CN116980113A - Method for screening out measurement abnormal value in atmospheric optical channel key extraction - Google Patents

Abstract

The invention discloses a measurement abnormal value screening method in atmospheric optical channel key extraction. This method compares the differential amplitude of the measured sampling values of the transmitted optical signals collected in the atmospheric optical channel, filters out the measurement abnormal values in the electrical signal data collected by the communicating parties, and reduces the impact of channel noise and equipment noise on channel reciprocity. It achieves the purpose of improving the consistency rate of the original shared random bit sequence extracted by both sides of the channel.

Description

Measurement outlier filtering method in atmospheric optical channel key extraction

Technical field

The invention belongs to the technical field of information security and relates to a method for filtering out measurement abnormal values in atmospheric optical channel key extraction.

Background technique

Today, information security has attracted much attention. In network communications, in order to protect the data transmitted by both communicating parties, it is usually necessary to encrypt the transmitted data. If a traditional public key system is used to achieve shared key distribution, its security will be challenged after quantum computers become practical. Quantum key distribution is also a technology that distributes shared keys to legitimate communication parties, but the current implementation cost of quantum key distribution is too high. How to distribute shared keys to legitimate communication parties in a low-cost and secure manner is an issue worthy of further study.

Some researchers have proposed a method to extract shared random bits from the random optical signals of reciprocal bidirectional atmospheric turbulence optical channels, and then use the extracted shared random bits to generate random keys shared by both communicating parties at both ends of the channel. When extracting random bits from random optical signals, you first need to measure and sample the random optical signals, and then perform threshold calculations on the sampled values. In an ideal state, the channel reciprocity is good, and the measured sample values do not contain noise. On this basis, the random bit sequences extracted at both ends of the channel are basically the same; but in fact, in the earth's atmospheric environment, two laser transceivers with visibility Random extreme situations will occur in the two-way optical transmission channel established by the end, which weakens the reciprocity of the channel, leads to abnormal measurement sampling values, and ultimately reduces the consistency rate of extracting random bit sequences at both ends of the channel. The Chinese invention patent with application number 202011376004.1 points out that the premise to ensure that the random bit sequences extracted at both ends of the channel (called the original shared random bit sequence) are basically the same is that the bidirectional optical transmission channel has good reciprocity, so when extracting the actual key It is necessary to filter out the outliers after obtaining the random optical signal measurement sample values, and then perform threshold calculation to obtain the original shared random bit sequence. Filtering out outliers through measurement can significantly improve the consistency rate of extracting the original shared random bit sequence at both ends of the channel. The invention discloses a method for filtering out measurement abnormal values in atmospheric optical channel key extraction. This method filters out measurement abnormal values by comparing the differential amplitudes of measured sample values at both ends of the channel, thereby improving the extraction of original values at both ends of the channel. Consistency rate of shared random bit sequences.

Contents of the invention

The purpose of the present invention is to provide a method for filtering out measurement abnormal values in atmospheric optical channel key extraction. By comparing the differential amplitudes of the measurement sample values at both ends of the atmospheric two-way optical channel, the measurement abnormal values are filtered out. On this basis Then quantization, negotiation and other operations are performed to improve the consistency rate of extracting the shared random bit sequence at both ends of the channel.

The technical solution of this method is implemented as follows: a measurement outlier differential amplitude comparison and screening method in atmospheric optical channel key extraction, which is characterized in that the required hardware system and execution steps are as follows:

Laser transceiver A and laser transceiver B are required, and laser transceiver A and laser transceiver B can see each other. Laser transceiver A includes laser A, transceiver optical system A, detector A and computer A. Laser transceiver B includes laser B, transceiver optical system B, detector B and computer B. As shown in Figure 1, the laser signal A001 emitted by the laser A is emitted into the atmospheric turbulence channel through the optical transmission system A. The laser signal A001 reaches the optical system B and then is incident on the detector B; the laser signal A001 emitted by the laser B is The laser signal B001 is emitted into the atmospheric turbulence channel through the optical system B. The laser signal B001 reaches the optical system A and then is incident on the detector A. The computer A collects the electrical signal output by the detector A in real time. The computer B Collect the electrical signal output by detector B in real time.

1) The first part of this method is to make laser transceiver A and laser transceiver B work normally. The specific operations include:

Step Step101: Make laser A and laser B work normally, make detector A and detector B work normally, make computer A and computer B work normally, make the receiving and receiving optical system A and the receiving and receiving optical system B align with each other and work normally.

2) The second part of this method performs the following operations in laser transceiver A:

Step Step201: Create a counter CounterA in computer A, let CounterA = 1; let time t _A = 0; create a one-dimensional array ArrayA containing N elements in the memory of computer A, and the array ArrayA is used to store the detector A The amplitude sample value of the output electrical signal; create a one-dimensional array ArrayA_1 containing N elements in the memory of computer A. The array ArrayA_1 is used to store the result of normalization processing of the sample values in the array ArrayA; in the memory of computer A Create a one-way queue QueueA with a length of m, where m is an even number less than N. The one-way queue QueueA is used to temporarily store the differential amplitude of adjacent elements in the array ArrayA_1; create a length of N in the memory of computer A One-dimensional array ArrayAA, array ArrayAA is used to store the sum of elements in the one-way queue QueueA at different times; create a one-dimensional array ArrayA_2 in the memory of computer A, and array ArrayA_2 is used to store the elements in array ArrayA_1 after filtering out outliers. Result: Create a list ListA in the memory of computer A. List ListA is used to store random bit sequences, making list ListA empty; the one-way queue structure is shown in Figure 2;

Step Step202: At time t _A , the collection program of laser transceiver A samples the amplitude of the electrical signal output by detector A and obtains a sampling value C001; assigns the CounterA-th element of the array ArrayA as the sampling value C001;

Step Step203: Let CounterA=CounterA+1; let t _A =t _A + δ _t , δ _t is the sampling time interval;

Step Step204: If CounterA>N, go to Step 205, otherwise go to Step 202;

Step Step205: In computer A, use the program to perform the following operations on i=1,2,...,N-1,N: perform normalization processing on each sample value in the array ArrayA:

Step Step205-1: Let I _A [i] represent the i-th sample value in the array ArrayA; I _{A_1} [i] represents the result of normalization of the i-th sample value in the array ArrayA;

Step Step205-2: Let Assign the i-th element in the array ArryaA_1 to I _{A_1} [i]; where i' and i" are both positive integers;

Step Step206: Target the Do the following:

Step Step206-1: Let I _{A_1} [i] represent the value of the i-th element in the array ArrayA_1, let V _A =|I _{A_1} [i]-I _{A_1} [i+1]|, where |x| represents the value of x absolute value;

Step Step206-2: Enqueue V _A into the one-way queue QueueA;

Step Step207: Target the Do the following:

Step Step207-1: Let I _{A_1} [i] represent the value of the i-th element in array ArrayA_1, and let V _A =|I _{A_1} [i]-I _{A_1} [i+1]|;

Step Step207-2: Enqueue V _A into the one-way queue QueueA, let S _A equal the sum of all element values in the current one-way queue QueueA, and add the first element in the array ArrayAA Each element is assigned the value S _A ; when the one-way queue QueueA is full, the head element of the queue is first dequeued, then the remaining elements are moved one unit toward the head of the queue, and finally the queue operation is performed, as shown in Figure 3 ;

Step Step208: Target the Do the following:

Step Step208-1: Let Q _A represent the head element of the current one-way queue QueueA, dequeue Q _A from the one-way queue QueueA, and move the remaining elements one unit toward the head of the queue;

Step Step208-2: Let S _A be equal to the sum of all element values in the current one-way queue QueueA; elements are assigned the value S _A ;

Step Step209: Laser transceiver A sends the array ArrayAA to laser transceiver B.

3) The third part of this method performs the following operations in laser transceiver B:

Step Step 301: Create a counter CounterB in computer B, let CounterB = 1; let time t _B = 0; create a one-dimensional array ArrayB containing N elements in the memory of computer B. ArrayB is used to store detector B. The amplitude sampling value of the output electrical signal; create a one-dimensional array ArrayB_1 containing N elements in the memory of computer B. ArrayB_1 is used to store the result of normalization of the sampling value of array ArrayB; in the memory of computer B Create a one-way queue QueueB with a length of m, where m is an even number less than N. The one-way queue QueueB is used to temporarily store the differential amplitude of adjacent elements in the array ArrayB_1; create a length of N in the memory of computer B One-dimensional array ArrayBB. ArrayBB is used to store the sum of elements in the one-way queue QueueA at different times. Create a one-dimensional array ArrayBD with a length of N in the memory of computer B. ArrayBD is used to store the first round of outlier screening. Marked index information; create a one-way queue QueueBD of length n in the memory of computer B, where n is an odd number less than N. The one-way queue QueueBD is used to temporarily store the data in the array ArrayBD; in the memory of computer B Create a one-dimensional array ArrayBP with a length of N to store the index information marked in the second round of outlier screening; create a one-dimensional array ArrayB_2 in the memory of computer B. ArrayB_2 is used to store the elements in array ArrayB_1 after exceptions. The result after value filtering; create a list ListB in the memory of computer B. ListB is used to store random bit sequences, making listB empty; the one-way queue structure is shown in Figure 2;

Step Step302: At time t _B , laser transceiver B samples the amplitude of the electrical signal output by detector B and obtains a sampling value D001; assigns the CounterB-th element of the array ArrayB as the sampling value D001;

Step Step303: Let CounterB=CounterB+1; let t _B =t _B + δ _t , δ _t is the sampling time interval;

Step Step304: If CounterB>N, go to Step 305, otherwise go to Step 302;

Step Step305: In computer B, use the program to perform the following operations on i=1, 2,..., N-1, N: perform normalization processing on each sample value in the array ArrayB:

Step Step305-1: Let I _B [i] represent the i-th sample value in the array ArrayB; I _{B_1} [i] represents the result of normalization of the i-th sample value in the array ArrayB;

Step Step305-2: Let Assign the i-th element in the array ArryaB_1 to I _{B_1} [i]; where i′ and i″ are both positive integers;

Step Step306: Target the Do the following:

Step Step306-1: Let I _{B_1} [i] represent the value of the i-th element in array ArrayB_1, and let V _B =|I _{B_1} [i]-I _{B_1} [i+1]|;

Step Step306-2: Enqueue V _B into the one-way queue QueueB;

Step Step307: Target the Do the following:

Step Step307-1: Let I _{B_1} [i] represent the value of the i-th element in array ArrayB_1, and let V _B =|I _{B_1} [i]-I _{B_1} [i+1]|;

Step Step 307-2: Enqueue V _B into the one-way queue QueueB. Let S _B be equal to the sum of all element values in the current one-way queue QueueB. Add the first element in the array ArrayBB. Each element is assigned a value of S _B ; when the one-way queue QueueB is full, the head element of the queue is first dequeued, then the remaining elements are moved one unit toward the head of the queue, and finally the queue operation is performed, as shown in Figure 3 ;

Step Step308: Target the Do the following:

Step Step 308-1: Let Q _B represent the head element of the current one-way queue QueueB, dequeue Q _B from the one-way queue QueueB, and move the remaining elements one unit toward the head of the team;

Step Step308-2: Let S _B be equal to the sum of all element values in the current one-way queue QueueB; elements are assigned the value S _B .

4) In the fourth part of this method, after the laser transceiver B receives the array ArrayAA sent by the laser transceiver A in step 209, the computer B of the laser transceiver B determines the measurement abnormal value index. The specific operation steps are as follows:

Step Step 401: Let T _B be the first round of abnormal screening decision threshold, and perform the following operations for i=1, 2,..., N-1, N respectively:

Step Step401-1: Let I _AA [i] represent the value of the i-th element in the array ArrayAA, and let I _BB [i] represent the value of the i-th element in the array ArrayBB;

Step Step401-2: Let

Step Step401-3: If P _B ≥ T _B , assign the i-th element in the array ArrayBD to 1;

Step Step401-4: If P _B <T _B , assign the i-th element in the array ArrayBD to 0;

Step Step402: Indicates that x is rounded down to the nearest integer, respectively, for/> Do the following:

Step Step402-1: Let I _BD [i] represent the value of the i-th element in the array ArrayBD, and enqueue I _BD [i] into the one-way queue QueueBD;

Step Step 403: Let T _BD be the second round of abnormal screening judgment threshold, Indicates that x is rounded up, and each is directed to/> Do the following:

Step Step403-1: Let I _BD [i] represent the value of the i-th element in the array ArrayBD, enqueue I _BD [i] into the one-way queue QueueBD, and let S _BD equal the value of all elements in the current one-way queue QueueBD and; when the one-way queue QueueBD is full, the head element of the queue is first dequeued, and then the remaining elements are moved one unit toward the head of the queue, and finally the queue operation is performed, as shown in Figure 3;

Step Step403-2: If Then the /> in the array ArrayBP elements are assigned a value of 1;

Step Step403-3: If Then the /> in the array ArrayBP elements are assigned a value of 0;

Step Step404: Target in turn Do the following:

Step Step 404-1: Let Q _BD represent the head element of the one-way queue QueueBD, dequeue Q _BD from the one-way queue QueueBD, and move the remaining elements one unit toward the head of the team, and let S _BD be equal to the current one-way queue QueueBD. The sum of all element values;

Step Step404-2: If Then the /> in the array ArrayBP elements are assigned a value of 1;

Step Step404-3: If Then the /> in the array ArrayBP elements are assigned a value of 0;

Step Step 405: Laser transceiver B sends the array ArrayBP to laser transceiver A.

5) In the fifth part of this method, after the laser transceiver A receives the array ArrayBP sent by the laser transceiver B in Step 405, the computer A of the laser transceiver A performs outlier filtering and thresholding operations on the array ArrayA_1. Calculation, the specific steps are as follows:

Step Step501: Let j=1, j is always a positive integer, and do the following operations for i=1,2,…,N-1,N respectively:

Step Step501-1: Let I _BP [i] represent the value of the i-th element in the array ArrayBP, let I _{A_1} [i] represent the value of the i-th element in the array ArrayA_1; let I _{A_2} [j] represent the value of the i-th element in the array ArrayA_2 The value of j elements;

Step Step501-2: If I _BP [i]=0, then let I _{A_2} [j]=I _{A_1} [i], let j=j+1;

Step Step501-3: If I _BP [i]=1, no operation is performed;

Step Step502: Use the quantization algorithm to perform threshold calculation on each element in the array ArrayA_2 to obtain a random bit sequence, and store the random bit sequence in the list ListA;

Step Step 503: Laser transceiver A completes the original shared random bit sequence extraction operation.

6) In the sixth part of this method, computer B of laser transceiver B performs outlier filtering and threshold calculation on array ArrayB_1. The specific steps are as follows:

Step Step601: Let j=1, and do the following operations for i=1,2,…,N-1,N respectively:

Step Step601-1: Let I _BP [i] represent the value of the i-th element in the array ArrayBP, let I _{B_1} [i] represent the value of the i-th element in the array ArrayB_1; let I _{B_2} [j] represent the value of the i-th element in the array ArrayB_2 The value of j elements;

Step Step601-2: If I _BP [i]=0, then let I _{B_2} [j]=I _{B_1} [i], let j=j+1;

Step Step601-3: If I _BP [i]=1, do not perform any operation;

Step Step602: Use the quantization algorithm to perform threshold calculation on each element in the array ArrayB_2 to obtain a random bit sequence, and store the random bit sequence in the list ListB;

Step Step 603: Laser transceiver B completes the original shared random bit sequence extraction operation.

7) The seventh part of this method corrects the inconsistent bits in the original shared random bit sequence extracted by laser transceiver A and laser transceiver B. The specific steps are as follows:

Step Step 701: Use error estimation, key agreement, and error checking technology in quantum key distribution post-processing to find and correct the inconsistent bits in the original shared random bit sequences stored in ListA and ListB, so that ListA and ListB The random bits in the list ListB are consistent, so that the laser transceiver A and the laser transceiver B have the same bit sequence.

When implementing this method, first execute the first part of this method, then start executing the second and third parts of this method at the same time, then execute the fourth part, then execute the fifth and sixth parts at the same time, and finally execute this method Part VII of.

Positive effects of the present invention: The method of the present invention is to filter out measurement abnormal values in atmospheric optical channel key extraction through differential amplitude comparison; use this method to calculate the differential amplitude of the measurement sampling values of both communicating parties respectively, and transmit the differential amplitude value, and compares the differential amplitude of the measured sample values at both ends of the atmospheric bidirectional optical channel to filter out measurement outliers. Screening out outliers and then performing threshold calculations on them can significantly improve the consistency rate of both sides of the channel in extracting the original shared random bit sequence.

Description of the drawings

Figure 1 is a schematic diagram of the system hardware structure.

Figure 2 is a schematic diagram of the one-way queue structure.

Figure 3 is an example diagram of one-way queuing.

Detailed ways

In order to make the features and advantages of this method more clear, this method will be further described below with reference to specific embodiments. Obviously, the described embodiments are only some of the embodiments of the present invention, but not all of the embodiments. In this embodiment, laser transceiver A and laser transceiver B are located on the roofs of two high-rise buildings respectively. Detector A and detector B are both PIN photoelectric detectors. Computer A and laser transceiver of laser transceiver A Computer B of terminal B is connected to the Internet. Computer A and computer B can communicate with each other through the Internet to perform error estimation, key negotiation, and error checking operations through the Internet channel. Both laser A and laser B output laser signals with stable power, and the power of the laser signal output by laser A is equal to the power of the laser signal output by laser B. The paper published in the Journal of Cryptozoology, Volume 2, Issue 2, 2015, pages 113-121, provides a detailed introduction to the error estimation, key negotiation, and error checking operations in quantum key distribution post-processing. By borrowing the error estimation, key negotiation, and error checking technologies used in quantum key distribution post-processing, we can perform inconsistent bit error correction on the original shared random bit sequence extracted by the two laser transceivers, and determine the final shared randomness. The bit sequence becomes a shared random bit sequence that can be used in practice. The receiving and receiving optical system A and the receiving and receiving optical system B use the method described in the paper on pages 16422 to 16441 of "Optics Express", Volume 26, Issue 13, 2018, to ensure that the two-way channel between the laser transceiver A and the laser transceiver B is reciprocal.

The technical solution of this method is implemented as follows: a measurement outlier differential amplitude comparison and screening method in atmospheric optical channel key extraction, which is characterized in that the required hardware system and execution steps are as follows:

Laser transceiver A and laser transceiver B are required, and laser transceiver A and laser transceiver B can see each other. Laser transceiver A includes laser A, transceiver optical system A, detector A and computer A. Laser transceiver B includes laser B, transceiver optical system B, detector B and computer B. As shown in Figure 1, the laser signal A001 emitted by the laser A is emitted into the atmospheric turbulence channel through the optical transmission system A. The laser signal A001 reaches the optical system B and then is incident on the detector B; the laser signal A001 emitted by the laser B is The laser signal B001 is emitted into the atmospheric turbulence channel through the optical system B. The laser signal B001 reaches the optical system A and then is incident on the detector A. The computer A collects the electrical signal output by the detector A in real time. The computer B Collect the electrical signal output by detector B in real time.

1) The first part of this method is to make laser transceiver A and laser transceiver B work normally. The specific operations include:

Step Step101: Make laser A and laser B work normally, make detector A and detector B work normally, make computer A and computer B work normally, make the receiving and receiving optical system A and the receiving and receiving optical system B align with each other and work normally.

2) The second part of this method performs the following operations in laser transceiver A:

Step Step201: Create a counter CounterA in computer A, let CounterA = 1; let time t _A = 0; create a one-dimensional array ArrayA containing N elements in the memory of computer A, and the array ArrayA is used to store the detector A The amplitude sample value of the output electrical signal; create a one-dimensional array ArrayA_1 containing N elements in the memory of computer A. The array ArrayA_1 is used to store the result of normalization processing of the sample values in the array ArrayA; in the memory of computer A Create a one-way queue QueueA with a length of m, where m is an even number less than N. The one-way queue QueueA is used to temporarily store the differential amplitude of adjacent elements in the array ArrayA_1; create a length of N in the memory of computer A One-dimensional array ArrayAA, array ArrayAA is used to store the sum of elements in the one-way queue QueueA at different times; create a one-dimensional array ArrayA_2 in the memory of computer A, and array ArrayA_2 is used to store the elements in array ArrayA_1 after filtering out outliers. Result: Create a list ListA in the memory of computer A. List ListA is used to store random bit sequences, making list ListA empty; the one-way queue structure is shown in Figure 2;

Step Step202: At time t _A , the collection program of laser transceiver A samples the amplitude of the electrical signal output by detector A and obtains a sampling value C001; assigns the CounterA-th element of the array ArrayA as the sampling value C001;

Step Step203: Let CounterA=CounterA+1; let t _A =t _A + δ _t , δ _t is the sampling time interval;

Step Step204: If CounterA>N, go to Step 205, otherwise go to Step 202;

Step Step205: In computer A, use the program to perform the following operations on i=1,2,...,N-1,N: perform normalization processing on each sample value in the array ArrayA:

Step Step205-1: Let I _A [i] represent the i-th sample value in the array ArrayA; I _{A_1} [i] represents the result of normalization of the i-th sample value in the array ArrayA;

Step Step205-2: Let Assign the i-th element in the array ArryaA_1 to I _{A_1} [i]; where i' and i" are both positive integers;

Step Step206: Target the Do the following:

Step Step206-1: Let I _{A_1} [i] represent the value of the i-th element in the array ArrayA_1, let V _A =|I _{A_1} [i]-I _{A_1} [i+1]|, where |x| represents the value of x absolute value;

Step Step206-2: Enqueue V _A into the one-way queue QueueA;

Step Step207: Target the Do the following:

Step Step207-1: Let I _{A_1} [i] represent the value of the i-th element in array ArrayA_1, and let V _A =|I _{A_1} [i]-I _{A_1} [i+1]|;

Step Step207-2: Enqueue V _A into the one-way queue QueueA, let S _A equal the sum of all element values in the current one-way queue QueueA, and add the first element in the array ArrayAA Each element is assigned the value S _A ; when the one-way queue QueueA is full, the head element of the queue is first dequeued, then the remaining elements are moved one unit toward the head of the queue, and finally the queue operation is performed, as shown in Figure 3 ;

Step Step208: Target the Do the following:

Step Step208-1: Let Q _A represent the head element of the current one-way queue QueueA, dequeue Q _A from the one-way queue QueueA, and move the remaining elements one unit toward the head of the queue;

Step Step208-2: Let S _A be equal to the sum of all element values in the current one-way queue QueueA; elements are assigned the value S _A ;

Step Step209: Laser transceiver A sends the array ArrayAA to laser transceiver B.

3) The third part of this method performs the following operations in laser transceiver B:

Step Step 301: Create a counter CounterB in computer B, let CounterB = 1; let time t _B = 0; create a one-dimensional array ArrayB containing N elements in the memory of computer B. ArrayB is used to store detector B. The amplitude sampling value of the output electrical signal; create a one-dimensional array ArrayB_1 containing N elements in the memory of computer B. ArrayB_1 is used to store the result of normalization of the sampling value of array ArrayB; in the memory of computer B Create a one-way queue QueueB with a length of m, where m is an even number less than N. The one-way queue QueueB is used to temporarily store the differential amplitude of adjacent elements in the array ArrayB_1; create a length of N in the memory of computer B One-dimensional array ArrayBB. ArrayBB is used to store the sum of elements in the one-way queue QueueA at different times. Create a one-dimensional array ArrayBD with a length of N in the memory of computer B. ArrayBD is used to store the first round of outlier screening. Marked index information; create a one-way queue QueueBD of length n in the memory of computer B, where n is an odd number less than N. The one-way queue QueueBD is used to temporarily store the data in the array ArrayBD; in the memory of computer B Create a one-dimensional array ArrayBP with a length of N to store the index information marked in the second round of outlier screening; create a one-dimensional array ArrayB_2 in the memory of computer B. ArrayB_2 is used to store the elements in array ArrayB_1 after exceptions. The result after value filtering; create a list ListB in the memory of computer B. ListB is used to store random bit sequences, making listB empty; the one-way queue structure is shown in Figure 2;

Step Step302: At time t _B , laser transceiver B samples the amplitude of the electrical signal output by detector B and obtains a sampling value D001; assigns the CounterB-th element of the array ArrayB as the sampling value D001;

Step Step303: Let CounterB=CounterB+1; let t _B =t _B + δ _t , δ _t is the sampling time interval;

Step Step304: If CounterB>N, go to Step 305, otherwise go to Step 302;

Step Step305: In computer B, use the program to perform the following operations on i=1,2,...,N-1,N: perform normalization processing on each sample value in the array ArrayB:

Step Step305-1: Let I _B [i] represent the i-th sample value in the array ArrayB; I _{B_1} [i] represents the result of normalization of the i-th sample value in the array ArrayB;

Step Step305-2: Let Assign the i-th element in the array ArryaB_1 to I _{B_1} [i]; where i' and i" are both positive integers;

Step Step306: Target the Do the following:

Step Step306-1: Let I _{B_1} [i] represent the value of the i-th element in array ArrayB_1, and let V _B =|I _{B_1} [i]-I _{B_1} [i+1]|;

Step Step306-2: Enqueue V _B into the one-way queue QueueB;

Step Step307: Target the Do the following:

Step Step307-1: Let I _{B_1} [i] represent the value of the i-th element in array ArrayB_1, and let V _B =|I _{B_1} [i]-I _{B_1} [i+1]|;

Step Step 307-2: Enqueue V _B into the one-way queue QueueB. Let S _B be equal to the sum of all element values in the current one-way queue QueueB. Add the first element in the array ArrayBB. Each element is assigned a value of S _B ; when the one-way queue QueueB is full, the head element of the queue is first dequeued, then the remaining elements are moved one unit toward the head of the queue, and finally the queue operation is performed, as shown in Figure 3 ;

Step Step308: Target the Do the following:

Step Step 308-1: Let Q _B represent the head element of the current one-way queue QueueB, dequeue Q _B from the one-way queue QueueB, and move the remaining elements one unit toward the head of the team;

Step Step308-2: Let S _B be equal to the sum of all element values in the current one-way queue QueueB; elements are assigned the value S _B .

4) In the fourth part of this method, after the laser transceiver B receives the array ArrayAA sent by the laser transceiver A in step 209, the computer B of the laser transceiver B determines the measurement abnormal value index. The specific operation steps are as follows:

Step Step 401: Let T _B be the first round of abnormal screening decision threshold, and perform the following operations for i=1, 2,..., N-1, N respectively:

Step Step401-1: Let I _AA [i] represent the value of the i-th element in the array ArrayAA, and let I _BB [i] represent the value of the i-th element in the array ArrayBB;

Step Step401-2: Let

Step Step401-3: If P _B ≥ T _B , assign the i-th element in the array ArrayBD to 1;

Step Step401-4: If P _B <T _B , assign the i-th element in the array ArrayBD to 0;

Step Step402: Indicates that x is rounded down to the nearest integer, respectively, for/> Do the following:

Step Step402-1: Let I _BD [i] represent the value of the i-th element in the array ArrayBD, and enqueue I _BD [i] into the one-way queue QueueBD;

Step Step 403: Let T _BD be the second round of abnormal screening judgment threshold, Indicates that x is rounded up, and each is directed to/> Do the following:

Step Step403-1: Let I _BD [i] represent the value of the i-th element in the array ArrayBD, enqueue I _BD [i] into the one-way queue QueueBD, and let S _BD equal the value of all elements in the current one-way queue QueueBD and; when the one-way queue QueueBD is full, the head element of the queue is first dequeued, and then the remaining elements are moved one unit toward the head of the queue, and finally the queue operation is performed, as shown in Figure 3;

Step Step403-2: If Then the /> in the array ArrayBP elements are assigned a value of 1;

Step Step403-3: If Then the /> in the array ArrayBP elements are assigned a value of 0;

Step Step404: Target in turn Do the following:

Step Step 404-1: Let Q _BD represent the head element of the one-way queue QueueBD, dequeue Q _BD from the one-way queue QueueBD, and move the remaining elements one unit toward the head of the team, and let S _BD be equal to the current one-way queue QueueBD. The sum of all element values;

Step Step404-2: If Then the /> in the array ArrayBP elements are assigned a value of 1;

Step Step404-3: If Then the /> in the array ArrayBP elements are assigned a value of 0;

Step Step 405: Laser transceiver B sends the array ArrayBP to laser transceiver A.

5) In the fifth part of this method, after the laser transceiver A receives the array ArrayBP sent by the laser transceiver B in Step 405, the computer A of the laser transceiver A performs outlier filtering and thresholding operations on the array ArrayA_1. Calculation, the specific steps are as follows:

Step Step501: Let j=1, j is always a positive integer, and do the following operations for i=1,2,…,N-1,N respectively:

Step Step501-1: Let I _BP [i] represent the value of the i-th element in the array ArrayBP, let I _{A_1} [i] represent the value of the i-th element in the array ArrayA_1; let I _{A_2} [j] represent the value of the i-th element in the array ArrayA_2 The value of j elements;

Step Step501-2: If I _BP [i]=0, then let I _{A_2} [j]=I _{A_1} [i], let j=j+1;

Step Step501-3: If I _BP [i]=1, no operation is performed;

Step Step502: Use the quantization algorithm to perform threshold calculation on each element in the array ArrayA_2 to obtain a random bit sequence, and store the random bit sequence in the list ListA;

Step Step 503: Laser transceiver A completes the original shared random bit sequence extraction operation.

6) In the sixth part of this method, computer B of laser transceiver B performs outlier filtering and threshold calculation on array ArrayB_1. The specific steps are as follows:

Step Step601: Let j=1, and do the following operations for i=1,2,…,N-1,N respectively:

Step Step601-1: Let I _BP [i] represent the value of the i-th element in the array ArrayBP, let I _{B_1} [i] represent the value of the i-th element in the array ArrayB_1; let I _{B_2} [j] represent the value of the i-th element in the array ArrayB_2 The value of j elements;

Step Step601-2: If I _BP [i]=0, then let I _{B_2} [j]=I _{B_1} [i], let j=j+1;

Step Step601-3: If I _BP [i]=1, do not perform any operation;

Step Step602: Use the quantization algorithm to perform threshold calculation on each element in the array ArrayB_2 to obtain a random bit sequence, and store the random bit sequence in the list ListB;

Step Step 603: Laser transceiver B completes the original shared random bit sequence extraction operation.

7) The seventh part of this method corrects the inconsistent bits in the original shared random bit sequence extracted by laser transceiver A and laser transceiver B. The specific steps are as follows:

Step Step 701: Use error estimation, key agreement, and error checking technology in quantum key distribution post-processing to find and correct the inconsistent bits in the original shared random bit sequences stored in ListA and ListB, so that ListA and ListB The random bits in the list ListB are consistent, so that the laser transceiver A and the laser transceiver B have the same bit sequence.

When implementing this method, first execute the first part of this method, then start executing the second and third parts of this method at the same time, then execute the fourth part, then execute the fifth and sixth parts at the same time, and finally execute this method Part VII of.

In this embodiment, N = 20000; δ _t = 0.2 milliseconds; m = 4; n = 5; _TB = 0.9; T _BD = 0.5; the output light intensities of laser A and laser B are stable in time. The light intensity output by laser A and laser B is the same.

Those skilled in the art should understand that arrays and lists are concepts in computer programming. They are both collections composed of a series of elements arranged in order from front to back, and are containers for storing data. A queue is a first-in, first-out linear list that only allows insertions at one end of the list and deletion of elements at the other end. Regarding the list, there is a detailed description in 2.1 of Chapter 2 of the book "Data Structure (C Language Edition)" published by Tsinghua University Press with ISBN number 978-7-302-14751-0 and edited by Yan Weimin and Wu Weimin; Regarding arrays, there are details in Chapter 5.1 and 5.2 of Chapter 5 of the book "Data Structure (C Language Edition)" published by Tsinghua University Press with ISBN number 978-7-302-14751-0 and edited by Yan Weimin and Wu Weimin. Description: In this embodiment, the elements of arrays and lists are numbered starting from 1. For an array or list containing N elements, the first element stored is called the first element, and the last element stored is called the first element. The element is called the Nth element; array ArrayBD and array ArrayBP are arrays that mark the index information of measurement outliers. If the element value in array ArrayBD and array ArrayBP is 1, it means that the element in array ArrayA_1 and array ArrayB_1 with the same index as the element is Outliers; the difference amplitude is the absolute value of the difference between two adjacent element values. The calculation process is as shown in Step 206-1 and Step 306-1; Regarding the definition and operation of one-way queues, published by Tsinghua University Press The ISBN number is 978-7-302-14751-0 and is described in detail in Chapter 3.4 of Chapter 3 of the book "Data Structure (C Language Edition)" edited by Yan Weimin and Wu Weimin; the one-way queue structure is shown in Figure 2 ; An example of the one-way queuing process is shown in Figure 3. Array transfer is involved in Step 209 and Step 405, which can be transferred using laser communication or network communication. In step Step502 and step Step602, a quantization algorithm is used. The quantization algorithm of step Step502 and step602 in the application of the present invention refers to performing threshold calculation on the value of each element of array ArrayA_2 and array ArrayB_2 to obtain 0 and 1 bits. Sequence, for example, in this embodiment, the CQA quantization algorithm in the paper "IEEE Transactions on Mobile Computing", Volume 10, Issue 2, pages 205-215 is used for threshold calculation to obtain the 0 and 1 bit sequence. Other papers can also be used. The corresponding quantization algorithm is used for threshold calculation. Figure 3 is an example diagram of one-way queue enqueuing. Take Figure 3 as an example to briefly describe the one-way queue enqueuing and dequeuing process. In this example, the one-way queue length is 4, where D _A1 , D _A2 ..., etc. represent Elements that perform enqueue and dequeue operations. In this example diagram, when the number of elements in the queue reaches 4 and still needs to be re-entered, the head element of the queue needs to be dequeued first, and the remaining elements move one unit towards the head of the queue. , and then perform the enqueuing operation of the next element. In the present invention, the index of the elements that need to be deleted is finally obtained through two rounds of abnormal screening and determination, and the abnormal elements are deleted one by one. On this basis, operations such as quantification and information negotiation are performed on the remaining elements in the sequence.

Claims (1)

1. The differential amplitude comparison screening method for the measured outliers in the atmospheric optical channel key extraction is characterized by comprising the following steps of:

The technical scheme of the method is realized as follows: the differential amplitude comparison screening method for the measured outliers in the atmospheric optical channel key extraction is characterized by comprising the following steps of:

the laser transceiver A and the laser transceiver B are needed to be mutually viewed; the laser transceiver A comprises a laser A, a transceiver optical system A, a detector A and a computer A; the laser transceiver B comprises a laser B, a transceiver optical system B, a detector B and a computer B; the laser signal A001 sent by the laser A is sent to an atmospheric turbulence channel through the receiving and transmitting optical system A, and the laser signal A001 is incident on the detector B after reaching the receiving and transmitting optical system B; the laser signal B001 sent by the laser B is sent to an atmospheric turbulence channel through the receiving and transmitting optical system B, and the laser signal B001 is incident on the detector A after reaching the receiving and transmitting optical system A; the computer A acquires the electric signals output by the detector A in real time, and the computer B acquires the electric signals output by the detector B in real time;

1) The first part of the method is to make the laser transceiver A and the laser transceiver B work normally, and the specific operations include:

Step101: the laser A and the laser B are enabled to work normally, the detector A and the detector B are enabled to work normally, the computer A and the computer B are enabled to work normally, and the transceiver optical system A and the transceiver optical system B are enabled to align with each other and work normally;

2) The second part of the method performs the following operations in the laser transceiver a:

step201: creating a counter in computer a, wherein counter=1; let time t _A =0; creating a one-dimensional array ArrayA containing N elements in a memory of the computer A, wherein the array ArrayA is used for storing amplitude sampling values of the electric signals output by the detector A; creating a one-dimensional array ArrayA_1 containing N elements in a memory of the computer A, wherein the array ArrayA_1 is used for storing a result obtained by normalizing sampling values in the array ArrayA; creating a unidirectional queue A with the length of m in a memory of the computer A, wherein m is an even number smaller than N, and the unidirectional queue A is used for temporarily storing differential amplitude values of adjacent elements in the array ArrayA_1; creating a one-dimensional array ArrayAA with the length of N in a memory of the computer A, wherein the array ArrayAA is used for storing the sum of elements in the unidirectional queue QueueA at different times; creating a one-dimensional array ArrayA_2 in a memory of the computer A, wherein the array ArrayA_2 is used for storing a result of removing the abnormal value of the element in the array ArrayA_1; creating a list ListA in the memory of computer a, the list ListA being for storing a random bit sequence, leaving the list ListA empty;

Step202: at time t _A The acquisition program of the laser transceiver A samples the amplitude of the electric signal output by the detector A once to obtain a sampling value C001; assigning the CounterA element of the array ArrayA as a sampling value C001;

step Step203 and 203: let coutera = coutera+1; let t _A ＝t _A +δ _t ，δ _t Is a sampling time interval;

step204: if CounterA > N, go to Step205, otherwise go to Step202;

step205: in computer a, the following operations are performed for i=1, 2, …, N-1, N, respectively, in order by the program: and (3) carrying out normalization processing on each sampling value in the array A:

step205-1: let I _A [i]Representing the ith sampling value in the array ArrayA; i _{A_1} [i]Representing the result of normalized processing of the ith sampling value in the array ArrayA;

step205-2: order theAssigning the ith element in the array ArryaA_1 as I _{A_1} [i]The method comprises the steps of carrying out a first treatment on the surface of the Wherein i' and i "are both positive integers;

step206: respectively in turn forThe following operations are performed:

step206-1: let I _{A_1} [i]Representing the value of the ith element in array ArrayA_1, let V _A ＝|I _{A_1} [i]-I _{A_1} [i+1]I, wherein |x| represents taking the absolute value of x;

step206-2: will V _A Enqueue into a unidirectional queue a;

step207: respectively in turn for The following operations are performed:

step207-1: let I _{A_1} [i]Representing the value of the ith element in array ArrayA_1, let V _A ＝|I _{A_1} [i]-I _{A_1} [i+1]|；

Step207-2: will V _A Enqueue in a unidirectional queue QueueA, let S _A Equal to that in the current unidirectional queue aWith sum of element values, the first in array ArrayAAThe individual elements are assigned S _A The method comprises the steps of carrying out a first treatment on the surface of the When the queue A of the unidirectional queue is full, dequeuing the queue head element, moving the other elements to the direction of the queue head by one unit, and finally performing enqueuing operation;

step208: respectively in turn forThe following operations are performed:

step208-1: let Q _A The queue head element representing the current unidirectional queue QueueA, will Q _A Dequeuing from the unidirectional queue QueueA, and moving the other elements by one unit towards the direction of the queue head;

step208-2: let S _A Equal to the sum of all element values in the current unidirectional queue QueueA; array ArrayAA No.The individual elements are assigned S _A ；

Step209: the laser transceiver A sends the array ArrayAA to the laser transceiver B;

3) The third part of the method performs the following operations in the laser transceiver B:

step301: creating a counter in computer B, letting counter=1; let time t _B =0; creating a one-dimensional array ArrayB containing N elements in a memory of the computer B, wherein the array ArrayB is used for storing amplitude sampling values of the electric signals output by the detector B; creating a one-dimensional array ArrayB_1 containing N elements in a memory of the computer B, wherein the array ArrayB_1 is used for storing a result of normalization processing of sampling values of the array ArrayB; creating a unidirectional queue B with a length of m in a memory of the computer B, wherein m is an even number smaller than N, and the unidirectional queue B is used for temporarily storing differential amplitudes of adjacent elements in the array ArrayB_1; creation in memory of computer B A one-dimensional array ArrayBB with the length of N, wherein the array ArrayBB is used for storing the sum of elements in the unidirectional queue QueueA at different moments; creating a one-dimensional array ArrayBD with the length of N in a memory of a computer B, wherein the array ArrayBD is used for storing index information marked during the first round of outlier screening; creating a unidirectional queue QueueBD with the length of N in a memory of the computer B, wherein N is an odd number smaller than N, and the unidirectional queue QueueBD is used for temporarily storing data in an array ArrayBD; creating a one-dimensional array ArrayBP with the length of N in a memory of a computer B for storing index information of the marker during the second round of outlier screening; creating a one-dimensional array ArrayB_2 in a memory of the computer B, wherein the array ArrayB_2 is used for storing the result of the elements in the array ArrayB_1 after the abnormal values are screened out; creating a list in the memory of the computer B, the list being used for storing the random bit sequence, leaving the list empty;

step302: at time t _B The laser transceiver B samples the amplitude of the electric signal output by the detector B once to obtain a sampling value D001; assigning the CounterB elements of the array ArrayB to a sampling value D001;

Step303: let counterb=counterb+1; let t _B ＝t _B +δ _t ，δ _t Is a sampling time interval;

step304: if CounterB > N, go to Step305, otherwise go to Step302;

step305: in computer B, the following operations are performed for i=1, 2, …, N-1, N, respectively, in order by the program: and (3) carrying out normalization processing on each sampling value in the array B:

step305-1: let I _B [i]Representing the ith sampling value in the array ArrayB; i _{B_1} [i]Representing the result of normalized processing of the ith sampling value in the array ArrayB;

step305-2: order theAssigning the ith element in the array ArryaB_1 as I _{B_1} [i]The method comprises the steps of carrying out a first treatment on the surface of the Wherein i 'and i' are both positive integers；

Step306: respectively in turn forThe following operations are performed:

step306-1: let I _{B_1} [i]Representing the value of the ith element in array ArrayB_1, let V _B ＝|I _{B_1} [i]-I _{B_1} [i+1]|；

Step306-2: will V _B Enqueue into a unidirectional queue b;

step307: respectively in turn forThe following operations are performed:

step307-1: let I _{B_1} [i]Representing the value of the ith element in array ArrayB_1, let V _B ＝|I _{B_1} [i]-I _{B_1} [i+1]|；

Step307-2: will V _B Enqueue in a unidirectional queue QueueB, let S _B Equal to the sum of all element values in the current unidirectional queue QueueB, the first element in the array ArrayBBThe individual elements are assigned S _B The method comprises the steps of carrying out a first treatment on the surface of the When the queue B is full, dequeuing the queue head element, moving the other elements to the direction of the queue head by one unit, and finally performing enqueuing operation;

step308: respectively in turn forThe following operations are performed:

step308-1: let Q _B The queue head element representing the current unidirectional queue QueueB, will Q _B Dequeuing from the unidirectional queue QueueB, and moving the other elements by one unit towards the direction of the queue head;

step308-2: let S _B Equal to the sum of all element values in the current unidirectional queue QueueB; putting the array ArrayBB intoFirst, theThe individual elements are assigned S _B ；

4) After the fourth part of the method receives the array ArrayAA sent by the laser transceiver A in Step209 by the laser transceiver B, the computer B of the laser transceiver B determines the index of the measured abnormal value, and the specific operation steps are as follows:

step401: let T _B For the first round of abnormal screening decision threshold, the following operations are performed for i=1, 2, …, N-1, N in sequence:

step401-1: let I _AA [i]Representing the value of the ith element in the array ArrayAA, let I _BB [i]A value representing the ith element in the array ArrayBB;

step401-2: order the

Step401-3: if P _B ≥T _B The i element in the array ArrayBD is assigned to be 1;

Step401-4: if P _B ＜T _B Then the i element in the array ArrayBD is assigned to 0;

step402:represents rounding down on x, respectively for ++>The following operations are performed:

step402-1: let I _BD [i]Representing the value of the ith element in the array ArrayBD, will be I _BD [i]Enqueue into a unidirectional queue QueueBD;

step403: let T _BD The decision threshold is screened out for the second round of anomalies,the representation is rounded up to x, respectively forN does the following operations:

step403-1: let I _BD [i]Representing the value of the ith element in the array ArrayBD, will be I _BD [i]Enqueue in a unidirectional queue QueueBD, let S _BD Equal to the sum of all element values in the current unidirectional queue QueueBD; when the one-way queue QueueBD is full, dequeuing the queue head element, moving the other elements to the direction of the queue head by one unit, and finally performing enqueuing operation;

step403-2: if it isThen the +.>The value of each element is 1;

step403-3: if it isThen the +.>The value of each element is 0;

step404: in turn forThe following operations are performed:

step404-1: let Q _BD Queue head element representing unidirectional queue QueueBD, will Q _BD Dequeuing from the unidirectional queue QueueBD, and moving the other elements by one unit towards the direction of the queue head to enable S _BD Equal to the sum of all element values in the current unidirectional queue QueueBD;

step404-2: if it isThen the +.>The value of each element is 1;

step404-3: if it isThen the +.>The value of each element is 0;

step405: the laser transceiver B sends the array ArrayBP to the laser transceiver A;

5) After the fifth part of the method receives the array ArrayBP sent by the laser transceiver B in Step405, the computer A of the laser transceiver A performs outlier screening operation and thresholding calculation on the array ArrayA_1, and the specific steps are as follows:

step501: let j=1, j be a positive integer, and the following operations are performed for i=1, 2, …, N-1, N in order:

step501-1: let I _BP [i]Representing the value of the ith element in the array ArrayBP, let I _{A_1} [i]A value representing the i-th element in array ArrayA_1; let I _{A_2} [j]A value representing the j-th element in the array ArrayA_2;

step501-2: if I _BP [i]=0, let I _{A_2} [j]＝I _{A_1} [i]Let j=j+1;

step501-3: if I _BP [i]=1, then no operation is done;

step502: thresholding each element in the array ArrayA_2 by using a quantization algorithm to obtain a random bit sequence, and storing the random bit sequence into a list ListA;

Step503: the laser transceiver A completes the original shared random bit sequence extraction operation;

6) In the sixth part of the method, the abnormal value screening operation and thresholding calculation are carried out on the data ArrayB_1 by the computer B of the laser transceiver B, and the specific steps are as follows:

step601: let j=1, the following operations are performed for i=1, 2, …, N-1, N, respectively, in order:

step601-1: let I _BP [i]Representing the value of the ith element in the array ArrayBP, let I _{B_1} [i]A value representing the i-th element in array ArrayB_1; let I _{B_2} [j]A value representing the j-th element in the array ArrayB_2;

step601-2: if I _BP [i]=0, let I _{B_2} [j]＝I _{B_1} [i]Let j=j+1;

step601-3: if I _BP [i]=1, then no operation is done;

step602: thresholding each element in the array ArrayB_2 by using a quantization algorithm to obtain a random bit sequence, and storing the random bit sequence into a list ListB;

step603: the laser transceiver B completes the original shared random bit sequence extraction operation;

7) The seventh part of the method corrects inconsistent bits in the original shared random bit sequence extracted by the laser transceiver A and the laser transceiver B, and comprises the following specific steps:

step701: using error code estimation, key negotiation and error checking technology in the quantum key distribution post-processing to find and correct inconsistent bits in original shared random bit sequences stored in a list LittA and a list LittB, so that the random bits in the list LittA and the list LittB are consistent, and the laser transceiver A and the laser transceiver B have the same bit sequence;

In practicing the method, a first portion of the method is performed, then a second portion and a third portion of the method are performed simultaneously, then a fourth portion is performed, then a fifth portion and a sixth portion are performed simultaneously, and finally a seventh portion of the method is performed.