A dynamic encryption security communication system based on multi-longitudinal mode chaotic synchronization

Abstract

The application provides a kind of dynamic encryption security communication system device and method based on multi-longitudinal mode chaos synchronization, belongs to the technical field of chaos communication carrier and space division multiplexing technical field.The device includes chaos signal generation module, information encryption module, optical fiber transmission module, chaos signal synchronization module, information decryption module.In the chaos signal generation module, broadband noise drives Fabry-Perot laser to generate multiple longitudinal mode chaos signals, and the chaos signals of arbitrary longitudinal mode combination are used to encrypt the user information of different cores of seven-core optical fiber, thereby increasing the system key space.In the information encryption module, the confidential information of different users of seven-core optical fiber is first disturbed in intensity by a dispersion element, and then the chaos signals of different longitudinal mode combinations are used to phase-encrypt the confidential information, thereby realizing two-dimensional encryption of the confidential signal in intensity and phase.Meanwhile, the use of space division multiplexing technology effectively improves the communication capacity of the secure communication system.

Description

Technical Field

[0001] This invention relates to the technical fields of chaotic communication carriers and spatial multiplexing, and more specifically, to a dynamic encrypted secure communication system based on multi-mode chaotic synchronization. Background Technology

[0002] With the widespread application of 5G communication, cloud computing, and artificial intelligence in people's daily lives, fiber optic communication has become an important physical carrier and backbone infrastructure for network information, exerting a positive and far-reaching impact on people's lives and production methods. However, as fiber optic communication develops towards high capacity and long distance, fiber optic eavesdropping technology is also constantly evolving. In recent years, frequent cybersecurity incidents have led to increasing public concern about communication network security. my country attaches great importance to cybersecurity, enacting relevant laws and regulations to safeguard its network security. However, the cybersecurity situation facing my country remains very serious, making it imperative to improve network security. In communication networks, traditional encryption methods use algorithms to encrypt information. However, with the rapid increase in computer computing power, these traditional algorithm encryption methods are potentially vulnerable to being cracked by computers. Therefore, finding a secure method for communication system confidentiality is of great significance. Chaotic lasers, due to their non-periodic, noise-like, and wide-spectrum characteristics, can effectively enhance the security of optical communication systems when used in physical layer secure communication.

[0003] In recent years, researchers have proposed many meaningful chaotic secure communication schemes, which have greatly improved the security of fiber optic communication systems. As optical transmission technology develops towards ultra-high capacity and ultra-long distance, chaotic secure communication should also conduct research on ultra-high capacity and ultra-long distance fiber optic secure communication systems in advance. Chinese patent application CN114142933A, published in March 2022, discloses a secure communication device and method based on multi-core optical fibers. The invention generates a broadband phase chaotic carrier in a chaotic carrier generation module. An information encryption and transmission module modulates information onto the broadband chaotic carrier through a first IQ modulator to achieve information masking. The optical fiber transmission link couples multiple channels into the multi-core optical fiber for transmission and then couples the output to multiple single-mode optical fibers. The coherent demodulation and receiving module decrypts the encrypted signal to obtain the information. This invention directly transmits the generated broadband phase chaotic signal to the receiving end through the middle core of a seven-core optical fiber. If an eavesdropper obtains the chaotic signal of the middle core by eavesdropping on the seven-core optical fiber, the security of the communication system will be greatly reduced. Therefore, it is necessary to invent a communication system that can achieve both high-capacity transmission and improved security. Summary of the Invention

[0004] This invention provides a dynamic encrypted secure communication system based on multi-mode chaotic synchronization, which solves the system security problem of chaotic secure communication systems during large-capacity transmission. It can realize the secure transmission of large-capacity confidential information, enhance the confidentiality and security of the communication system, and the system supports secure communication with signals of different signal rates and different modulation formats.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0006] This invention provides a dynamic encrypted secure communication system based on multi-mode chaotic synchronization. The system includes 1-chaotic signal generation module, 2-information encryption module, 3-optical fiber transmission module, 4-chaotic signal synchronization module, and 5-information decryption module.

[0007] The 1-chaotic signal generation module is implemented using the following technical solution:

[0008] Includes: 101-Superluminescent Diode, 102-First Optical Coupler, 103-First Erbium-Doped Fiber Amplifier, 104-First Tunable Optical Filter, 105-First Polarization Controller, 106-First Optical Circulator, 107-First Fabry-Perot Laser, 108-Second Optical Coupler, 109-Second Tunable Optical Filter to 134-Seventh Tunable Optical Filter, 110-First Tunable Dispersion Module to 135-Sixth Tunable Dispersion Module, 111-First Photodetector to 136-Sixth Photodetector, 112-First Electrical Switch to 137-Sixth Electrical Switch, 113-First Radio Frequency Amplifier to 138-Sixth Radio Frequency Amplifier, 139-First Electrical Adder.

[0009] The connection relationships between the modules are as follows:

[0010] 101 - The output terminal of the superluminescent diode is connected to the input terminal of 102 - the first optical coupler. The first output terminal of 102 - the first optical coupler is connected to the seventh input terminal of the 301 - fan-in device of the optical fiber transmission module. The second output terminal of 102 - the first optical coupler is connected to the input terminal of 103 - the first erbium-doped fiber amplifier. The output terminal of 103 - the first erbium-doped fiber amplifier is connected to the input terminal of 104 - the first tunable optical filter. The output terminal of 104 - the first tunable optical filter is connected to the input terminal of 105 - the first polarization controller. 05-The output of the first polarization controller is connected to one input of 106-the first optical circulator. The two inputs of 106-the first optical circulator are connected to 107-the first Fabry-Perot laser. The output of 106-the first optical circulator is connected to the input of 108-the second optical coupler. The six outputs of 108-the second optical coupler are connected to the inputs of 109-the second tunable optical filter to 134-the seventh tunable optical filter, respectively. In the photoelectric conversion path of the first longitudinal mode chaotic signal, the output of 109-the second tunable optical filter... The output terminal of the 110-first adjustable dispersion module is connected to the input terminal of the 110-first adjustable dispersion module. The output terminal of the 110-first adjustable dispersion module is connected to the optical input terminal of the 111-first photodetector. The electrical output terminal of the 111-first photodetector is connected to the input terminal of the 112-first electrical switch. The output terminal of the 112-first electrical switch is connected to the input terminal of the 113-first radio frequency amplifier. The output terminal of the 113-first radio frequency amplifier is connected to the input terminal of the 139-first electrical adder. The output terminal of the 139-first electrical adder is connected to the 203-... of the information encryption module. The first phase modulator is connected to the electrical input terminal of the 216-sixth phase modulator. The photoelectric conversion paths of the remaining five longitudinal mode chaotic signals are connected in the same way as the photoelectric conversion path of the first longitudinal mode chaotic signal. The broadband noise signal output by the superluminescent diode is injected into the Fabry-Perot laser to generate multiple longitudinal mode chaotic signals. Six different longitudinal mode chaotic signals are selected. The information encryption module encrypts the information of different users by dynamically selecting one longitudinal mode chaotic signal or adding two or more longitudinal mode chaotic signals through the electric switch.

[0011] 2. The information encryption module adopts the following technical solution:

[0012] Includes: 201-first user confidential signal generator to 216-sixth user confidential signal generator, 202-first dispersive element to 217-sixth dispersive element, 203-first phase modulator to 218-sixth phase modulator.

[0013] The connection relationships between the modules are as follows:

[0014] The output terminal of the 201-first user confidential signal generator of User 1 is connected to the input terminal of the 202-first dispersive element. The output terminal of the 202-first dispersive element is connected to the optical input terminal of the 203-first phase modulator. The electrical input terminal of the 203-first phase modulator is connected to the output terminal of the 139-first electrical adder. The output terminal of the 203-first phase modulator is connected to the sixth input terminal of the 301-fan-in device of the optical fiber transmission module. The connections of the information encryption links of the remaining users 2 to 6 are the same as those of User 1. The output terminals of the first to sixth phase modulators in the information encryption links of users 1 to 6 are connected to the first to sixth input terminals of the fan-in device of the optical fiber transmission link.

[0015] 3. The fiber optic transmission module adopts the following technical solution:

[0016] Includes: 301 - Fan-in device, 302 - Seven-core optical fiber, 303 - Fan-out device.

[0017] The connection relationships between the modules are as follows:

[0018] The first to sixth input terminals of the 301-fan-in device are respectively connected to the output terminals of the 203-first phase modulator to the 218-sixth phase modulator in the information encryption module. The first output terminal of the 102-first optical coupler of the chaotic signal generation module is connected to the seventh input terminal of the 301-fan-in device. The output terminal of the 301-fan-in device is connected to the input terminal of the seven-core optical fiber. The output terminal of the 302-seven-core optical fiber is connected to the input terminal of the 303-fan-out device. The first to sixth output terminals of the 303-fan-out device are connected to the optical input terminals of the 501-seventh phase modulator to the 511-twelfth phase modulator in the information decryption module. The seventh output terminal of the 303-fan-out device is connected to the input terminal of the 401-second erbium-doped fiber amplifier in the chaotic signal synchronization module.

[0019] 4. The chaotic signal synchronization module adopts the following technical solution:

[0020] Includes: 401-Second erbium-doped fiber amplifier, 402-Eighth tunable optical filter, 403-Second polarization controller, 404-Second optical circulator, 405-Second Fabry-Perot laser, 406-Third optical coupler, 407-Ninth tunable optical filter to 432-Fourteenth tunable optical filter, 408-Seventh tunable dispersion module to 433-Twelfth tunable dispersion module, 409-Seventh photodetector to 434-Twelfth photodetector, 410-Seventh electrical switch to 435-Twelfth electrical switch, 411-Seventh RF amplifier to 436-Twelfth RF amplifier, 437-Second electrical adder.

[0021] The connection relationships between the modules are as follows:

[0022] The input terminal of the second erbium-doped fiber amplifier (401) is connected to the seventh output terminal of the fan-out device (303) of the fiber optic transmission module. The output terminal of the second erbium-doped fiber amplifier (401) is connected to the input terminal of the eighth tunable optical filter (402). The output terminal of the eighth tunable optical filter (402) is connected to the input terminal of the second polarization controller (403). The output terminal of the second polarization controller (403) is connected to one input terminal of the second optical circulator (404). The two input terminals of the second optical circulator (404) are connected to the second Fabry-Perot laser (405). The output terminal of the second optical circulator (404) is connected to the input terminal of the third optical coupler (406). The six output terminals of the third optical coupler (406) are respectively connected to the input terminals of the ninth tunable optical filter (407) to the fourteenth tunable optical filter (432). In the chaotic signal synchronization module, in the photoelectric conversion path of the first longitudinal mode chaotic signal, 4 The output of the 07-ninth tunable optical filter is connected to the input of the 408-seventh tunable dispersion module. The output of the 408-seventh tunable dispersion module is connected to the optical input of the 409-seventh photodetector. The electrical output of the 409-seventh photodetector is connected to the input of the 410-seventh electrical switch. The output of the 410-seventh electrical switch is connected to the input of the 411-seventh RF amplifier. The output of the 411-seventh RF amplifier is connected to the input of the 437-second electrical adder. The output of the 437-second electrical adder is connected to the electrical inputs of the 501-seventh phase modulator to the 511-twelfth phase modulator of the information decryption module. The photoelectric conversion paths of the remaining five longitudinal modes of the chaotic signal synchronization module are connected in the same way as the photoelectric conversion path of the first longitudinal mode. A high-quality chaotic synchronization signal is the guarantee of the decryption performance of the chaotic secure communication system.

[0023] 5. The information decryption module adopts the following technical solution:

[0024] Includes: 501-Seventh phase modulator to 511-Twelfth phase modulator, 502-Seventh dispersive element to 512-Twelfth dispersive element.

[0025] The connection relationships between the modules are as follows:

[0026] The optical input terminals of the 501-seventh phase modulator to the 511-twelfth phase modulator are respectively connected to the first to sixth output terminals of the 303-fan-out device. The output terminal of the 437-second electrical adder of the chaotic signal synchronization module is respectively connected to the electrical input terminals of the 501-seventh phase modulator to the 511-twelfth phase modulator. The output terminals of the 501-seventh phase modulator to the 511-twelfth phase modulator are connected to the input terminals of the 502-seventh dispersive element to the 512-twelfth dispersive element. The output terminals of the 502-seventh dispersive element to the 512-twelfth dispersive element output the confidential signals decrypted by users one to six.

[0027] The method of this invention mainly utilizes a dispersive element to intensify and disrupt the confidential signals of users one through six. Then, a broadband noise-driven Fabry-Perot laser in a chaotic signal generation module generates multiple longitudinal-mode chaotic signals. Six longitudinal-mode chaotic signals are arbitrarily filtered out from the generated multi-mode chaotic signals for dynamic encryption. The user's confidential signals undergo two-dimensional encryption from intensity to phase. In the dynamic combination of multiple longitudinal-mode chaotic signals, one of these six longitudinal-mode chaotic signals can be arbitrarily selected to drive a phase modulator to complete the phase encryption of the six different user confidential signals on a seven-core fiber. Alternatively, two or more longitudinal-mode chaotic signals can be arbitrarily selected, added together by an electric adder, and then used to drive the phase modulator to complete the phase encryption of the six different user confidential signals on the seven-core fiber. The different combinations of chaotic signals on different cores of the seven-core fiber... The user information is encrypted, and eavesdroppers cannot know which longitudinal mode chaotic signals correspond to the chaotic signals encrypted by each user. In this way, the dynamic combination of different longitudinal mode chaotic signals can effectively improve the system key space and ensure the system security. This invention uses broadband noise to jointly drive the Fabry-Perot lasers at the transmitting and receiving ends to achieve high-quality chaotic synchronization. The correlation between each longitudinal mode chaotic signal and the broadband noise driving signal is less than 0.1. In this way, even if an eavesdropper hears the broadband noise driving signal in the middle core of the seven-core optical fiber, they cannot obtain the chaotic synchronization signal. The system security is effectively improved compared to directly transmitting chaotic signals on a public transmission link. At the same time, the use of spatial division multiplexing technology effectively improves the capacity of the secure communication system, providing an effective physical layer security method for the large-scale commercial use of spatial division multiplexing in the future. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a dynamic encrypted secure communication system based on multi-mode chaotic synchronization. Detailed Implementation

[0029] To clearly illustrate the present invention, a dynamic encrypted secure communication system based on multi-mode chaotic synchronization, the present invention will be further described in conjunction with embodiments and accompanying drawings, but this should not be construed as limiting the scope of protection of the present invention.

[0030] Example

[0031] Figure 1 This is a schematic diagram of a dynamic encrypted secure communication system based on multi-mode chaotic synchronization. From... Figure 1It can be seen that in the 1-chaotic signal generation module, the broadband noise output from the 101-superluminescent diode is split into two paths by the 102-first optical coupler. One path is input to the 103-first erbium-doped fiber amplifier. After the power amplification, the optical signal is adjusted by the 104-first tunable optical filter, and the broadband noise driving signal is injected into the 107-first Fabry-Perot laser to generate a multi-longitudinal-mode chaotic signal. The multi-longitudinal-mode chaotic signal is split into six optical signals by the 108-second optical coupler. By adjusting the 109-second tunable filter to the 134-seventh tunable filter, six chaotic signals of different longitudinal modes are filtered out. These six chaotic signals of different longitudinal modes are set with different dispersion values ​​for each chaotic signal by the 110-first tunable dispersion module to the 135-sixth tunable dispersion module, so as to reduce the correlation between chaotic signals of different longitudinal modes and increase the key space of the system. The detector, from 136 to the sixth photodetector, converts chaotic optical signals of different longitudinal modes into chaotic electrical signals. The chaotic signals are dynamically selected by the first electrical switch (112) to the sixth electrical switch (137) for combination. The electrical signals are adjusted by the first radio frequency amplifier (113) to the sixth radio frequency amplifier (138). Then, the chaotic signals of different longitudinal modes are dynamically selected by the electrical switches and added together by the first electrical adder (139). The electrical switches can select one of the six longitudinal modes, two of the six longitudinal mode chaotic signals for addition, or multiple longitudinal modes for addition to form the driving signal. Eavesdroppers cannot know which longitudinal mode chaotic signals correspond to the chaotic signals encrypted by different users in the multi-core optical fiber. In this way, the dynamic combination of different longitudinal mode chaotic signals can effectively improve the system key space and ensure the security of the system.

[0032] In the 2-Information Encryption Module, taking the encryption of User 1's confidential signal as an example, 201-The first user confidential signal generator outputs the confidential signal to be encrypted. The confidential signal first passes through 202-The first dispersive element to scramble the waveform of the user confidential signal in terms of intensity. The confidential signal after intensity scrambling is injected into 203-The first phase modulator. Then, the chaotic electrical signal drives the phase modulator to scramble the confidential signal in terms of phase. This completes the encryption of User 1's confidential signal from intensity to phase. The encryption process of User 2 to User 6's confidential signals is the same as that of User 1. In this embodiment, the confidentiality of six different users in the multi-core fiber is not limited to a specific rate and modulation format of communication signals. This embodiment is compatible with communication signals of different rates and modulation formats, such as four-level pulse amplitude modulation (PAM4), quadrature amplitude modulation (QAM), and quadrature phase keying (QPSK) at different rates. The first dispersive element (202) to the sixth dispersive element (217) can be selected in various ways, such as using chirped fiber gratings or dispersive fibers. Under the combined effect of dispersion and chaotic phase encryption, the confidential signals of the six users are encrypted in both amplitude and phase.

[0033] In the 3-fiber transmission module, the encrypted signals of users one to six and the broadband noise drive signal output by the superluminescent diode are injected into the 302-seven-core fiber for transmission after passing through the 301-fan-in device. The 303-fan-out device injects the six encrypted signals into the information decryption module and one broadband noise signal into the chaotic signal synchronization module.

[0034] In the 4-chaotic signal synchronization module, a broadband noise driving signal transmitted through a seven-core optical fiber is injected into a structure symmetrical to the chaotic signal generation module and has the same device parameters, generating a chaotic signal that is highly synchronized with the chaotic signal generation module. Each user uses the same longitudinal mode chaotic signal combination as the information encryption module for decryption. The chaotic electrical signals driving the phase modulators of users one to six in the information decryption module have the same amplitude but opposite amplitude to the chaotic electrical signals of the information encryption module.

[0035] In the 5-information decryption module, taking User 1 as an example, the encrypted signal after transmission is erased by the 501-seventh phase modulator to remove the chaotic phase encryption component in the encrypted signal. At this time, the encrypted signal is a confidential signal with dispersion disordered in intensity. The encrypted signal is restored by the 502-seventh dispersion element, which has the same dispersion value and opposite dispersion coefficient as the information encryption module. The decryption of confidential information of Users 2 to 6 is the same as that of User 1.

[0036] As illustrated by specific examples, this invention proposes a dynamic encrypted secure communication system based on multi-mode chaotic synchronization. It encrypts user information from different cores of a seven-core optical fiber using chaotic signals with arbitrary combinations of longitudinal modes, increasing the system's key space. The correlation between the broadband noise-driven signal and the chaotic signals with different combinations of longitudinal modes is less than 0.1. Even if an eavesdropper obtains the broadband noise-driven signal of the public transmission link, they cannot achieve chaotic synchronization and thus steal the user's confidential signals. The system security is effectively improved. Simultaneously, the use of spatial division multiplexing technology effectively increases the capacity of the secure communication system, providing an effective physical layer security method for future high-capacity optical fiber communication networks.

[0037] Although the illustrative specific embodiments of the present invention have been described above to enable those skilled in the art to understand the present invention, it should also be noted that the present invention is not limited to the specific details in the above embodiments, and various simplifications and modifications within the scope of the principles and methods of the present invention are all within the scope of protection of the present invention.

Claims

1. A dynamic encryption security communication system based on multi-longitudinal mode chaotic synchronization, characterized in that, It comprises the following parts: chaotic signal generation module (1), information encryption module (2), optical fiber transmission module (3), chaotic signal synchronization module (4), information decryption module (5). The output end of the first electric adder of the chaotic signal generation module is connected with the electric input end of the first phase modulator to the sixth phase modulator of the information encryption module respectively, the first output end of the first optical coupler of the chaotic signal generation module is connected with the seventh input end of the fan-in device of the optical fiber transmission module, the optical output end of the first phase modulator to the sixth phase modulator in the information encryption module is connected with the first input end to the sixth input end of the fan-in device in the optical fiber transmission module respectively, the first output end to the sixth output end of the fan-out device in the optical fiber transmission module is connected with the optical input port of the seventh phase modulator to the twelfth phase modulator in the information decryption module respectively, the seventh output end of the fan-out device is connected with the input end of the second erbium-doped fiber amplifier of the chaotic signal synchronization module, the output end of the second electric adder of the chaotic signal synchronization module is connected with the electric input end of the seventh phase modulator to the twelfth phase modulator of the information decryption module respectively, the legal receiving end can realize the decryption of the information of different users of the seven-core optical fiber by using the chaotic synchronization signal and the matched dispersion; The chaotic signal generation module comprises: super radiation light emitting diode, first optical coupler, first erbium-doped fiber amplifier, first adjustable optical filter, first polarization controller, first optical ring, first Fabry-Perot laser, second optical coupler, second adjustable optical filter to seventh adjustable optical filter, first adjustable dispersion module to sixth adjustable dispersion module, first photoelectric detector to sixth photoelectric detector, first electric switch to sixth electric switch, first radio frequency amplifier to sixth radio frequency amplifier, first electric adder, wherein: The super radiation light emitting diode output end is connected with the input end of the first optical coupler, the first output end of the first optical coupler is connected with the seventh input end of the fan-in device of the optical fiber transmission module, the second output end of the first optical coupler is connected with the input end of the first erbium-doped fiber amplifier, the output end of the first erbium-doped fiber amplifier is connected with the input end of the first adjustable optical filter, the output end of the first adjustable optical filter is connected with the input end of the first polarization controller, the output end of the first polarization controller is connected with one input end of the first optical circulator, the second input end of the first optical circulator is connected with the first Fabry-Perot laser, the output end of the first optical circulator is connected with the input end of the second optical coupler, the six output ends of the second optical coupler are connected with the input ends of the second adjustable optical filter to the seventh adjustable optical filter respectively, the output end of the second adjustable optical filter in the photoelectric conversion path of the first longitudinal mode chaotic signal is connected with the input end of the first adjustable dispersion module, the output end of the first adjustable dispersion module is connected with the light input end of the first photoelectric detector, the electric output end of the first photoelectric detector is connected with the input end of the first electric switch, the output end of the first electric switch is connected with the input end of the first radio frequency amplifier, the output end of the first radio frequency amplifier is connected with the input end of the first electric adder, the output end of the first electric adder is connected with the electric input ends of the first phase modulator to the sixth phase modulator of the information encryption module respectively, the photoelectric conversion paths of the remaining five longitudinal mode chaotic signals are the same as the photoelectric conversion path of the first longitudinal mode chaotic signal, the broadband noise signal output by the super radiation light emitting diode is injected into the Fabry-Perot laser to generate a plurality of longitudinal mode chaotic signals, six chaotic signals of different longitudinal modes are selected, one longitudinal mode chaotic signal is dynamically selected through the electric switch, or two or more longitudinal mode chaotic signals are superimposed and combined, and the information of different users in the information encryption module is encrypted.

2. The dynamic encryption security communication system based on multi-longitudinal mode chaotic synchronization according to claim 1, characterized in that, The information encryption module comprises: a first user secret signal generator to a sixth user secret signal generator, a first dispersion element to a sixth dispersion element, and a first phase modulator to a sixth phase modulator, wherein: The output end of the first user secret signal generator of user one is connected with the input end of the first dispersion element, the output end of the first dispersion element is connected with the light input end of the first phase modulator, the electric input end of the first phase modulator is connected with the output end of the first electric adder, and the output end of the first phase modulator is connected with the sixth input end of the fan-in device of the optical fiber transmission module, the connection of the information encryption links of the remaining users two to six is the same as that of user one, and the output ends of the first to sixth phase modulators in the information encryption links of user one to user six are connected with the first to sixth input ends of the fan-in device of the optical fiber transmission link.

3. A dynamic encryption security communication system based on multi-longitudinal mode chaotic synchronization according to claim 2, characterized in that, The optical fiber transmission module comprises: a fan-in device, a seven-core optical fiber, and a fan-out device, wherein: The first to sixth inputs of the fan-in device are connected with the outputs of the first to sixth phase modulators in the information encryption module respectively, the first output of the first optical coupler of the chaos signal generation module is connected with the seventh input of the fan-in device, the output of the fan-in device is connected with the input of the seven-core fiber, the output of the seven-core fiber is connected with the input of the fan-out device, the first to sixth outputs of the fan-out device are connected with the optical inputs of the seventh to twelfth phase modulators in the information decryption module respectively, the seventh output of the fan-out device is connected with the input of the second erbium-doped fiber amplifier of the chaos signal synchronization module, and the use of the seven-core fiber can effectively increase the communication capacity of the chaos secure communication system.

4. The dynamic encryption security communication system based on multi-longitudinal mode chaotic synchronization according to claim 3, characterized in that, The chaos signal synchronization module comprises a second erbium-doped fiber amplifier, an eighth adjustable optical filter, a second polarization controller, a second optical circulator, a second Fabry-Perot laser, a third optical coupler, a ninth adjustable optical filter to a fourteenth adjustable optical filter, a seventh adjustable dispersion module to a twelfth adjustable dispersion module, a seventh photoelectric detector to a twelfth photoelectric detector, a seventh electric switch to a twelfth electric switch, a seventh radio frequency amplifier to a twelfth radio frequency amplifier, and a second electric adder, wherein: The input of the second erbium-doped fiber amplifier is connected with the seventh output of the fan-out device of the fiber transmission module, the output of the second erbium-doped fiber amplifier is connected with the input of the eighth adjustable optical filter, the output of the eighth adjustable optical filter is connected with the input of the second polarization controller, the output of the second polarization controller is connected with the first input of the second optical circulator, the second input of the second optical circulator is connected with the second Fabry-Perot laser, the output of the second optical circulator is connected with the input of the third optical coupler, the six outputs of the third optical coupler are connected with the inputs of the ninth adjustable optical filter to the fourteenth adjustable optical filter respectively, in the photoelectric conversion path of the first longitudinal mode chaos signal in the chaos signal synchronization module, the output of the ninth adjustable optical filter is connected with the input of the seventh adjustable dispersion module, the output of the seventh adjustable dispersion module is connected with the optical input of the seventh photoelectric detector, the electrical output of the seventh photoelectric detector is connected with the input of the seventh electric switch, the output of the seventh electric switch is connected with the input of the seventh radio frequency amplifier, the output of the seventh radio frequency amplifier is connected with the input of the second electric adder, and the output of the second electric adder is connected with the electrical inputs of the seventh to twelfth phase modulators in the information decryption module respectively.

5. A dynamic encryption security communication system based on multi-longitudinal mode chaotic synchronization according to claim 4, characterized in that, The information decryption module comprises The seventh phase modulator to the twelfth phase modulator, the seventh dispersion element to the twelfth dispersion element, wherein: the light input end of the seventh phase modulator to the twelfth phase modulator is connected with the first to sixth output ends of the fan-out device, the second electric adder output end of the chaotic signal synchronization module is connected with the electric input end of the seventh phase modulator to the twelfth phase modulator respectively, the output end of the seventh phase modulator to the twelfth phase modulator is connected with the input end of the seventh dispersion element to the twelfth dispersion element, and the output end of the seventh dispersion element to the twelfth dispersion element outputs the confidential signal decrypted by the first to sixth users.

6. The dynamic encryption security communication system based on multi-longitudinal mode chaotic synchronization according to claim 1 or 4, characterized in that: The first to sixth radio frequency amplifiers are respectively connected with the driving electric signal output by the seventh to twelfth radio frequency amplifiers, and the amplitude of the driving electric signal output by the first to sixth radio frequency amplifiers is the same as that of the seventh to twelfth radio frequency amplifiers and the amplitude is opposite; the dispersion values of the first to seventh adjustable dispersion modules are respectively the same as those of the seventh to twelfth adjustable dispersion modules; the dispersion value of the first dispersion element in the information encryption module is the same as that of the seventh dispersion element in the information decryption module and the dispersion coefficients are opposite, the dispersion value of the second dispersion component is the same as that of the eighth dispersion component and the dispersion coefficients are opposite, and the dispersion values of the third to sixth dispersion components are the same as those of the ninth to twelfth dispersion components and the dispersion coefficients are opposite.

7. The dynamic encryption security communication system based on multi-longitudinal mode chaotic synchronization according to claim 1 or 4, characterized in that: The working parameters of the first Fabry-Perot laser and the second Fabry-Perot laser are the same.

8. A dynamic encryption security communication system based on multi-longitudinal-mode chaotic synchronization, comprising the following steps: In the chaotic signal generation module (1), broadband noise output by the super radiation light emitting diode (101) is divided into two ways by the first optical coupler (102), one way signal is input to the first erbium-doped fiber amplifier (103), the power amplified optical signal passes through the first adjustable optical filter (104) to adjust the bandwidth of the signal, then the broadband noise driving signal is injected into the first Fabry-Perot laser (107) to generate multi-longitudinal mode chaotic signal, the multi-longitudinal mode chaotic signal is divided into six ways of optical signal by the second optical coupler (108), the six ways of different longitudinal mode chaotic signals are filtered out by adjusting the second adjustable filter (109) to the seventh adjustable filter (134), the six ways of different longitudinal mode chaotic signals set different dispersion values for each longitudinal mode chaotic signal by the first adjustable dispersion module (110) to the sixth adjustable dispersion module (135), so as to reduce the correlation between different longitudinal mode chaotic signals, the different longitudinal mode chaotic optical signals are converted into chaotic electrical signals by the first photoelectric detector (111) to the sixth photoelectric detector (136), the chaotic electrical signals are dynamically selected by the first electrical switch (112) to the sixth electrical switch (137) to combine each longitudinal mode chaotic signal, the electrical signals are adjusted in amplitude by the first radio frequency amplifier (113) to the sixth radio frequency amplifier (138), then the different longitudinal mode chaotic signals are dynamically selected by the electrical switch to add and combine by the first electrical adder (139), the electrical switch selects one of the six longitudinal mode chaotic signals, or selects two of the six longitudinal mode chaotic signals to add and combine, or selects multiple longitudinal mode chaotic signals from the six longitudinal mode chaotic signals to add and combine into the driving signal; in the information encryption module (2), the first user confidential signal generator (201) outputs the confidential signal to be encrypted, the confidential signal is first disturbed in intensity by the first dispersion element (202), the intensity disturbed confidential signal is injected into the first phase modulator (203), then the chaotic electrical signal drives the phase modulator to disturb the confidential signal in phase, so that the encryption of the user's confidential signal from intensity to phase is completed, the confidential signals of user two to user six are encrypted in the same way as user one; in the optical fiber transmission module (3), the encrypted signals of user one to user six and the broadband noise driving signal output by the super radiation light emitting diode pass through the fan-in device (301) and are injected into the seven-core optical fiber (302) for transmission, the fan-out device (303) injects six ways of encrypted signals into the information decryption module, and one way of broadband noise is injected into the chaotic signal synchronization module; in the chaotic signal synchronization module (4), the broadband noise driving signal is injected into the architecture which is symmetrical to the chaotic signal generation module and has the same device parameters, the chaotic synchronization signal which is synchronous with the chaotic signal generation module is generated, each user uses the same longitudinal mode combination as the information encryption module for decryption, wherein the chaotic electrical signals corresponding to the phase modulators of user one to user six in the information decryption module have the same amplitude and opposite amplitude with the chaotic electrical signals in the information encryption module.In the information decryption module (5), the encrypted signal after transmission is erased by the seventh phase modulator (501) to encrypt the chaotic phase in the encrypted signal. At this time, the encrypted signal is the confidential signal disturbed in intensity after dispersion. The encrypted signal passes through the seventh dispersion element (502) with the same dispersion value and opposite dispersion coefficient as the information encryption module, and the confidential signal of user one is recovered. The decryption of the confidential information of users two to six is the same as that of user one.

Images