Device and method for generating quantum random number based on time difference of arrival

Abstract

The invention discloses a device and a method for generating a quantum random number based on a time difference of arrival, and belongs to the field of information security. The device comprises at least two single-photon detection modules, a time measurement module and an entropy source extraction module, all the single-photon detection modules are connected with the time measurement module, the time measurement module is connected with the entropy source extraction module, and the single-photon detection modules are used for realizing avalanche detection signal output; the time measurement module is used for realizing time measurement of the avalanche detection signals and taking a time measurement difference value of different avalanche detection signals as an entropy source; and the entropy source extraction module is used for evaluating the minimum entropy and entropy extraction according to the entropy source, and finally outputting a quantum random number. According to the invention, the influence of post-pulse is overcome, and quantum random numbers with higher quality can be obtained.

Description

Technical Field

[0001] The present invention belongs to the field of information security, and in particular, relates to a device and method for generating quantum random numbers based on arrival time differences. Background Art

[0002] In quantum mechanics, the state of microscopic particles is probabilistic. A quantum bit (qubit) can be in a superposition of multiple states. When the quantum bit is measured, its state will randomly collapse to a certain state, and the result of each measurement is random and unpredictable. This randomness comes from the inherent unpredictability of the quantum system. Each measurement result is independent and cannot be predicted or controlled, overcoming the limitations of traditional random number generators.

[0003] Quantum random number generation technology has been widely used in many fields. In the field of simulation, it can be used to build a more realistic random number model and improve the accuracy and reliability of the simulation. In the field of cryptography, it can be used to generate security parameters such as encryption keys and digital signatures to improve the security of communications and data. Especially in the field of information security, high-quality random numbers are crucial to ensure communication and data security. Traditional random number generation methods often rely on complex algorithms and initial conditions, which are vulnerable to attacks and predictions. Therefore, for high security needs, quantum random number generation technology has unique advantages. Secondly, quantum random number generators can generate a large number of random numbers in a very short time, meeting the needs of modern information processing systems for high speed and high efficiency.

[0004] At present, the rate of random number generation is getting faster and faster. The main implementation schemes of quantum random number generators include: single photon path selection, single photon arrival time measurement, laser phase fluctuation measurement, vacuum state fluctuation, amplified spontaneous radiation and other schemes. In the existing single photon arrival time measurement scheme, the main technical indicators of single photon detection are: dark count, detection efficiency, and after-pulse probability. Detection efficiency and dark count have no effect on the minimum entropy of the entropy source, but the probability of after-pulse is related to the previous avalanche detection, which will lead to a decrease in the minimum entropy; in addition, the probability of after-pulse is related to the process, temperature, bias and material, which will also affect the accuracy of the minimum entropy evaluation of the entropy source. After-pulse is a unique feature of the Geiger mode of single-photon avalanche diodes. After the carrier avalanche of the single-photon avalanche diode occurs, some carriers will be retained in the trap of the multiplication layer. When these retained carriers are subsequently released, they will also trigger avalanche, resulting in erroneous counting. After-pulse is different from the dark count rate, and it is different from other thermal effects and tunneling effects. The dark count is random, and the after-pulse is strongly correlated. To this end, the present invention proposes a device and method for generating quantum random numbers based on arrival time differences. Summary of the invention

[0005] The present invention aims to overcome the shortcomings of the prior art and proposes a device and method for generating quantum random numbers based on arrival time differences to achieve the following purposes: to solve the problem of the reduction of minimum entropy caused by the pulse probability after the single-photon avalanche diode and the impact on the accuracy of minimum entropy evaluation, and to remove the temporal correlation of a single single-photon avalanche diode detection signal to obtain higher quality quantum random numbers.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a device for generating quantum random numbers based on arrival time differences, the device comprising at least two single-photon detection modules, a time measurement module, and an entropy source extraction module, all of the single-photon detection modules are connected to the time measurement module, and the time measurement module is connected to the entropy source extraction module, wherein the single-photon detection module is used to realize the output of avalanche detection signals; the time measurement module is used to realize the time measurement of the avalanche detection signal, and use the time measurement difference of different avalanche detection signals as an entropy source; the entropy source extraction module is used to evaluate the minimum entropy and entropy extraction according to the entropy source, and finally output a quantum random number.

[0007] Preferably, the single-photon detection module includes a bias voltage terminal, a quenching resistor, a single-photon avalanche diode and a sampling resistor, wherein one end of the quenching resistor is connected to the bias voltage terminal, and the other end is connected to the cathode of the single-photon avalanche diode; one end of the sampling resistor is grounded, and the other end is connected to the anode of the single-photon avalanche diode and the lead-out terminal serves as the output end of the avalanche detection signal.

[0008] Preferably, types of the single photon avalanche diode include avalanche diodes made of Si-based materials, avalanche diodes made of InGaAs / InP materials, and avalanche diodes made of SiGe materials.

[0009] Preferably, the single-photon avalanche diode supports incident external light source to cause single-photon avalanche diode avalanche, and the external light source includes a single-photon source and a weak coherent light source; the single-photon avalanche diode supports no external light source incident to cause single-photon avalanche diode avalanche,

[0010] Preferably, when the bias voltage is higher than the avalanche level of the single-photon avalanche diode, a carrier avalanche occurs in the single-photon avalanche diode. At this time, the sampling resistor converts the carrier avalanche current into a high-level output; then, after the carrier avalanche, the quenching resistor reduces the bias voltage across the single-photon avalanche diode through resistance voltage division to quench the carrier avalanche, and restores the single-photon avalanche diode to an operable state to wait for the next carrier avalanche. At this time, the output of the sampling resistor is a low level.

[0011] Preferably, the time measurement module implements the time measurement of the avalanche detection signal based on time digital conversion technology, and uses the time measurement difference of different avalanche detection signals as an entropy source. The time digital conversion technology includes time digital conversion technology based on counter, time digital conversion technology based on analog-to-digital conversion, delay line time digital conversion technology and vernier ring time digital conversion technology.

[0012] Preferably, the measurement time of the avalanche detection signal output by any single-photon detection module is recorded as a reference start time. Taking the reference start time as the starting point, before the next reference start time is generated, the measurement time of the avalanche detection signal output by any one of the remaining single-photon detection modules is recorded as the end time, and the difference time between the end time and the reference start time is calculated as the entropy source; when the next reference start time is generated, if no end time is generated, the reference start time is updated.

[0013] Preferably, the entropy source extraction module uses a post-processing algorithm to extract quantum random numbers, and the post-processing algorithm includes XOR processing, differential processing, Toeplitz hash matrix algorithm and secure hash algorithm.

[0014] At the same time, the present invention also proposes a method for generating quantum random numbers based on arrival time differences, which is applied to the above-mentioned device for generating quantum random numbers based on arrival time differences, and the method comprises the following steps:

[0015] S1. Any single photon detection module outputs an avalanche detection signal and transmits it to the time measurement module for time measurement. The corresponding measurement time is recorded as the reference start time.

[0016] S2, starting from the reference start time, waiting for the output of the avalanche detection signal of any one of the remaining single-photon detection modules, if the output of the avalanche detection signal is waited for, transmitting it to the time measurement module for time measurement, and the corresponding measurement time is recorded as the end time;

[0017] S3. If the output of the avalanche detection signal is not waited for before the next reference start time is generated, that is, the end time is not generated, the current reference start time is updated using the next reference start time;

[0018] S4, calculating the difference between the end time and the reference start time as the entropy source;

[0019] S5. Input the entropy source into an entropy source extraction module for minimum entropy evaluation and entropy extraction, and finally output a quantum random number.

[0020] The technical effect of the present invention is: in view of the influence of the post-pulse on the minimum entropy of the quantum random number scheme using a single-photon avalanche diode, the present invention proposes a device and method for generating quantum random numbers based on the arrival time difference, which is no longer based on the avalanche time of one avalanche diode as the entropy source, but uses the avalanche time difference of different avalanche diodes as the entropy source. Because the avalanche time of each avalanche diode is independent of the avalanche time of other avalanche diodes, the correlation between the front and rear avalanche times can be completely removed. In practical applications, when the process, temperature, bias voltage, and material all affect the size of the post-pulse, it is very difficult to estimate the minimum entropy at this time, which poses a hidden danger to the quality of random numbers. The present invention can obtain higher quality quantum random numbers without considering the influence of the post-pulse in the process of evaluating the minimum entropy of the entropy source. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a structural diagram of a device for generating quantum random numbers based on arrival time differences according to an embodiment of the present invention;

[0022] Figure 2 This is a structural diagram of a single photon detection module according to an embodiment of the present invention;

[0023] Figure 3 The present invention is a flowchart of a method for generating quantum random numbers based on arrival time differences according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The following is a further detailed description of the specific implementation of the present invention by describing the embodiments with reference to the accompanying drawings, with the purpose of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention and to facilitate its implementation. In order to make the technical solution of the present invention clearer, the present invention is explained by the following embodiments.

[0025] A device for generating quantum random numbers based on arrival time differences, such as Figure 1 As shown, the device includes at least two single-photon detection modules, a time measurement module, and an entropy source extraction module, all of which are connected to the time measurement module, and the time measurement module is connected to the entropy source extraction module, wherein the single-photon detection module is used to realize the output of the avalanche detection signal; the time measurement module is used to realize the time measurement of the avalanche detection signal, and use the time measurement difference of different avalanche detection signals as the entropy source; the entropy source extraction module is used to evaluate the minimum entropy and entropy extraction according to the entropy source, and finally output a quantum random number.

[0026] The single photon detection module of this embodiment is as follows: Figure 2As shown, the single-photon detection module includes a bias voltage terminal, a quenching resistor, a single-photon avalanche diode and a sampling resistor, wherein one end of the quenching resistor is connected to the bias voltage terminal, and the other end is connected to the cathode of the single-photon avalanche diode; one end of the sampling resistor is grounded, and the other end is connected to the anode of the single-photon avalanche diode and the lead-out terminal is used as the output end of the avalanche detection signal.

[0027] The working principle of the single-photon detection module is as follows: when the bias voltage is higher than the avalanche level of the single-photon avalanche diode, the single-photon avalanche diode undergoes carrier avalanche. At this time, the sampling resistor converts the carrier avalanche current into a high level as the output of the single-photon detection module; then, the role of the quenching resistor is to quench the avalanche diode after the avalanche, so that the single-photon avalanche diode is restored to a workable state. Specifically, after the carrier avalanche, the quenching resistor reduces the bias voltage at both ends of the single-photon avalanche diode through resistance voltage division, thereby suppressing the carrier avalanche to quench the carrier avalanche, and restoring the single-photon avalanche diode to a workable state, waiting for the next carrier avalanche. At this time, the output of the sampling resistor is a low level as the output of the single-photon detection module.

[0028] Specifically, the single-photon avalanche diode works in Geiger mode and can be gated or normally open to achieve single-photon avalanche detection signal output or dark count avalanche signal output, and the types of single-photon avalanche diodes in this embodiment include but are not limited to avalanche diodes made of Si-based materials, avalanche diodes made of InGaAs / InP materials, and avalanche diodes made of SiGe materials. That is, the present invention is applicable to various types of single-photon avalanche diodes and has a wide range of applications.

[0029] In this embodiment, the single-photon avalanche diode supports the incidence of an external light source to cause single-photon avalanche diode avalanche, and the external light source includes a single-photon source, a weak coherent light source, etc. At this time, the avalanche detection signal output by the single-photon detection module includes not only the carrier avalanche caused by photon incidence, but also the carrier avalanche caused by dark noise; the single-photon avalanche diode supports no external light source incidence to cause single-photon avalanche diode avalanche, and at this time, the avalanche detection signal output by the single-photon detection module only contains the carrier avalanche caused by dark noise.

[0030] In this embodiment, the time measurement module implements the time measurement of the avalanche detection signal based on the time digital conversion technology, and uses the time measurement difference of different avalanche detection signals as the entropy source. The time digital conversion technology includes the time digital conversion technology based on the counter, the time digital conversion technology based on the analog-to-digital conversion, the delay line time digital conversion technology and the vernier ring time digital conversion technology. The time digital conversion technology is a common technology of those skilled in the art, and the present invention will not be described in detail here.

[0031] In view of the influence of the post-pulse on the minimum entropy of the quantum random number scheme generated by the single-photon avalanche diode, the present invention no longer uses the avalanche time of one avalanche diode as the entropy source, but uses the difference in avalanche time of different avalanche diodes as the entropy source. Specifically, in the time measurement module of the present embodiment, the measurement time of the avalanche detection signal output by any single-photon detection module is recorded as the reference start time, and the reference start time is used as the starting point. Before the next reference start time is generated, the measurement time of the avalanche detection signal output by any of the remaining single-photon detection modules is recorded as the end time, and the difference between the end time and the reference start time is calculated as the entropy source; when the next reference start time is generated, if the end time is not generated, the reference start time is updated. The advantage of this is that the avalanche time of each avalanche diode is independent of the avalanche time of other avalanche diodes, so the correlation between the previous and next avalanche times can be completely removed, thereby overcoming the influence of the post-pulse. At the same time, the post-pulse is related to the process, temperature, bias voltage, and material, which will also affect the accuracy of the minimum entropy evaluation of the entropy source. However, the present invention does not need to consider the influence of the post-pulse in the process of evaluating the minimum entropy of the entropy source, thereby obtaining high-quality random numbers.

[0032] After obtaining the entropy source, the entropy source extraction module implements minimum entropy evaluation to determine the number of random number sequences, and uses a post-processing algorithm to extract quantum random numbers. The post-processing algorithm includes but is not limited to XOR processing, differential processing, Toeplitz hash matrix algorithm and secure hash algorithm.

[0033] The post-processing algorithms are all common techniques used by those skilled in the art and will not be described in detail in the present invention.

[0034] After removing the influence of the post-pulse on the quality of the entropy source, the entropy source extraction module can improve the minimum entropy of the entropy source and ultimately obtain higher quality quantum random numbers.

[0035] At the same time, the present invention also proposes a method for generating quantum random numbers based on arrival time differences, and the method is applied to the above-mentioned device for generating quantum random numbers based on arrival time differences, such as Figure 3 As shown, the method comprises the following steps:

[0036] S1. Any single photon detection module outputs an avalanche detection signal and transmits it to the time measurement module for time measurement. The corresponding measurement time is recorded as the reference start time.

[0037] S2, starting from the reference start time, waiting for the output of the avalanche detection signal of any one of the remaining single-photon detection modules, if the output of the avalanche detection signal is waited for, transmitting it to the time measurement module for time measurement, and the corresponding measurement time is recorded as the end time;

[0038] S3. If the output of the avalanche detection signal is not waited for before the next reference start time is generated, that is, the end time is not generated, the current reference start time is updated using the next reference start time;

[0039] S4, calculating the difference between the end time and the reference start time as the entropy source;

[0040] S5. Input the entropy source into an entropy source extraction module for minimum entropy evaluation and entropy extraction, and finally output a quantum random number.

[0041] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A device for generating quantum random numbers based on arrival time differences, characterized in that: The device includes at least two single-photon detection modules, a time measurement module, and an entropy source extraction module. All the single-photon detection modules are connected to the time measurement module, and the time measurement module is connected to the entropy source extraction module. The single-photon detection module is used to realize the output of avalanche detection signals; the time measurement module is used to realize the time measurement of the avalanche detection signal, and use the time measurement difference of different avalanche detection signals as an entropy source; the entropy source extraction module is used to evaluate the minimum entropy and entropy extraction according to the entropy source, and finally output a quantum random number.

2. The device for generating quantum random numbers based on arrival time difference according to claim 1, characterized in that: The single-photon detection module includes a bias voltage terminal, a quenching resistor, a single-photon avalanche diode and a sampling resistor, wherein one end of the quenching resistor is connected to the bias voltage terminal, and the other end is connected to the cathode of the single-photon avalanche diode; one end of the sampling resistor is grounded, and the other end is connected to the anode of the single-photon avalanche diode and a lead-out terminal is used as an output end of an avalanche detection signal.

3. The device for generating quantum random numbers based on arrival time difference according to claim 2, characterized in that: The types of the single photon avalanche diode include avalanche diodes made of Si-based materials, avalanche diodes made of InGaAs / InP materials, and avalanche diodes made of SiGe materials.

4. The device for generating quantum random numbers based on arrival time difference according to claim 2, characterized in that: The single-photon avalanche diode supports incident external light source to cause single-photon avalanche diode avalanche, and the external light source includes a single-photon source and a weak coherent light source; the single-photon avalanche diode supports no external light source incident to cause single-photon avalanche diode avalanche.

5. A device for generating quantum random numbers based on arrival time differences according to claim 2 or 3, characterized in that: When the bias voltage is higher than the avalanche level of the single-photon avalanche diode, a carrier avalanche occurs in the single-photon avalanche diode. At this time, the sampling resistor converts the carrier avalanche current into a high-level output; then, after the carrier avalanche, the quenching resistor reduces the bias voltage across the single-photon avalanche diode through resistance voltage division to quench the carrier avalanche, and restores the single-photon avalanche diode to an operable state to wait for the next carrier avalanche. At this time, the output of the sampling resistor is a low level.

6. The device for generating quantum random numbers based on arrival time difference according to claim 1, characterized in that: The time measurement module realizes the time measurement of the avalanche detection signal based on the time digital conversion technology, and uses the time measurement difference of different avalanche detection signals as the entropy source. The time digital conversion technology includes the time digital conversion technology based on the counter, the time digital conversion technology based on the analog-to-digital conversion, the delay line time digital conversion technology and the vernier ring time digital conversion technology.

7. A device for generating quantum random numbers based on arrival time differences according to claim 1 or 6, characterized in that: The measurement time of the avalanche detection signal output by any single-photon detection module is recorded as the reference start time. Taking the reference start time as the starting point, before the next reference start time is generated, the measurement time of the avalanche detection signal output by any one of the remaining single-photon detection modules is recorded as the end time. The difference time between the end time and the reference start time is calculated as the entropy source. When the next reference start time is generated, if no end time is generated, the reference start time is updated.

8. The device for generating quantum random numbers based on arrival time difference according to claim 1, characterized in that: The entropy source extraction module uses a post-processing algorithm to extract quantum random numbers, and the post-processing algorithm includes XOR processing, differential processing, Toeplitz hash matrix algorithm and secure hash algorithm.

9. A method for generating quantum random numbers based on arrival time differences, characterized in that: The method is applied to a device for generating quantum random numbers based on arrival time differences according to any one of claims 1 to 8, and the method comprises the following steps: S1. Any single photon detection module outputs an avalanche detection signal and transmits it to the time measurement module for time measurement. The corresponding measurement time is recorded as the reference start time. S2, starting from the reference start time, waiting for the output of the avalanche detection signal of any one of the remaining single-photon detection modules, if the output of the avalanche detection signal is waited for, transmitting it to the time measurement module for time measurement, and the corresponding measurement time is recorded as the end time; S3. If the output of the avalanche detection signal is not waited for before the next reference start time is generated, that is, the end time is not generated, the current reference start time is updated using the next reference start time; S4, calculating the difference between the end time and the reference start time as the entropy source; S5. Input the entropy source into an entropy source extraction module for minimum entropy evaluation and entropy extraction, and finally output a quantum random number.

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