Interferometric encryption sensing method and system based on random laser

Abstract

The invention relates to an interference type encryption sensing method and system based on random laser, and is applied to the field of fiber lasers, and the method comprises the steps: carrying out the beam splitting of pump light generated by a pump light source, obtaining a first pump light beam and a second pump light beam, injecting the first pump light beam into an annular cavity, and generating random laser; splitting the random laser to obtain a first random laser beam and a second random laser beam; emitting the first random laser beam to the surface of a target, and generating a Doppler frequency shift signal according to reflected light reflected by the target and the first random laser beam; mixing the second random laser beam with the second pump light beam to generate a beat frequency signal, and converting the beat frequency signal into a corresponding electric signal; processing the electric signal through a spectrum analyzer and outputting a true random number; and carrying out algorithm processing on the true random number and the Doppler frequency shift signal to generate a ciphertext, and transmitting the ciphertext to a preset receiving end. The technical effect of the application is that the randomness of the ciphertext and the security of data transmission are improved.

Description

Technical Field

[0001] The present application relates to the technical field of fiber lasers, and in particular, to an interferometric encryption sensing method and system based on random laser. Background Art

[0002] With the rapid development of Internet of Things, cloud computing, and big data technologies, people's demand for communication security and sensing technologies is increasing day by day. Although traditional fiber optic sensing technologies can achieve high-precision physical quantity measurements (such as speed, temperature, strain, etc.), there are security risks of being stolen during data transmission. Existing encryption technologies usually rely on a pseudo-random number generator (PRNG) to generate a seed source through an algorithm, and the pseudo-random number generator (PRNG) generates a key stream based on the seed source to achieve encryption.

[0003] The method of generating encryption by relying on a pseudo-random number generator has a high generation rate. However, the pseudo-random number generator has a risk of being cracked, resulting in limited randomness and security of the pseudo-random number generator encryption method. Summary of the Invention

[0004] In order to help solve the problem that the pseudo-random number generator has a risk of being cracked, resulting in limited randomness and security of the pseudo-random number generator encryption method, the present application provides an interferometric encryption sensing method and system based on random laser.

[0005] In a first aspect, the present application provides an interferometric encryption sensing method based on random laser, adopting the following technical solution: The method includes:

[0006] Splitting the pump light generated by a pump light source to obtain a first pump light beam and a second pump light beam, and injecting the first pump light beam into a ring cavity to generate random laser;

[0007] Splitting the random laser to obtain a first random laser beam and a second random laser beam;

[0008] Emitting the first random laser beam to a target surface, and generating a Doppler frequency shift signal based on the reflected light reflected by the target and the first random laser beam;

[0009] Mixing the second random laser beam with the second pump light beam to generate a beat frequency signal, and converting it into a corresponding electrical signal;

[0010] Processing the electrical signal through a spectrum analyzer and outputting a true random number;

[0011] Generating a ciphertext by processing the true random number and the Doppler frequency shift signal through an algorithm and transmitting it to a preset receiving end.

[0012] In a specific feasible implementation, the ring cavity includes a Brillouin gain fiber and a single-mode fiber; injecting the first pump light beam into the ring cavity to generate random laser includes:

[0013] Inject the first pump light beam into the Brillouin gain fiber to excite stimulated Brillouin scattering and generate Stokes light;

[0014] Inject the Stokes light into the single-mode fiber to excite Rayleigh scattering and generate Rayleigh scattered light;

[0015] Inject the Rayleigh scattered light into the Brillouin gain fiber to trigger Brillouin gain amplification;

[0016] Circulate stimulated Brillouin scattering and Rayleigh scattering to continuously perform Brillouin gain amplification. When the gain after Brillouin gain amplification is greater than the total loss in the ring cavity, random laser is generated.

[0017] In a specific feasible implementation, splitting the pump light generated by the pump light source to obtain a first pump light beam and a second pump light beam includes:

[0018] Generate original pump light through the pump light source;

[0019] Inject the original pump light into an erbium-doped fiber amplifier to amplify the optical signal and obtain amplified pump light;

[0020] Split the amplified pump light and obtain a first pump light beam and a second pump light beam.

[0021] In a specific feasible implementation, generating a Doppler frequency shift signal according to the reflected light reflected by the target and the first random laser beam includes:

[0022] Perform self-mixing interference on the reflected light reflected by the target and the first random laser beam to generate a Doppler frequency shift signal.

[0023] In a specific feasible implementation, processing the electrical signal through a spectrum analyzer and outputting a true random number includes:

[0024] Collect, through the spectrum analyzer, the peak frequency signal at the peak of the random frequency within a preset frequency domain range of the electrical signal;

[0025] Set the collected peak frequency signal as the true random number.

[0026] In a specific feasible implementation, the preset frequency domain range is the range of the frequency of the signal greater than 10 GHz.

[0027] In a specific feasible implementation, the process of generating ciphertext by algorithm processing the true random number and the Doppler frequency shift signal and transmitting it to a preset receiving end includes:

[0028] Convert the Doppler frequency shift signal into a binary representation;

[0029] Perform an exclusive OR calculation on the Doppler frequency shift signal in binary representation and the true random number to generate ciphertext and transmit it to a preset receiving end.

[0030] In a specific feasible implementation, the ratio of the first pump light beam to the second pump light beam is 9:1; the ratio of the first random laser beam to the second random laser beam is 5:5.

[0031] In a second aspect, the present application provides an interferometric encryption sensing system based on random lasers, adopting the following technical solution: The system includes a random laser generation module, a sensing module, and a random number generation module;

[0032] The random laser generation module is used to generate an original pump light, generate random lasers according to the original pump light, and split the random lasers to obtain a first random laser beam and a second random laser beam;

[0033] The sensing module is used to receive the first random laser beam and generate a Doppler frequency shift signal according to the first random laser beam;

[0034] The random number generation module is used to receive the second random laser beam, generate a true random number according to the second random laser beam and the original pump light, and encrypt and transmit the Doppler frequency shift signal using the true random number.

[0035] In a specific feasible implementation, the random laser generation module includes a pump light source, an erbium-doped fiber amplifier, a first optical circulator, a second optical circulator, a Brillouin gain fiber, a single-mode fiber, a first optical coupler, and a second optical coupler;

[0036] The pump light source is used to generate the original pump light;

[0037] The erbium-doped fiber amplifier is connected to the pump light source and is used to receive the original pump light and amplify the optical signal;

[0038] The first optical coupler is connected to the erbium-doped fiber amplifier and is used to split the amplified pump light to obtain a first pump light beam and a second pump light beam;

[0039] The first optical circulator is connected to the first optical coupler and is used to control the transmission direction of the first pump light beam;

[0040] The Brillouin gain fiber is connected to the first optical circulator, and is configured to receive the first pump light beam, excite stimulated Brillouin scattering, and generate Stokes light;

[0041] The second optical circulator is connected to the Brillouin gain fiber and the first optical circulator, and is configured to control the transmission direction of the Stokes light;

[0042] The single-mode fiber is connected to the second optical circulator, and is configured to receive the Stokes light, excite Rayleigh scattering, and generate Rayleigh scattered light;

[0043] The second optical coupler is connected to the single-mode fiber, and is configured to split the generated random laser.

[0044] In summary, the present application has the following beneficial technical effects:

[0045] 1. Utilize the unpredictability of the random laser to generate true random numbers, improving the security of encryption keys;

[0046] 2. Based on the self-mixing interference principle, achieve high-precision speed measurement, and be applicable to various sensing scenarios;

[0047] 3. Integrate the sensing and encryption functions into the same system, simplifying the device structure and reducing costs;

[0048] 4. Can be applicable to the sensing and encryption of physical quantities such as temperature and strain, and can be widely applied to fields such as the Internet of Things and military communications. Description of the Drawings

[0049] Figure 1 is a schematic diagram of an interference-based encryption sensing system based on random laser in an embodiment of the present application;

[0050] Figure 2 is a flowchart of an interference-based encryption sensing method based on random laser in an embodiment of the present application;

[0051] Figure 3 is a schematic diagram of the linear change of the generated Doppler frequency shift signal in an embodiment of the present application. Detailed Description of the Embodiment

[0052] The following is a further detailed description of the present application in conjunction with Figures 1-3 to further illustrate the present application.

[0053] An embodiment of the present application discloses an interference-based encryption sensing method based on random laser. By using this encryption sensing method, high-quality true random numbers can be generated, and the generated true random numbers are difficult to predict, thereby solving the problem that the encrypted data may be cracked in traditional sensing encryption technologies that rely on pseudo-random number generators.

[0054] With the rapid development of Internet of Things, cloud computing and big data technologies, people's demand for communication security and sensing technologies is increasing day by day. Although traditional fiber optic sensing technologies can achieve high-precision physical quantity measurements (such as speed, temperature, strain, etc.), there are security risks of being stolen during data transmission. Existing encryption technologies usually rely on a pseudo-random number generator (PRNG), which generates a seed source through an algorithm, and the pseudo-random number generator (PRNG) generates a key stream according to the seed source to achieve encryption.

[0055] The method of generating encryption by relying on a pseudo-random number generator has a high generation rate. However, the pseudo-random number generator has a risk of being cracked, resulting in limited randomness and security of the pseudo-random number generator encryption method. To help improve the randomness and security of encryption, the present application provides an interference encryption sensing method based on random laser.

[0056] Refer to Figure 1 , which is a schematic structural diagram of an interference encryption sensing system based on random laser. The interference encryption sensing system includes a random laser generation module, a sensing module, and a random number generation module.

[0057] The random laser generation module includes a 980nm pump laser source, an erbium-doped fiber amplifier (EDFA), and a ring cavity structure. Among them, the ring cavity includes 20km of Brillouin gain fiber (SMF1), 10km of single-mode fiber (SMF2), and two circulators (CIR1 and CIR2). Stimulated Brillouin scattering and Rayleigh scattering are used to perform Brillouin gain amplification to excite random laser. Specifically, the first split pump laser beam is injected into the 20km Brillouin gain fiber (SMF1) to excite stimulated Brillouin scattering to generate Stokes light. The Stokes light is injected into the 10km single-mode fiber (SMF2) to excite Rayleigh scattering to generate Rayleigh scattered light. The Rayleigh scattered light is injected back into the 20km Brillouin gain fiber (SMF1) for Brillouin gain amplification; the laser circulates in the ring cavity for Brillouin gain amplification. When the gain in the ring cavity is greater than the loss, random laser is generated and split at the optical coupler OC2; the two circulators (CIR1 and CIR2) are used to control the optical transmission direction.

[0058] The sensing module includes a collimator and a rotating disk target. The collimator is used to adjust the path of the emitted random laser. The generated random laser is split at the optical coupler OC2 to obtain a first random laser beam and a second random laser beam. The first random laser beam is emitted to the surface of the rotating disk target through the collimator. Using the self-mixing interference principle, the reflected light on the target surface and the first random laser beam perform self-mixing interference to form a Doppler frequency shift signal that linearly changes with speed, realizing interference sensing of speed.

[0059] The random number generation module includes a photodetector (PD) and a spectrum analyzer (RSA). The photodetector is used to convert optical signals into electrical signals, and the spectrum analyzer is used to analyze electrical signals and generate true random numbers. The second random laser beam split at the optical coupler OC2 and the second pump light beam split at the optical coupler OC1 are combined at the optical coupler OC3, converted into electrical signals by the photodetector (PD), and output true random numbers after being analyzed by the spectrum analyzer. The generated random number is used to encrypt the sensor data, and the encrypted data is transmitted through the communication link. The receiving end uses the same random number to decrypt the encrypted data to restore the original sensor information.

[0060] Reference Figure 2 , the random laser based interferometric encryption sensing method includes the following steps:

[0061] S10, splitting the pump light generated by the pump light source into a first pump light beam and a second pump light beam, and injecting the first pump light beam into the ring cavity to generate random laser.

[0062] Specifically, a pump light source (Pump Lser) generates pump light, and the generated pump light is split by an optical coupler OC1 in a ratio of 9:1 to obtain a first pump light beam and a second pump light beam, wherein the first pump light beam is injected into the ring cavity to generate random laser, and the second pump light beam is used to generate true random numbers.

[0063] S20, splitting the random laser beam to obtain a first random laser beam and a second random laser beam.

[0064] Specifically, after the first pump light beam is injected into the ring cavity to generate random laser through stimulated Brillouin scattering and Rayleigh scattering, the generated random laser is split by an optical coupler OC2 at a ratio of 5:5 to obtain a first random laser beam and a second random laser beam.

[0065] S30, emitting a first random laser beam to a target surface, and generating a Doppler frequency shift signal according to the reflected light reflected by the target and the first random laser beam.

[0066] Specifically, the first random laser beam is emitted to the target surface through a collimator. In the embodiment of the present application, the target is a rotating turntable. The target will reflect back a portion of the light, and the light reflected by the target and the incident light, that is, the first random laser beam, will self-mix and interfere to generate a Doppler frequency shift signal. The Doppler frequency shift signal is a signal generated in the low-frequency region that changes linearly with speed. Figure 3, which is a schematic diagram of the linear change of the Doppler frequency shift signal in the embodiment of the present application. In the figure, the horizontal axis represents the Doppler frequency, and the vertical axis represents the signal intensity. From the first figure to the last figure, the Doppler frequency shift signals corresponding to the turntable increasing from 100 revolutions per minute to 1000 revolutions per minute are shown. It can be seen that as the rotational speed increases, the peak value of the signal intensity also changes linearly. It should be noted that after generating the Doppler frequency shift signal, the Doppler frequency shift signal can be converted into a corresponding electrical signal by a photoelectric sensor, and then the Doppler electrical signal can be analyzed by a spectrum analyzer to detect the linear change of the speed in real time.

[0067] S40, Mix the second random laser beam and the second pump light beam to generate a beat signal and convert it into a corresponding electrical signal.

[0068] Specifically, the second random laser beam and the second pump light beam obtained after splitting the random laser are mixed. The random laser and the pump light interact to generate a beat signal. Then, the beat signal is converted into a corresponding electrical signal by a photodetector (PD).

[0069] S50, Process the electrical signal through a spectrum analyzer and output a true random number.

[0070] Specifically, after generating the beat signal, it is converted into an electrical signal by a photoelectric sensor and then transmitted to the spectrum analyzer for processing. The spectrum analyzer collects the peak frequency signal at the peak of the random frequency within the range where the signal frequency of the beat electrical signal is greater than 10 GHz, and sets the collected peak frequency signal as the true random number.

[0071] S60, Process the true random number and the Doppler frequency shift signal through an algorithm to generate a ciphertext and transmit it to a preset receiving end.

[0072] Specifically, after saving the collected true random number and the Doppler frequency shift signal, a ciphertext is obtained through algorithm processing and transmitted to a preset receiving end. After receiving the ciphertext, the receiving end can use the same random number for decryption to restore the original speed information. Specifically, the method of obtaining the ciphertext by processing the true random number and the Doppler frequency shift signal through an algorithm may include the following steps. First, the Doppler frequency shift signal is converted into a binary representation. Then, the binary representation of the Doppler frequency shift signal and the true random number are subjected to an exclusive OR calculation to generate a ciphertext and transmit it to a preset receiving end.

[0073] In the solution of this application, true random numbers are generated by using the unpredictability of a random laser, ensuring the high security of the encryption key and improving the security of data transmission. Secondly, based on the principle of self-mixing interference, high-precision speed measurement is achieved, which can be applied to various sensing scenarios. In addition, the system structure designed in this application integrates sensing and encryption functions, simplifies the device structure, and thus can reduce costs.

[0074] In one embodiment, the ring cavity includes a Brillouin gain fiber and a single-mode fiber; the method of injecting the first pump light beam into the ring cavity to generate random laser can be specifically implemented as follows:

[0075] First, the first pump light beam is injected into the Brillouin gain fiber to excite stimulated Brillouin scattering to generate Stokes light. Specifically, referring to Figure 1 , the first pump light beam split at a ratio of 9:1 at the first optical coupler OC1 enters from port 1 of the first circulator CIR1 and exits from port 2, and is injected into the Brillouin gain fiber SMF1 to excite stimulated Brillouin scattering to generate Stokes light.

[0076] After that, the Stokes light is injected into the single-mode fiber to excite Rayleigh scattering to generate Rayleigh scattered light. Specifically, referring to Figure 1 , the generated Stokes light enters from port 2 of the first circulator CIR1 and exits from port 3, then enters from port 1 of the second circulator CIR2 and exits from port 2, and is injected into the single-mode fiber SMF2 to excite Rayleigh scattering to generate Rayleigh scattered light. The Rayleigh scattered light is injected into the Brillouin gain fiber to trigger Brillouin gain amplification. Rayleigh scattering, as a random feedback mechanism, reflects part of the light as a seed light source back into the Brillouin gain fiber. Combining Figure 1 It can also be understood that the Rayleigh scattered light enters from port 2 of the second circulator CIR2 and exits from port 3, and is injected into the Brillouin gain fiber SMF1, thereby triggering Brillouin gain amplification. Finally, stimulated Brillouin scattering and Rayleigh scattering are cycled to continuously perform Brillouin gain amplification. When the gain after Brillouin gain amplification is greater than the total loss in the ring cavity, random laser is generated.

[0077] In one embodiment, considering that the optical signal will gradually attenuate due to fiber loss and long-distance transmission, therefore, the method of splitting the pump light generated by the pump light source to obtain the first pump light beam and the second pump light beam can be specifically implemented as follows:

[0078] First, the original pump light is generated by the pump light source, where the wavelength of the original pump light is 980 nm. After that, the original pump light is injected into an erbium-doped fiber amplifier (EDFA) for optical signal amplification to obtain amplified pump light; finally, the amplified pump light is split to obtain the first pump light beam and the second pump light beam.

[0079] In the solution of this application, an erbium-doped fiber amplifier is used to amplify the originally generated pump light for optical signal amplification to compensate for transmission losses and extend the communication distance. In addition, random lasers are generated through stimulated Brillouin scattering and Rayleigh scattering, and true random numbers are generated using the unpredictability of the random lasers, thereby improving the security of data transmission.

[0080] Figure 2 FIG. is a schematic flow chart of an interference encryption method based on random lasers in an embodiment. It should be understood that although Figure 2 each step in the flow chart is shown in sequence according to the indication of the arrow, these steps do not necessarily have to be executed in the order indicated by the arrow; unless otherwise clearly stated in this article, the execution of these steps has no strict order restriction, and these steps can be executed in other orders; and Figure 2 at least a part of the steps in may include multiple sub-steps or multiple stages. These sub-steps or stages do not necessarily have to be executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages does not necessarily have to be in sequence, but can be executed alternately or alternately with at least a part of other steps or sub-steps or stages of other steps.

[0081] This specific embodiment is only an explanation of the present invention and does not limit the present invention. Those skilled in the art can make modifications without creative contributions to this embodiment after reading this specification, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

Claims

1. An interferometric encryption sensing method based on random laser, characterized in that: The method includes: Splitting the pump light generated by a pump light source to obtain a first pump light beam and a second pump light beam, and injecting the first pump light beam into a ring cavity to generate random laser light; Splitting the random laser light to obtain a first random laser beam and a second random laser beam; Emitting the first random laser beam onto a target surface, and generating a Doppler frequency shift signal based on the reflected light reflected by the target and the first random laser beam; Mixing the second random laser beam with the second pump light beam to generate a beat frequency signal, and converting it into a corresponding electrical signal; Processing the electrical signal through a spectrum analyzer and outputting a true random number; Processing the true random number and the Doppler frequency shift signal through an algorithm to generate ciphertext and transmitting it to a preset receiving end.

2. The method according to claim 1, characterized in that: The ring cavity includes a Brillouin gain fiber and a single-mode fiber; the injecting the first pump light beam into the ring cavity to generate random laser light includes: Injecting the first pump light beam into the Brillouin gain fiber to stimulate stimulated Brillouin scattering to generate Stokes light; Injecting the Stokes light into the single-mode fiber to stimulate Rayleigh scattering to generate Rayleigh scattered light; Injecting the Rayleigh scattered light into the Brillouin gain fiber to trigger Brillouin gain amplification; Cyclically performing stimulated Brillouin scattering and Rayleigh scattering to continuously perform Brillouin gain amplification. When the gain after Brillouin gain amplification is greater than the total loss in the ring cavity, random laser light is generated.

3. The method according to claim 1, wherein: The splitting the pump light generated by a pump light source to obtain a first pump light beam and a second pump light beam includes: Generating original pump light through a pump light source; Injecting the original pump light into an erbium-doped fiber amplifier to amplify the optical signal to obtain amplified pump light; Splitting the amplified pump light to obtain a first pump light beam and a second pump light beam.

4. The method according to claim 1, wherein: The generating a Doppler frequency shift signal based on the reflected light reflected by the target and the first random laser beam includes: Performing self-mixing interference on the reflected light reflected by the target and the first random laser beam to generate a Doppler frequency shift signal.

5. The method according to claim 1, wherein: The processing the electrical signal through a spectrum analyzer and outputting a true random number includes: Collecting, through the spectrum analyzer, the peak frequency signal at the peak of the random frequency within a preset frequency domain range of the electrical signal; Setting the collected peak frequency signal as the true random number.

6. The method according to claim 5, characterized in that: The preset frequency domain range is the range of the region where the frequency of the signal is greater than 10 GHz.

7. The method according to claim 1, characterized in that: The processing the true random number and the Doppler frequency shift signal through an algorithm to generate ciphertext and transmitting it to a preset receiving end includes: Converting the Doppler frequency shift signal into a binary representation; Performing an exclusive OR calculation on the Doppler frequency shift signal in binary representation and the true random number to generate ciphertext and transmitting it to a preset receiving end.

8. The method according to claim 1, wherein: The ratio of the first pump light beam to the second pump light beam is 9:1; the ratio of the first random laser beam to the second random laser beam is 5:

5.

9. An interferometric encryption sensing system based on random laser, for implementing the interferometric encryption sensing method based on random laser according to any one of claims 1-8, characterized in that: The system includes a random laser generation module, a sensing module, and a random number generation module; The random laser generation module is used to generate an original pump light, generate a random laser based on the original pump light, and split the random laser to obtain a first random laser beam and a second random laser beam; The sensing module is used to receive the first random laser beam and generate a Doppler frequency shift signal based on the first random laser beam; The random number generation module is used to receive the second random laser beam, generate a true random number based on the second random laser beam and the original pump light, and encrypt and transmit the Doppler frequency shift signal by using the true random number.

10. The system according to claim 9, characterized in that: The random laser generation module includes a pump light source, an erbium-doped fiber amplifier, a first optical circulator, a second optical circulator, a Brillouin gain fiber, a single-mode fiber, a first optical coupler and a second optical coupler; The pump light source is used to generate an original pump light; The erbium-doped fiber amplifier is connected to the pump light source and is used to receive the original pump light and amplify the optical signal; The first optical coupler is connected to the erbium-doped fiber amplifier and is used to split the amplified pump light to obtain a first pump light beam and a second pump light beam; The first optical circulator is connected to the first optical coupler and is used to control the transmission direction of the first pump light beam; The Brillouin gain fiber is connected to the first optical circulator and is used to receive the first pump light beam, stimulate stimulated Brillouin scattering and generate Stokes light; The second optical circulator is connected to the Brillouin gain fiber and the first optical circulator and is used to control the transmission direction of the Stokes light; The single-mode fiber is connected to the second optical circulator and is used to receive the Stokes light, stimulate Rayleigh scattering and generate Rayleigh scattering light; The second optical coupler is connected to the single-mode fiber and is used to split the generated random laser.

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