Heterodyne detection-based self-evaluation quantum random number generation system and method

Abstract

The invention discloses a heterodyne detection-based self-evaluation quantum random number generation system and method, and the method comprises the steps: extracting two corresponding orthogonal component fluctuations of a quantum state at the same time based on a heterodyne detection method, and enabling the two corresponding orthogonal component fluctuations to serve as an entropy source of a random number generator; two-component measurement original data is randomly extracted based on a synchronous clock to reconstruct quantum state phase space distribution in real time, entropy source safety is comprehensively evaluated, then the result is fed back to a hardware hash post-processing link, the scale of a Toeplitz matrix constructed in an FPGA is adjusted in real time, and the real-time safety of generated quantum moments is guaranteed; meanwhile, on the basis that quantum fluctuations of two orthogonal components of a quantum state are extracted at the same time to serve as entropy sources, multiple high-frequency quantum sideband modes in a balanced zero beat detection bandwidth are extracted in parallel from the two orthogonal components to serve as sub-entropy sources, and the quantum random number generation rate is doubled in a double parallel quantum entropy source extraction mode.

Description

Technical Field

[0001] The present invention belongs to the field of encryption technology, and in particular relates to a self-evaluation quantum random number generation system and method based on heterodyne detection. Background Art

[0002] Random numbers are the key to encryption protocols and fundamentally determine the privacy and security of information and communication systems. Quantum random number generators are the core components of quantum secure communication. Based on the intrinsic uncertainty of quantum physics, they have randomness that can be proven by information theory. In the past decade, relevant fields at home and abroad have conducted a lot of theoretical and experimental research on quantum random number generators, exploring a variety of quantum entropy sources to generate random numbers, such as photon arrival time, photon number statistics, quantum state component fluctuations, etc. The continuous variable quantum random number generator scheme based on the measurement of quantum state orthogonal component fluctuations can fully establish the physical model of quantum entropy source and quantum measurement process, and has the advantages of easy preparation of quantum state, high detection bandwidth, system robustness and strong integrability, etc. It has a particularly promising application prospect. The coherent detection method it adopts usually has two methods: homodyne detection and heterodyne detection. However, the generation rate of random numbers also has a bottleneck, which is restricted by detection bandwidth, spectrum gain, data transmission bandwidth, etc. This embodiment requires new considerations for the random number generator system.

[0003] On the other hand, the improvement of random number generation rate requires the premise that its security is guaranteed. If security is not guaranteed, the rate is meaningless. Any defects in the physical implementation of the quantum random number generator may leak information related to the generation of random numbers, the so-called side information. In the presence of side information, the fundamental security of quantum random numbers lies in the reconstruction and evaluation of the quantum characteristics of its entropy source. In previous random number generation schemes, the minimum entropy is usually evaluated once and for all, which cannot guarantee the security of QRNG. Summary of the invention

[0004] The purpose of the present invention is to provide a self-evaluation quantum random number generation system and method based on heterodyne detection to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides a self-evaluation quantum random number generation system based on heterodyne detection, comprising a heterodyne detection system and a host computer connected to the heterodyne detection system;

[0006] The heterodyne detection system comprises: a laser, an optical mixer, a balanced zero-beat detector and a host computer; the laser is used to emit laser light, the optical mixer is arranged on the laser emission optical path, the laser light is optically mixed by the optical mixer and then divided into four beams of split light, the four beams of split light are evenly divided into two groups according to a preset arrangement order, a balanced zero-beat detector and a power divider are arranged on the optical path corresponding to each group of beams of light, each group of beams of light is detected by the corresponding balanced zero-beat detector to obtain two electrical signals, and each electrical signal obtained is evenly distributed by the power divider to obtain a first signal and a second signal; a first signal processing unit is arranged on the first signal corresponding to each power divider, and a second signal processing unit is arranged on the second signal corresponding to each power divider;

[0007] The first signal processing unit and the second signal processing unit have the same structure, and both include a frequency mixing module, a low-pass filtering module, an analog-to-digital conversion module, and an FPGA module which are sequentially arranged on the light beam;

[0008] Each of the FPGA modules is correspondingly connected to a host computer.

[0009] Optionally, an optical attenuator and an optical fiber polarizer are sequentially arranged on the optical path between the laser and the optical mixer.

[0010] Optionally, the mixing module includes a plurality of mixers arranged in parallel, and adjacent mixers are connected via a signal generator.

[0011] Optionally, the low-pass filtering module includes a plurality of low-pass filters arranged in parallel.

[0012] Optionally, the FPGA module integrates a Toeplitz module and a DMA module which are arranged in series in sequence, the input ends of the Toeplitz module and the DMA module are connected to the analog-to-digital conversion module, the output end of the DMA module is connected to the KLD module via an AXI4 bus, and the KLD module is also connected to the host computer.

[0013] A self-evaluation quantum random number generation method based on heterodyne detection, applied to a self-evaluation quantum random number generation system based on heterodyne detection, comprising:

[0014] Step 1: Build and start the heterodyne detection system;

[0015] Step 2: Use the laser emitted by the laser as the local oscillator light and the vacuum state quantum entropy source as the signal light, mix the local oscillator light and the signal light through an optical mixer to obtain two mixed lights, use a balanced zero-beat detector to convert the corresponding mixed light into a photoelectric signal, and use a power divider to divide the photoelectric signal into several parts, mix the divided photoelectric signal with the radio frequency signal and filter it to obtain a filtered signal, so as to realize multi-band mode parallel extraction;

[0016] Step 3: Perform analog-to-digital conversion on the filtered signal using an analog-to-digital conversion module to obtain an original random sequence;

[0017] Step 4: In each clock cycle, the original random sequence is input into the FPGA module for post-processing, a data stream is constructed, and the data stream is transmitted to the host computer for channel analysis to obtain the original random number and the true random number, and the true random number is used as a control signal to trigger the clock for randomly extracting the original random number;

[0018] Randomly extract some original random numbers, perform quantum state reconstruction and quantum entropy content calculation to obtain relative entropy. When the relative entropy is outside the preset safety range, recalculate the relative entropy. When the relative entropy is within the preset safety range, continue to generate random numbers and perform subsequent steps.

[0019] Based on the relative entropy within the preset safety range, the Toeplitz matrix in the FPGA module is updated and the edge information is removed to obtain an updated FPGA module;

[0020] The original random sequence is post-processed according to the updated FPGA module to output secure quantum random numbers.

[0021] Optionally, the constructing of the data flow specifically includes:

[0022] Randomly extract some original random numbers, and construct a data stream with the extracted original random numbers and true random numbers according to a preset ratio.

[0023] Optionally, the quantum state reconstruction and quantum entropy content calculation specifically include:

[0024] Reconstruct the Husimi distribution of the vacuum state phase space based on the randomly drawn original random numbers;

[0025] The distance between the Husimi distribution in the phase space of the reconstructed vacuum state and the ideal distribution is calculated to obtain the relative entropy.

[0026] The technical effects of the present invention are:

[0027] (1) The present invention realizes the extraction of dual-component multi-channel parallel quantum entropy sources. Heterodyne detection can realize the synchronous detection of dual components, with higher quantum tomography reconstruction accuracy. In addition, by performing multi-band parallel processing on each component, dual or multiple entropy source extraction can be realized, thereby doubling the random number generation rate.

[0028] (2) The present invention realizes real-time quantum state holographic monitoring and entropy content calculation. First, the quantum fluctuations of the vacuum field are detected and amplified based on heterodyne detection, and the two orthogonal component quantum fluctuations detected are used as the entropy source of random numbers. The clocks of each FPGA module are synchronized, and true random numbers are used as control signals to trigger the clock for randomly extracting original random numbers. The original random numbers are used to reconstruct the phase space distribution of the quantum state in real time and evaluate the quantum entropy content in real time.

[0029] (3) The present invention realizes real-time entropy evaluation feedback. The relative entropy of the original random number is collected and calculated to measure the deviation between the entropy source quantum state and the pure quantum state. When the relative entropy fluctuates greatly, the quantum minimum entropy evaluation is performed again, and the evaluation result is fed back to the post-processing module in real time, ensuring the security of the random number generation process.

[0030] (4) The present invention realizes real-time adjustable hardware post-processing of the Toeplitz matrix scale. Based on the FPGA post-processing module, the Toeplitz matrix extractor can effectively remove the side information of the system. At the same time, the real-time entropy evaluation results are fed back in real time through the PCIe interface. The Toeplitz matrix scale can be adjusted in real time according to the feedback content to meet the requirements of real-time random number generation and uninterrupted post-processing, so that the system can still generate safe and reliable random numbers in real time based on the extraction ratio of quantum minimum entropy under the condition of quantum attack or unsafe entropy source. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0033] Figure 1 A schematic diagram of a self-evaluation quantum random number generation system of the present invention;

[0034] Figure 2The spectrum diagram of vacuum shot noise in the present invention and the two extracted frequency bands are used as entropy sources;

[0035] Figure 3 This is a flow chart of real-time entropy evaluation and matrix scale feedback of the present invention;

[0036] Figure 4 The KLD fluctuation diagram of the system of the present invention before and after being attacked by a thermal state;

[0037] Figure 5 It is the Husimi phase space fluctuation diagram of the system of the present invention before and after being attacked by the thermal state;

[0038] Figure 6 The various test diagrams that the random numbers generated by the present invention pass;

[0039] Explanation of reference numerals: 1. 1550nm LD-TC40 semiconductor laser; 2. Optical attenuator; 3. Optical fiber polarizer; 4. 90° optical mixer; 5. Balanced zero-beat detector; 6. Power divider; 7. Signal generator; 8. Mixer; 9. Low-pass filter; 10. Analog-to-digital converter; 11. Field programmable gate array; 12. Host computer. DETAILED DESCRIPTION

[0040] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0041] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0042] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those of ordinary skill in the art generally understood by the present invention. Although the present invention describes only preferred methods, any method similar or equivalent to that described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0043] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

[0044] The words “include,” “including,” “have,” “contain,” etc. used in this article are open-ended terms, meaning including but not limited to.

[0045] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0046] Embodiment 1

[0047] like Figure 1 - Figure 6 As shown, in this embodiment, a self-evaluation quantum random number generation system based on heterodyne detection is provided, including a heterodyne detection system and a host computer connected to the heterodyne detection system;

[0048] The heterodyne detection system comprises: a laser, an optical mixer, a balanced zero-beat detector and a host computer; the laser is used to emit laser light, the optical mixer is arranged on the laser emission optical path, the laser light is optically mixed by the optical mixer and then divided into four beams of split light, the four beams of split light are evenly divided into two groups according to a preset arrangement order, a balanced zero-beat detector and a power divider are arranged on the optical path corresponding to each group of beams of light, each group of beams of light is detected by the corresponding balanced zero-beat detector to obtain two electrical signals, and each electrical signal obtained is evenly distributed by the power divider to obtain a first signal and a second signal; a first signal processing unit is arranged on the first signal corresponding to each power divider, and a second signal processing unit is arranged on the second signal corresponding to each power divider;

[0049] The first signal processing unit and the second signal processing unit have the same structure, and both include a frequency mixing module, a low-pass filtering module, an analog-to-digital conversion module, and an FPGA module which are sequentially arranged on the light beam;

[0050] Each of the FPGA modules is correspondingly connected to a host computer.

[0051] A self-evaluation quantum random number generation method based on heterodyne detection, applied to a self-evaluation quantum random number generation system based on heterodyne detection, comprising:

[0052] Step 1: Build and start the heterodyne detection system;

[0053] Step 2: Use the laser emitted by the laser as the local oscillator light and the vacuum state quantum entropy source as the signal light, mix the local oscillator light and the signal light through an optical mixer to obtain two mixed lights, use a balanced zero-beat detector to convert the corresponding mixed light into a photoelectric signal, and use a power divider to divide the photoelectric signal into several parts, mix the divided photoelectric signal with the radio frequency signal and filter it to obtain a filtered signal, so as to realize multi-band mode parallel extraction;

[0054] Step 3: Perform analog-to-digital conversion on the filtered signal using an analog-to-digital conversion module to obtain an original random sequence;

[0055] Step 4: In each clock cycle, the original random sequence is input into the FPGA module for post-processing, a data stream is constructed, and the data stream is transmitted to the host computer for channel analysis to obtain the original random number and the true random number, and the true random number is used as a control signal to trigger the clock for randomly extracting the original random number;

[0056] Randomly extract some original random numbers, perform quantum state reconstruction and quantum entropy content calculation to obtain relative entropy. When the relative entropy is outside the preset safety range, recalculate the relative entropy. When the relative entropy is within the preset safety range, continue to generate random numbers and perform subsequent steps.

[0057] Based on the relative entropy within the preset safety range, the Toeplitz matrix in the FPGA module is updated and the edge information is removed to obtain an updated FPGA module;

[0058] The original random sequence is post-processed according to the updated FPGA module to output secure quantum random numbers.

[0059] This embodiment provides a high-speed real-time self-evaluation quantum random number generation method, comprising the following steps:

[0060] (1) First, the quantum fluctuations of the vacuum field are detected and amplified based on heterodyne detection, and the two orthogonal component quantum fluctuations detected simultaneously are used as the entropy source of continuous variable quantum random numbers.

[0061] (2) A true random number generator is used to extract a clock, and part of the original random numbers of the two components are randomly extracted for reconstructing and monitoring the quantum state, evaluating the quantum entropy content in real time, and feeding the evaluation results back to the post-processing module in real time.

[0062] (3) The scale of the FPGA-based Toeplitz matrix is ​​adjusted in real time based on the feedback to remove side information, so that the system can still generate safe and reliable random numbers in real time at the extraction ratio based on quantum minimum entropy even when it is under quantum attack or the entropy source is unsafe.

[0063] (4) The heterodyne detection system can realize the synchronous detection of two components. At the same time, by performing multi-band parallel processing on each component, a dual continuous variable quantum entropy source extraction is realized, which can increase the generation rate of continuous variable quantum random numbers in a highly integrated and scalable manner.

[0064] The generation system of the quantum random number can be implemented as follows: a heterodyne detection system of the light field vacuum state is built to extract vacuum quantum fluctuations as an entropy source for generating true random numbers. The vacuum state quantum entropy source is used as the signal input, and the single-mode semiconductor continuous laser is used as the local oscillator light source. The signal light and the local oscillator light pass through a 90° optical mixer, and are output and detected by two sets of symmetrical balanced zero-beat detection systems, respectively, and the two-component shot noise is photoelectrically converted and amplified respectively. The photocurrent signal obtained by the balanced zero-beat detection is divided into two or more parts by a power divider, and each part is mixed with a radio frequency signal of a certain frequency and filtered by a low-pass filter, thereby realizing the parallel extraction of the multi-band mode of the continuous variable quantum state. Then, the analog-to-digital converter performs analog-to-digital conversion to obtain the original random sequence. Finally, the FPGA is post-processed, and based on the channel parsing of the original sequence and the true random sequence, part of the original sequence is randomly extracted for quantum state reconstruction and quantum entropy content calculation, and is fed back to the post-processing module through entropy evaluation. The scale of the Toeplitz matrix constructed in the FPGA is adjusted in real time according to the feedback, and the secure quantum random number is generated in real time after the side information is removed.

[0065] The steps of the quantum state holographic monitoring are as follows: first, data acquisition is performed through ADC, and then the data is entered into FPGA for post-processing. A random number real-time high-speed transmission and feedback system is designed based on the high-speed interface PCIe, AXI4 bus, DMA control module and DDR4 cache. The post-processing is divided into parallel processing of multiple modules, and the clocks of each module are matched with each other. During the post-processing process, during the sampling operation of each clock cycle, the obtained true random numbers and part of the original random numbers are jointly formed into a data stream according to a specific ratio and written into a large-capacity cache DDR4 through the DMA module. The data is read from DDR4 through the AXI4 bus and transmitted to the host computer through the PCIe high-speed interface for channel parsing, and the original random numbers and true random numbers are parsed respectively. The original random sequence is used for holographic reconstruction of the phase space Husimi distribution of the vacuum state. In order to realize the post-processing process of real-time quantum state holographic monitoring and uninterrupted process.

[0066] The step of randomly extracting the original random number is feasible:

[0067] First, the trigger clock for randomly extracting the original random number is controlled by the true random number generated by post-processing. The true random number after Toeplitz post-processing is a continuous bit stream, from which the true random number is extracted as a control signal, which is combined with the counter in the controller to determine the timing and frequency of random extraction, and realize the random extraction of the original random number stored in the FIFO buffer queue.

[0068] The steps of real-time entropy evaluation feedback and real-time adjustment of matrix size are as follows: relative entropy KLD measures the distance between the real-time reconstructed entropy source phase space Husimi distribution and the ideal distribution. If the fluctuation of KLD is within a safe range, the system is considered safe and can continuously generate random numbers. When the KLD changes by more than a threshold, it is considered that the system is attacked by an enemy or disturbed by the environment, and the quantum conditional minimum entropy of the system is recalculated. The matrix size is changed according to the size of the minimum entropy, PCIe writes the new random seed into the memory of the FPGA, and writes the new matrix size into the register of the FPGA through the PCIe interface or the UART serial port. Finally, the Toeplitz module changes the matrix size according to the register value.

[0069] The dual parallel extraction process of the quantum entropy source is feasible as follows: first, the heterodyne detection system has a higher quantum tomography reconstruction accuracy and can realize the synchronous detection of the two components; the photocurrent signal converted by the detector can be divided into two or more parts by a power divider, and then mixed with the radio frequency signal and filtered by a filter to realize the multi-band mode parallel extraction of the fluctuation of the continuous variable quantum state component. This solution is scalable and highly integrated.

[0070] The high-speed real-time security self-assessment quantum random number generator adopts a quasi-real-time method, builds the clock synchronization of the post-processing module, randomly extracts the original random number in the time domain, and performs data processing by the host computer after channel analysis, reconstructs and evaluates the quantum entropy source state and entropy content of the quantum random number system, and realizes the post-processing uninterrupted real-time quantum random number generation. Comprehensively and rigorously guarantee the security of the quantum random number generator.

[0071] It can be implemented that the background light is a continuous wave laser output by a LD-TC40 semiconductor laser with a central wavelength of 1550nm;

[0072] The 90° optical mixer is a C-band HB-C2AFAS501 for mixing signal light and local light.

[0073] The radio frequency signal is generated by a HP8648A signal generator with a frequency range of 100kHz to 4000MHz.

[0074] The balanced detection uses two 1.6 GHz PDB480C-AC balanced detectors;

[0075] The filter is a ZFM-11+ mixer with a frequency range of 1MHz-2GHz and a BLP-100+ low-pass filter;

[0076] The field programmable gate array model uses Kintex UltraScale 115 FPGA as a hardware platform for post-processing.

[0077] The analog-to-digital converter ADC has a sampling rate of 1 GSPS, a sampling accuracy of 16 bits, and a model number of ADS54J60.

[0078] This embodiment realizes the multi-channel parallel quantum entropy source extraction of dual components. Heterodyne detection can realize the synchronous detection of dual components, with higher quantum tomography reconstruction accuracy. In addition, by performing multi-band parallel processing on each component, double or multiple entropy source extraction can be realized, which can increase the random number generation rate exponentially.

[0079] This embodiment realizes real-time quantum state holographic monitoring and entropy content calculation. First, the quantum fluctuations of the vacuum field are detected and amplified based on heterodyne detection, and the two orthogonal component quantum fluctuations detected are used as the entropy source of random numbers. The clocks of each FPGA module are synchronized, and the true random number is used as the control signal to trigger the clock for randomly extracting the original random number. The original random number is used to reconstruct the phase space distribution of the quantum state in real time and evaluate the quantum entropy content in real time.

[0080] This embodiment realizes real-time entropy evaluation feedback. The relative entropy of the original random number is collected and calculated to measure the deviation between the entropy source quantum state and the pure quantum state. When the relative entropy fluctuates greatly, the quantum minimum entropy evaluation is performed again, and the evaluation results are fed back to the post-processing module in real time, ensuring the security of the random number generation process.

[0081] This embodiment implements real-time adjustable hardware post-processing of the Toeplitz matrix scale. Based on the FPGA post-processing module, the Toeplitz matrix extractor can effectively remove the system's side information. At the same time, the real-time entropy evaluation results are fed back in real time through the PCIe interface. The Toeplitz matrix scale can be adjusted in real time according to the feedback content to meet the requirements of real-time random number generation and uninterrupted post-processing, so that the system can still generate safe and reliable random numbers in real time based on the extraction ratio of quantum minimum entropy under the condition of quantum attack or unsafe entropy source.

[0082] The specific implementation process of this embodiment includes:

[0083] Step 1: Build a heterodyne detection system for the light field vacuum state. Figure 1Schematic diagram of a high-speed real-time self-evaluation quantum random number generation system based on heterodyne detection in this embodiment, wherein the dotted line represents a multi-path parallel scheme and the dotted arrow represents a feedback loop; Figure 1 As shown, a 1550nm central wavelength LD-TC40 semiconductor laser 1 is used to continuously output continuous wave laser as the local oscillator light of the heterodyne detection system. The laser power is controlled by an attenuator 2, and a group of polarization controllers 3 cooperate to adjust the local oscillator light and inject it into a commercial 90° optical mixer module 4. The signal is input from the signal port, and two beams are split in the module respectively, one of which is delayed by 90° in phase and coupled with each other for interference. Before the light enters the optical mixer 4, the polarization controller is used to accurately adjust and control the orthogonal amplitude and orthogonal phase of the two components to make the input light intensity equal. After the output, two sets of Thorlabs PDB480C balanced zero-beat detectors 5 with symmetrical performance are used to detect respectively. The other input end of the optical mixer uses a vacuum state quantum entropy source as the signal input, and the signal light and the local oscillator light are coherent in the 90° optical mixer 4. By adjusting the parameters of the optical attenuator, polarization controller and other equipment, a synchronous dual-flux shot noise is prepared, and two integrals are measured simultaneously for dual-component detection, which has a higher random number generation rate.

[0084] Step 2: If Figure 1 As shown, the photocurrent output of the balanced zero-beat detector 5 is processed in parallel by the power divider 6, and mixed with the radio frequency signal by the ZFM-11+ mixer 8, and the radio frequency signal is generated by the HP8648A signal generator 7, in which two components are a group, so as to extract the quantum sideband mode of different center frequencies. Then it is filtered by the BLP-100+ low-pass filter 9 to meet the Nyquist double sampling law; and then the four-way entropy source is sampled and quantized by the analog-to-digital converter 10 with a sampling rate of 1GSPS and a sampling accuracy of 16 bits and a model ADS54J60.

[0085] Step 3: Before collecting the signal, you can also use a spectrum analyzer to observe the frequency domain information of the signal, such as Figure 2 As shown, it is the spectrum diagram of vacuum shot noise in this embodiment, and the figure extracts two frequency bands as entropy sources. Under the optimal sampling range of ADC, the original random sequences after sampling and quantization are input into FPGA respectively, and two independent post-processing channels are constructed in each FPGA to post-process the two groups of original random sequences. The random numbers generated by post-processing and the randomly extracted part of the original random sequences constitute the data stream in proportion and are written into the large-capacity high-speed cache DDR4 through the DMA module. The PCIe high-speed transmission module reads data from DDR4 through the AXI4 bus by means of interrupt response. The read data stream includes the post-processed data and the original random sequence of two channels. In this embodiment, it is necessary to perform channel parsing on the read data stream to obtain the randomly extracted original random sequence and the post-processed random number.

[0086] Step 4: Real-time entropy evaluation and feedback. The randomly extracted original random sequence is used to reconstruct the Husimi distribution of the vacuum state, and the KLD is used to measure the distance between the reconstructed distribution and the ideal distribution. The KLD relative entropy is used to measure the gap between the experimental vacuum state and the ideal vacuum state. By grasping the changes in the purity of the quantum state in real time, quantum attacks can be discovered in a timely manner. Figure 3 The process of randomly extracting original random numbers, real-time entropy evaluation, and matrix scale feedback is shown. If the fluctuation of KLD is within the safe range, the system is considered safe and can continue to generate random numbers. When the KLD changes beyond the threshold, the system's quantum conditional minimum entropy is recalculated. Figure 4 and Figure 5 As shown in the figure, the KLD fluctuation diagram before and after the system is attacked by the thermal state and the Husimi phase space fluctuation diagram before and after the system is attacked by the thermal state are respectively shown. At this time, PCIe writes the new random seed into the memory of FPGA and writes the new matrix scale into the register of FPGA through PCIe interface or UART serial port. Toeplitz module changes the matrix scale according to the register value.

[0087] Step 5: For the real-time entropy evaluation quantum random number generator, this embodiment needs to rigorously measure its security and find out possible security vulnerabilities. This embodiment performs a system performance test on data transmission and executes a complete workflow. Its security vulnerability time includes the specific time consumed by random number transmission, software reconstruction of quantum state distribution and matrix scale feedback adjustment in the real-time entropy evaluation quantum random number system, and identifies and minimizes the time bottleneck in the real-time evaluation feedback process of the quantum entropy source. In order to test the randomness of the random numbers generated in real time, the extracted random numbers are subjected to an offline randomness test on a computer to evaluate the quality of the post-processed random numbers. This embodiment uses the randomness test suite, DieHard test suite and Test U01 test suite provided by NIST. Figure 6 As shown, the random numbers generated by the real-time entropy evaluation quantum random number generator in this embodiment can all pass the test, indicating that the random numbers generated in the scheme of this embodiment have excellent randomness.

[0088] This embodiment realizes real-time quantum state monitoring based on heterodyne detection system, real-time entropy evaluation feedback and real-time adjustable Toeplitz matrix scale post-processing based on FPGA, and realizes a high-speed quantum random number generator through dual-component detection and multi-channel parallel. The original true random sequence is randomly collected to reconstruct the distribution of vacuum state Husimi function in phase space, and the relative entropy is used to measure the deviation. When the relative entropy exceeds the threshold, the minimum entropy is re-evaluated, and the evaluation result is fed back to the post-processing module in real time to adjust the real-time Toeplitz matrix scale, so that the system can still generate reliable and secure random numbers in real time under the condition of quantum attack or unsafe entropy source under the measurement based on pure quantum state. And based on rigorous security considerations, the security vulnerabilities of the system are fully calculated, which improves the security and practicality of the quantum random number generator.

[0089] The above is only a preferred specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A self-evaluating quantum random number generation system based on heterodyne detection, characterized in that: It includes a heterodyne detection system and a host computer connected to the heterodyne detection system; The heterodyne detection system comprises: a laser, an optical mixer, a balanced zero-beat detector and a host computer; The laser is used to emit laser light, and the optical mixer is arranged on the laser emission optical path. After the laser light passes through the optical mixer for optical mixing, it is divided into four beams of split light, and the four beams of split light are evenly divided into two groups according to a preset arrangement order. A balanced zero-beat detector and a power divider are arranged on the optical path corresponding to each group of beams of light. Each group of beams of light is detected by the corresponding balanced zero-beat detector to obtain two electrical signals. After the obtained electrical signals are evenly distributed by the power divider, a first signal and a second signal are obtained; a first signal processing unit is arranged on the first signal corresponding to each power divider, and a second signal processing unit is arranged on the second signal corresponding to each power divider; The first signal processing unit and the second signal processing unit have the same structure, and both include a frequency mixing module, a low-pass filtering module, an analog-to-digital conversion module, and an FPGA module which are sequentially arranged on the light beam; Each of the FPGA modules is correspondingly connected to a host computer.

2. A self-evaluation quantum random number generation system based on heterodyne detection according to claim 1, characterized in that: An optical attenuator and an optical fiber polarizer are arranged in sequence on the optical path between the laser and the optical mixer.

3. A self-evaluation quantum random number generation system based on heterodyne detection according to claim 1, characterized in that: The frequency mixing module includes a plurality of mixers arranged in parallel, and adjacent mixers are connected via a signal generator.

4. A self-evaluation quantum random number generation system based on heterodyne detection according to claim 1, characterized in that: The low-pass filtering module includes a plurality of low-pass filters arranged in parallel.

5. A self-evaluation quantum random number generation system based on heterodyne detection according to claim 1, characterized in that: The FPGA module integrates a Toeplitz module and a DMA module which are arranged in series in sequence. The input ends of the Toeplitz module and the DMA module are connected to the analog-to-digital conversion module. The output end of the DMA module is connected to the KLD module via the AXI4 bus. The KLD module is also connected to the host computer.

6. A self-evaluation quantum random number generation method based on heterodyne detection, applied to a self-evaluation quantum random number generation system based on heterodyne detection as claimed in any one of claims 1 to 5, characterized in that: include: Step 1: Build and start the heterodyne detection system; Step 2: Use the laser emitted by the laser as the local oscillator light and the vacuum state quantum entropy source as the signal light, mix the local oscillator light and the signal light through an optical mixer to obtain two mixed lights, use a balanced zero-beat detector to convert the corresponding mixed light into a photoelectric signal, and use a power divider to divide the photoelectric signal into several parts, mix the divided photoelectric signal with the radio frequency signal and filter it to obtain a filtered signal, so as to realize multi-band mode parallel extraction; Step 3: Perform analog-to-digital conversion on the filtered signal using an analog-to-digital conversion module to obtain an original random sequence; Step 4: In each clock cycle, the original random sequence is input into the FPGA module for post-processing, a data stream is constructed, and the data stream is transmitted to the host computer for channel analysis to obtain the original random number and the true random number, and the true random number is used as a control signal to trigger the clock for randomly extracting the original random number; Randomly extract some original random numbers, perform quantum state reconstruction and quantum entropy content calculation to obtain relative entropy. When the relative entropy is outside the preset safety range, recalculate the relative entropy. When the relative entropy is within the preset safety range, continue to generate random numbers and perform subsequent steps. Based on the relative entropy within the preset safety range, the Toeplitz matrix in the FPGA module is updated and the edge information is removed to obtain an updated FPGA module; The original random sequence is post-processed according to the updated FPGA module to output secure quantum random numbers.

7. A self-evaluation quantum random number generation method based on heterodyne detection according to claim 6, characterized in that: The data flow construction specifically includes: Randomly extract some original random numbers, and construct a data stream with the extracted original random numbers and true random numbers according to a preset ratio.

8. A self-evaluation quantum random number generation method based on heterodyne detection according to claim 6, characterized in that: The quantum state reconstruction and quantum entropy content calculation specifically include: Reconstruct the Husimi distribution of the vacuum state phase space based on the randomly drawn original random numbers; The distance between the Husimi distribution in the phase space of the reconstructed vacuum state and the ideal distribution is calculated to obtain the relative entropy.

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