Quantum key distribution post-processing method introducing differential evolution

Abstract

The invention discloses a quantum key distribution post-processing method introducing differential evolution, which is used for a QKD system, the QKD system comprises N pairs of sending ends and receiving ends, N is greater than or equal to 1, and the method comprises the following steps: S1, obtaining an original quantum key; s2, carrying out key screening; s3, public comparison is carried out, and the quantum bit error rate is calculated; s4, judging whether the quantum bit error rate is lower than a preset bit error rate threshold; s5, error codes are corrected through error code negotiation; and S6, carrying out confidentiality enhancement to obtain a final quantum key. The invention discloses a quantum key distribution post-processing method introducing differential evolution, which is characterized in that a population can retain a common coding structure as much as possible by introducing a variation operation of differential evolution in an error negotiation process, the population can effectively evolve by utilizing the influence of a differential vector, the overall construction efficiency of an error correction code and the error negotiation efficiency can be improved, and the error negotiation efficiency can be improved. And the safety of QKD post-treatment is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of quantum secure communication and quantum network, and in particular to a quantum key distribution post-processing method introducing differential evolution. Background Art

[0002] Quantum information technology is a strategic high ground for the world's major economic powers. It is mainly divided into three major areas according to its application fields: quantum computing, quantum communication and quantum precision measurement. Globally, quantum communication technology is the most mature and has the fastest industrialization process. Among them, quantum key distribution (QKD) is the most mature technology in the field of quantum secure communication and is the most widely used in practice.

[0003] A complete QKD process consists of two steps: (1) preparation, distribution and measurement of quantum states; (2) post-processing. In actual systems, due to channel attenuation, noise, and the limitations of detection technology, the keys transmitted through the quantum channel are not completely secure. In order to further improve the security of the QKD system, the legitimate communicating parties need to post-process the partially secure keys.

[0004] Polar code is a forward error correction (FEC) technology with many significant advantages such as low complexity, low latency, no error level, and good short code performance. It is an error correction code that has been strictly proven to reach the Shannon limit. The coding construction algorithm of polar code can be regarded as solving the optimal setting of frozen bits. The existing solution is solved by genetic algorithm.

[0005] However, the mutation operation in the genetic algorithm usually changes the coding of individuals in the population with a small probability, thereby generating new gene combinations. The most common form of this change is bit flipping at random positions, and the resulting mutant offspring are less different from the parent generation, which is not conducive to enriching the diversity of solutions, resulting in insufficient efficiency in the construction of error correction codes, affecting the efficiency of error negotiation in the post-processing process. Summary of the invention

[0006] In order to solve the problem that the construction efficiency of error correction codes in existing solutions is not high enough, the present invention provides a quantum key distribution post-processing method introducing differential evolution.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] A quantum key distribution post-processing method introducing differential evolution is used in a QKD system, wherein the QKD system includes N pairs of transmitting ends and receiving ends, where N≥1, and the method includes the following steps:

[0009] S1: The sender and receiver obtain their original quantum keys respectively;

[0010] S2: The sender and the receiver perform key screening based on their original quantum keys to obtain their own screened quantum keys.

[0011] S3: The sender and receiver randomly select some of the screened quantum keys for public comparison and calculate the quantum bit error rate;

[0012] S4: determining whether the quantum bit error rate is lower than a preset bit error rate threshold;

[0013] If yes, execute step S5;

[0014] If not, all information bits of this transmission are discarded and the process returns to step S1;

[0015] S5: Correct the bit errors of the remaining post-screening quantum key through bit error negotiation, so that the sender and the receiver have the same quantum key string;

[0016] In the error negotiation process, polarization code construction is performed based on a genetic algorithm that introduces differential evolution;

[0017] S6: The sender and receiver perform confidentiality enhancement based on the quantum key string to obtain the final quantum key.

[0018] In the above scheme, by introducing the mutation operation of differential evolution in the error negotiation process, the population can retain the common coding structure as much as possible. At the same time, due to the influence of the differential vector, the population can evolve effectively, so that the overall construction efficiency of the error correction code is improved, which is ultimately beneficial to improving the efficiency of error negotiation and improving the security of QKD post-processing.

[0019] Preferably, in step S1, the sender sends quantum bits through the quantum channel and records the original quantum key K of the sender. Ra ; The receiving end receives the quantum bit through the quantum channel and obtains the original quantum key K Rb .

[0020] Preferably, in step S2, the receiving end announces the moment when the quantum is detected, and performs basis vector comparison and time comparison with the sending end; the sending end and the receiving end discard the key bits corresponding to the moment when the quantum is not received by the receiving end, and retain the available key bits according to the content of the quantum key distribution protocol actually selected, and respectively constitute the sieved quantum key K of the sending end. Sa and the receiving end's post-sieving quantum key K Sb .

[0021] Preferably, in step S5, the bit error negotiation includes polar code construction and polar code decoding.

[0022] Preferably, polar code construction based on a genetic algorithm introducing differential evolution includes the following steps:

[0023] S51: Generate codeword structures under different signal-to-noise ratio conditions as initial populations;

[0024] S52: Calculate the fitness of each individual in the population and perform selection operations based on the fitness;

[0025] S53: Perform a crossover operation on the individuals left by the selection operation to generate crossover offspring;

[0026] S54: performing differential mutation operation on each individual in the crossover offspring to generate mutant offspring and form a new population;

[0027] S55: repeating steps S52 to S54 until the maximum number of evolution times is reached or a preset condition is met;

[0028] S56: Select an optimal solution from the output codeword set to obtain an optimal codeword structure.

[0029] Preferably, in step S51, a Gaussian approximation construction algorithm is used to generate codeword structures under different signal-to-noise ratio conditions.

[0030] Preferably, the fitness is a block error rate of a codeword.

[0031] Preferably, in step S52, a truncation selection method is used to perform the selection operation.

[0032] Preferably, the differential mutation operation is performed according to the following formula:

[0033]

[0034] Among them, T i is a mutant offspring, P best is the best individual in the current population. and They are different individuals in the current population, r1 and r2∈[1,m] and are different from each other, and m is the number of individuals in the population.

[0035] Preferably, an SCL decoding algorithm or a CRC-SCL decoding algorithm is used to perform polar code decoding.

[0036] Beneficial technical effects of the present invention:

[0037] The present invention provides a quantum key distribution post-processing method that introduces differential evolution. By introducing the mutation operation of differential evolution in the error negotiation process, the population can retain the common coding structure as much as possible. At the same time, due to the influence of the differential vector, the population can evolve effectively, so that the overall construction efficiency of the error correction code is improved, which is ultimately beneficial to improving the error negotiation efficiency and improving the security of QKD post-processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the framework of QKD post-processing in the present invention;

[0039] Figure 2 It is a flow chart of the implementation steps of the technical solution of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments, but the scope of protection claimed in the present invention is not limited to the following specific embodiments.

[0041] Example 1

[0042] like Figure 1-2 As shown, a quantum key distribution post-processing method introducing differential evolution is used in a QKD system, wherein the QKD system includes N pairs of transmitters and receivers, N≥1, and the method includes the following steps:

[0043] S1: The sender and receiver obtain their original quantum keys respectively;

[0044] S2: The sender and the receiver perform key screening based on their original quantum keys to obtain their own screened quantum keys.

[0045] S3: The sender and receiver randomly select some of the screened quantum keys for public comparison and calculate the quantum bit error rate;

[0046] S4: determining whether the quantum bit error rate is lower than a preset bit error rate threshold;

[0047] If yes, execute step S5;

[0048] If not, all information bits of this transmission are discarded and the process returns to step S1;

[0049] S5: Correct the bit errors of the remaining post-screening quantum key through bit error negotiation, so that the sender and the receiver have the same quantum key string;

[0050] In the error negotiation process, polarization code construction is performed based on a genetic algorithm that introduces differential evolution;

[0051] S6: The sender and receiver perform confidentiality enhancement based on the quantum key string to obtain the final quantum key.

[0052] In the specific implementation process, by introducing the mutation operation of differential evolution in the error negotiation process, the population can retain the common coding structure as much as possible. At the same time, due to the influence of the differential vector, the population can evolve effectively, so that the overall construction efficiency of the error correction code is improved, which is ultimately beneficial to improving the efficiency of error negotiation and improving the security of QKD post-processing.

[0053] Example 2

[0054] A quantum key distribution post-processing method introducing differential evolution is used in a QKD system, wherein the QKD system includes N pairs of transmitting ends and receiving ends, where N≥1, and the method includes the following steps:

[0055] S1: The sender and receiver obtain their original quantum keys respectively;

[0056] More specifically, in step S1, the information interaction unit of the sending end and the information interaction unit of the receiving end perform information interaction. The sending end first sends the quantum bit through the quantum channel and records the original quantum key K of the sending end. Ra ; The receiving end receives the quantum bit through the quantum channel and obtains the original quantum key K Rb .

[0057] S2: The sender and the receiver perform key screening based on their original quantum keys to obtain their own screened quantum keys.

[0058] More specifically, in step S2, the receiving end announces the moment when the quantum is detected, and performs basis vector comparison and time comparison with the sending end; the sending end and the receiving end discard the key bits corresponding to the moment when the quantum is not received by the receiving end, and retain the available key bits according to the content of the quantum key distribution protocol actually selected, respectively forming the sieved quantum key K of the sending end Sa and the receiving end's post-sieving quantum key K Sb .

[0059] In the specific implementation process, basis vector comparison and time comparison are performed through the information interaction unit at the sending end and the information interaction unit at the receiving end.

[0060] S3: The sender and receiver randomly select some of the screened quantum keys for public comparison and calculate the quantum bit error rate;

[0061] In the specific implementation process, the parameter estimation unit at the transmitting end and the parameter estimation unit at the receiving end perform a public comparison of the screened quantum key, and the quantum bit error rate is calculated based on the result of the public comparison.

[0062] S4: determining whether the quantum bit error rate is lower than a preset bit error rate threshold;

[0063] If yes, execute step S5;

[0064] If not, all information bits of this transmission are discarded and the process returns to step S1;

[0065] S5: Correct the bit errors of the remaining post-screening quantum key through bit error negotiation, so that the sender and the receiver have the same quantum key string;

[0066] More specifically, in step S5, the error negotiation includes polar code construction and polar code decoding.

[0067] In the error negotiation process, polarization code construction is performed based on a genetic algorithm that introduces differential evolution;

[0068] More specifically, polar code construction based on a genetic algorithm that introduces differential evolution includes the following steps:

[0069] S51: Generate codeword structures under different signal-to-noise ratio conditions as initial populations;

[0070] S52: Calculate the fitness of each individual in the population and perform selection operations based on the fitness;

[0071] S53: Perform a crossover operation on the individuals left by the selection operation to generate crossover offspring;

[0072] S54: performing differential mutation operation on each individual in the crossover offspring to generate mutant offspring and form a new population;

[0073] S55: repeating steps S52 to S54 until the maximum number of evolution times is reached or a preset condition is met;

[0074] S56: Select an optimal solution from the output codeword set to obtain an optimal codeword structure.

[0075] More specifically, in step S51, a Gaussian approximation construction algorithm is used to generate codeword structures under different signal-to-noise ratio conditions.

[0076] More specifically, the fitness is the block error rate of the codeword.

[0077] More specifically, in step S52, a truncation selection method is used to perform the selection operation.

[0078] More specifically, the differential mutation operation is performed according to the following formula:

[0079]

[0080] Among them, T i is a mutant offspring, P best is the best individual in the current population. and They are different individuals in the current population, r1 and r2∈[1,m] and are different from each other, and m is the number of individuals in the population.

[0081] More specifically, the SCL decoding algorithm or the CRC-SCL decoding algorithm is used to perform polar code decoding.

[0082] In a specific implementation process, error negotiation is performed in a classical channel by an error negotiation unit at a transmitting end and an error negotiation unit at a receiving end.

[0083] S6: The sender and receiver perform confidentiality enhancement based on the quantum key string to obtain the final quantum key.

[0084] In the specific implementation process, the confidentiality enhancement unit at the sending end and the confidentiality enhancement unit at the receiving end use a hash function to remove information that may be leaked to an eavesdropper from the coordinated data based on the rate upper limit obtained during the error correction process, and obtain a secure key as the final quantum key.

[0085] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs may also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the invention should also fall within the scope of protection of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A quantum key distribution post-processing method introducing differential evolution, used in a QKD system, wherein the QKD system comprises N pairs of transmitting ends and receiving ends, N≥1, characterized in that: The method comprises the following steps: S1: The sender and receiver obtain their original quantum keys respectively; S2: The sender and the receiver perform key screening based on their original quantum keys to obtain their own screened quantum keys. S3: The sender and receiver randomly select some of the screened quantum keys for public comparison and calculate the quantum bit error rate; S4: determining whether the quantum bit error rate is lower than a preset bit error rate threshold; If yes, execute step S5; If not, all information bits of this transmission are discarded and the process returns to step S1; S5: Correct the bit errors of the remaining post-screening quantum key through bit error negotiation, so that the sender and the receiver have the same quantum key string; In the error negotiation process, polarization code construction is performed based on a genetic algorithm that introduces differential evolution; S6: The sender and receiver perform confidentiality enhancement based on the quantum key string to obtain the final quantum key.

2. According to claim 1, a quantum key distribution post-processing method introducing differential evolution is characterized in that: In step S1, the sender sends quantum bits through the quantum channel and records the sender's original quantum key K Ra ; The receiving end receives the quantum bit through the quantum channel and obtains the original quantum key K Rb .

3. According to claim 1, a quantum key distribution post-processing method introducing differential evolution is characterized in that: In step S2, the receiving end announces the moment when the quantum is detected, and performs basis vector comparison and time comparison with the sending end; the sending end and the receiving end discard the key bits corresponding to the moment when the quantum is not received by the receiving end, and retain the available key bits according to the content of the quantum key distribution protocol actually selected, respectively forming the sieved quantum key K of the sending end Sa and the receiving end's post-sieving quantum key K Sb .

4. According to claim 1, a quantum key distribution post-processing method introducing differential evolution is characterized in that: In step S5, error negotiation includes polar code construction and polar code decoding.

5. A quantum key distribution post-processing method introducing differential evolution according to claim 1 or 4, characterized in that: The polar code construction based on the genetic algorithm of differential evolution includes the following steps: S51: Generate codeword structures under different signal-to-noise ratio conditions as initial populations; S52: Calculate the fitness of each individual in the population and perform selection operations based on the fitness; S53: Perform a crossover operation on the individuals left by the selection operation to generate crossover offspring; S54: performing differential mutation operation on each individual in the crossover offspring to generate mutant offspring and form a new population; S55: repeating steps S52 to S54 until the maximum number of evolution times is reached or a preset condition is met; S56: Select an optimal solution from the output codeword set to obtain an optimal codeword structure.

6. The post-processing method of quantum key distribution introducing differential evolution according to claim 5, characterized in that: In step S51, a Gaussian approximation construction algorithm is used to generate codeword structures under different signal-to-noise ratio conditions.

7. The post-processing method of quantum key distribution introducing differential evolution according to claim 5, characterized in that: The fitness is the block error rate of the codeword.

8. The post-processing method of quantum key distribution introducing differential evolution according to claim 5, characterized in that: In step S52, a truncation selection method is used to perform a selection operation.

9. The post-processing method of quantum key distribution introducing differential evolution according to claim 5, characterized in that: The differential mutation operation is performed according to the following formula: Among them, T i is a mutant offspring, P best is the best individual in the current population. and They are different individuals in the current population, r1 and r2∈[1,m] and are different from each other, and m is the number of individuals in the population.

10. The post-processing method of quantum key distribution introducing differential evolution according to claim 4, characterized in that: The SCL decoding algorithm or the CRC-SCL decoding algorithm is used for polar code decoding.

Images