier silence position, and the silence position is set in a three-dimensional constellation point, and the three-dimensional constellation diagram is encrypted and transmitted at the same time. More information can be transmitted without increasing the transmission power of the sending end and under the condition of limited frequency spectrum, so as to improve the frequency spectrum efficiency of the transmission system, and at the same time, the chaotic key can be mapped into the subcarrier silence position, the chaotic key initial value can be hidden in the information of the subcarrier silence position, and the signal transmission security is improved. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a flowchart of the three-dimensional signal secure transmission method based on index modulation according to an embodiment of the present application;

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

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

[0024] Figure 4 It is a three-dimensional index modulation subcarrier silence diagram according to an embodiment of the present application;

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

[0026] Figure 6 A three-dimensional constellation diagram with subcarrier muting position according to an embodiment of the present application;

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

[0028] Figure 8 A bit error rate curve diagram of an illegal receiving end and a legal receiving end according to an embodiment of the present application. DETAILED DESCRIPTION

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

[0030] In the description of the present application, if the meaning of several is more than one, the meaning of multiple is more than two, greater than, less than, more than, etc. are understood as not including the number, above, below, within, etc. are understood as including the number. If it is described as first, 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 indicated technical features or the sequence of indicated technical features.

[0031] In the description of the present application, the description of the reference terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example" 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 the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0032] The term "and / or", only describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / ", generally represents that the associated objects before and after are in an "or" relationship.

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

[0034] S1, obtaining a key initial value and original data to be sent;

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

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

[0037] S4, converting the key initial value into binary to obtain a binary key initial value composed of N four-bit groups;

[0038] S5, dividing the encrypted data into N groups, each group having 15 subcarriers, determining the to-be-inserted mute position of each group of subcarriers according to the binary key initial value, inserting a mute subcarrier at the mute position, changing each group into 16 subcarriers, performing three-dimensional mapping, and setting the mute subcarrier at the original position to obtain a three-dimensional constellation diagram;

[0039] S6, performing constellation masking on the three-dimensional constellation diagram by using Y and Z in the four-dimensional chaotic sequence to obtain a 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 serial-to-parallel conversion to obtain transmission data;

[0041] S8, transmitting the transmission data to the receiving end through an optical fiber channel.

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

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

[0044]

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

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

[0047] In this embodiment, the key initial values X0, Y0, Z0, U0 of the chaotic model are 0.34978641, 1.25812974, 0.80056479, and 0.10078942, respectively. The chaotic model partial differential equation can be solved by a fourth-order Runge-Kutta method. The phase diagram of the chaotic model is shown in Figure 2 In this embodiment, the phase diagram of the chaotic model is shown in Figure 2It can be found 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) respectively.

[0048] In some embodiments, the encrypted sequence R generated by using X and U in the four-dimensional chaotic sequence in step S3 is XOR operated with the original data in binary form to obtain encrypted data, including:

[0049] S31, generating an encrypted sequence R by using X and U in the binary four-dimensional chaotic sequence;

[0050] In this step S31, in the present embodiment, two columns X and U in the four-dimensional chaotic sequence are each taken as half the length of the original data T in binary form, and multiplied by 10 4 to increase the randomness of the encrypted sequence. Replacing it with different numbers can change the encryption order, but similar encryption effects can still be achieved. Taking the remainder of 2, a sequence of 0 and 1 is obtained from the chaotic distribution. X1 and U1 are the sequences processed from 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] Concatenating X1 and U1 obtains the encrypted sequence R;

[0054] S32, XOR operating the original data T in binary form with the encrypted sequence R to obtain encrypted data.

[0055]

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

[0057] In the present embodiment, the key initial values X0 and Y0 of the chaotic model are converted into binary representations, as shown in Figure 3 X0 = 0.34978641 and Y0 = 1.25812974 are respectively binary converted. The key initial values after being binary converted will be used in the subsequent process of subcarrier silence position mapping.

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

[0059] In some embodiments, in step S5, the to-be-inserted mute position of each group of subcarriers is determined according to the binary key initial value, including:

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

[0061] Figure 5 For a normal three-dimensional constellation diagram of a regular tetrahedron, Figure 6 That is, a three-dimensional constellation example diagram of the three-dimensional signal security transmission method based on index modulation, which can be seen by comparison that the three-dimensional constellation diagram after three-dimensional index modulation has an additional point position at the origin position 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 binary chaotic key initial value to the subcarrier mute position information, the subcarrier mute position is set at the origin position of the three-dimensional constellation diagram, that is, as Figure 4 As shown, the three-dimensional subcarrier mute position is represented as 0, and the specific three-dimensional constellation point is Figure 5 Inside the red dotted circle.

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

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

[0064] First, sort the chaotic sequences Y and Z in ascending order and generate a matrix by taking the inverse, then multiply the original chaotic sequence matrix Y and Z to generate a scrambling square matrix, the order is the number of subcarriers and the number of symbols, respectively, and each row and column of the square matrix has a 1, and the remaining elements are all marked as 0. Extract the positions of 1 in the scrambling square matrices Y1 and Z1 generated by Y and Z, respectively, to generate a first scrambling sequence and a second scrambling sequence.

[0065]

[0066]

[0067] Wherein, Y1, Z1 are scrambling matrixes generated by Y and Z respectively, and sort(-) is an ascending order sorting function.

[0068] S62, scrambling the subcarriers and the symbols of the three-dimensional constellation diagram by using the first scrambling sequence and the second scrambling sequence respectively, to obtain a three-dimensional constellation diagram after constellation masking.

[0069] Further, in some embodiments, the method further comprises the following steps performed by the receiving end after receiving the transmission data:

[0070] Converting the received transmission data into a serial-parallel form, removing a postfix, and performing FFT to obtain a three-dimensional constellation diagram;

[0071] Performing a silence position information demodulation on the three-dimensional constellation diagram to obtain a key initial value;

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

[0073] Performing a masking recovery and an XOR recovery on the three-dimensional constellation diagram by using the four-dimensional chaotic sequence to obtain received data.

[0074] The error code rate performance of the key recovery is a key step for the key with transmission scheme. If the key information cannot be accurately extracted at the receiving end, a completely different chaotic sequence will be generated due to the sensitivity of the key initial value of the chaotic system, and thus the decryption cannot be completed, which will result in a large error code rate of the data. As shown in the above steps, the key is cyclically sampled 15 times, and after the key information is extracted, a comparison is performed, and the information with the maximum number of occurrences of each bit in the 15 times is taken as the final key, which can effectively ensure the accuracy of the key. Figure 7 As shown in the figure, the error code rate performance of the key recovery at the receiving end of the method proposed in the application can be seen. Even when the signal-to-noise ratio condition is poor, the accuracy of the key of the application can still be maintained at 0. Under the action of the front error correction threshold in actual transmission, the key of the application can be accurately recovered, and thus it can be seen that the key can be accurately and correctly transmitted to the receiving end.

[0075] In the case of ensuring the accuracy of the key, the decrypted data is finally decrypted. After the initial signal is converted into a serial-parallel form, QPSK demapping is performed, and the original generated bit information is compared, as shown in the figure. Figure 8 The figure is a comparison of the error code 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, and thus the error code rate is always maintained at about 0.5. The legal receiving end can accurately extract the key information for demodulation. With the increase of the signal-to-noise ratio condition, the error code rate continuously decreases, and the transmission effect is good.

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

[0077] The storage medium is configured to store instructions.

[0078] The processor is configured to operate according to the instructions to perform the method according to embodiment 1.

[0079] Embodiment 3: Based on embodiment 1, this embodiment provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the method according to embodiment 1.

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

[0081] Embodiment 5: Based on embodiment 1, this embodiment provides a computer program product comprising a computer program, wherein the computer program is executed by a processor to implement the method according to embodiment 1.

[0082] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0083] The present application is described with reference to flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams and the combination of flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing apparatus to produce a machine, so that the instructions executed by the computer or other programmable data processing apparatus produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in one or more flows and / or blocks Figure 1 The device that implements the functions specified in one or more flows and / or blocks.

[0084] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the flow Figure 1 The flow or flows and / or blocks Figure 1 The flow or flows and / or blocks

[0085] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions that are executed on the computer or other programmable apparatus provide steps for implementing the flow Figure 1 The flow or flows and / or blocks Figure 1 The flow or flows and / or blocks

[0086] The above description is merely the preferred embodiment of this application, and it is obvious that, for those skilled in the art, some improvements and refinements can be made without departing from the principles of the application, and these improvements and refinements should also be considered as falling within the scope of protection of the application.

Claims

1. A method for three-dimensional signal security transmission based on index modulation, characterized in that, The method comprises the following steps: obtaining a key initial value and original data to be sent; generating a four-dimensional chaotic sequence X, Y, Z, U from the key initial value through a chaotic model; performing XOR operation on the original data in binary form by using an encryption sequence R generated from 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 composed of N four-bit groups; dividing the encrypted data into N groups, each group having 15 subcarriers, and determining the silent position to be inserted for each group of subcarriers according to the binary key initial value, for the nth group of subcarriers, the silent position to be inserted is obtained according to the value F represented by the nth four-bit group of the binary key initial value, which is between the Fth subcarrier and the F+1th subcarrier; inserting a silent subcarrier at the silent position to make each group have 16 subcarriers, then performing three-dimensional mapping and setting the silent subcarrier at the original 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 chaotic sequence to obtain a three-dimensional constellation diagram after constellation masking; performing IFFT on the three-dimensional constellation diagram after constellation masking, adding a suffix, and converting the series to obtain transmission data; transmitting the transmission data to a receiving end through an optical fiber channel.

2. The method of claim 1, wherein, The method for generating a four-dimensional chaotic sequence from the key initial value comprises the following steps: the chaotic model adopts 4D Zhang model, which is expressed as: where X, Y, Z, U are state variables, are the derivatives of X, Y, Z, U with respect to time t, and a, b, c, d, e are system parameters.

3. The method of claim 2, wherein, the key initial values X0, Y0, Z0, U0 of the chaotic model are 0.34978641, 1.25812974, 0.80056479, and 0.10078942, respectively.

4. The method of claim 2, wherein, 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), respectively.

5. The method of claim 1, wherein, The method for performing XOR operation on the original data in binary form by using an encryption sequence R generated from X and U in the four-dimensional chaotic sequence to obtain encrypted data comprises the following steps: X1 = mod(floor(X*10 4 ),2) U1 = mod(floor(U * 10 4 ), 2) generating the encryption sequence R from X and U in the binary four-dimensional chaotic sequence; performing XOR operation on the original data in binary form by using the encryption sequence R to obtain encrypted data; wherein the encryption sequence R is generated from X and U in the binary four-dimensional chaotic sequence, which comprises the following steps:

6. The method of claim 1, wherein, concatenating X1 and U1 to obtain the encryption sequence R. The method for performing constellation masking on the three-dimensional constellation diagram by using Y and Z in the four-dimensional chaotic sequence to obtain a three-dimensional constellation diagram after constellation masking comprises the following steps: generating a first scrambling sequence and a second scrambling sequence from Y and Z in the four-dimensional chaotic sequence, respectively; 7. The method of claim 6, wherein, scrambling the subcarriers and symbols of the three-dimensional constellation diagram by using the first scrambling sequence and the second scrambling sequence, respectively, to obtain the three-dimensional constellation diagram after constellation masking. The method for generating a first scrambling sequence and a second scrambling sequence from Y and Z in the four-dimensional chaotic sequence comprises the following steps: performing ascending order sorting on Y, then generating a matrix by removing the last element, and then multiplying Y to generate a first scrambling matrix Y1; performing ascending order sorting on Z, then generating a matrix by removing the last element, and then multiplying Z to generate a second scrambling matrix Z1; wherein sort(-) is an ascending order sorting function. The positions of 1 in the first scrambling matrix Y1 and the second scrambling matrix Z1 are extracted respectively to generate a first scrambling sequence and a second scrambling sequence.

8. An index modulation based three-dimensional signal secure transmission apparatus, characterized in that, The storage medium is used for storing instructions; The storage medium is used for storing instructions; The processor is configured to operate according to the instructions to perform the method according to any one of claims 1 to 7.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the method according to any one of claims 1 to 7.

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