阅读说明：本技术 一种用于量子密钥分发的多矩阵自适应译码装置及方法 (Multi-matrix self-adaptive decoding device and method for quantum key distribution ) 是由 李扬 徐兵杰 杨杰 马荔 黄伟 于 2019-09-26 设计创作，主要内容包括：本发明公开了一种用于量子密钥分发的多矩阵自适应译码装置及方法,发送端包括依次连接的信号发送模块A、数据后处理模块A和密钥存储模块A,接收端包括依次连接的信号探测模块B、数据后处理模块B和密钥存储模块B；所述信号发送模块A同时将信号发送给信号探测模块B；所述数据后处理模块A和数据后处理模块B相互进行信息交互并各自进行数据处理,得到密钥,发送给各自的密钥存储模块进行保存。本发明可以依据通信数据的实时信噪比选择最优的纠错矩阵,并结合纠错矩阵的既定协调效率计算自适应译码的参数,同时保障了纠错成功率和协调效率；本发明可以有效保证数据信噪比发生变化时CVQKD系统的性能,提升系统的鲁棒性和自动化水平。(The invention discloses a multi-matrix self-adaptive decoding device and a method for quantum key distribution.A sending end comprises a signal sending module A, a data post-processing module A and a key storage module A which are sequentially connected, and a receiving end comprises a signal detection module B, a data post-processing module B and a key storage module B which are sequentially connected; the signal sending module A simultaneously sends a signal to the signal detection module B; and the data post-processing module A and the data post-processing module B mutually perform information interaction and data processing respectively to obtain keys, and the keys are sent to respective key storage modules for storage. The invention can select the optimal error correction matrix according to the real-time signal-to-noise ratio of the communication data, and calculate the parameters of the adaptive decoding by combining the established coordination efficiency of the error correction matrix, and simultaneously ensure the error correction success rate and the coordination efficiency; the invention can effectively ensure the performance of the CVQKD system when the signal-to-noise ratio of the data changes, and improve the robustness and the automation level of the system.)

1. A multi-matrix adaptive decoding apparatus for quantum key distribution, characterized by: the sending end comprises a signal sending module A, a data post-processing module A and a key storage module A which are sequentially connected, and the receiving end comprises a signal detection module B, a data post-processing module B and a key storage module B which are sequentially connected; the signal sending module A simultaneously sends a signal to the signal detection module B; and the data post-processing module A and the data post-processing module B mutually perform information interaction and data processing respectively to obtain keys, and the keys are sent to respective key storage modules for storage.

2. The apparatus of claim 1, wherein the apparatus comprises: the data post-processing module A of the sending end comprises a base comparison screening unit A, a parameter estimation unit A, a discrete data processing unit A, a decoding calculation unit A, a key recombination unit A and a private key confidentiality amplification unit A which are sequentially connected; the parameter estimation unit A is respectively connected with the error correction matrix determination unit and the safety code rate calculation unit A; the error correction matrix determining unit is connected with the decoding calculating unit A.

3. The apparatus of claim 2, wherein the apparatus comprises: the error correction matrix determination unit comprises a basic error correction matrix selection unit and an error correction matrix fine-tuning unit.

4. The apparatus of claim 1, wherein the apparatus comprises: the data post-processing module B of the receiving end comprises a base comparison screening unit B, a parameter estimation unit B, a discrete data processing unit B, a secret key recombination unit B and a private key confidentiality amplification unit B which are sequentially connected; the parameter estimation unit B is respectively connected with the error correction matrix determination unit and the private key confidentiality amplification unit B; and the error correction matrix determining unit and the discrete data processing unit B are both connected with the syndrome computing unit B.

5. The apparatus of claim 4, wherein the apparatus comprises: the error correction matrix determination unit comprises a basic error correction matrix selection unit and an error correction matrix fine-tuning unit.

6. A multi-matrix adaptive decoding method for quantum key distribution is characterized in that: the method comprises the following steps:

step one, a sending end and a receiving end respectively obtain the data with the same measuring base through respective base comparison screening units and transmit the data to respective parameter estimation units;

step two, the receiving end selects data C 'for parameter estimation from the data with the same measurement basis and sends the data C' to a parameter estimation unit of the sending end;

step three, the parameter estimation unit A of the sending end sends the obtained parameter estimation values to the safety code rate calculation unit A and the error correction matrix determination unit respectively, the error correction matrix determination unit transmits the final error correction matrix to the decoding calculation unit A, and sends error correction matrix information A to the receiving end; the parameter estimation unit A sends data needing discrete data processing to the discrete data processing unit A, obtains discretized data by utilizing discretization negotiation information AB and sends the discretized data to the decoding calculation unit A; the security code rate calculation unit A calculates a security code rate estimation value according to the code rate of the final error correction matrix and the parameter estimation result, transmits the security code rate estimation value to the private key confidentiality amplification unit A as a compression factor, and sends the security code rate estimation value to the receiving end;

fourthly, a parameter estimation unit of a receiving end receives error correction matrix information A, a safety code rate estimation value A and parameter estimation data selection information A from a sending end, then the error correction matrix information A is respectively transmitted to a syndrome calculation unit B, and the safety code rate estimation value A is transmitted to a private key confidentiality amplification unit B; the parameter estimation unit B sends data needing discrete data processing to the discrete data processing unit B, and discretized data obtained by the discretization negotiation information AB are respectively sent to the syndrome calculation unit B and the key recombination unit B;

step five, the key recombination units of the sending end and the receiving end continuously accumulate the successfully decoded data, recombine the data according to the same rule, and when the data are accumulated to a preset data amount, the data of the unit are respectively transmitted to the respective private key confidentiality amplification units;

and sixthly, compressing the data transmitted by the key recombination unit by private key confidentiality amplification units of the sending end and the receiving end according to the obtained security code rate to obtain a security key.

7. The multi-matrix adaptive decoding method for quantum key distribution according to claim 6, wherein: the syndrome calculation unit B is used for multiplying the final error correction matrix H and the discretization data to obtain a syndrome SPC, and sending the syndrome SPC to the decoding calculation unit A of the sending end; the decoding calculation unit A performs decoding calculation by using the final error correction matrix H, the syndrome SPC and the discretized data: if the decoding is successful, sending the decoding result data A to a receiver, and transmitting the decoded data to a key recombination unit A; if the decoding fails, sending the decoding result data A to a receiver and informing the key recombination unit A that the decoding fails in the current round; and the receiver transmits the discrete data obtained by the data discrete processing unit B to the key recombination unit B according to the decoding result data A if the decoding result data A is successful, and informs the data discrete processing unit B that the decoding fails in the current round if the decoding result data A is failed.

8. The multi-matrix adaptive decoding method for quantum key distribution according to claim 6, wherein: the method for determining the final error correction matrix comprises the following steps:

first, according to the real-time SNR, an optimal error correction matrix H is selected from all error correction matrices_iSatisfy the following requirements

And secondly, fine tuning is carried out by adopting a puncturing or shortening method based on the basic error correction matrix according to the specific numerical value of the signal-to-noise ratio to obtain a final error correction matrix required by the error correction.

9. The multi-matrix adaptive decoding method for quantum key distribution according to claim 8, wherein: the method for fine tuning the basic error correction matrix comprises the following steps:

(1) determining whether SNR > SNR is satisfied_iIf yes, entering into (2), otherwise entering into (5);

(2) the error correction adopts a puncturing method;

(3) the length p of the punctured bits is calculated and the position of the code word where the punctured bits are randomly inserted is recorded as { u }_p}；

(4) The sending end sums the real-time SNR value with the { u_pSending the data to a receiving end, and then entering (8);

(5) the error correction adopts a shortening method;

(6) calculating the length s of the shortened bits, and recording the position and value of the randomly inserted shortened bits in the code word as { u }_sAnd { v } and_s}；

(7) the sending end sums the real-time SNR value with the { u_s}、{v_sSending the data to a receiving end;

(8) and finishing fine adjustment.

10. The multi-matrix adaptive decoding method for quantum key distribution according to claim 9, wherein:

(1) the length p of the punctured bits is calculated according to the following formula:

(2) the length s of the shortening bit is calculated according to the following formula:

wherein: m and n are error correction matrixes H respectively_iNumber of rows and columns, β_iIs an error correction matrix H_iGiven coordination efficiency.

Technical Field

The invention relates to a multi-matrix self-adaptive decoding device and method for quantum key distribution.

Background

With the development of quantum computing technology, a classical cryptosystem based on computational complexity faces a significant potential safety hazard. Quantum Key Distribution (QKD) is a Key Distribution system based on the Quantum physical principle, has unconditional security, and has attracted extensive attention and research. Continuous variable Quantum Key Distribution (CV-QKD) adopts the regular component of an optical field as an information carrier, most devices are general to classical coherent optical communication, and have good compatibility with a traditional optical communication network, so that the method is a Quantum Key Distribution technology with great development prospect.

For the CV-QKD system, after weak quantum signals are transmitted through a long-distance optical fiber, the signal-to-noise ratio is very low, so that the error rate of original data of a transmitting party and a receiving party of key distribution is very high. In order to realize that the receiver shares the same key with the sender, data negotiation through data post-processing is required.

An important step in data post-processing is data error correction. The code rate selection of the error correction matrix needs to match the signal-to-noise ratio of the signal. If the code rate of the error correction matrix is too high, data error correction may not be completed, so that the secure key cannot be generated in the quantum key distribution process. If the code rate of the error correction matrix is too low, the error correction efficiency is low, although data error correction can be completed, in the aspect of information theory, the secure key rate of the two parties of quantum key distribution is very low or even no secure key exists.

In the actual quantum key distribution process, the signal-to-noise ratio of the data link changes with time due to changes of the optical fiber link and changes of devices at the transmitting end and the receiving end. The conventional scheme is to modify the error correction matrix by puncturing and puncturing to adapt to the variation of the signal-to-noise ratio. However, for the continuous variable quantum key distribution system, the error correction difficulty is very large, on one hand, the application range of the scheme based on puncturing reduction is limited, and on the other hand, the scheme based on puncturing brings about improvement of the frame error rate.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a multi-matrix self-adaptive decoding device and method for quantum key distribution, which can select an optimal error correction matrix according to the real-time signal-to-noise ratio of communication data, calculate the parameters of self-adaptive decoding by combining the established coordination efficiency of the error correction matrix, and simultaneously ensure the error correction success rate and the coordination efficiency; the invention can effectively ensure the performance of the CVQKD system when the signal-to-noise ratio of the data changes, and improve the robustness and the automation level of the system.

The technical scheme adopted by the invention for solving the technical problems is as follows: a multi-matrix self-adaptive decoding device for quantum key distribution is disclosed, wherein a sending end comprises a signal sending module A, a data post-processing module A and a key storage module A which are sequentially connected, and a receiving end comprises a signal detection module B, a data post-processing module B and a key storage module B which are sequentially connected; the signal sending module A simultaneously sends a signal to the signal detection module B; and the data post-processing module A and the data post-processing module B mutually perform information interaction and data processing respectively to obtain keys, and the keys are sent to respective key storage modules for storage.

The invention also provides a multi-matrix self-adaptive decoding method for quantum key distribution, which comprises the following steps:

step one, a sending end and a receiving end respectively obtain the data with the same measuring base through respective base comparison screening units and transmit the data to respective parameter estimation units;

step two, the receiving end selects data C 'for parameter estimation from the data with the same measurement basis and sends the data C' to a parameter estimation unit of the sending end;

step three, the parameter estimation unit A of the sending end sends the obtained parameter estimation values to the safety code rate calculation unit A and the error correction matrix determination unit respectively, the error correction matrix determination unit transmits the final error correction matrix to the decoding calculation unit A, and sends error correction matrix information A to the receiving end; the parameter estimation unit A sends data needing discrete data processing to the discrete data processing unit A, obtains discretized data by utilizing discretization negotiation information AB and sends the discretized data to the decoding calculation unit A; the security code rate calculation unit A calculates a security code rate estimation value according to the code rate of the final error correction matrix and the parameter estimation result, transmits the security code rate estimation value to the private key confidentiality amplification unit A as a compression factor, and sends the security code rate estimation value to the receiving end;

fourthly, a parameter estimation unit of a receiving end receives error correction matrix information A, a safety code rate estimation value A and parameter estimation data selection information A from a sending end, then the error correction matrix information A is respectively transmitted to a syndrome calculation unit B, and the safety code rate estimation value A is transmitted to a private key confidentiality amplification unit B; the parameter estimation unit B sends data needing discrete data processing to the discrete data processing unit B, and discretized data obtained by the discretization negotiation information AB are respectively sent to the syndrome calculation unit B and the key recombination unit B;

step five, the key recombination units of the sending end and the receiving end continuously accumulate the successfully decoded data, recombine the data according to the same rule, and when the data are accumulated to a preset data amount, the data of the unit are respectively transmitted to the respective private key confidentiality amplification units;

and sixthly, compressing the data transmitted by the key recombination unit by private key confidentiality amplification units of the sending end and the receiving end according to the obtained security code rate to obtain a security key.

Compared with the prior art, the invention has the following positive effects:

the invention can solve the problem of the adaptation of the error correction matrix and the signal-to-noise ratio of the continuous variable quantum key distribution system, thereby improving the signal-to-noise ratio application range of the continuous variable quantum key distribution system and improving the stable operation capability of the system.

Drawings

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a general system block diagram of the present invention;

fig. 2 is a schematic diagram of a sender data processing module a;

FIG. 3 is a diagram of a receiving-end data processing module B;

fig. 4 is a schematic diagram of matrix selection.

Detailed Description

As shown in fig. 1, for the continuous variable quantum key distribution system, a sending end sends a signal to a receiving end through a signal sending module a, and simultaneously, sends the sent information to a data processing module a. The receiving end receives the signal sent from the sending end through the signal detection module B and transmits the signal to the data processing module B. And the data processing module A performs data processing on the data transmitted by the signal transmitting module A and the information obtained by information interaction with the receiving end to obtain a secret key, and stores the secret key in the secret key storage module A. And the data processing module B performs data processing on the data transmitted by the signal detection module B and the information obtained by information interaction with the transmitting end to obtain a secret key, and stores the secret key in the secret key storage module B.

As shown in fig. 2 and fig. 3, for the data processing module, the transmitting end and the receiving end first obtain the data with the same measurement basis through the basis comparison screening unit, and transmit the data to the respective parameter estimation units.

The calculation process for performing parameter estimation may be performed at the transmitting end or at the receiving end, and the following description will take parameter estimation performed at the transmitting end as an example. The invention also protects the scheme of parameter estimation of the receiving end.

According to the convention, the receiving end selects data C 'used for parameter estimation from the part of data with the same measurement base and sends the data C' to the sending end.

The parameter estimation unit at the transmitting end performs parameter estimation using the data C' transmitted from the receiving end and the data corresponding to the data. The obtained parameter estimation value is sent to a safety code rate calculation unit A on one hand, and on the other hand, error correction matrix selection is carried out according to the obtained signal-to-noise ratio data. The selection of the error correction matrix is divided into two steps. As shown in FIG. 4, in a first step, an optimal error correction matrix H is selected from all error correction matrices according to the real-time SNR_iSatisfy the following requirements

Wherein the matrix H_iAt its corresponding standard signal-to-noise ratio SNR_iCoordination efficiency of lower is β_i，

Is a matrix H_iThe signal-to-noise ratio range for adaptive error correction can be realized, that is, when the real-time SNR of the communication data is in the range, the adaptive decoding algorithm can be based on the matrix H_iError correction is carried out on communication data and the coordination efficiency is ensured to be stable to β_i(ii) a Secondly, based on the specific value of the SNR, based on the basic error correction matrix, fine adjustment is performed by adopting a puncturing or shortening method (when the puncturing method is adopted, the number p of punctured bits is calculated, and the position of randomly inserting the punctured bits in the code word is recorded as { u }_p}; when the shortening method is adopted, the number of shortening bits s is calculated, and the position and value of the randomly inserted shortening bits in the code word are recorded as { u }_sAnd { v } and_sthe details are shown later), obtain the final error correction matrix required by the error correction, transmit the final error correction matrix to the decoding calculation unit, and transmit the error correction matrix information a (including the basic error correction matrix selection information and the puncturing shortening information (when puncturing is adopted, the puncturing is { u) }_pAdopting a shortened time of { u }_sAnd { v } and_s}) to the receiving end. And the safety code rate calculation unit A calculates to obtain a safety code rate estimated value according to the code rate of the final error correction matrix and the parameter estimation result, transmits the safety code rate estimated value to the private key confidentiality amplification unit as a compression factor, and sends the safety code rate estimated value to the receiving end.

And a parameter estimation unit of the receiving end receives the error correction matrix information A, the safety code rate estimation value A and the parameter estimation data selection information A from the sending end, respectively transmits the error correction matrix information A to the syndrome calculation unit, and transmits the safety code rate estimation value A to the private key confidentiality amplification unit.

For the discrete data processing unit, the sending end and the receiving end respectively remove the data used for parameter estimation from the data obtained by the base comparison screening unit to obtain the data required to be processed by the discrete data. The discretized data are respectively obtained by using the discretization negotiation information AB.

For the error correction decoding part, the receiving end obtains an error correction matrix H used for decoding calculation according to the error correction matrix information A. And in a syndrome calculation unit B, multiplying the error correction matrix H by the discretization data to obtain a syndrome SPC. The syndrome SPC is sent to the transmitting end. And the transmitting end performs decoding calculation by using the error correction matrix H, the syndrome SPC and the discretized data. If the decoding is successful, the decoding result data A is sent to a receiver, and the decoded data is transmitted to a key recombination unit A; if the decoding fails, the decoding result data A is sent to a receiver, and the key recombination unit A is informed that the decoding fails in the current round. And the receiver transmits the discrete data obtained by the data discrete processing unit B to the key recombination unit B according to the decoding result data A if the decoding result data A is successful, and informs the data discrete processing unit B that the decoding fails in the current round if the decoding result data A is failed.

For the key reassembly unit. The sending end and the receiving end continuously accumulate the successfully decoded data, the data are recombined according to the same rule, and when the data are accumulated to the preset data amount, the data of the unit are respectively transmitted to the respective private key confidentiality amplifying units.

For the private key confidentiality amplification unit. The sending end and the receiving end compress the data transmitted by the key recombination unit according to the security code rate obtained in the introduction to obtain the security key.

The detailed steps of deletion and shortening are as follows:

the sending end combines the optimal error correction matrix H according to the real-time SNR of the current communication data_iStandard signal-to-noise ratio SNR of_iAnd judging the self-adaptive decoding method adopted by the current error correction:

(1) when SNR > SNR_iThen, the error correction adopts a puncturing method;

(2) when SNR < SNR_iThen, the error correction adopts a shortening method.

Real-time SNR and optimal error correction matrix H of sending end combined with current communication data_iPredetermined coordination efficiency β_iAnd calculating relevant parameters of the current self-adaptive decoding, wherein the detailed calculation is as follows:

(1) when the puncturing method is adopted, according to

The length p of the punctured bits is calculated and the position of the code word where the punctured bits are randomly inserted is recorded as { u }_p}；

(2) When the shortening method is adopted, according to

Calculating the length s of the shortened bits, and recording the position and value of the randomly inserted shortened bits in the code word as { u }_sAnd { v } and_s}。

where m and n are error correction matrices H, respectively_iThe number of rows and columns.

When the puncturing method is adopted, the sending end sums the real-time SNR value with the { u }_pSending the data to a receiving end;

when the shortening method is adopted, the sending end sums the real-time SNR value with the { u }_s}、{v_sAnd sending the data to a receiving end.