Random number generator

Abstract

The embodiment of the invention provides a random number generator. The random number generator comprises a laser light source, a processing device and a detection device, the laser light source comprises a laser; the laser is used for providing pulse signals; the processing device comprises a beam splitting module and a delay processing module; wherein the beam splitting module is used for sequentially splitting light pulses in a pulse signal into multiple paths of sub-pulse signals after the pulse signal is attenuated; the delay processing module is used for carrying out delay processing on the multiple paths of sub-pulse signals and then carrying out beam combination on the multiple paths of sub-pulse signals in sequence to generate a pulse sequence; and the detection device is used for receiving the pulse sequence and generating a random number according to the digital information corresponding to the detected time window of the photons in the pulse sequence.

Description

Technical Field

[0001] The present disclosure relates to the field of cryptographic security, and in particular to a random number generator. Background Art

[0002] Quantum Random Number Generator (QRNG) uses quantum physics phenomena to generate unpredictable true random sequences, which can be used in cryptography, simulation, modeling, data analysis and other fields.

[0003] There are many implementation schemes for quantum random number generators. For example, a quantum random number generator based on a continuous variable scheme (such as measuring vacuum noise fluctuations, phase noise, amplified spontaneous radiation, etc.) can generate high-rate random numbers; however, this quantum random number generator requires complex quantum measurement and signal processing technology, and is difficult to implement. Summary of the invention

[0004] The embodiment of the present disclosure provides a random number generator, including: a laser light source, a processing device and a detection device;

[0005] The laser light source comprises a laser; the laser is used to provide a pulse signal;

[0006] The processing device comprises a beam splitting module and a delay processing module; wherein the beam splitting module is used to attenuate the pulse signal and then sequentially split the optical pulses in the pulse signal into multiple sub-pulse signals; the delay processing module is used to perform delay processing on the multiple sub-pulse signals and then sequentially combine the multiple sub-pulse signals to generate a pulse sequence;

[0007] The detection device is used to receive the pulse sequence and generate a random number according to the digital information corresponding to the time window in which the photons in the pulse sequence are detected.

[0008] In some embodiments, the beam splitting module comprises:

[0009] At least one beam splitter, arranged to have at least one level of distribution, for beam splitting the optical pulses in the pulse signal to generate the sub-pulse signals randomly transmitted through N transmission optical paths; N is 2 n , n is an integer greater than or equal to 1.

[0010] In some embodiments, the delay processing module includes:

[0011] At least one delay waveguide, respectively arranged on at least one of the transmission optical paths, for delaying the sub-pulse signal on at least one of the transmission optical paths;

[0012] At least one beam combiner is configured to have at least one level of distribution, and is used to perform beam combining processing on the sub-pulse signals transmitted on the N transmission optical paths to generate the pulse sequence.

[0013] In some embodiments, the delay waveguides are N-1 in number, which are sequentially arranged on the N-1 transmission optical paths, and are used to delay the sub-pulse signals on the N-1 transmission optical paths;

[0014] Wherein, the time difference between the delays of the sub-pulse signals on any two of the transmission optical paths is not less than the recovery time of the detection device.

[0015] In some embodiments, the delay processing module further includes:

[0016] N-1 first attenuators are sequentially arranged on N-1 transmission optical paths outside the transmission optical path with the highest transmission loss, and are used to attenuate the energy of the sub-pulse signal on the corresponding transmission optical path based on the transmission optical path with the highest transmission loss.

[0017] In some embodiments, the processing device is an optical integrated chip, and the laser light source further comprises:

[0018] The polarization controller is used to receive the pulse signal, adjust the polarization state of the pulse signal, and output it to the processing device.

[0019] In some embodiments, the beam splitting module further includes a second attenuator for receiving the pulse signal and transmitting the pulse signal to the at least one beam splitter after attenuating the pulse signal to a single photon level.

[0020] In some embodiments, the laser is further used to provide a first trigger signal for the pulse signal; the detection device comprises:

[0021] A first detector, used for receiving the pulse sequence and converting the photons in the pulse sequence into a first electrical signal;

[0022] The first time-to-digital converter is used to receive the first trigger signal and the first electrical signal, and after receiving the first trigger signal, count the first electrical signal to generate the random number.

[0023] In some embodiments, the beam splitting module further comprises:

[0024] a nonlinear optical structure for receiving the pulse signal and generating correlated photon pairs based on optical pulses in the pulse signal;

[0025] a wavelength division multiplexer, configured to receive the associated photon pairs and separate the associated photon pairs into a first optical signal and a second optical signal;

[0026] The first optical signal is used as the sub-pulse signal and is split by the at least one beam splitter to a random transmission optical path for transmission; the second optical signal is used as the second trigger signal and is transmitted to the detection device.

[0027] In some embodiments, the detection device comprises:

[0028] A second detector, used for receiving the pulse sequence and converting the photons in the pulse sequence into a second electrical signal;

[0029] a third detector, configured to receive the second optical signal and output a second trigger signal based on the second optical signal;

[0030] The second time-to-digital converter is used to receive the second trigger signal and the second electrical signal, and after receiving the second trigger signal, count the second electrical signal to generate the random number.

[0031] The embodiment of the present disclosure provides a random number generator, including: a laser light source, a processing device and a detection device; the laser light source includes a laser; the laser is used to provide a pulse signal; the processing device includes a beam splitting module and a delay processing module; wherein the beam splitting module is used to attenuate the pulse signal and then sequentially split the light pulses in the pulse signal into multiple sub-pulse signals; the delay processing module is used to perform delay processing on the multiple sub-pulse signals and then sequentially combine the multiple sub-pulse signals to generate a pulse sequence; the detection device is used to receive the pulse sequence and generate a random number according to the digital information corresponding to the time window in which the photons in the pulse sequence are detected. Here, the path selection of the photons (sub-pulse signals) is random and independent, so that the probability of the photons in the pulse sequence appearing in each time window is the same, and since the random number is generated based on the digital information corresponding to the time window in which the photons in the pulse sequence are detected, the generated random number is random and unpredictable; the generation process is simple and easy to count, test and verify. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of a random number generator provided in an embodiment of the present disclosure Figure 1 ;

[0033] Figure 2 A schematic diagram of a random number generator provided in an embodiment of the present disclosure Figure 2 ;

[0034] Figure 3 A schematic diagram of a random number generator provided in an embodiment of the present disclosure Figure 3 ;

[0035] Figure 4 A schematic diagram of a random number detection process provided by an embodiment of the present disclosure;

[0036] Figure 5 A schematic diagram of a random number generator provided in an embodiment of the present disclosure Figure 4 . DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. It is understood that the specific embodiments described herein are only used to explain the relevant disclosure, rather than to limit the disclosure. It should also be noted that, for the convenience of description, only the parts related to the relevant disclosure are shown in the drawings.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. The terms used herein are only for the purpose of describing the embodiments of the present disclosure and are not intended to limit the present disclosure.

[0039] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0040] It should be pointed out that the terms "first\second\third" involved in the embodiments of the present disclosure are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of the present disclosure described here can be implemented in an order other than that illustrated or described here.

[0041] The random number generator in the embodiment of the present disclosure is described in detail below with reference to the accompanying drawings.

[0042] In one embodiment of the present disclosure, see Figure 1 , a random number generator 100 provided in an embodiment of the present disclosure includes: a laser light source 110, a processing device 120 and a detection device 130.

[0043] Please continue to refer to Figure 1 , the laser light source 110 includes a laser 111; the laser 111 is used to provide a pulse signal.

[0044] In the disclosed embodiment, the laser 111 may be a device or system capable of emitting a pulse signal, such as a semiconductor laser or a fiber laser. Here, a pulse signal refers to an optical signal in which the optical energy is not continuous but exists in the form of a short optical pulse; wherein the duration of the optical pulse may be from nanoseconds (ns), picoseconds (ps) or even femtoseconds (fs), and may be specifically designed according to the requirements of the random number generator 100.

[0045] Please continue to refer to Figure 1 The processing device 120 includes a beam splitting module 121 and a delay processing module 122; wherein the beam splitting module 121 is used to attenuate the pulse signal and then split the optical pulses in the pulse signal into multiple sub-pulse signals in sequence; the delay processing module 122 is used to perform delay processing on the multiple sub-pulse signals and then combine the multiple sub-pulse signals in sequence to generate a pulse sequence.

[0046] In the embodiment of the present disclosure, the beam splitting module 121 splits the optical pulses in the pulse signal into multiple sub-pulse signals in sequence, which means that: there are multiple transmission optical paths in the processing device 120, and the beam splitting module 121 can split the multiple optical pulses in the pulse signal in sequence, so that each optical pulse is randomly split into one of the multiple transmission optical paths for transmission, wherein the optical pulse split into the transmission optical path is called a sub-pulse signal.

[0047] In order to ensure that each sub-pulse signal is randomly transmitted through one of the transmission optical paths, the beam splitting module 121 can specifically attenuate the optical pulse in the pulse signal to a single photon level, so that the sub-pulse signal is a single photon. In this way, each sub-pulse optical signal can be split onto only one transmission optical path.

[0048] In this way, when the beam splitting module 121 splits the optical pulses in the pulse signal, since the selection of each optical pulse in multiple transmission paths is random, that is, the transmission path of each sub-pulse signal is randomly selected, the randomness of the generated random numbers is ensured, so that the subsequently generated random numbers cannot be predicted or copied.

[0049] Furthermore, in order to ensure uniform distribution of 0 and 1 in the random number, the number of transmission optical paths (represented by N) needs to be set to N = 2 n The number of time windows in which the subsequent detection device 130 responds is determined by the number of transmission optical paths. One time window corresponds to one data. The data of all time windows are concatenated to form a random number. The data corresponding to one time window is binary data. This ensures that the random number is consistent with a large number of optical pulses (for example, the number of optical pulses is 10). 6 / s) shows that the statistics of 0 and 1 are evenly distributed (that is, the probability of 0 and 1 appearing is the same). For example, when the number of transmission optical paths is set to 8, the number of time windows responded by the detection device 130 is 8; wherein the digital information corresponding to each time window is a 3-bit (bit) binary number, and the digital information corresponding to the 8 time windows can be 000, 001, 010, 011, 100, 101, 110, 111, thus ensuring that the probability of 0 and 1 appearing is the same (that is, 0 appears 12 times, and 1 appears 12 times). For another example, when the number of transmission optical paths is set to 4, the number of time windows responded by the detection device 130 is 4; wherein the digital information corresponding to each time window is a 2-bit binary number, and the digital information corresponding to the 4 time windows can be 00, 01, 10, 11, thus ensuring that the probability of 0 and 1 appearing is the same (that is, 0 appears 4 times, and 1 appears 4 times).

[0050] In addition, under the condition of the same pulse laser repetition rate, the more transmission light paths there are, the higher the number of random numbers (or rate) that can be generated per second. To facilitate the description of the random number generation process, the number of light pulses emitted is 10 at a pulse laser repetition rate of 1s (second). 6 For example, when the number of transmission optical paths is 8, the number of time windows responded by the detection device 130 is 8, and the digital information corresponding to each time window is a 3-bit binary number. Ideally, the random number that can be obtained in 1s is 30. 6 When the number of transmission optical paths is 4, the number of time windows that the detection device 130 responds to is 4, and the digital information corresponding to each time window is a 2-bit binary number. Ideally, the random number that can be obtained in 1s is 20. 6 A sequence of random numbers.

[0051] It should be noted that in actual implementation, the randomness of random numbers requires a sufficient number of samples (for example, the number of light pulses is 10 6 / s) can be reflected. If the number of samples is too small, the generated random number (i.e., binary sequence) cannot fully reflect the randomness. In addition, due to optical path loss and detector detection omissions, the number of bits of random numbers actually obtained per second will be less than the number of bits of random numbers obtained under ideal conditions. At the same time, considering the noise in the system, including stray photons and detector electrical noise, there are errors in some detection response time windows. This influencing factor requires corresponding post-processing of the collected random numbers, but it does not fall within the scope of consideration of this patent and will not be further explained.

[0052] In the embodiment of the present disclosure, after beam splitting, the sub-pulse signal is delayed by the delay processing module 122; specifically, the delay processing module 122 is arranged on at least one transmission optical path, and is used to delay the sub-pulse signal on at least one transmission optical path. The number of transmission optical paths for delaying the sub-pulse signal can be set according to actual needs. For example, when the number of transmission optical paths is N, the number of delayed transmission optical paths can be N-1, that is, the delay processing module 122 is arranged on N-1 transmission optical paths, so that the sub-pulse signals on the N-1 transmission optical paths can be delayed. In this way, each transmission optical path can correspond to a time window.

[0053] Among them, the delay time of the transmission optical path needs to ensure that the time difference between the delays of sub-pulse signals on any two transmission optical paths is not less than the recovery time of the detection device 130; for example, the recovery time of the detection device 130 is τ, and the number of transmission optical paths is 4, of which the delay times of 3 transmission optical paths can be τ, 2τ, and 3τ, respectively, or the delay time can be τ, 3τ, and 4τ, respectively, and further the delay time can be τ, 2τ, and 5τ, respectively, and so on.

[0054] It should be noted that if the time difference between the sub-pulse signal delays on the two transmission optical paths is smaller than the recovery time of the detection device 130 (such as the dead time of the single-photon detector), the latter sub-pulse signal cannot be detected, thus affecting the randomness of the random number.

[0055] After the delay, the delayed sub-pulse signals are combined by the delay processing module 122 to generate a pulse sequence. In this way, the number of detection devices 130 (such as single photon detectors) can be reduced, saving device costs.

[0056] Please continue to refer to Figure 1 The detection device 130 is used to receive the pulse sequence and generate a random number according to the digital information corresponding to the time window in which the photons in the pulse sequence are detected.

[0057] In the embodiment of the present disclosure, taking the number of transmission optical paths as 4 as an example, each transmission optical path corresponds to a time window, and the time of arrival of each sub-pulse signal in the pulse sequence is recorded by the detection device 130 to generate a random number. For example, the photon is detected and recorded as "00" in the first time window (Time Window, TW); the photon is detected and recorded as "01" in the second time window; the photon is detected and recorded as "10" in the third time window; the photon is detected and recorded as "11" in the fourth time window, and the pulse laser repetition rate is 1s and the number of pulses emitted is 10; since the probability of the sub-pulse signal randomly appearing on the four transmission optical paths is the same, the probability of the corresponding sub-pulse signal appearing in the four time windows is the same, so that the 20-bit binary random number that can be extracted in 1s can be, for example, 00000110111100011011.

[0058] It should be noted that the aforementioned 20-bit binary random number is only an example for ease of understanding. In actual implementation, the number of pulses emitted by a pulse laser with a repetition rate of 1s is usually much greater than 10, for example, 10 6 In addition, the sequence recorded in each time window can be set according to actual needs. For example, it can also be set that the photon is detected in the first time window and recorded as "11", "01" or "11".

[0059] In the disclosed embodiment, since the random numbers are generated based on the time window in which the photons in the pulse sequence are detected, and the path selection of the light pulses (sub-pulse signals) is random and independent, the probability of the photons in the pulse sequence appearing in each time window is the same, making the generated random numbers random and unpredictable; the discrete values ​​of this scheme are easy to measure and count, so that the generation process is simple.

[0060] In the embodiment of the present disclosure, the processing device 120 may be an optical integrated chip. Since the optical chip is selective to the polarization state of light, please refer to Figure 2 The laser light source 110 may further include a polarization controller 112, which is used to receive a pulse signal, adjust the polarization state of the pulse signal, and output it to the processing device 120. For example, when the pulse signal in the optical integrated chip needs to be in TE mode, the polarization state of the pulse signal can be set to TE mode through the polarization controller 112.

[0061] In the embodiment of the present disclosure, a polarization controller 112 is provided after the laser 111 to adjust the polarization state of the pulse signal so that the pulse signal can be transmitted more efficiently in the subsequent optical element (processing device 120).

[0062] In some embodiments, Figure 3As shown, the processing device 120 can also be a discrete optical device, such as a fiber optic splitter (corresponding to the beam splitter 1211 in the following text), a delay fiber (corresponding to the delay waveguide 1221 in the following text), a fiber optic combiner (corresponding to the combiner 1222 in the following text), etc. Since the fiber optic device is not sensitive to the polarization state of the pulse signal, the polarization controller 112 may not be set.

[0063] It should be noted that Figure 2 and Figure 3 The random number generator 100 shown differs in that: Figure 2 The processing device 120 is an optical integrated chip (i.e., an optical chip). Figure 3 The processing device 120 is a discrete optical device; wherein, Figure 2 and Figure 3 The principle of generating random numbers by the random number generator 100 shown in FIG. Figure 2 and Figure 3 Taking the random number generator 100 shown in FIG. 1 as an example, the random number generator 100 is introduced in detail.

[0064] In some embodiments, please refer to Figure 2 and Figure 3 The beam splitting module 121 includes: at least one beam splitter 1211, which is set to at least one level of distribution, and is used to split the optical pulses in the pulse signal to generate sub-pulse signals that are randomly transmitted through N transmission optical paths.

[0065] In the disclosed embodiment, the beam splitter 1211 may be a 1:X beam splitter (BS), where X≥1; wherein 1:X represents 1 input and X outputs, and the number and type of the beam splitter 1211 may be set according to the required transmission optical path. In addition, the beam splitter 1211 may be set to one level or multiple levels.

[0066] For example, see Figure 2 and Figure 3 , when the number of transmission optical paths is 4, three 1:2 beam splitters can be used, and the three 1:2 beam splitters can be set to a two-level distribution, namely the first-level beam splitter 1211a, and the second-level beam splitters 1211b and 1211c. In this way, the optical pulses in the pulse signal are split into four transmission optical paths for transmission through the three 1:2 beam splitters; wherein the optical pulses split into the transmission optical paths are called sub-pulse signals. For another example, one 1:4 beam splitter can be used, and the optical pulses in the pulse signal are split into four transmission optical paths for transmission through the three 1:2 beam splitters.

[0067] In the disclosed embodiment, since the path selection of the optical pulse in the pulse signal is random, it ensures that the probability of each generated sub-pulse signal being split into N transmission optical paths is equal, so that the subsequently generated random numbers are random and cannot be predicted or copied.

[0068] In addition, the disclosed embodiment also has strong scalability, that is, the number of transmission optical paths can be expanded through the beam splitter 1211, so as to increase the number of time windows to which the subsequent detection device 130 responds, and greatly improve the random number generation rate when the pulse repetition rate of the pulse laser output remains unchanged. For example, by increasing the number of levels of the beam splitter 1211 and setting a 3-level beam splitter 1211 to increase the number of transmission optical paths, the number of time windows to which the subsequent detection device 130 responds can be increased, and the random number generation rate can be increased when the pulse repetition rate of the laser output remains unchanged.

[0069] In some embodiments, please refer to Figure 2 and Figure 3 The beam splitting module 120 also includes a second attenuator 123 for receiving a pulse signal and transmitting the pulse signal to the first-stage beam splitter 1211 after attenuating the pulse signal to a single-photon level.

[0070] In the disclosed embodiment, the intensity of the optical pulse in the pulse signal is attenuated to a single-photon level by the second attenuator 123, so that the sub-pulse signal in each optical path can be a single photon, thereby improving the true randomness of the random number.

[0071] In some embodiments, please refer to Figure 2 and Figure 3 The delay processing module 122 includes: at least one delay waveguide 1221, which is arranged on at least one transmission optical path and is used to delay the sub-pulse signal on at least one transmission optical path.

[0072] In the embodiment of the present disclosure, the delay waveguide 1221 may be a waveguide delay line (eg Figure 2 The scheme shown) or delayed fiber (such as Figure 3 In this way, the delay time of the sub-pulse signal can be controlled by controlling the length of the delay waveguide 1221; in other embodiments, the delay waveguide 1221 can also be other devices that can achieve delay, which is not limited to this.

[0073] In the embodiment of the present disclosure, the number of delay waveguides 1221 can be set according to actual needs. For example, Figure 2 and Figure 3 In the figure, the number of delay waveguides 1221 is 3, so that the sub-pulse signals on the three optical paths can be delayed.

[0074] In some embodiments, please refer to Figure 2 and Figure 3 There are N-1 delay waveguides 1221, which are arranged in sequence on N-1 transmission optical paths, and are used to delay the sub-pulse signals on the N-1 transmission optical paths; wherein the time difference between the delays of the sub-pulse signals on any two transmission optical paths is not less than the recovery time of the detection device 130.

[0075] For example, see Figure 2 and Figure 3 The number of transmission optical paths is 4, and the number of delay waveguides 1221 is 3, which are sequentially arranged on the 3 transmission optical paths, so that the sub-pulse signal on the first transmission optical path is not delayed, and the sub-pulse signals on the remaining 3 transmission optical paths are sequentially delayed through delay waveguides 1221a, 1221b, and 1221c, and the delay time can be τ, 2τ, 3τ, or τ, 2τ, 4τ, etc.; τ is the recovery time of the detection device.

[0076] It should be noted that in Figure 2 In the example, when the delay waveguide 1221 is a waveguide delay line, the delay time of each waveguide delay line can be greater than or equal to the recovery time of the detection device 130; for example, when the delay time of the waveguide delay line is equal to the recovery time τ of the detection device 130, and the delay time on the transmission optical path can be τ, 2τ, and 3τ in sequence, the delay waveguide 1221a can include 1 waveguide delay line, the delay waveguide 1221b can include 2 waveguide delay lines, and the delay waveguide 1221c can include 3 waveguide delay lines. Since the waveguide delay line has the characteristics of high precision, high stability, small size and easy integration, using the waveguide delay line as the delay waveguide 1221 can enhance the practicality of the random number generator 100.

[0077] In addition, Figure 3 In the embodiment, when the delay waveguide 1221 is a delay optical fiber, the delay time of each delay optical fiber can be greater than or equal to the recovery time (i.e., τ) of the detection device 130; for example, when the delay time of the delay optical fiber is equal to the recovery time τ of the detection device 130, and the delay time on the transmission optical path can be τ, 2τ, and 3τ respectively, the three delay waveguides can include 1, 2, and 3 delay optical fibers respectively; since the delay optical fiber is insensitive to the polarization state of the pulse signal, the setting of the polarization controller can be reduced, thereby reducing the device cost.

[0078] In the disclosed embodiment, the delay waveguide 1221 can be used to create a time difference between sub-pulse signals on different transmission optical paths, thereby providing a basis for the subsequent detection device 130 to detect photons in different time windows.

[0079] Furthermore, the sub-pulse signal is delayed in the delay waveguide 1221, and the sub-pulse signal has a certain energy loss. To ensure the randomness of the subsequent random number generation, the transmission loss of the sub-pulse signal energy on each optical path must be consistent. Therefore, please refer to Figure 2 and Figure 3 The delay processing module 122 further includes: at least one first attenuator 1223, which is arranged on the transmission optical path of each sub-pulse signal outside the transmission optical path with the highest transmission loss, and is used to attenuate the energy of the sub-pulse signal on the corresponding transmission optical path based on the transmission optical path with the highest transmission loss. The number of the first attenuators 1223 may be N-1.

[0080] For example, see Figure 2 and Figure 3 , the sub-pulse signal on the first transmission optical path is not delayed, and the sub-pulse signals on the remaining three transmission optical paths are delayed by τ, 2τ, and 3τ in sequence through the delay waveguides 1221a, 1221b, and 1221c. When the delay waveguide is a waveguide delay line or a delay optical fiber, the delay time of the sub-pulse signal on the fourth transmission optical path is the longest (3τ), and its delay loss is the largest. Therefore, based on the transmission loss of the fourth transmission optical path (or the energy of the sub-pulse signal), the energy of the sub-pulse signals on the first, second, and third transmission optical paths is attenuated in sequence through the first attenuator 1223a, the first attenuator 1223b, and the first attenuator 1223c. In this way, the energy of the sub-pulse signal on each transmission path can be made the same.

[0081] In the embodiment of the present disclosure, the first attenuator 1223 and the second attenuator 123 may both be variable optical attenuators (VOA); in other embodiments, the first attenuator 1223 and the second attenuator 123 may be other devices capable of performing optical attenuation, which is not limited in the present disclosure.

[0082] In some embodiments, please refer to Figure 2 and Figure 3 The delay processing module 122 also includes: at least one beam combiner 1222, which is configured to have at least one level of distribution and is used to perform beam combining processing on sub-pulse signals transmitted on N transmission optical paths to generate a pulse sequence.

[0083] In the embodiment of the present disclosure, the beam combiner 1222 may be a Y:1 optical beam combiner, where Y is an integer and Y≥1; wherein Y:1 represents Y inputs and 1 output, and the number and type of the beam combiner 1222 may be set according to actual needs. In addition, the beam combiner 1222 may be set to one level or multiple levels.

[0084] For example, see Figure 2 and Figure 3 , three 2:1 beam combiners 1222 may be used, and the three 2:1 beam combiners may be set to a two-stage distribution, and after passing through the first-stage beam combiner 1222a and the beam combiner 1222b, the sub-pulse signals transmitted on the four transmission optical paths are beam combined and processed to generate a pulse sequence. For another example, a 4:1 beam combiner may be used to beam combine the sub-pulse signals transmitted on the four transmission optical paths to generate a pulse sequence.

[0085] In the embodiment of the present disclosure, by combining a plurality of delayed sub-pulse signals to generate a pulse sequence, the first detector 131 can be multiplexed in time, thereby reducing the complexity of device design and the cost of the random number generator 100.

[0086] In some embodiments, please refer to Figure 2 and Figure 3 The laser 111 is also used to provide a first trigger signal of a pulse signal. The detection device 130 includes: a first detector 131, used to receive a pulse sequence and convert the photons in the pulse sequence into a first electrical signal; a first time-to-digital converter 132, used to receive the first trigger signal and the first electrical signal, and after receiving the first trigger signal, count the first electrical signal, and the binary bits corresponding to the time window in which the count is located are used to generate a random number.

[0087] Here, the first detector 131 may be an off-chip single photon detector (Single Photon Detector, SPD); the first time-to-digital converter 132 may be a time-to-digital signal converter (Time-Digital Convertor, TDC); wherein the recovery time of the detection device 130 may be the recovery time of the off-chip single photon detector.

[0088] In the embodiment of the present disclosure, since the sub-pulse signal on the transmission optical path is delayed by the above-mentioned delay waveguide 1221, different transmission optical paths can correspond to different time windows. Therefore, after the first detector 131 sequentially converts the photons (i.e., sub-pulse signals) detected in the pulse sequence into first electrical signals, each first electrical signal can correspond to a time window.

[0089] Specifically, each optical pulse in the pulse signal corresponds to a first trigger signal, and the first time-to-digital converter 132 is used to record the time difference between the reception of the first trigger signal and the first electrical signal, and determine the time window in which the corresponding first electrical signal arrives; and according to the time window in which the first electrical signal arrives, the corresponding binary sequence is extracted, and then the extracted random binary sequences are spliced ​​in chronological order to finally obtain a random number sequence.

[0090] For example, see Figure 4 , set the first electrical signal to be received in the first time window TW1, and the recorded sequence is "00"; set the second time window TW2 to be received, and the recorded sequence is "01"; set the third time window TW3 to be received, and the recorded sequence is "10"; set the fourth time window TW4 to be received, and the recorded sequence is "11". The first time-to-digital converter 132 records that the time difference between the first trigger signal and the first electrical signal falls in the first time window TW1, and the extracted sequence is "00"; similarly, if the time difference is τ, it means that the first electrical signal is received in the second time window TW2, and the extracted sequence is "01", and so on. In this way, the first time-to-digital converter 132 can obtain a binary sequence according to the time window of each arrival of the first electrical signal, and then the binary bits can be spliced ​​in the time order of the acquired sequence to finally obtain a binary random number sequence.

[0091] It should be noted that the first time-to-digital converter 132 obtains the time difference information of the corresponding first electrical signal received through the first trigger signal; that is, if the first trigger signal is not set, the first electrical signal does not have a fixed time window, that is, the time window for detecting the sub-pulse signal cannot be known. In addition, each photon detection in the pulse signal can be converted into a first trigger signal through an off-chip single-photon detector.

[0092] In the disclosed embodiment, since the random numbers are generated based on the time when the photons in the pulse sequence are detected, and the path selection of the photons (sub-pulse signals) is random and independent, the generated bit sequence is random and unpredictable; the discrete values ​​of this scheme are easy to measure and count, so the random number generation process is simple.

[0093] In the embodiments of the present disclosure, when the optical pulse source (i.e., pulse signal) is attenuated to obtain a single-photon sub-pulse signal, it is difficult to avoid the appearance of a multi-photon sub-pulse signal, thereby affecting the true randomness of the random number. Therefore, in some embodiments, please refer to Figure 5 The embodiment of the present disclosure provides another random number generator 100 , which includes: a laser light source 110 , a processing device 120 and a detection device 130 .

[0094] The laser light source 110 includes a laser 111 and a polarization controller 112; the processing device 120 includes a beam splitting module 121 and a delay processing module 122. In the embodiment of the present disclosure, the laser light source 110, the beam splitter 1211 in the beam splitting module 121, and the delay processing module 122 are similar to the above embodiment, please refer to the above embodiment for understanding, and will not be repeated here.

[0095] In some embodiments, please refer to Figure 5The beam splitting module 121 also includes: a nonlinear optical structure 124, which is used to receive a pulse signal and generate associated photon pairs based on the optical pulses in the pulse signal; a wavelength division multiplexer 125, which is used to receive the associated photon pairs and separate the associated photon pairs into a first optical signal and a second optical signal; wherein the first optical signal is used as a sub-pulse signal and is split into a random transmission optical path for transmission through at least one beam splitter 1211 (i.e., all beam splitters 1211); and the second optical signal is used as a second trigger signal and is transmitted to the detection device 130.

[0096] In the disclosed embodiment, the nonlinear optical structure 124 can be a micro-ring based on silicon-based materials, or a periodically polarized lithium niobate waveguide structure based on lithium niobate materials. When the light pulse in the pulse signal (i.e., the off-chip pump light) enters the nonlinear optical structure 124, a nonlinear optical effect occurs, generating a correlated photon pair; wherein the correlated photon pair includes a first light signal and a second light signal that are correlated with each other.

[0097] In the embodiment of the present disclosure, the first optical signal and the second optical signal in the associated photon pair are separated by the wavelength division multiplexer 125; wherein the first optical signal is transmitted as a sub-pulse signal to at least one beam splitter 1211 (e.g. Figure 5 The beam splitter 1211a to the beam splitter 1211c) and the delay processing module 122 finally generate a pulse sequence, which is used to convert into a random number.

[0098] In some embodiments, the second detector 133 is used to receive a pulse sequence and convert the photons in the pulse sequence into a second electrical signal; the third detector 134 is used to receive a second optical signal and output a second trigger signal based on the second optical signal; the second time-to-digital converter 135 is used to receive the trigger signal and the second electrical signal, and after receiving the second trigger signal, count the second electrical signal to generate a random number.

[0099] Here, the second detector 133 and the third detector 134 may be off-chip single photon detectors (SPDs); and the second time-to-digital converter 135 may be a time-to-digital converter (TDC).

[0100] In the embodiment of the present disclosure, since the sub-pulse signal on the transmission optical path is delayed by the delay waveguide 1221, different transmission optical paths can correspond to different time windows, so that the second detector 133 can convert the photons (i.e., sub-pulse signals) detected in the pulse sequence into second electrical signals, so that each second electrical signal can correspond to a time window.

[0101] Specifically, after receiving the second optical signal, the third detector 134 outputs a second trigger signal to the second time-to-digital converter 135; for example, please refer to Figure 4, set the second electrical signal to be received in the first time window TW1, and the recorded sequence is "00"; set the second time window TW2 to be received, and the recorded sequence is "01"; set the third time window TW3 to be received, and the recorded sequence is "10"; set the fourth time window TW4 to be received, and the recorded sequence is "11"; the second time digital converter 135 records that the time difference between the second trigger signal and the second electrical signal falls in the first time window TW1, and the extracted sequence is "00"; similarly, if the time difference is τ, it means that the second electrical signal is received in the second time window TW2, and the extracted sequence is "01", and so on. In this way, the second time digital converter 135 can obtain a binary sequence according to the time window of each second electrical signal arrival, and then the binary bits can be spliced ​​according to the time order of the acquired sequence to finally obtain a binary random number sequence.

[0102] It should be noted that the second time-to-digital converter 135 obtains the time difference information of the corresponding second electrical signal received through the second trigger signal; that is, if the second trigger signal is not set, the second electrical signal does not have a fixed time window, that is, the time window for sub-pulse signal detection cannot be known.

[0103] In the disclosed embodiment, by associating photons so that the second trigger signal generated by the detection is generated, it can be clearly used to detect the light pulse (i.e., sub-pulse signal) that generates random numbers at the single-photon level, so that the random numbers generated by the pulse sequence have stronger randomness.

[0104] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the protection scope of the present disclosure.

[0105] It should be noted that in the present disclosure, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0106] The serial numbers of the above-mentioned embodiments of the present disclosure are only for description and do not represent the advantages or disadvantages of the embodiments.

[0107] The methods disclosed in several method embodiments provided in the present disclosure can be arbitrarily combined without conflict to obtain new method embodiments.

[0108] The features disclosed in several product embodiments provided in the present disclosure can be arbitrarily combined without conflict to obtain new product embodiments.

[0109] The features disclosed in several method or device embodiments provided in the present disclosure may be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0110] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A random number generator, characterized in that: include: Laser light source, processing device and detection device; The laser light source comprises a laser; the laser is used to provide a pulse signal; The processing device comprises a beam splitting module and a delay processing module; wherein the beam splitting module is used to split the optical pulses in the pulse signal into multiple sub-pulse signals in sequence after attenuating the pulse signal; The delay processing module is used to perform delay processing on the multiple sub-pulse signals and then combine the multiple sub-pulse signals in sequence to generate a pulse sequence; The detection device is used to receive the pulse sequence and generate a random number according to the digital information corresponding to the time window in which the photons in the pulse sequence are detected.

2. The random number generator according to claim 1, characterized in that The beam splitting module comprises: At least one beam splitter, arranged to have at least one level of distribution, for beam splitting the optical pulses in the pulse signal to generate the sub-pulse signals randomly transmitted through N transmission optical paths; N is 2 n , n is an integer greater than or equal to 1.

3. The random number generator according to claim 2, characterized in that The delay processing module comprises: At least one delay waveguide, respectively arranged on at least one of the transmission optical paths, for delaying the sub-pulse signal on at least one of the transmission optical paths; At least one beam combiner is configured to have at least one level of distribution, and is used to perform beam combining processing on the sub-pulse signals transmitted on the N transmission optical paths to generate the pulse sequence.

4. The random number generator according to claim 3, characterized in that: The delay waveguides are N-1 in number, which are sequentially arranged on the N-1 transmission optical paths, and are used to delay the sub-pulse signals on the N-1 transmission optical paths; Wherein, the time difference between the delays of the sub-pulse signals on any two of the transmission optical paths is not less than the recovery time of the detection device.

5. The random number generator according to claim 4, characterized in that: The delay processing module also includes: N-1 first attenuators are sequentially arranged on N-1 transmission optical paths outside the transmission optical path with the highest transmission loss, and are used to attenuate the energy of the sub-pulse signal on the corresponding transmission optical path based on the transmission optical path with the highest transmission loss.

6. The random number generator according to claim 2, characterized in that: The processing device is an optical integrated chip, and the laser light source further comprises: The polarization controller is used to receive the pulse signal, adjust the polarization state of the pulse signal, and output it to the processing device.

7. The random number generator according to any one of claims 2 to 6, characterized in that: The beam splitting module also includes a second attenuator, which is used to receive the pulse signal, and transmit the pulse signal to the at least one beam splitter after attenuating it to a single photon level.

8. The random number generator according to claim 7, characterized in that The laser is also used to provide a first trigger signal for the pulse signal; The detection device comprises: A first detector, used for receiving the pulse sequence and converting the photons in the pulse sequence into a first electrical signal; The first time-to-digital converter is used to receive the first trigger signal and the first electrical signal, and after receiving the first trigger signal, count the first electrical signal to generate the random number.

9. The random number generator according to any one of claims 2 to 6, characterized in that: The beam splitting module also includes: a nonlinear optical structure for receiving the pulse signal and generating correlated photon pairs based on optical pulses in the pulse signal; a wavelength division multiplexer, configured to receive the associated photon pairs and separate the associated photon pairs into a first optical signal and a second optical signal; The first optical signal is used as the sub-pulse signal and is split by the at least one beam splitter to a random transmission optical path for transmission; the second optical signal is used as the second trigger signal and is transmitted to the detection device.

10. The random number generator according to claim 9, characterized in that The detection device comprises: A second detector, used for receiving the pulse sequence and converting the photons in the pulse sequence into a second electrical signal; a third detector, configured to receive the second optical signal and output a second trigger signal based on the second optical signal; The second time-to-digital converter is used to receive the second trigger signal and the second electrical signal, and after receiving the second trigger signal, count the second electrical signal to generate the random number.

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