A method and apparatus for generating source-device-independent quantum random numbers

Abstract

The application provides a source-device-independent quantum random number generation method and device, the method comprising: an untrusted light source device generating first photons and second photons; obtaining original random bits; performing second measurement on the first photons in a second preset proportion and the second photons in a third preset proportion, and performing time correlation coincidence calculation on the measurement results after discretization to generate a criterion, the criterion being used to determine whether a preset rule for generating quantum random numbers is established; if the criterion is less than 2, the preset rule is established, and conditional min-entropy is calculated; and quantum random numbers are extracted according to the original random bits and the conditional min-entropy. The application uses a modified entropy uncertainty relationship to calculate the conditional min-entropy, quantifies the true randomness of the system, extracts the original random bits to generate true random numbers, and solves the problems of a huge experimental scale, a very low generation rate of random bits and poor practicability of the current device-independent quantum random number.

Description

Technical Field

[0001] This application relates to the field of quantum random number generation technology, and in particular to a method and apparatus for generating quantum random numbers that are independent of source devices. Background Technology

[0002] Random numbers play a crucial role in many applications, such as cryptography, simulation, and basic scientific research. Pseudo-random number generators or classical random number generators can produce high-speed random bits that follow any random distribution; however, classical mechanics denies the existence of unpredictability, indicating that the random bits in these generators are inherently predictable. In contrast, quantum randomness stems from the principle of quantum superposition; therefore, quantum random number generators can produce true randomness, and their security can be rigorously verified by quantum mechanics. Currently realized optical quantum random number generators come in various types, with entropy sources including photon spatial patterns, time patterns, vacuum noise, and amplified spontaneous emission. Recently, high-speed, real-time, and integrated quantum random number generators have been developed for various applications in quantum information processing, such as quantum key distribution and delayed-choice experiments.

[0003] Mathematically, only statistical tests can be performed on random number sequences; it's difficult to directly provide criteria for verifying true randomness. Therefore, the true randomness of a random number generator can only be verified and calculated based on the essence of quantum mechanics. Currently, various quantum random number schemes with verifiable randomness have been implemented, categorized into several types according to the trustworthiness of the device. For a quantum random number generator with completely trustworthy equipment, randomness can be verified using classical minimum entropy. However, real-world devices are often imperfect and can leak marginal information that could be obtained by eavesdroppers to predict random bits, thus threatening the security of the quantum random number generator. The concept of device independence enables the evaluation of the performance of untrusted quantum devices, where the source and measurement are treated as a black box, relying solely on the observational statistics of the measurement results and conditional minimum entropy. Quantify randomness. It is the minimum number of bits required for attacker E to reconstruct measurement result X using the obtained marginal information; it is defined as... ,in It is the attacker's maximum probability of guessing random bits.

[0004] It should be noted that even without an eavesdropper, E will still affect the randomness of the system as an environment. Therefore, the introduction of minimum entropy is important and necessary, as it can provide true randomness computation even with imperfect or attacked devices. Device-independent random number generators offer the highest level of security, but this protocol requires performing a flawless Bell inequality measurement, which results in huge experimental scale, extremely low random bit generation rate, and poor practicality. Summary of the Invention

[0005] This application provides a method and apparatus for generating source device-independent quantum random numbers to solve the problems of large experimental scale, extremely low generation rate of random bits, and poor practicality of current device-independent quantum random number generation.

[0006] Firstly, this application provides a method for generating source-device-independent quantum random numbers.

[0007] A method for generating source-device-independent quantum random numbers includes: generating a first photon and a second photon using an untrusted light source device; obtaining an initial random bit, wherein the initial random bit is obtained by performing a first measurement on the first photon at a first preset ratio and then discretizing it, the first measurement being a measurement of the arrival time of the first photon; performing a second measurement on the first photon at a second preset ratio and the second photon at a third preset ratio, and performing time-correlation calculation on the measurement results after discretization to generate a criterion; the second measurement being a measurement of the arrival time of the first photon and the second photon after passing through a dispersive medium; the criterion being used to determine whether a preset rule for generating quantum random numbers is valid; if the criterion is less than 2, then the preset rule is valid, and a conditional minimum entropy is calculated; and extracting quantum random numbers based on the initial random bit and the conditional minimum entropy.

[0008] Furthermore, the quantum states of the first photon and the second photon are generated by a trustless source device.

[0009] Furthermore, the first preset ratio is the same as the second preset ratio, both being half the number of the first photons; the third preset ratio is half the number of the second photons.

[0010] Furthermore, the discretization accuracy is calculated using a first preset formula, which is:

[0011] ;

[0012] For discretization accuracy, It is the full width at half maximum (FWHM) of the coincidence peak obtained by performing time-correlated coincidence calculation on the results of the first measurement of the first photon and the second photon.

[0013] Furthermore, in the second measurement, the dispersion provided by the dispersion medium introduced during the transmission of the first photon and the second photon is equal in magnitude but opposite in sign, in order to verify the dispersion cancellation effect. The degree of entanglement between the first photon and the second photon is verified by the dispersion cancellation effect. According to the uncertainty principle of entropy, if an attacker obtains information from one of the photons, the entanglement will weaken or even disappear. Therefore, the security of an untrusted source device can be verified by verifying the entanglement.

[0014] Furthermore, the criterion is calculated using a second preset formula. The second preset formula is determined by the standard deviation of the coincidence peak obtained from the time-correlated coincidence calculation of the results of the second measurement performed by the first photon and the second photon, and the corresponding discretization accuracy. The criterion is used to verify the dispersion cancellation effect, and to authenticate the degree of temporal energy entanglement between the first photon and the second photon through the dispersion cancellation effect, so as to test the security of the source device.

[0015] Furthermore, the conditional minimum entropy is calculated using the modified entropy uncertainty relation and the third preset formula.

[0016] Furthermore, the modified entropy uncertainty relation improves the accuracy of quantum randomness by considering the problem of finite measurement range.

[0017] In a second aspect, this application provides a source device-independent quantum random number generation apparatus, the apparatus being used to perform a source device-independent quantum random number generation method as described in the first aspect, the apparatus comprising an electrically connected untrusted light source device, a trusted measurement device, and auxiliary devices;

[0018] The untrusted light source device is used to provide a first photon and a second photon. The untrusted light source device includes an electrically connected laser, a polarization controller, a first focusing component, a periodically polarized titanium-diffused lithium niobate waveguide crystal, a second focusing component, a polarization beam splitter, a first filter, a second filter, a first fiber coupler, and a second fiber coupler.

[0019] The reliable measurement device includes electrically connected: a first 50:50 fiber optic beam splitter, a second 50:50 fiber optic beam splitter, a first circulator, a positive dispersion chirped Bragg grating, a second circulator, a negative dispersion chirped Bragg grating, a first single-photon detector, a second single-photon detector, a third single-photon detector, and a fourth single-photon detector.

[0020] The auxiliary equipment includes an electrically connected computer device, a first output terminal, a second output terminal, a first circulator two-port, a first circulator three-port, a third output terminal, a fourth output terminal, a second circulator two-port, and a second circulator three-port.

[0021] Furthermore, the first photon and the second photon use a chirped Bragg grating as the dispersion medium, and the two photons enter the grating through different ports, introducing positive and negative dispersion respectively.

[0022] As can be seen from the above technical solutions, this application provides a method and apparatus for generating source-device-independent quantum random numbers. The method includes generating a first photon and a second photon using an untrusted light source device; obtaining original random bits, which are obtained by performing a first measurement on the first photon at a first preset ratio and then discretizing it; performing a second measurement on the first photon at a second preset ratio and the second photon at a third preset ratio, and performing time-correlation calculation on the measurement results after discretization to generate a criterion. The criterion is used to determine whether a preset rule for generating quantum random numbers is valid; if the criterion is less than 2, the preset rule is valid, and the conditional minimum entropy is calculated; and quantum random numbers are extracted based on the original random bits and the conditional minimum entropy. This application uses a modified entropy uncertainty principle to calculate the conditional minimum entropy, quantifies the true randomness of the system, extracts the original random bits, and generates true random numbers, solving the problems of large experimental scale, extremely low generation rate of random bits, and poor practicality of current device-independent quantum random number experiments. At the same time, the modified entropy uncertainty principle considers the impact of the finite measurement range, improving the security of the system. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a flowchart illustrating the generation method of source device-independent quantum random numbers in the embodiments of this application;

[0025] Figure 2 This is a schematic diagram of the principle of the source device-independent quantum random number generation device in the embodiments of this application. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. The technical solutions provided by each embodiment of this application will be described in detail below with reference to the accompanying drawings.

[0027] In recent years, semi-device-independent random number generators have been proposed. These protocols selectively trust certain devices, such as source devices, measurement settings, system dimensions, or energy. Based on these trusted devices, the scale of experiments is simplified, balancing security and practicality.

[0028] Given the current limitations of device-independent quantum random number experiments, such as their enormous scale, extremely low random bit generation rate, and poor practicality, this application provides a method for generating source device-independent quantum random numbers. The process includes the following steps: An untrusted light source device generates a first photon and a second photon; raw random bits are obtained, which are obtained by performing a first measurement on the first photon at a first preset ratio and then discretizing it (for example, raw random bits can be understood as converting the measurement result into a binary string of 010100, which is an unextracted random number, meaning that part of the string is not random or classically random, and needs to be extracted to be entirely quantum random numbers). The first measurement is the measurement of the arrival time of the first photon; a second measurement is performed on the first photon at a second preset ratio and the second photon at a third preset ratio, and the measurement results are discretized and time-correlation calculations are performed to generate a criterion; the second measurement is the measurement of the arrival time of the first and second photons after passing through a dispersive medium; the criterion is used to determine whether the preset rule for generating quantum random numbers is valid; if the criterion is less than 2, the preset rule is valid, and the conditional minimum entropy is calculated; quantum random numbers are extracted based on the raw random bits and the conditional minimum entropy.

[0029] A random number generator consists of a source device and a measurement device. The source device generates a quantum state, and the measurement device measures it to generate random numbers. In this embodiment, "source device independent" means that the form of the quantum state generated by the source device does not need to be trusted. Instead, the quantum state is tested through trusted measurements to generate random quantum numbers. This quantum state could be provided by an attacker.

[0030] To facilitate a further understanding of the above methods, the steps will be described in detail below with reference to actual embodiments.

[0031] Figure 1 This is a flowchart illustrating the generation method of source device-independent quantum random numbers in an embodiment of this application. An untrusted light source device generates two photons: a first photon and a second photon. Assuming the first photon is A and the second photon is B, the untrusted light source device generates two photons A and B. The relationship between the two photons is unknown, and the two photons are different. The untrusted light source device is composed of untrusted devices and can be influenced by the surrounding environment, or even influenced or controlled by an attacker.

[0032] It should be noted that the quantum states of the first and second photons are generated by a trustless source device. Therefore, this embodiment of the application can authenticate the true randomness of the source device and extract quantum random numbers without requiring trust in the source device. The reason is as follows: if the source device is attacked, imperfect, or damaged, it cannot generate good quantum states, resulting in compromised randomness in the generated original bits, which may contain pseudo-random numbers. The method in this embodiment can detect the source device through reliable measurements, thereby authenticating the magnitude of true randomness in the original bits, and then extracting the original bits to ensure that the final generated random bits are truly quantum random numbers.

[0033] After two photons A and B are generated, each photon undergoes either a first measurement or a second measurement using a reliable measurement device. For ease of description, the first measurement can be denoted as the T measurement, which directly measures the photon's arrival time. The second measurement is denoted as the W measurement, which measures the arrival time after the photon has passed through a dispersive element. The T and W measurements are incompatible. The photons are emitted in pulses with a fixed repetition rate, and the probability of their arrival times follows a Gaussian distribution. A single measurement result occurs at any time within this Gaussian distribution.

[0034] After performing a T-measurement or W-measurement on each photon using a reliable measurement device, the measurement results are discretized. The precision used in the discretization is called the time precision. The corresponding measurement operator is written as and After discretization, binary encoding is performed to form the original bits. It should be noted that photons A and B are of equal status, and the measurement result of either one can be selected to generate the original random bits.

[0035] For example, photon A can be used to perform... The measurement results are used as the original random sequence. Two photons, A and B... The measurement results are used to perform time-correlation calculations to determine the correlation between two photons, and a criterion is calculated and expressed as follows: Time-correlated coincidence calculation is a calculation of time correlation, which can explain the magnitude of the time correlation between two photons. This reflects the magnitude of the dispersion cancellation effect (which can verify the temporal energy entanglement of two photons), i.e., the degree of entanglement between the two photons, and is therefore set as a criterion. The criterion is used to determine whether the preset rules for generating quantum random numbers are valid. If the preset rules are satisfied, the corresponding program is executed according to the preset rules.

[0036] In practical scenarios, the criterion can have a certain numerical range. For example, if the criterion is less than 2, the preset rule is valid. The preset rule can also be understood as a kind of protocol. If the preset rule is met, the protocol is executed. When the protocol is valid, the conditional minimum entropy is calculated (the minimum entropy is the number of purely random bits contained in a random variable). Quantum random numbers are extracted based on the original random bits and the conditional minimum entropy, that is, random numbers are generated by post-processing the original bits. In the original random bits, there may be some non-random or classical random numbers, which need to be removed. The conditional minimum entropy can obtain the proportion of truly quantum randomness, thus extracting true randomness from the original bits.

[0037] If the criterion A value greater than or equal to 2 indicates a protocol failure, meaning the random number generator failed to run and the device needs to be checked and restarted. In other words, If the value is less than 2, then this method is considered to be able to generate random numbers that meet the requirements. If the value is greater than 2, the condition is considered unsatisfactory, and the process stops. It should be noted that when... A value greater than or equal to 2 does not mean that the original bits are completely free of randomness. They may contain a small amount of randomness, but from a practical point of view, we believe it is unnecessary to spend resources to extract them.

[0038] In some embodiments, the first preset ratio and the second preset ratio are the same, both being half the number of the first photons; the third preset ratio is half the number of the second photons. That is, the ratio of T measurement and W measurement performed by each photon is 1:1 (in this embodiment, the photons can be pre-divided into two parts, one part is used to generate random numbers, and the other part is used for detection), in which case the maximum number of truly random numbers can be generated.

[0039] After performing T or W measurements on each photon using a reliable measurement device, and discretizing the measurement results, the discretization accuracy is calculated using a first preset formula, which is:

[0040] ;

[0041] in, For discretization accuracy, It is the full width at half maximum (FWHM) of the coincidence peak obtained by time-correlated coincidence calculation of the results of the first measurement of the first and second photons. The corresponding measurement operator is written as... and .

[0042] Photon A The measurement results are encoded into binary as raw random bits and stored for two photons. The measurement results are time-correlated consistency calculations, and the dispersion cancellation effect is used to verify the entanglement quality of the two photons and test the security of the source device. In one implementation, a criterion is used. The criterion for determining whether the protocol passes is calculated using a second preset formula. This second preset formula is determined by the standard deviation of the coincidence peaks obtained from the time-correlated coincidence calculation of the results of the second measurement performed by the first and second photons, and the corresponding discretization precision. In other words, this application calculates the criterion... The value of is used to determine whether the protocol is successful. This criterion is used to verify the dispersion cancellation effect, authenticating the temporal energy entanglement of the first and second photons to test the security of the source device. For example, using... Taking measurement as an example, the formula can be expressed as follows:

[0043] ;

[0044] in It is performed by two photons. The standard deviation of the coincidence peak, calculated using time-correlated coincidence analysis of the measurement results, reflects the magnitude of the dispersion cancellation effect. If... A value greater than or equal to 2 indicates a protocol failure, reflecting that the impact of the environment or attacker on the source device has exceeded the acceptable range. In this case, the source device needs to be modified and restarted. If the value is less than 2, the preset rule is valid, indicating that the protocol is passed and the minimum entropy is calculated.

[0045] In one implementation, the conditional minimum entropy is calculated using a modified entropy uncertainty relation and a third pre-defined formula. For example, the conditional minimum entropy is calculated based on measurement results. The conditional minimum entropy reflects the magnitude of true randomness in each measurement result when the light source device is unreliable. In some embodiments, a third preset formula for calculating the conditional minimum entropy using a modified entropy uncertainty relation can be:

[0046] ;

[0047] in, ( ) is A photon execution ( Measurement and discretization accuracy is The operator corresponding to the result; E is the attacker. Is execution ( The probability that the actual result is outside the measurement range during measurement. It's an incompatibility between the two measurements. It is the system's maximum entropy.

[0048] Once the conditional minimum entropy is determined, the stored original random bits are extracted based on the conditional minimum entropy. Then, the obtained random bits are subjected to NIST standard tests and autocorrelation tests to verify statistical randomness. If the tests pass, the final true random number sequence can be output.

[0049] In this embodiment, the advantage of using the modified entropy uncertainty relation to calculate the conditional minimum entropy is that the modified entropy uncertainty relation can improve the accuracy of quantum randomness by considering the problem of finite measurement range. The modified entropy uncertainty principle takes into account the impact of the finite measurement range problem, thus improving the system's security.

[0050] It should be noted that in the second measurement, the dispersion medium introduced during the transmission of the first and second photons provides equal magnitudes and opposite signs of dispersion to verify the dispersion cancellation effect. The degree of entanglement between the first and second photons is verified by the dispersion cancellation effect. According to the entropy uncertainty relation, if an attacker obtains information from one of the photons, the entanglement will weaken or even disappear. Therefore, the security of an untrusted source device can be verified by verifying the entanglement.

[0051] Based on the above-mentioned method for generating source-device-independent quantum random numbers, see [link to relevant documentation]. Figure 2 , Figure 2 This is a schematic diagram illustrating the principle of a source-device-independent quantum random number generation device according to an embodiment of this application. Another embodiment of this application also provides a source-device-independent quantum random number generation device. This device is used to execute a method for generating source-device-independent quantum random numbers. The device includes an electrically connected untrusted light source device 01, a trusted measurement device 02, and an auxiliary device 03.

[0052] An untrusted light source device 01 is used to provide two photons, namely, a first photon and a second photon. The untrusted light source device 01 includes an electrically connected laser 011, a polarization controller 012, a first focusing element 013, a periodically polarized titanium-diffused lithium niobate waveguide crystal 014, a second focusing element 015, a polarization beam splitter 016, a first filter 017, a second filter 018, a first fiber coupler 019, and a second fiber coupler 010.

[0053] The reliable measurement device 02 includes an electrically connected first fiber 50:50 beam splitter 021, a second fiber 50:50 beam splitter 022, a first circulator 023, a positive dispersion chirped Bragg grating 024, a second circulator 025, a negative dispersion chirped Bragg grating 026, a first single-photon detector 027, a second single-photon detector 028, a third single-photon detector 029, and a fourth single-photon detector 020;

[0054] Auxiliary equipment 03 (the entire scope of auxiliary equipment 03 is not delineated in the figure for clarity and neatness) includes electrically connected computer equipment 031, first output terminal 032, second output terminal 033, first circulator two-port 034, first circulator three-port 035, third output terminal 036, fourth output terminal 037, second circulator two-port 038, and second circulator three-port 039.

[0055] Combination Figure 2 In specific implementation, the pump laser generated by laser 011 is polarized by polarization controller 012 and then injected into a periodically polarized titanium-diffused lithium niobate waveguide crystal 014 through first focusing component 013. For example, two parametric photons are generated through a type-II spontaneous parametric down-conversion process, i.e., a high-brightness entangled photon pair is generated (which is beneficial for improving random number generation and reducing energy consumption). After generating the high-brightness two-photon pair, the two photons are collected by second focusing component 015, and then separated by polarization beam splitter 016. The transmitted and reflected photons pass through first filter 017 and second filter 018 respectively, and are then collected into the optical fiber by first fiber coupler 019 and second fiber coupler 010 (i.e., each photon is filtered and then coupled into the optical fiber through the fiber coupler), forming an unreliable two-photon state. The transmitted photon is labeled as photon A, and the reflected photon is labeled as photon B, as follows. Figure 2 As shown.

[0056] A photon collected by fiber optic couplers such as the first fiber optic coupler 019 and the second fiber optic coupler 010 enters the first 50:50 fiber optic beam splitter 021, and B photon enters the second 50:50 fiber optic beam splitter 022. The first output terminal 032 of the first fiber optic beam splitter 021 is connected to the first single-photon detector 027 to perform T measurement on the A photon; the second output terminal 033 is connected to the first circulator 023, the first circulator port 034 of the first circulator 023 is connected to the positive dispersion chirped Bragg grating 024, and the first circulator port 035 is connected to the second single-photon detector 028 to perform W measurement on the A photon. The third output terminal 036 of the second fiber 50:50 beam splitter 022 is connected to the third single-photon detector 029 to perform T measurement on B photons; the fourth output terminal 037 is connected to the second circulator 025, the second circulator two-port 038 of the second circulator 025 is connected to the negative dispersion chirped Bragg grating 026, and the second circulator three-port 039 is connected to the fourth single-photon detector 020 to perform W measurement on B photons.

[0057] In this embodiment, a photon provided by an untrusted light source device 01 is connected to a first fiber optic 50:50 beam splitter 021. The first output end 032 of the first fiber optic 50:50 beam splitter 021 is connected to a first single-photon detector 027 to achieve T measurement of the photon. The other output end, the second output end 033, is connected to a dispersive medium through a first circulator 023 and detected by a second single-photon detector 028 to achieve W measurement of the photon. The measurement method for the other photon is based on the same principle as described above and will not be repeated here. In some embodiments, a chirped Bragg grating is used as the dispersive medium for the first and second photons. The ports through which the first and second photons enter the grating are different; the first photon introduces positive dispersion, and the second photon introduces negative dispersion.

[0058] exist Figure 2 In this configuration, the first single-photon detector 027, the second single-photon detector 028, the third single-photon detector 029, and the fourth single-photon detector 020 are all electrically connected to computer equipment 031. Computer equipment 031 is a post-processing device used to acquire the measurement signals from the four detectors and perform discretization processing, with a discretization accuracy of [insert accuracy here]. In this way, the detector results can be fed back to the computer device 031 in real time. Specifically, the output results of the first single-photon detector 027 and the third single-photon detector 029 are the results of two photons performing T measurement, respectively, and the output results of the second single-photon detector 028 and the fourth single-photon detector 020 are the measurement results of two photons performing W measurement, respectively.

[0059] In the specific implementation, computer device 031 reads and discretizes the detector signal, using the result of measurement T performed by photon A as the original random bits. The result of measurement W performed by two photons is used to calculate the criterion d to determine the success of the protocol. If successful, the system's randomness is calculated using the modified entropy uncertainty relation. Compared to the original form, which considers the problem of finite measurement range, this method calculates quantum randomness more accurately. By calculating the minimum entropy, the original random bits are extracted and further subjected to NIST standard tests and autocorrelation tests. If the tests pass, it indicates that truly random numbers have been generated; if unsuccessful, the source device needs to be checked and restarted.

[0060] In some embodiments, the first focusing element 013 and the second focusing element 015 are composed of aspherical mirrors, wherein the lens of the first focusing element 013 can be coated with a pump laser band antireflection coating, and the lens of the second focusing element 015 can be coated with a parametric photon band antireflection coating. In some embodiments, a high-brightness two-photon source can be generated using a periodically polarized titanium-diffused lithium niobate waveguide crystal 014 through a spontaneous parametric down-conversion process.

[0061] In the source-device-independent quantum random number generation device of this application embodiment, there is no need to trust the source device; a trusted measurement device 02 can be used to verify the source device. Specifically, the dispersion cancellation effect is used to verify the temporal energy entanglement of two photons. The tighter the entanglement between the two photons, the closer the two-photon state is to an ideal quantum state, and the less information an adversary can obtain, thus ensuring the security and randomness of the source device. Verifying the dispersion cancellation effect demonstrates that the two photons have a quantum correlation, specifically temporal energy entanglement. If an attacker obtains information from one of the photons, the entanglement will weaken or even disappear. Therefore, verifying the entanglement verifies the security of the untrusted source device.

[0062] In this embodiment, two photons are generated using an untrusted light source device 01. Trusted T and W measurements are performed on the two photons. The result of the T measurement on a single photon is used as the original random bit, and the result of the W measurement on both photons is used to verify the dispersion cancellation effect, thereby verifying the temporal energy entanglement of the two photons. The true randomness of the system is quantified by a modified entropy uncertainty relation, and the original random bit is extracted to generate truly random numbers. This solves the problems of the current device-independent quantum random number experiments being large-scale, having extremely low random bit generation rates, and poor practicality.

[0063] The source-device-independent quantum random number generator in this application does not require any assumptions about the light source equipment; system security testing and entropy calculation are performed solely through a trusted measurement device 02. This application can verify the randomness of the system without trusting the quality of the two-photon source, balancing system security and practicality. It provides more possibilities for the fabrication of high-speed and secure random number generators, thereby promoting the development of quantum information security.

[0064] As can be seen from the above technical solutions, this application provides a method and apparatus for generating source-device-independent quantum random numbers. The method includes generating a first photon and a second photon using an untrusted light source device; obtaining original random bits, which are obtained by performing a first measurement on the first photon at a first preset ratio and then discretizing it; performing a second measurement on the first photon at a second preset ratio and the second photon at a third preset ratio, and performing time-correlation calculation on the measurement results after discretization to generate a criterion. The criterion is used to determine whether a preset rule for generating quantum random numbers is valid; if the criterion is less than 2, the preset rule is valid, and the conditional minimum entropy is calculated; and extracting quantum random numbers based on the original random bits and the conditional minimum entropy. This application uses a modified entropy uncertainty relation to calculate the conditional minimum entropy, quantifies the true randomness of the system through the modified entropy uncertainty relation, extracts the original random bits, and generates true random numbers, solving the problems of large experimental scale, extremely low generation rate of random bits, and poor practicality of current device-independent quantum random number experiments. At the same time, the modified entropy uncertainty principle considers the impact of the finite measurement range problem, improving the security of the system.

[0065] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein.

[0066] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for generating source-device-independent quantum random numbers, characterized in that, include: Unreliable light source devices produce the first and second photons; Obtain the original random bits, which are obtained by performing a first measurement on the first photon of a first preset ratio and then discretizing the measurement. The first measurement is the measurement of the arrival time of the first photon. A second measurement is performed on the first photon at a second preset ratio and the second photon at a third preset ratio. The measurement results are then discretized and time-correlation calculations are performed to generate a criterion. The second measurement is the measurement of the arrival time of the first photon and the second photon after passing through the dispersive medium. The criterion is used to determine whether the preset rule for generating quantum random numbers is valid. The criterion is calculated using a second preset formula. The second preset formula is determined by the standard deviation of the coincidence peak and the corresponding discretization accuracy obtained by time correlation coincidence calculation based on the results of the second measurement performed by the first photon and the second photon. The criterion is used to verify the dispersion cancellation effect and to authenticate the degree of time-energy entanglement between the first photon and the second photon through the dispersion cancellation effect, so as to test the security of the source device. If the criterion is less than 2, then the preset rule is valid, and the conditional minimum entropy is calculated. Quantum random numbers are extracted based on the original random bits and the conditional minimum entropy.

2. The method for generating source device-independent quantum random numbers according to claim 1, characterized in that, The quantum states of the first photon and the second photon are generated by a trustless source device.

3. The method for generating source device-independent quantum random numbers according to claim 1, characterized in that, The first preset ratio is the same as the second preset ratio, both being half the number of the first photons; the third preset ratio is half the number of the second photons.

4. The method for generating source device-independent quantum random numbers according to claim 1, characterized in that, The discretization accuracy is calculated using a first preset formula, which is: ； For discretization accuracy, It is the full width at half maximum (FWHM) of the coincidence peak obtained by performing time-correlated coincidence calculation on the results of the first measurement of the first photon and the second photon.

5. The method for generating source device-independent quantum random numbers according to claim 1, characterized in that, In the second measurement, the dispersion provided by the dispersion medium introduced during the transmission of the first photon and the second photon is equal in magnitude but opposite in sign, in order to verify the dispersion cancellation effect and to authenticate the degree of entanglement between the first photon and the second photon through the dispersion cancellation effect.

6. The method for generating source device-independent quantum random numbers according to claim 4, characterized in that, The degree of entanglement between two photons can be determined based on a criterion, which is the magnitude of the temporal energy entanglement between the two photons; the criterion is calculated based on a second preset formula, which is: ； in, It is performed by two photons. The standard deviation of the coincidence peaks was obtained by time-correlated coincidence calculation of the measurement results. The precision used to discretize the results of the second measurement of the first photon and the second photon. This is a criterion that reflects the magnitude of the dispersion cancellation effect.

7. The method for generating source device-independent quantum random numbers according to claim 1, characterized in that, The conditional minimum entropy is calculated using the modified entropy uncertainty relation and the third preset formula. The third preset formula for calculating the conditional minimum entropy using the modified entropy uncertainty relation is as follows: ； in, ( ) is A photon execution ( Measurement and discretization accuracy is The operator corresponding to the result; E is the attacker. It is execution ( The probability that the actual result is outside the measurement range during measurement. It's an incompatibility between the two measurements. It is the system's maximum entropy.

8. The method for generating source device-independent quantum random numbers according to claim 7, characterized in that, The modified entropy uncertainty relation improves the accuracy of quantum randomness by taking into account the problem of finite measurement range.

9. A source device-independent quantum random number generation device, characterized in that, The apparatus is used to perform a method for generating a source device-independent quantum random number as described in any one of claims 1-8, the apparatus comprising an electrically connected untrusted light source device (01), a trusted measurement device (02), and an auxiliary device (03). The untrusted light source device (01) is used to provide a first photon and a second photon. The untrusted light source device (01) includes an electrically connected laser (011), a polarization controller (012), a first focusing element (013), a periodically polarized titanium diffused lithium niobate waveguide crystal (014), a second focusing element (015), a polarization beam splitter (016), a first filter (017), a second filter (018), a first fiber coupler (019), and a second fiber coupler (010). The reliable measuring device (02) includes electrically connected: a first fiber 50:50 beam splitter (021), a second fiber 50:50 beam splitter (022), a first circulator (023), a positive dispersion chirped Bragg grating (024), a second circulator (025), a negative dispersion chirped Bragg grating (026), a first single-photon detector (027), a second single-photon detector (028), a third single-photon detector (029), and a fourth single-photon detector (020); The auxiliary device (03) includes an electrically connected computer device (031), a first output terminal (032), a second output terminal (033), a first circulator two-port (034), a first circulator three-port (035), a third output terminal (036), a fourth output terminal (037), a second circulator two-port (038), and a second circulator three-port (039).

10. The source device-independent quantum random number generation device according to claim 9, characterized in that, The first photon and the second photon use a chirped Bragg grating as the dispersion medium; the first photon and the second photon enter the grating at different ports, the first photon introduces positive dispersion, and the second photon introduces negative dispersion.

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