CN113612611A - Continuous variable quantum key distribution asynchronous sampling method and system - Google Patents
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Abstract
The invention provides a continuous variable quantum key distribution asynchronous sampling method and a system, which relate to the technical field of computer information, and the method comprises the following steps: step S1: constructing quantum optical pulse signals which obey Gaussian distribution, constructing strong optical pulse signals with constant amplitude, and then inserting the strong optical pulse signals into the quantum optical pulse signals to be transmitted; step S2: and oversampling the received optical pulse signal, searching index bits of peak sampling points of the strong optical pulse signal, and extracting peak sampling values of the quantum optical pulse signal based on the index bits. The invention can utilize the strong light pulse signal with constant amplitude to judge the optimal sampling point and extract the optimal sampling value of the quantum light pulse signal based on the optimal sampling point, not only does not need to transmit synchronous clock signals to reduce the hardware complexity, but also can eliminate the sampling deviation caused by non-homologous clock jitter, and is beneficial to the realization of an integrated continuous variable quantum key distribution system.
Description
Technical Field
The invention relates to the technical field of computer information, in particular to a continuous variable quantum key distribution asynchronous sampling method and system, and particularly relates to a continuous variable quantum key distribution asynchronous sampling method.
Background
With the rapid development of the information society, the dependence of important fields such as military, finance and energy in the human society on the information technology is stronger and stronger, and high requirements on information security are brought. Quantum secure communication is a communication mode with higher security known at present, and communication information is protected from being acquired by an eavesdropper by means of quantum mechanical characteristics. Quantum secure communication is mainly divided into two parts: firstly, Quantum Key Distribution (QKD) is carried out, and a key with extremely high confidentiality is distributed in a quantum channel by utilizing the equal quantum mechanical characteristics of the inaccuracy measuring principle; the resulting key is then used to perform a one-time pad encryption scheme on the communication and to complete the information transfer using the classical channel. In the whole process, quantum key distribution is a very critical step, and the security of the step determines the security of the whole communication process, so that the quantum key distribution is widely researched and is a mature item developed in the current quantum information technology.
Quantum key distribution is mainly divided into two types, discrete variable quantum key distribution and continuous variable quantum key distribution. The main difference between discrete variable quantum key distribution and continuous variable quantum key distribution is that the carriers transporting the information are different. Discrete variable quantum key distribution represented by BB84 protocol proposed in 1984 uses discrete variables such as single photon polarization state for key distribution; while continuous variable quantum key distribution, represented by the GG02 protocol proposed in 2002, uses continuous variables such as the optical field canonical component for key distribution. Compared with discrete variable quantum key distribution, the continuous variable quantum key distribution has the advantages of being easy to detect signals, easy to fuse with a classical optical network and the like, and has a good practical application prospect, so that the method obtains attention and research in the industry. At present, the continuous variable quantum key distribution protocol which is most complete in safety certification and mature in development is a Gaussian modulation coherent state continuous variable quantum key distribution protocol, and the protocol uses Gaussian modulation coherent state signals to complete key distribution.
The invention patent with publication number CN106130943A discloses a data acquisition method and system for a continuous variable quantum key distribution system, wherein the system comprises a sending end and a receiving end which adopt homologous clocks, the clock of the sending end is divided into one path and transmitted to the receiving end through a classical channel, and the divided path is used as a system clock source of the receiving end; the receiving end samples the received signal by adopting the clock frequency which is the same as the modulation information of the sending end, and sends the sampled data to the data processing and control module for processing, the phase difference between the rising edge of the sampling clock and the peak position point of the signal is determined according to the information provided by the sampled data, and the rising edge of the sampling clock is strictly aligned with the peak position point by feeding back and adjusting the delay value of the delay module, so as to realize accurate peak value sampling.
The invention patent with publication number CN109039606A discloses a same-frequency sampling method and circuit in a continuous variable quantum key distribution system, which includes: sampling data on the optical path to obtain a section of sampled data; calculating the average value of the sampling data, and storing the obtained average value and the corresponding sampling point; adjusting the sampling phase when the data is sampled; repeating the steps, wherein the repetition times are the minimum granularity of adjustment of a single data period/DPS; and comparing the average values of the stored sampling points, taking the sampling point corresponding to the maximum average value as a final sampling point, and adjusting the sampling phase as the sampling phase corresponding to the final sampling point.
In order to ensure that the continuous variable quantum key distribution system works normally in practical implementation, it is necessary for the receiving end to accurately acquire signals. The traditional continuous variable quantum key distribution system uses local oscillator light emitted by a sending end as a clock signal or adopts another wavelength to independently transmit the clock signal, thereby ensuring the clock synchronization of the sending end and the receiving end and realizing the synchronous sampling of the signal. However, the scheme increases the complexity of hardware equipment and is not beneficial to the realization of an integrated continuous variable quantum key distribution system. The sampling is directly carried out by using a local clock signal, and the sampling is wrong due to the inherent clock skew at the two ends of the receiving and transmitting. And because the optical quantum signal is very weak, the traditional clock recovery scheme is not suitable. Therefore, an asynchronous sampling method needs to be provided for a continuous variable quantum key distribution system, and accurate transmission of key information of both communication parties is guaranteed.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a continuous variable quantum key distribution asynchronous sampling method and system.
According to the asynchronous sampling method and system for continuous variable quantum key distribution provided by the invention, the scheme is as follows:
in a first aspect, a continuous variable quantum key distribution asynchronous sampling method is provided, the method including:
step S1: constructing quantum optical pulse signals which obey Gaussian distribution, constructing strong optical pulse signals with constant amplitude, and then inserting the strong optical pulse signals into the quantum optical pulse signals to be transmitted;
step S2: and oversampling the received optical pulse signal, searching index bits of peak sampling points of the strong optical pulse signal, and extracting peak sampling values of the quantum optical pulse signal based on the index bits.
Preferably, the step S1 includes:
step S1.1: constructing a quantum optical pulse signal following a Gaussian distribution, the quantum optical pulse signal being generated by a random number generator and an optoelectronic modulator;
step S1.2: constructing an intense light pulse signal of constant amplitude, the intense light pulse signal being generated by an electro-optical modulator;
step S1.3: and (3) inserting the strong light pulse signal into the quantum light pulse signal to form a transmitting light pulse sequence, wherein the operation is completed by an optical time delay line and an optical beam combiner.
Preferably, the step S2 includes:
step S2.1: detecting the received optical pulse signal by using a coherent detector, and oversampling the output electric signal;
step S2.2: in a period, obtaining an index bit of a sampling point of a peak value of the strong light pulse signal based on an optimal index bit searching scheme;
step S2.3: and obtaining the index bit of the peak sampling point of the quantum optical pulse signal based on the index bit of the peak sampling point of the strong optical pulse signal and the optimal sampling value extraction scheme, and extracting the peak sampling value of the quantum optical pulse signal.
Preferably, the electrical signal oversampling scheme is that R ═ f is adoptedrepThe electrical signal is sampled at a sampling rate of x r, where frepFor the transmission frequency of the pulse signal, r is the oversampling rate, and the resulting sampling points can be expressed as:
[A[1]，A[2]，…，A[i]，…A[M]]；
where A [. cndot. ] represents the sample value, i represents the sample point index, and M represents the sample length.
Preferably, the optimal index bit search scheme is that all sampling points are divided by taking twice oversampling rate as a unit, and an array of sampling points in one period is obtained as follows:
[A[1]，A[2]，…，A[i]，…A[2r]]
finding the maximum value in the array to obtain the index bit i corresponding to the maximum valuemaxAnd r is the oversampling ratio.
Preferably, the optimal sampling value extraction scheme is that i is according tomaxLooking for quantum optical pulse peak index bits, i.e.
iopt＝mod((imax+r-1)，2r)+1
Wherein ioptIndexing bits for optimal quantum optical pulse peaks;
mod is the modulus operator; a [ i ]opt]Namely the peak sampling value of the quantum optical pulse signal.
Preferably, the quantum optical pulse signal following the gaussian distribution can be expressed as:
g[i]＝xi+jpi
wherein x isiAnd piThe canonical positions and the canonical momentums respectively representing continuous variables, both obey a Gaussian distribution, i.e. xi，pi～N(0，VA)，VAModulating the variance for the signal;
g [ i ] is the complex amplitude of the continuous variable;
i is a position index of the Gaussian data sequence, i belongs to { 1.., N };
n is the length of the quantum optical pulse signal;
j is an imaginary unit.
Preferably, the strong light pulse signal can be expressed as:
p[i]＝C
wherein C is a constant amplitude;
p [ i ] represents a specific value with a position index i in the strong light pulse signal, i ∈ { 1.,. N }.
Preferably, the intense light pulse signal is inserted between the quantum light pulse signals, and the emission light pulse sequence can be expressed as:
[p[1]，g[1]，p[2]，g[2]，…，p[N]，g[N]]。
in a second aspect, there is provided a continuous variable quantum key distribution asynchronous sampling system, the system comprising:
a sending end: constructing quantum optical pulse signals which obey Gaussian distribution, constructing strong optical pulse signals with constant amplitude, and inserting the strong optical pulse signals into the quantum optical pulse signals to be transmitted;
receiving end: receiving a quantum optical pulse signal, performing oversampling on the received optical pulse signal, searching an index bit of a peak sampling point of the strong optical pulse signal, and extracting a peak sampling value of the quantum optical pulse signal based on the index bit;
the transmitting end comprises:
module M1.1: constructing a quantum optical pulse signal following a Gaussian distribution, the quantum optical pulse signal being generated by a random number generator and an optoelectronic modulator;
module M1.2: constructing an intense light pulse signal of constant amplitude, the intense light pulse signal being generated by an electro-optical modulator;
module M1.3: inserting the strong light pulse signal into the quantum light pulse signal to form a transmitting light pulse sequence, wherein the operation is completed by an optical time delay line and an optical beam combiner;
the receiving end includes:
module M2.1: detecting the received optical pulse signal by using a coherent detector, and oversampling the output electric signal;
module M2.2: in a period, obtaining an index bit of a sampling point of a peak value of the strong light pulse signal based on an optimal index bit searching scheme;
module M2.3: and obtaining the index bit of the peak sampling point of the quantum optical pulse signal based on the index bit of the peak sampling point of the strong optical pulse signal and the optimal sampling value extraction scheme, and extracting the peak sampling value of the quantum optical pulse signal.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention judges the optimal sampling point by using the strong light pulse signal with constant amplitude, extracts the optimal sampling value of the quantum light pulse signal based on the optimal sampling point, does not need to transmit synchronous clock signals, reduces the hardware complexity and is beneficial to the integration of a continuous variable quantum key distribution system;
2. the invention can also eliminate the sampling deviation caused by non-homologous clock jitter, and because the quantum optical pulse signals in each period are subjected to optimal index bit search and optimal sampling value extraction, the sampling deviation caused by clock signal jitter can be eliminated;
3. the intense light pulse signal adopted by the invention can also be used for realizing polarization compensation and phase recovery, and the channel damage resistance of the system is improved.
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Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:
FIG. 1 is a schematic diagram of a continuous variable quantum key distribution asynchronous sampling method;
fig. 2 is a schematic diagram of a continuous variable quantum key distribution asynchronous sampling system.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.
The embodiment of the invention provides a continuous variable quantum key distribution asynchronous sampling method, which comprises the following specific steps as shown in figure 1:
step S1: the sending end firstly constructs quantum optical pulse signals which obey Gaussian distribution, then constructs strong optical pulse signals with constant amplitude, and finally inserts the strong optical pulse signals into the quantum optical pulse signals.
Specifically, in step S1, a quantum optical pulse signal complying with gaussian distribution is first constructed, and the signal is generated by a random number generator and an optoelectronic modulator; and reconstructing an intense light pulse signal with constant amplitude, wherein the signal is generated by an optoelectronic modulator, and the intense light pulse signal is interpolated in the quantum light pulse signal to form a transmitting light pulse sequence, and the operation is completed by an optical time delay line and an optical beam combiner.
Step S2: the receiving end firstly carries out oversampling on a received signal, then searches index bits of peak sampling points of the strong light pulse signal, and finally extracts peak sampling values of the quantum light pulse signal based on the index bits.
In step S2, specifically, a coherent detector is used to detect the received optical pulse signal and oversample the output electrical signal; in a period (including a strong light pulse signal and a quantum light pulse signal), obtaining a peak sampling point index bit of the strong light pulse signal based on an optimal index bit searching scheme; and obtaining the index bit of the peak sampling point of the quantum optical pulse signal based on the index bit of the peak sampling point of the strong optical pulse signal and the optimal sampling value extraction scheme, and extracting the peak sampling value of the quantum optical pulse signal.
The quantum optical pulse signal following a gaussian distribution can be expressed as:
g[i]＝xi+jpi
wherein x isiAnd piThe canonical positions and the canonical momentums respectively representing continuous variables, both obey a Gaussian distribution, i.e. xi，pi～N(0，VA)，VAModulating the variance for the signal;
g [ i ] is the complex amplitude of a continuous variable, i is the position index of a Gaussian data sequence, i belongs to { 1., N }, wherein N is the quantum optical pulse signal length; j is an imaginary unit.
The intense light pulse signal can be expressed as:
p[i]＝C
where C is a constant amplitude, p [ i ] represents a specific value with a position index i in the intense light pulse signal, i ∈ { 1., N }.
The emission light pulse sequence can be expressed as:
[p[1]，g[1]，p[2]，g[2]，…，p[N]，g[N]]
the electrical signal oversampling scheme is that R ═ frepThe electrical signal is sampled at a sampling rate of x r, where frepR is the oversampling rate for the transmission frequency of the pulse signal. The resulting sampling points can be expressed as:
[A[1]，A[2]，…，A[i]，…A[M]|
where A [. cndot. ] represents the sample value, i represents the sample point index, and M represents the sample length.
The optimal index bit searching scheme is that all sampling points are divided by taking twice oversampling rate as a unit, and the obtained sampling point array in a period is as follows:
|A[1]，A[2]，…，A[i]，…A[2r]|
finding the maximum value in the array to obtain the index bit i corresponding to the maximum valuemax。
The optimal sampling value extraction scheme is that according to imaxLooking for quantum optical pulse peak index bits, i.e.
iopt＝mod((imax+r-1)，2r)+1
Wherein ioptMod is the modulus operator for the optimal quantum optical pulse peak index bits. A [ i ]opt]Namely the peak sampling value of the quantum optical pulse signal.
The principle of the continuous variable quantum key distribution asynchronous sampling method is as follows:
in a continuous variable quantum key distribution system, a legal sender firstly prepares a quantum optical pulse signal which obeys Gaussian distribution, then prepares an intense optical pulse signal with constant amplitude, and then forms an emitted optical pulse sequence by the intense optical pulse signal through an optical time delay line and an optical beam combinerThe sequence can be represented as [ p [1 ]]，g[1]，p[2]，g[2]，…，p[N]，g[N]]Total length of transmission sequence N-108The transmitting end is connected with frepPulsed transmission is performed at a system frequency of 100 MHz.
After passing through a channel, a legal receiver receives an optical signal, obtains an output electrical signal through coherent detection, and oversamples the electrical signal, wherein the sampling rate is R ═ frepX r is 1GHz, i.e. the oversampling ratio r is 10; then all sampling points are divided by using twice oversampling rate as unit to obtain sampling point array in one period as [ A [1 ]]，A[2]，...，A[i]，…A[20]]Finding the maximum value in the array to obtain the index bit corresponding to the maximum value as imax12; according to imaxLooking up the quantum optical pulse peak index bit, iopt＝mod((imax+ r-1), 2r) +1 ═ 2; at this time A2]The peak sampling value of the quantum optical pulse signal is obtained; and performing the operation on each segmentation unit, extracting a peak value sampling value of the quantum optical pulse signal in each period, and completing asynchronous sampling of the quantum optical signal in continuous variable quantum key distribution.
The invention also provides a continuous variable quantum key distribution asynchronous sampling system, which comprises the following modules:
a sending end: firstly, quantum optical pulse signals which obey Gaussian distribution are constructed, then strong optical pulse signals with constant amplitude values are constructed, and finally the strong optical pulse signals are inserted into the quantum optical pulse signals.
The sending end specifically includes: firstly, constructing a quantum optical pulse signal which follows Gaussian distribution, wherein the signal is generated by a random number generator and a photoelectric modulator; then constructing a strong light pulse signal with constant amplitude, wherein the signal is generated by a photoelectric modulator; the module finally inserts the strong light pulse signal into the quantum light pulse signal to form a transmitting light pulse sequence, and the operation is completed by an optical time delay line and an optical beam combiner.
Receiving end: firstly, oversampling is carried out on a received signal, then index bits of sampling points of peaks of the strong light pulse signal are searched, and finally sampling values of the peaks of the quantum light pulse signal are extracted based on the index bits.
The sending end specifically includes: firstly, detecting a received optical pulse signal by using a coherent detector, and oversampling an output electric signal; in a period (including a strong light pulse signal and a quantum light pulse signal), obtaining a peak sampling point index bit of the strong light pulse signal based on an optimal index bit searching scheme; and finally, obtaining the index bit of the quantum optical pulse signal peak sampling point based on the index bit of the highlight optical pulse signal peak sampling point and the optimal sampling value extraction scheme, and extracting the peak sampling value of the quantum optical pulse signal.
The embodiment of the invention provides a continuous variable quantum key distribution asynchronous sampling method and system, which are characterized in that an optimal sampling point is judged by using a strong light pulse signal with constant amplitude, and the optimal sampling point of the quantum light pulse signal is extracted based on the optimal sampling point, so that a synchronous clock signal is not required to be transmitted, and the hardware complexity is reduced; the sampling deviation caused by non-homologous clock jitter can be eliminated, and the sampling deviation caused by clock signal jitter can be eliminated because the optimal index bit search and the optimal sampling value extraction are carried out on the quantum optical pulse signals in each period; the adopted intense light pulse signal can also be used for realizing polarization compensation and phase recovery, and the channel damage resistance of the system is improved.
Those skilled in the art will appreciate that, in addition to implementing the system and its various devices, modules, units provided by the present invention as pure computer readable program code, the system and its various devices, modules, units provided by the present invention can be fully implemented by logically programming method steps in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers and the like. Therefore, the system and various devices, modules and units thereof provided by the invention can be regarded as a hardware component, and the devices, modules and units included in the system for realizing various functions can also be regarded as structures in the hardware component; means, modules, units for performing the various functions may also be regarded as structures within both software modules and hardware components for performing the method.
The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.
Claims (10)
1. A continuous variable quantum key distribution asynchronous sampling method is characterized by comprising the following steps:
step S1: constructing quantum optical pulse signals which obey Gaussian distribution, constructing strong optical pulse signals with constant amplitude, and then inserting the strong optical pulse signals into the quantum optical pulse signals to be transmitted;
step S2: and oversampling the received optical pulse signal, searching index bits of peak sampling points of the strong optical pulse signal, and extracting peak sampling values of the quantum optical pulse signal based on the index bits.
2. The continuous variable quantum key distribution asynchronous sampling method according to claim 1, wherein the step S1 comprises:
step S1.1: constructing a quantum optical pulse signal following a Gaussian distribution, the quantum optical pulse signal being generated by a random number generator and an optoelectronic modulator;
step S1.2: constructing an intense light pulse signal of constant amplitude, the intense light pulse signal being generated by an electro-optical modulator;
step S1.3: and (3) inserting the strong light pulse signal into the quantum light pulse signal to form a transmitting light pulse sequence, wherein the operation is completed by an optical time delay line and an optical beam combiner.
3. The continuous variable quantum key distribution asynchronous sampling method according to claim 1, wherein the step S2 comprises:
step S2.1: detecting the received optical pulse signal by using a coherent detector, and oversampling the output electric signal;
step S2.2: in a period, obtaining an index bit of a sampling point of a peak value of the strong light pulse signal based on an optimal index bit searching scheme;
step S2.3: and obtaining the index bit of the peak sampling point of the quantum optical pulse signal based on the index bit of the peak sampling point of the strong optical pulse signal and the optimal sampling value extraction scheme, and extracting the peak sampling value of the quantum optical pulse signal.
4. The continuous variable quantum key distribution asynchronous sampling method according to claim 3, wherein the electrical signal oversampling scheme is R-frepThe electrical signal is sampled at a sampling rate of x r, where frepFor the transmission frequency of the pulse signal, r is the oversampling rate, and the resulting sampling points can be expressed as:
[A[1]，A[2]，…，A[i]，…A[M]]；
where A [. cndot. ] represents the sample value, i represents the sample point index, and M represents the sample length.
5. The continuous variable quantum key distribution asynchronous sampling method according to claim 3, wherein the optimal index bit search scheme is that all sampling points are divided by taking twice oversampling rate as a unit to obtain an array of sampling points within one period as follows:
[A[1]，A[2]，…，A[i]，…A[2r]]
finding the maximum value in the array to obtain the index bit i corresponding to the maximum valuemaxAnd r is the oversampling ratio.
6. The continuous variable quantum key distribution asynchronous sampling method according to claim 3, wherein the optimal sampling value extraction scheme is according to imaxLooking for quantum optical pulse peak index bits, i.e.
iopt＝mod((imax+r-1)，2r)+1
Wherein ioptIndexing bits for optimal quantum optical pulse peaks;
mod is the modulus operator; a [ i ]opt]Namely the peak sampling value of the quantum optical pulse signal.
7. The continuous variable quantum key distribution asynchronous sampling method according to claim 1, wherein the quantum optical pulse signal following gaussian distribution can be expressed as:
g[i]＝xi+jpi
wherein x isiAnd piThe canonical positions and the canonical momentums respectively representing continuous variables, both obey a Gaussian distribution, i.e. xi，pi～N(0，VA)，VAModulating the variance for the signal;
g [ i ] is the complex amplitude of the continuous variable;
i is a position index of the Gaussian data sequence, i belongs to { 1.., N };
n is the length of the quantum optical pulse signal;
j is an imaginary unit.
8. The continuous variable quantum key distribution asynchronous sampling method according to claim 1, wherein the intense light pulse signal is represented as:
p[i]＝C
wherein C is a constant amplitude;
p [ i ] represents a specific value with a position index i in the strong light pulse signal, i ∈ { 1.,. N }.
9. The continuous variable quantum key distribution asynchronous sampling method according to claim 1, wherein strong light pulse signals are inserted between quantum light pulse signals, and the emitted light pulse sequence is represented as:
[p[1]，g[1]，p[2]，g[2]，…，p[N]，g[N]]。
10. a continuous variable quantum key distribution asynchronous sampling system, comprising:
a sending end: constructing quantum optical pulse signals which obey Gaussian distribution, constructing strong optical pulse signals with constant amplitude, and inserting the strong optical pulse signals into the quantum optical pulse signals to be transmitted;
receiving end: receiving a quantum optical pulse signal, performing oversampling on the received optical pulse signal, searching an index bit of a peak sampling point of the strong optical pulse signal, and extracting a peak sampling value of the quantum optical pulse signal based on the index bit;
the transmitting end comprises:
module M1.1: constructing a quantum optical pulse signal following a Gaussian distribution, the quantum optical pulse signal being generated by a random number generator and an optoelectronic modulator;
module M1.2: constructing an intense light pulse signal of constant amplitude, the intense light pulse signal being generated by an electro-optical modulator;
module M1.3: inserting the strong light pulse signal into the quantum light pulse signal to form a transmitting light pulse sequence, wherein the operation is completed by an optical time delay line and an optical beam combiner;
the receiving end includes:
module M2.1: detecting the received optical pulse signal by using a coherent detector, and oversampling the output electric signal;
module M2.2: in a period, obtaining an index bit of a sampling point of a peak value of the strong light pulse signal based on an optimal index bit searching scheme;
module M2.3: and obtaining the index bit of the peak sampling point of the quantum optical pulse signal based on the index bit of the peak sampling point of the strong optical pulse signal and the optimal sampling value extraction scheme, and extracting the peak sampling value of the quantum optical pulse signal.
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| CN115189763B (en) * | 2022-07-12 | 2023-12-01 | 安徽问天量子科技股份有限公司 | Quantum pulse interception method based on TDC and quantum key distribution system |
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