A security key distribution apparatus, control method, medium and computer device

Abstract

The application belongs to the technical field of optical secret communication and optical signal processing, and discloses a secure key distribution device, a control method, a medium and computer equipment, the secure key distribution device comprising: a first optical signal initialization module, a first wideband digital chaos signal module, a first orthogonal polarization modulation module, a first secure key extraction module, an optical fiber channel transmission module, a second optical signal initialization module, a second wideband digital chaos signal module, a second orthogonal polarization modulation module and a second secure key extraction module. The application combines polarization multiplexing chaos modulation and optical fiber channel reciprocity characteristics and applies them to secure key distribution, which can effectively improve the secure key distribution rate and the stability of the distribution process rate, realize high-security physical layer secure key distribution with long-term stability, and provide security for the secure key distribution process because the optical fiber channel characteristics shared by both parties change over time and are difficult for eavesdroppers to obtain.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of optical secure communication and optical signal processing, and particularly relates to a secure key distribution device, a control method, a medium and a computer device. BACKGROUND

[0002] At present, more than 90% of information communication in the world is carried by optical networks. The transparency of optical networks improves network performance, but also brings new hidden dangers to network security. The ability to intercept information from optical networks has been mastered at home and abroad. Secure optical communication at the physical layer has become an effective strategy to protect large-scale data exchange security in modern communication networks. The secure key distribution process plays an important role in the symmetric encryption system. There are many secure key distribution schemes based on physical laws in classical channels. One of them is a secure key distribution scheme based on chaos synchronization. The optical chaos system has unique advantages of high randomness and high spectral bandwidth, and can realize security at the information theory level based on the synchronization characteristics of chaos. In this type of secure key distribution scheme, the efficiency of secure key generation is restricted by factors such as chaos synchronization recovery time and key random extraction strategy. At the same time, the bandwidth of the chaos entropy source, the robustness of chaos synchronization, and the efficiency of information mediation are also aspects that need to be considered in the design of this type of secure key distribution system. Another secure key distribution scheme is based on the reciprocity of the fiber channel. The security of this type of secure key distribution scheme lies in that the eavesdropper at a specific interception point cannot measure the dynamic characteristics of the entire fiber channel, and it only exists between the legal communication parties. However, the inherent random characteristics of the fiber channel are usually slow-changing, which limits the further development of the secure key distribution rate.

[0003] The subsequent secure key distribution scheme based on active disturbance to some extent accelerates the secure key distribution rate and enhances the security of secure key distribution. However, the key distribution scheme based on broadband chaos entropy source and polarization reciprocity of fiber channel only modulates the chaos signal on a single polarization state. When passing through the polarizer at the receiving end, the phenomenon of light polarization state being orthogonal to the polarizer and resulting in too low light intensity is inevitable, which will cause the key rate to be high at times and low at times, and the key cannot be extracted stably for a long time.

[0004] Through the above analysis, the problems and defects of the prior art are:

[0005] (1) In the existing secure key distribution scheme based on the reciprocity of the fiber channel, the inherent random characteristics of the fiber channel are usually slow-changing, which limits the further development of the secure key distribution rate.

[0006] (2) The existing key distribution scheme based on broadband chaotic entropy source and polarization reciprocity of fiber channel only modulates chaotic signal on a single polarization state, and the phenomenon of low light intensity caused by the orthogonality between light polarization state and polarizer occurs, resulting in high and low key rate, and the key cannot be extracted stably for a long time. SUMMARY

[0007] In view of the problems in the prior art, the present application provides a secure key distribution device, a control method, a medium and a computer device, and particularly relates to a secure key distribution device, a control method, a medium and a computer device based on orthogonal polarization state chaotic modulation and fiber channel reciprocity.

[0008] The present application is implemented as follows: a secure key distribution device, the secure key distribution device comprising:

[0009] A first optical signal initialization module is configured to provide a specific polarization state optical signal and output the specific polarization state optical signal to a first input port of a first orthogonal polarization modulation module;

[0010] A first broadband digital chaotic signal module is configured to provide a broadband digital chaotic signal and transmit the broadband digital chaotic signal to a second input port of the first orthogonal polarization modulation module and a second input port of a second orthogonal polarization modulation module;

[0011] The first orthogonal polarization modulation module is configured to perform high-speed polarization state change of the optical signal driven by the digital chaotic signal and output the polarization state changed optical signal to a first input port of a fiber channel transmission module;

[0012] A first secure key extraction module is configured to detect the polarization characteristic change in the fiber channel and convert the polarization characteristic change into light intensity change, and perform photoelectric conversion, sampling quantization, error correction and other post-processing on the light intensity changed optical signal to extract a secure key;

[0013] The fiber channel transmission module is configured to transmit the polarization changed optical signal in the fiber channel and output the signal to the first secure key extraction module and a second secure key extraction module;

[0014] A second optical signal initialization module is configured to provide a specific polarization state optical signal and output the specific polarization state optical signal to a first input port of the second orthogonal polarization modulation module;

[0015] A second broadband digital chaotic signal module is configured to provide a broadband digital chaotic signal and transmit the broadband digital chaotic signal to a third input port of the first orthogonal polarization modulation module and a third input port of the second orthogonal polarization modulation module;

[0016] a second orthogonal polarization modulation module, configured to perform high-speed polarization state variation of the optical signal under the digital chaotic signal driving, and output the optical signal with the synchronous polarization state variation to a second input port of the fiber channel transmission module;

[0017] a second security key extraction module, configured to detect polarization characteristic variation in the fiber channel and convert the polarization characteristic variation into optical intensity variation, and perform photoelectric conversion, sampling quantization, error correction and other post-processing on the optical signal with the optical intensity variation, and extract a security key.

[0018] Further, the first optical signal initialization module comprises:

[0019] a first light source, configured to provide a direct-current optical signal with a stable linear polarization state;

[0020] a first polarization controller, configured to adjust the polarization state of the linearly polarized optical signal.

[0021] The second optical signal initialization module comprises:

[0022] a second light source, configured to provide a direct-current optical signal with a stable linear polarization state;

[0023] a second polarization controller, configured to adjust the polarization state of the linearly polarized optical signal.

[0024] The initial polarization states of the optical signals adjusted by the first polarization controller and the second polarization controller are the same.

[0025] Further, the first orthogonal polarization modulation module comprises:

[0026] a first polarization beam splitter, configured to split the input linearly polarized optical signal into two orthogonal polarization modes and output the two orthogonal polarization modes to two optical fiber output ends respectively;

[0027] a first dual-polarization Mach-Zehnder modulator, configured to apply deterministic intensity modulation to the optical signal;

[0028] a first polarization beam combiner, configured to combine the two orthogonal polarization mode optical signals and output the combined optical signal to an optical fiber output end;

[0029] The second orthogonal polarization modulation module comprises:

[0030] a second polarization beam splitter, configured to split the input linearly polarized optical signal into two orthogonal polarization modes and output the two orthogonal polarization modes to two optical fiber output ends respectively;

[0031] a second dual-polarization Mach-Zehnder modulator, configured to apply deterministic intensity modulation consistent with the first dual-polarization Mach-Zehnder modulator to the optical signal;

[0032] a second polarization beam combiner, configured to combine the two orthogonal polarization mode optical signals and output the combined optical signal to an optical fiber output end.

[0033] Further, the first orthogonal polarization modulation module and the second orthogonal polarization modulation module have similar parameters; the similar parameters include similar modulation coefficients of the first and second dual-polarization Mach-Zehnder modulators and similar light attenuation ratios of the two light beams after the light signal is split.

[0034] The fiber channel transmission module includes a fiber transmission channel for carrying bidirectional transmission of the optical signal and introducing characteristics caused by external environment and fiber characteristics.

[0035] Further, the first wideband digital chaotic signal module includes:

[0036] a first arbitrary waveform generator for generating a wideband digital chaotic signal with noise-like characteristics;

[0037] a first beam splitter for realizing equal proportion distribution of the wideband digital chaotic signal so that the digital chaotic signal is consistent at the user end A and the user end B;

[0038] The second wideband digital chaotic signal module includes:

[0039] a second arbitrary waveform generator for generating a wideband digital chaotic signal different from the signal generated by the first arbitrary waveform generator;

[0040] a second beam splitter for realizing equal proportion distribution of the wideband digital chaotic signal so that the digital chaotic signal is consistent at the user end A and the user end B.

[0041] Further, the first security key extraction module includes:

[0042] a first optical circulator for guiding the modulated optical signal into the fiber transmission channel and guiding the received optical signal into a second optical detector;

[0043] a first polarization state detector for detecting the polarization state of the optical signal after passing through the fiber transmission channel and converting the polarization change information of the optical signal into intensity change information;

[0044] a first optical detector for performing photoelectric conversion on the received optical signal and inputting the signal to a first data processing unit;

[0045] the first data processing unit for sampling and quantizing the input signal, error correction, interleaving, privacy amplification, and other post-processing, and outputting a security key K1.

[0046] The second security key extraction module includes:

[0047] a second optical circulator for guiding the modulated optical signal into the fiber transmission channel and guiding the received optical signal into a second optical detector;

[0048] a second polarization state detector for detecting the polarization state of the optical signal after passing through the optical fiber transmission channel, converting the polarization change information of the optical signal into intensity change information, and the polarization angle of the second polarization state detector being consistent with that of the first polarization state detector;

[0049] a second optical detector for performing photoelectric conversion on the received optical signal and inputting to the second data processing unit;

[0050] a second data processing unit for performing sampling and quantization, error correction, interleaving, privacy amplification and other post-processing on the input signal, and outputting a security key K2.

[0051] Another object of the present application is to provide a security key distribution device control method for the security key distribution device, the security key distribution device control method comprising the following steps:

[0052] a wideband digital chaotic signal with noise-like characteristics is generated by using the first arbitrary waveform generator and the second arbitrary waveform generator, and is proportionally and evenly distributed to both parties of communication, i.e. user end A and user end B;

[0053] generating a security key at user end A:

[0054] a specific first polarization state optical signal is generated by using the first light source arranged at user end A, and the first polarization controller is used to adjust the first polarization state optical signal and the second polarization state optical signal at user end B to be consistent with the initial polarization state;

[0055] the first polarization beam splitter is used to decompose the first polarization state optical signal into two orthogonal polarization modes and output to two optical fiber output ends, and the first dual-polarization Mach-Zehnder modulator is used to apply deterministic intensity modulation to the two orthogonal polarization modes;

[0056] the first polarization beam combiner is used to combine the two orthogonal polarization mode optical signals and output to one optical fiber output end;

[0057] the first optical circulator is used to guide the optical signal after passing through the optical fiber transmission into the first polarization state detector, the first polarization state detector is used to convert the polarization change information after passing through the optical fiber channel into intensity change information, the first optical detector is used to realize photoelectric conversion on the received optical signal and input to the first data processing unit, and the first data processing unit is used to perform sampling and quantization, error correction, interleaving, privacy amplification and other post-processing on the input signal and output a security key K1;

[0058] generating a security key at user end B:

[0059] A second light source is arranged at the user terminal B to generate a second polarization state light signal, and a second polarization controller is used to adjust the polarization initial state of the second polarization state light signal to be consistent with that of the first polarization state light signal;

[0060] A second polarization beam splitter is used to split the second polarization state light signal into two orthogonal polarization modes and output them to two optical fiber output ends; meanwhile, a second dual Mach-Zehnder modulator is used to apply the same deterministic intensity modulation to the second light signal as to the first light signal;

[0061] A second polarization beam combiner is used to combine the two orthogonal polarization mode light signals and output them to one optical fiber output end;

[0062] A second optical circulator is used to guide the light signal transmitted through the optical fiber into a second polarization state detector; the second polarization state detector is used to convert the polarization change information transmitted through the optical fiber channel into intensity change information; a second photodetector is used to realize photoelectric conversion of the received light signal and input it to a second data processing unit; the second data processing unit is used to sample, quantize, correct errors, interleave, amplify privacy and perform other post-processing on the input signal, and output a security key K2;

[0063] The security key K1 is consistent with the security key K2.

[0064] Another object of the present application is to provide a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the computer program is executed by the processor to make the processor execute the steps of the control method of the security key distribution device.

[0065] Another object of the present application is to provide a computer readable storage medium storing a computer program, wherein the computer program is executed by a processor to make the processor execute the steps of the control method of the security key distribution device.

[0066] Another object of the present application is to provide an information data processing terminal for realizing the security key distribution device.

[0067] In combination with the above technical solutions and the technical problems solved, the technical solution to be protected by the present application has the following advantages and positive effects:

[0068] The application provides a secure key distribution device based on orthogonal polarization state chaotic modulation and fiber channel reciprocity, which combines polarization multiplexing chaotic modulation with fiber channel reciprocity and is applied to secure key distribution, so that the secure key distribution rate and the distribution process rate stability can be effectively improved, and the physical layer secure key distribution with long-term stability and high security is realized.

[0069] In the application, the first orthogonal polarization modulation module and the second orthogonal polarization modulation module are used for polarization multiplexing chaotic modulation by the two communication parties, and the signals transmitted in two directions share the fiber channel characteristic change, which is difficult to be obtained by an eavesdropper, so that the security of the secure key distribution process is ensured by the fiber channel transmission module. The polarization multiplexing ensures that the light intensity is relatively stable when the optical signal passes through the polarization state detector, and a rate-stable secure key distribution scheme is realized.

[0070] The technical scheme of the application can be made into a packaged module after transformation, which is convenient for security protection with dual polarization transmission link compatibility and has great commercial value.

[0071] The technical scheme of the application fills the technical blank in the industry at home and abroad: the technical scheme of the application uses polarization multiplexing to combine with fiber channel reciprocity for the first time to distribute the key, and in the past, only single polarization state was used. The stability of the key distribution rate is improved on the basis of the existing technical scheme.

[0072] The technical scheme of the application solves the technical problems that people have been eager to solve but have failed to succeed: the technical scheme of the application combines polarization multiplexing chaotic modulation with fiber channel reciprocity to distribute the secure key, realizes long-time stable key extraction on the basis of ensuring high key distribution rate and high security. The key distribution scheme using fiber channel reciprocity in the past is limited by slow channel characteristic change, and the application can effectively improve the key distribution rate by using chaotic signal modulation; the polarization chaotic modulation scheme in the past is difficult to realize stable key distribution, and the application solves the problem. BRIEF DESCRIPTION OF DRAWINGS

[0073] In order to more clearly illustrate the technical scheme of the embodiments of the application, the drawings needed in the embodiments of the application will be briefly introduced as follows. Obviously, the drawings described below are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0074] Figure 1 is the control method principle diagram of the security key distribution device provided by the embodiment of the present application;

[0075] Figure 2 is the structure diagram of the security key distribution device provided by the embodiment of the present application;

[0076] Figure 3 is the time domain waveform diagram of the analog key stream signals generated by the security key distribution device at the user end 1 and the user end 2 provided by the embodiment of the present application;

[0077] Figure 4 is the frequency spectrum diagram of the analog key stream signals generated by the security key distribution device at the user end 1 and the user end 2 provided by the embodiment of the present application;

[0078] Figure 5 is the correlation scatter diagram of the analog key stream signals generated by the security key distribution device at the user end 1 and the user end 2 provided by the embodiment of the present application;

[0079] Figure 6 is the correlation coefficient time-varying diagram of the analog key stream signals at the user end 1 and the user end 2 provided by the security key distribution device provided by the embodiment of the present application. DETAILED DESCRIPTION

[0080] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0081] In view of the problems existing in the prior art, the present application provides a security key distribution device, a control method, a medium and a computer device, which are described in detail below in combination with the drawings.

[0082] In order to enable those skilled in the art to fully understand how the present application is specifically implemented, this part is an explanatory embodiment of the description of the technical scheme of the claims.

[0083] As shown in Figure 1 the control method of the security key distribution device provided by the embodiment of the present application comprises the following steps:

[0084] A wideband digital chaotic signal with noise-like characteristics is generated by using a first arbitrary waveform generator and a second arbitrary waveform generator, and is proportionally and evenly distributed to both sides of communication, i.e. at the user end A and the user end B;

[0085] The security key is generated at the user end A:

[0086] A first polarization state light signal is generated by a first light source arranged at user terminal A, and a first polarization controller is used to adjust the first polarization state light signal to be consistent with a second polarization state light signal at user terminal B in a polarization initial state;

[0087] The first polarization state light signal is split into two orthogonal polarization modes by a first polarization beam splitter and output to two fiber output ends, and a first dual-polarization Mach-Zehnder modulator is used to apply deterministic intensity modulation to the two orthogonal polarization modes;

[0088] The two orthogonal polarization mode light signals are combined by a first polarization beam combiner and output to one fiber output end;

[0089] The light signal after fiber transmission is guided into a first polarization state detector by a first optical circulator, the polarization change information after fiber channel transmission is converted into intensity change information by the first polarization state detector, photoelectric conversion of the received light signal is realized by a first optical detector and input to a first data processing unit, and the input signal is sampled, quantized, error corrected, interleaved, privacy amplified and other post-processed by the first data processing unit, and a security key K1 is output;

[0090] A security key is generated at user terminal B:

[0091] A second polarization state light signal is generated by a second light source arranged at user terminal B, and a second polarization controller is used to adjust the second polarization state light signal to be consistent with the polarization initial state of the first polarization state light signal;

[0092] The second polarization state light signal is split into two orthogonal polarization modes by a second polarization beam splitter and output to two fiber output ends, and a second dual-polarization Mach-Zehnder modulator is used to apply the same deterministic intensity modulation to the first light signal;

[0093] The two orthogonal polarization mode light signals are combined by a second polarization beam combiner and output to one fiber output end;

[0094] The light signal after fiber transmission is guided into a second polarization state detector by a second optical circulator, the polarization change information after fiber channel transmission is converted into intensity change information by the second polarization state detector, photoelectric conversion of the received light signal is realized by a second optical detector and input to a second data processing unit, and the input signal is sampled, quantized, error corrected, interleaved, privacy amplified and other post-processed by the second data processing unit, and a security key K2 is output;

[0095] The security key K1 is consistent with the security key K2.

[0096] As Figure 2As shown, the security key distribution device provided by the embodiment of the application comprises:

[0097] The first optical signal initialization module 1 is configured to provide a specific polarization state optical signal and output the specific polarization state optical signal to a first input port of the first orthogonal polarization modulation module;

[0098] The first wideband digital chaotic signal module 8 is configured to provide a wideband chaotic modulation signal and transmit the wideband chaotic modulation signal to a second input port of the first orthogonal polarization modulation module and a second input port of the second orthogonal polarization modulation module;

[0099] The first orthogonal polarization modulation module 2 is configured to perform high-speed polarization state change of the optical signal driven by the digital chaotic signal and output the optical signal with the changed polarization state to the first input port of the fiber channel transmission module;

[0100] The fiber channel transmission module 7 is configured to carry bidirectional transmission of the optical signal and introduce characteristics caused by external environment and fiber itself, and output the signal to the first security key extraction module and the second security key extraction module;

[0101] The first security key extraction module 3 is configured to perform photoelectric conversion, sampling quantization, error correction and other post-processing on the optical signal with the changed optical intensity, and extract the security key;

[0102] The second optical signal initialization module 4 is configured to provide a specific polarization state optical signal and output the specific polarization state optical signal to a first input port of the second orthogonal polarization modulation module;

[0103] The second orthogonal polarization modulation module 5 is configured to perform high-speed polarization state change of the optical signal driven by the digital chaotic signal and output the optical signal with the changed polarization state to the second input port of the fiber channel transmission module;

[0104] The second security key extraction module 6 is configured to process the received signal and extract the security key.

[0105] As shown in the figure, Figure 2 The first optical signal initialization module 1 provided by the embodiment of the application comprises:

[0106] The first light source 11 is configured to provide a direct current optical signal with a stable linear polarization state;

[0107] The first polarization controller 12 is configured to adjust the polarization state of the linearly polarized optical signal.

[0108] The second optical signal initialization module 4 provided by the embodiment of the application comprises:

[0109] The second light source 41 is configured to provide a direct current optical signal with a stable linear polarization state;

[0110] a second polarization controller 42 for adjusting the polarization state of the linearly polarized optical signal;

[0111] The first polarization controller and the second polarization controller provided by the embodiment of the present application adjust the initial polarization states of the optical signals to be the same.

[0112] The first orthogonal polarization modulation module 2 provided by the embodiment of the present application comprises:

[0113] A first polarization beam splitter 21 for splitting the input linearly polarized optical signal into two orthogonal polarization modes and outputting the two orthogonal polarization modes to two optical fiber output ends respectively;

[0114] A first dual-polarization Mach-Zehnder modulator 22 for applying deterministic intensity modulation to the optical signal;

[0115] A first polarization beam combiner 23 for combining the two orthogonal polarization mode optical signals and outputting the combined optical signal to one optical fiber output end.

[0116] The second orthogonal polarization modulation module 5 provided by the embodiment of the present application comprises:

[0117] A second polarization beam splitter 51 for splitting the input linearly polarized optical signal into two orthogonal polarization modes and outputting the two orthogonal polarization modes to two optical fiber output ends respectively;

[0118] A second dual-polarization Mach-Zehnder modulator 52 for applying deterministic intensity modulation to the optical signal, which is consistent with the first dual-polarization Mach-Zehnder modulator;

[0119] A second polarization beam combiner 53 for combining the two orthogonal polarization mode optical signals and outputting the combined optical signal to one optical fiber output end.

[0120] The first orthogonal polarization modulation module 2 and the second orthogonal polarization modulation module 5 provided by the embodiment of the present application have similar parameters; the similar parameters include but are not limited to: the modulation coefficients of the first dual-polarization Mach-Zehnder modulator and the second dual-polarization Mach-Zehnder modulator are similar, and the light attenuation ratios of the two optical signals after splitting are similar.

[0121] The optical fiber channel transmission module 7 provided by the embodiment of the present application comprises:

[0122] An optical fiber transmission channel 71 for carrying bidirectional transmission of the optical signal and introducing characteristics caused by external environment and characteristics of the optical fiber itself.

[0123] The first wideband digital chaotic signal module 8 provided by the embodiment of the present application comprises:

[0124] A first arbitrary waveform generator 81 for generating a first wideband digital chaotic signal with noise-like characteristics;

[0125] The first beam splitter 82 is used for realizing proportional distribution of electric signals, so that the wideband digital chaotic signals are consistent at the user end A and the user end B.

[0126] The second wideband digital chaotic signal module 9 provided by the embodiment of the present application comprises:

[0127] The second arbitrary waveform generator 91 is used for generating the second wideband digital chaotic signal with noise-like characteristics.

[0128] The second beam splitter 92 is used for realizing proportional distribution of electric signals, so that the wideband digital chaotic signals are consistent at the user end A and the user end B.

[0129] The first wideband digital chaotic signal and the second wideband digital chaotic signal provided by the embodiment of the present application are not the same in time sequence.

[0130] The first security key extraction module 3 provided by the embodiment of the present application comprises:

[0131] The first optical circulator 31 is used for guiding the modulated optical signal into the optical fiber transmission channel and guiding the transmitted optical signal into the first polarization state detector.

[0132] The first polarization state detector 32 is used for detecting the polarization state of the optical signal after passing through the optical fiber transmission channel, and converting the polarization change information of the optical signal into intensity change information.

[0133] The first optical detector 33 is used for performing photoelectric conversion on the received optical signal and inputting into the first data processing unit.

[0134] The first data processing unit 34 is used for sampling and quantizing the input signal, error correction, interleaving, privacy amplification and other post-processing, and outputting the security key K1.

[0135] The second security key extraction module 6 provided by the embodiment of the present application comprises:

[0136] The second optical circulator 61 is used for guiding the modulated optical signal into the optical fiber transmission channel and guiding the transmitted optical signal into the second polarization state detector.

[0137] The second polarization state detector 62 is used for detecting the polarization state of the optical signal after passing through the optical fiber transmission channel, and converting the polarization change information of the optical signal into intensity change information.

[0138] The second optical detector 63 is used for performing photoelectric conversion on the received optical signal and inputting into the second data processing unit.

[0139] The second data processing unit 64 is used for sampling and quantizing the input signal, error correction, interleaving, privacy amplification and other post-processing, and outputting the security key K2.

[0140] As a preferred embodiment, the security key distribution device provided by the embodiment of the present application comprises a first optical signal initialization module 1, a first orthogonal polarization modulation module 2, and a first security key extraction module 3 of the user terminal 1; a second optical signal initialization module 4, a second orthogonal polarization modulation module 5, and a second security key extraction module 6 of the user terminal 2; an optical fiber channel transmission module 7 shared by the user terminal 1 and the user terminal 2, a first wideband digital chaotic signal module 8, and a second wideband digital chaotic signal module 9.

[0141] At the user terminal 1, the first optical signal initialization module 1 comprises a first light source 11 and a first polarization controller 12. The first light source 11 generates a direct-current light signal in a linear polarization state, and the first polarization controller 12 is used to adjust the polarization state of the direct-current linearly polarized light, thereby completing the setting of the initial polarization state of the light signal.

[0142] The light signal generated by the first optical signal initialization module 1 enters the first orthogonal polarization modulation module 2, which comprises a first polarization beam splitter 21, a first double-polarization Mach-Zehnder modulator 22, and a first polarization beam combiner 23. The first polarization beam splitter 21 is used to decompose the input linearly polarized light signal into two orthogonal polarization modes E x and E y , which are respectively output to two optical fiber output ends; the first double-polarization Mach-Zehnder modulator 22 is used to apply deterministic intensity modulation to the light signal; and the first polarization beam combiner 23 is used to combine the two orthogonal polarization mode light signals and output them to one optical fiber output end. In the first orthogonal polarization modulation module 2, the modulation signals of the two optical paths split by the first polarization beam splitter 21 are c x (t) and c y (t), the attenuation coefficients of the two optical paths are α x and α y , the light signal micro-phase changes are θ x and θ y , and the transformation matrix of the first orthogonal polarization modulation module can be represented as to complete the conversion from intensity modulation to polarization modulation.

[0143] At the user terminal 2, the second optical signal initialization module 4 comprises a second light source 41 and a second polarization controller 42. The second light source 41 is used to provide a direct-current light signal with a stable linear polarization state; and the second polarization controller 42 is used to adjust the polarization state of the linearly polarized light signal, so as to ensure that the initial polarization state of the light signal of the user terminal 2 is consistent with that of the user terminal 1. In the technical scheme disclosed by the embodiment of the present application, the initial polarization states of the light signals of the user terminal 1 and the user terminal 2 are both +45-degree linear polarization states, thereby ensuring that the light signals have the best polarization modulation efficiency after entering the first polarization beam splitter 21 and the second polarization beam splitter 51.

[0144] The second polarization modulation module 5 comprises a second polarization beam splitter 51, a second dual-polarization Mach-Zehnder modulator 52 and a second polarization beam combiner 53. The second polarization beam splitter 51 is used to decompose the input linearly polarized optical signal into two orthogonal polarization modes and output to two optical fiber output ends respectively; the second dual-polarization Mach-Zehnder modulator 52 is used to apply a deterministic intensity modulation to the optical signal consistent with the first dual-polarization Mach-Zehnder modulator 22; and the second polarization beam combiner 53 is used to combine the two orthogonal polarization mode optical signals and output to one optical fiber output end. In the second orthogonal polarization modulation module 5, the modulation signals of the two optical paths decomposed by the second polarization beam splitter 51 are c x (t) and c y (t) respectively, the attenuation coefficients of the two optical paths are β x and β y respectively, and the optical signal phase changes are and respectively. The transformation matrix of the second orthogonal polarization modulation module 5 can be represented as to complete the conversion from intensity modulation to polarization modulation.

[0145] In the embodiment of the present application, the second orthogonal polarization modulation module 5 has similar performance level and configuration parameters with the first orthogonal polarization modulation module 2, that is, even if M1=M2, the modulation coefficients of the first dual-polarization Mach-Zehnder modulator 22 and the second dual-polarization Mach-Zehnder modulator 52 are similar. In the embodiment of the present application, the modulation coefficient is 0.4; the optical attenuation ratios of the two paths after the optical signal is split are similar, that is, α x / β x = α y / β y ; and the phase differences introduced after the optical signal is split are similar, that is,

[0146] The user terminal 1 and the user terminal 2 share the same first wideband digital chaotic signal module 8 and the second wideband digital chaotic signal module 9. The first arbitrary waveform generator 81 and the second arbitrary waveform generator 91 are used to generate wideband digital signals with noise-like characteristics that are distributed differently. The first beam splitter 82 and the second beam splitter 92 are used to realize equal proportion distribution of the wideband digital chaotic signals, realize the consistency of the wideband digital chaotic signals at the user terminal 1 and the user terminal 2, and ensure that the first orthogonal polarization modulation module 2 and the second orthogonal polarization modulation module 5 are driven by the same modulation signal and have the same polarization state, denoted as E A and E B .

[0147] The fiber channel transmission module 7 connects the user terminal 1 and the user terminal 2. The fiber transmission channel 71 (10 km standard single-mode fiber) is used to carry the bidirectional transmission of optical signals and introduces the characteristics caused by the external environment and the characteristics of the fiber itself. The transmission matrix of the fiber transmission channel 71 can be recorded as a unitary matrix U, which represents a series of phase shifts and polarization rotations in the fiber. The optical signals sent by the user terminal 1 and the user terminal 2 have reciprocal characteristics when bidirectionally transmitted in the fiber transmission channel 71, that is, U = U T , where the operator T represents the transpose matrix.

[0148] The first security key extraction module 3 at the user terminal 1 includes a first optical circulator 31, a first polarization state detector 32, a first optical detector 33, and a first data processing unit 34. The first optical circulator 31 is used to guide the modulated optical signal into the fiber channel transmission module 7 and guide the received optical signal into the first polarization state detector 32; the first polarization state detector 32 is used to detect the polarization state of the optical signal after passing through the fiber transmission channel, and converts the polarization change information of the optical signal into intensity change information, and its transmission matrix is recorded as P A ; the first optical detector 33 is used to realize photoelectric conversion of the received optical signal and input into the first data processing unit 34. The received optical intensity can be represented as , where the operators and * represent the Hermitian matrix and the conjugate matrix. The first data processing unit 34 is used for post-processing operations such as sampling quantization, error correction, interleaving, and privacy amplification of the input signal, and outputs the security key K1.

[0149] The second security key extraction module 6 at the user terminal 2 includes a second optical circulator 61, a second polarization state detector 62, a second optical detector 63, and a second data processing unit 64. The second optical circulator 61 is used to guide the modulated optical signal into the fiber channel transmission module 7 and guide the received optical signal into the second polarization state detector 62; the first polarization state detector 62 is used to detect the polarization state of the optical signal after passing through the fiber transmission channel, and converts the polarization change information of the optical signal into intensity change information, and its transmission matrix is recorded as P B ; in the embodiment of the application, the polarization angles corresponding to the first polarization state detector 32 and the second polarization state detector 62 are arbitrary angles; the second optical detector 63 is used to realize photoelectric conversion of the received optical signal and input into the second data processing unit 64. The received optical intensity can be represented as The second data processing unit 64 is used for post-processing operations such as sampling quantization, error correction, interleaving, and privacy amplification of the input signal, and outputs the security key K2.

[0150] According to the scalar projection of the optical intensity, the optical intensity received by the user terminal 2 can also be represented as That is, the user terminal 1 and the user terminal 2 can receive the same light intensity signal, and consistent security keys K1 and K2 can be obtained at the user terminal 1 and the user terminal 2 after the same processing operation of the first data processing unit 34 and the second data processing unit 64.

[0151] The security key distribution device provided by the embodiment of the present application generates analog key stream signals at the user terminal 1 and the user terminal 2 respectively, as shown in the figure, the user terminal 1 and the user terminal 2 can obtain consistent normalized signal changes. Figure 3 As shown in the figure, the spectrum of the analog key stream signals generated at the user terminal 1 and the user terminal 2 respectively is wide and flat, which is beneficial to extracting high-speed keys. Figure 4 As shown in the figure, the correlation coefficient of the two is 0.93, which is close to the theoretical maximum value 1, which indicates that the analog key stream signals received by the user terminal 1 and the user terminal 2 have good consistency, which provides a foundation for high-quality security key distribution. Figure 5 As shown in the figure, the correlation coefficient of the two is 0.93, which is close to the theoretical maximum value 1, which indicates that the analog key stream signals received by the user terminal 1 and the user terminal 2 have good consistency, which provides a foundation for high-quality security key distribution. Figure 6 As shown in the figure, the correlation coefficient of the two is 0.93, which is close to the theoretical maximum value 1, which indicates that the analog key stream signals received by the user terminal 1 and the user terminal 2 have good consistency, which provides a foundation for high-quality security key distribution.

[0152] The first data processing unit 34 and the second data processing unit 64 provided by the embodiment of the present application sample the analog key stream signals, double-threshold quantize them into binary bit streams, perform the steps of random block interleaving, error correction based on BCH encoding, and privacy amplification based on the SHA-3 algorithm between the user terminal 1 and the user terminal 2, and obtain the final security keys K1 and K2, with a distribution rate of 2.07 Gbit / s. In the case of achieving the same performance level, the data processing method used by the first data processing unit 34 and the second data processing unit 64 in the embodiment is not limited to the processing method and sequence used in this embodiment.

[0153] In order to prove the creativity and technical value of the technical scheme of the present application, this part is an application embodiment of the technical scheme of the claim on a specific product or related technology.

[0154] Application Embodiment 1:

[0155] At the user terminal 1, the first optical signal initialization module 1 includes a first light source 11 and a first polarization controller 12. The first light source 11 generates a direct-current light signal in linear polarization state, and the first polarization controller 12 is used to adjust the polarization state of the direct-current linearly polarized light, to complete the setting of the initial polarization state of the light signal.

[0156] The light signal generated by the first light signal initialization module 1 enters the first orthogonal polarization modulation module 2, which comprises a first polarization beam splitter 21, a first double Mach-Zehnder modulator 22 and a first polarization beam combiner 23. The first polarization beam splitter 21 is used to decompose the input linearly polarized light signal into two orthogonal polarization modes E x and E y , and output to two optical fiber output ends respectively; the first double Mach-Zehnder modulator 22 is used to apply deterministic intensity modulation to the light signal; and the first polarization beam combiner 23 is used to combine the two orthogonal polarization mode light signals and output to one optical fiber output end. In the first orthogonal polarization modulation module 2, the modulation signals of the two light paths split by the first polarization beam splitter 21 are c x (t) and c y (t) respectively, the attenuation coefficients of the two light paths are α x and α y , the light signal micro-phase changes are θ x and θ y , and the transformation matrix of the first orthogonal polarization modulation module can be represented as to complete the conversion from intensity modulation to polarization modulation.

[0157] At the user end 2, the second light signal initialization module 4 comprises a second light source 41 and a second polarization controller 42. The second light source 41 is used to provide a direct-current light signal with a stable linear polarization state; and the second polarization controller 42 is used to adjust the polarization state of the linearly polarized light signal to ensure that the initial polarization state of the light signal at the user end 2 is consistent with that at the user end 1. In the technical scheme disclosed in the embodiment of the present application, the initial polarization states of the light signals at the user end 1 and the user end 2 are both +45-degree linear polarization states, which ensures that the light signals have the best polarization modulation efficiency after entering the first polarization beam splitter 21 and the second polarization beam splitter 51.

[0158] The second polarization modulation module 5 comprises a second polarization beam splitter 51, a second double Mach-Zehnder modulator 52 and a second polarization beam combiner 53. The second polarization beam splitter 51 is used to decompose the input linearly polarized light signal into two orthogonal polarization modes and output to two optical fiber output ends respectively; the second double Mach-Zehnder modulator 52 is used to apply deterministic intensity modulation to the light signal, which is consistent with the first double Mach-Zehnder modulator 22; and the second polarization beam combiner 53 is used to combine the two orthogonal polarization mode light signals and output to one optical fiber output end. In the second orthogonal polarization modulation module 5, the modulation signals of the two light paths split by the second polarization beam splitter 51 are c x (t) and c y (t) respectively, the attenuation coefficients of the two light paths are β x and β y , the light signal micro-phase changes are and The transformation matrix of the second orthogonal polarization modulation module 5 can be expressed as The conversion from intensity modulation to polarization modulation is completed.

[0159] In the embodiment of the present application, the second orthogonal polarization modulation module 5 has similar performance level and configuration parameters with the first orthogonal polarization modulation module 2, i.e. M1=M2, the modulation coefficients of the first dual-bi Mach-Zehnder modulator 22 and the second dual-bi Mach-Zehnder modulator 52 are similar. In the embodiment of the present application, the modulation coefficient is 0.4; the light attenuation ratios of the two light beams after the light signal splitting are similar, i.e. α x / β x =α y / β y ; the phase differences introduced after the light signal splitting are similar, i.e.

[0160] The user terminal 1 and the user terminal 2 share the same first wideband digital chaotic signal module 8 and the second wideband digital chaotic signal module 9. The first arbitrary waveform generator 81 and the second arbitrary waveform generator 91 are used to generate wideband digital signals with noise-like characteristics which are distributed differently. The first beam splitter 82 and the second beam splitter 92 are used to realize equal proportion distribution of the wideband digital chaotic signals, realize the consistency of the wideband digital chaotic signals at the user terminal 1 and the user terminal 2, and ensure that the first orthogonal polarization modulation module 2 and the second orthogonal polarization modulation module 5 are driven by the same modulation signal and have the same polarization state, denoted as E A and E B .

[0161] The fiber channel transmission module 7 connects the user terminal 1 and the user terminal 2. The fiber transmission channel 71 (10 km standard single-mode fiber) is used to carry the bidirectional transmission of the optical signal and introduce the characteristics caused by the external environment and the characteristics of the fiber itself. The transmission matrix of the fiber transmission channel 71 can be denoted as a unitary matrix U, which is used to represent a series of phase shifts and polarization rotations in the fiber. The optical signals transmitted by the user terminal 1 and the user terminal 2 have reciprocal characteristics when bidirectionally transmitted in the fiber transmission channel 71, i.e. U=U T , where the operator T represents the transpose matrix.

[0162] The first security key extraction module 3 at the user terminal 1 includes a first optical circulator 31, a first polarization state detector 32, a first optical detector 33 and a first data processing unit 34. The first optical circulator 31 is used to guide the modulated optical signal into the fiber channel transmission module 7 and guide the received optical signal into the first polarization state detector 32; the first polarization state detector 32 is used to detect the polarization state of the optical signal after passing through the fiber transmission channel, and convert the polarization change information of the optical signal into intensity change information, and its transmission matrix is denoted as P AThe first optical detector 33 is used to realize photoelectric conversion of the received optical signal and input to the first data processing unit 34. Wherein the operators and * represent Hermitian matrix and conjugate matrix. The first data processing unit 34 is used to realize sampling quantization, error correction, interleaving, privacy amplification and other post-processing operations on the input signal and output the security key K1.

[0163] The second security key extraction module 6 at the user end 2 includes a second optical circulator 61, a second polarization state detector 62, a second optical detector 63 and a second data processing unit 64. The second optical circulator 61 is used to guide the modulated optical signal into the optical fiber channel transmission module 7 and guide the received optical signal into the second polarization state detector 62; the first polarization state detector 62 is used to detect the polarization state of the optical signal after passing through the optical fiber transmission channel, and convert the polarization change information of the optical signal into intensity change information, and the transmission matrix is denoted as P B In the embodiment of the application, the polarization angles corresponding to the first polarization state detector 32 and the second polarization state detector 62 are arbitrary angles; the second optical detector 63 is used to realize photoelectric conversion of the received optical signal and input to the second data processing unit 64. The received optical intensity can be represented as The second data processing unit 64 is used to realize sampling quantization, error correction, interleaving, privacy amplification and other post-processing operations on the input signal and output the security key K2.

[0164] According to the scalar projection of the optical intensity, the optical intensity received by the user end 2 can also be represented as That is, the user end 1 and the user end 2 can receive the same optical intensity signal, and after the same processing operation of the first data processing unit 34 and the second data processing unit 64, consistent security keys K1 and K2 can be obtained at the user end 1 and the user end 2.

[0165] During the development or use of the embodiment of the application, some positive effects have been achieved, and compared with the prior art, the embodiment indeed has great advantages, which will be described below in combination with the data and graphs of the test process.

[0166] The security key distribution device provided by the embodiment of the application generates analog key stream signals at the user end 1 and the user end 2 respectively, as shown in Figure 3 The user end 1 and the user end 2 can obtain consistent normalized signal changes. The spectrum of the analog key stream signals generated by the user end 1 and the user end 2 respectively is as shown in Figure 4 The spectrum is wide and flat, which is beneficial to extracting high-speed keys. The correlation scatter diagram of the analog key stream signals received by the user end 1 and the user end 2 is as shown in Figure 5As shown, the correlation coefficient of both is 0.93, which approaches the theoretical maximum value 1, indicating that the analog key stream signals received by user terminal 1 and user terminal 2 have good consistency, which provides a foundation for high-quality secure key distribution. The correlation coefficient of the analog key stream signals received by user terminal 1 and user terminal 2 changes with time as shown in Figure 6 As shown, the correlation coefficient is maintained at about 0.928 within 30 minutes, and it can be seen that the secure key distribution scheme based on orthogonal polarization state chaos modulation and fiber channel reciprocity can realize high-speed and stable secure key distribution.

[0167] It should be noted that the embodiments of the present application can be realized by hardware, software or a combination of software and hardware. The hardware part can be realized by special logic; the software part can be stored in a memory and executed by a suitable instruction execution system, such as a microprocessor or a specially designed hardware. Those skilled in the art can understand that the above-mentioned devices and methods can be realized by computer executable instructions and / or included in processor control code, such as provided on a carrier medium, such as a magnetic disk, CD or DVD-ROM, a programmable memory, such as a read-only memory (firmware), or a data carrier, such as an optical or electronic signal carrier. The devices of the present application and their modules can be realized by hardware circuits, such as very large scale integrated circuits or gate arrays, semiconductors, such as logic chips, transistors, etc., or programmable hardware devices, such as field programmable gate arrays, programmable logic devices, etc., by software executed by various types of processors, or by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0168] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any modification, equivalent replacement and improvement made by those skilled in the art within the technical range disclosed by the present application, as long as it is within the spirit and principle of the present application, should be covered within the protection scope of the present application.

Claims

1. A secure key distribution apparatus, characterized by, The system comprises: a first optical signal initialization module for providing a specific polarization state optical signal and outputting the specific polarization state optical signal to a first input port of a first orthogonal polarization modulation module; a first wideband digital chaotic signal module for providing a wideband digital chaotic signal and transmitting the wideband digital chaotic signal to a second input port of the first orthogonal polarization modulation module and a second input port of a second orthogonal polarization modulation module; the first orthogonal polarization modulation module is used for high-speed change of polarization state of the optical signal driven by the digital chaotic signal and outputs the polarization state changed optical signal to a first input port of a fiber channel transmission module; a first security key extraction module for detecting polarization characteristic change in the fiber channel and converting the polarization characteristic change into optical intensity change, photoelectrically converting the optical intensity changed optical signal, sampling and quantizing, error correcting and privacy amplifying, and extracting a security key; the fiber channel transmission module is used for transmitting the polarization changed optical signal in the fiber channel and outputting the signal to the first security key extraction module and a second security key extraction module; a second optical signal initialization module for providing a specific polarization state optical signal and outputting the specific polarization state optical signal to a first input port of the second orthogonal polarization modulation module; a second wideband digital chaotic signal module for providing a wideband digital chaotic signal and transmitting the wideband digital chaotic signal to a third input port of the first orthogonal polarization modulation module and a third input port of the second orthogonal polarization modulation module; the second orthogonal polarization modulation module is used for high-speed change of polarization state of the optical signal driven by the digital chaotic signal and outputs the polarization state synchronous changed optical signal to a second input port of the fiber channel transmission module; the second security key extraction module is used for detecting polarization characteristic change in the fiber channel and converting the polarization characteristic change into optical intensity change, photoelectrically converting the optical intensity changed optical signal, sampling and quantizing, error correcting and privacy amplifying, and extracting a security key; the first optical signal initialization module comprises: a first light source for providing a direct current optical signal with a stable linear polarization state; a first polarization controller for adjusting the polarization state of the linear polarization optical signal; the second optical signal initialization module comprises: a second light source for providing a direct current optical signal with a stable linear polarization state; a second polarization controller for adjusting the polarization state of the linear polarization optical signal; the initial polarization states of the optical signals adjusted by the first polarization controller and the second polarization controller are the same; the first orthogonal polarization modulation module comprises: a first polarization beam splitter for decomposing the input linear polarization optical signal into two orthogonal polarization modes and outputting the two orthogonal polarization modes to two optical fiber output ends respectively; a first dual-polarization Mach-Zehnder modulator for applying deterministic intensity modulation to the optical signal; a first polarization beam combiner for combining the two orthogonal polarization mode optical signals and outputting the combined optical signal to an optical fiber output end; the second orthogonal polarization modulation module comprises: a second polarization beam splitter for decomposing the input linear polarization optical signal into two orthogonal polarization modes and outputting the two orthogonal polarization modes to two optical fiber output ends respectively; a second dual-polarization Mach-Zehnder modulator for applying deterministic intensity modulation to the optical signal consistent with the first dual-polarization Mach-Zehnder modulator; a second polarization combiner for combining the two orthogonal polarization mode optical signals and outputting to the optical fiber output end.

2. The secure key distribution apparatus of claim 1, wherein, The first orthogonal polarization modulation module and the second orthogonal polarization modulation module have similar parameters; the similar parameters include similar modulation coefficients of the first dual-polarization Mach-Zehnder modulator and the second dual-polarization Mach-Zehnder modulator, and similar light attenuation ratios of the two light beams after the light signal is split; The optical fiber channel transmission module includes an optical fiber transmission channel for carrying bidirectional transmission of the optical signal and introducing characteristics caused by external environment and characteristics of the optical fiber itself.

3. The secure key distribution apparatus of claim 1, wherein, The first wideband digital chaotic signal module includes: a first arbitrary waveform generator for generating a wideband digital chaotic signal with noise-like characteristics; a first beam splitter for realizing equal proportion allocation of the wideband digital chaotic signal, so that the digital chaotic signal is consistent at the user end A and the user end B; The second wideband digital chaotic signal module includes: a second arbitrary waveform generator for generating a wideband digital chaotic signal different from the signal generated by the first arbitrary waveform generator; a second beam splitter for realizing equal proportion allocation of the wideband digital chaotic signal, so that the digital chaotic signal is consistent at the user end A and the user end B.

4. The secure key distribution apparatus of claim 1, wherein, The first security key extraction module includes: a first optical circulator for guiding the modulated optical signal into the optical fiber transmission channel and guiding the received optical signal into the first optical detector; a first polarization state detector for detecting the polarization state of the optical signal after passing through the optical fiber transmission channel, and converting the polarization change information of the optical signal into intensity change information; a first optical detector for performing photoelectric conversion on the received optical signal and inputting to the first data processing unit; a first data processing unit for sampling and quantizing the input signal, error correction, interleaving, and privacy amplification, and outputting a security key K1; The second security key extraction module includes: a second optical circulator for guiding the modulated optical signal into the optical fiber transmission channel and guiding the received optical signal into the second optical detector; a second polarization state detector for detecting the polarization state of the optical signal after passing through the optical fiber transmission channel, and converting the polarization change information of the optical signal into intensity change information, and the polarization angle of the second polarization state detector is consistent with that of the first polarization state detector; a second optical detector for performing photoelectric conversion on the received optical signal and inputting to the second data processing unit; a second data processing unit for sampling and quantizing the input signal, error correction, interleaving, and privacy amplification, and outputting a security key K2.

5. A control method of a security key distribution apparatus using the security key distribution apparatus according to any one of claims 1 to 4, characterized by, The control method of the security key distribution device includes the following steps: generating wideband digital chaotic signals with noise-like characteristics using the first arbitrary waveform generator and the second arbitrary waveform generator, and distributing them to both parties of communication, i.e., the user end A and the user end B, in proportion; generating a security key at the user end A: A first light source is arranged at user terminal A to generate a specific first polarization state light signal, and a first polarization controller is used to adjust the first polarization state light signal to be consistent with a second polarization state light signal at user terminal B to a polarization initial state; A first polarization beam splitter is used to split the first polarization state light signal into two orthogonal polarization modes and output to two optical fiber output ends; meanwhile, a first dual-polarization Mach-Zehnder modulator is used to apply deterministic intensity modulation to the two orthogonal polarization modes; A first polarization beam combiner is used to combine the two orthogonal polarization mode light signals and output to one optical fiber output end; A first optical circulator is used to guide the light signal after fiber transmission into a first polarization state detector; the first polarization state detector is used to convert the polarization change information transmitted through the fiber channel into intensity change information; a first optical detector is used to realize photoelectric conversion of the received light signal and input to a first data processing unit; the first data processing unit is used to sample, quantize, correct errors, interleave, and amplify privacy of the input signal, and output a security key K1; A security key is generated at user terminal B: A second light source is arranged at user terminal B to generate a specific second polarization state light signal, and a second polarization controller is used to adjust the second polarization state light signal to be consistent with the polarization initial state of the first polarization state light signal; A second polarization beam splitter is used to split the second polarization state light signal into two orthogonal polarization modes and output to two optical fiber output ends; meanwhile, a second dual-polarization Mach-Zehnder modulator is used to apply the same deterministic intensity modulation to the first light signal; A second polarization beam combiner is used to combine the two orthogonal polarization mode light signals and output to one optical fiber output end; A second optical circulator is used to guide the light signal after fiber transmission into a second polarization state detector; the second polarization state detector is used to convert the polarization change information transmitted through the fiber channel into intensity change information; a second optical detector is used to realize photoelectric conversion of the received light signal and input to a second data processing unit; the second data processing unit is used to sample, quantize, correct errors, interleave, and amplify privacy of the input signal, and output a security key K2; The security key K1 is consistent with the security key K2.

6. The control method of the security key distribution apparatus according to claim 5, characterized by, The first polarization beam splitter is used to decompose the input linearly polarized optical signal into two orthogonal polarization modes E x and E y , and output to two optical fiber output ends respectively; the first dual-polarization Mach-Zehnder modulator is used to apply deterministic intensity modulation to the optical signal; The first polarization beam combiner is used for combining two orthogonal polarization mode optical signals and outputting to one optical fiber output end; in the first orthogonal polarization modulation module, the modulation signals of the two optical paths divided by the first polarization beam splitter are c 1x (t) and c 1y (t) respectively, the attenuation coefficients of the two optical paths are α x and α y respectively, the small phase changes of the optical signals are θ x and θ y respectively, and the transformation matrix of the first orthogonal polarization modulation module is The conversion from intensity modulation to polarization modulation is completed; In the second orthogonal polarization modulation module, the modulation signals of the two light paths split by the second polarization beam splitter are c 2x (t) and c 2y (t), respectively, and c 1x (t)≈c 2x (t), c 1y (t)≈c 2y (t); the attenuation coefficients of the two light paths are β x and β y , respectively, and the small phase changes of the optical signals are and The transformation matrix of the second orthogonal polarization modulation module is represented as The conversion from intensity modulation to polarization modulation is completed.

7. A computer device, comprising: The computer device includes a memory and a processor, and the memory stores a computer program, and the computer program is executed by the processor to make the processor execute the steps of the control method of the security key distribution device according to claim 5.

8. A computer readable storage medium storing a computer program, the computer program being executed by a processor to make the processor execute the steps of the control method of the security key distribution device according to claim 5.

Images