Quantum encryption key determination method and related hardware

Abstract

The embodiment of the invention provides a quantum encryption key determination method and related hardware, a first device and a second device transmit a target quantum signal carrying continuous variable information, the second device determines transmission information corresponding to the target quantum signal as target distribution information, determines a quantum encryption key according to the target distribution information, and sends the quantum encryption key to the first device. And reference information corresponding to a part of reference quantum signals in the target quantum signals is coded according to a channel signal-to-noise ratio and then is sent to the first equipment. The first device determines transmission information corresponding to the target quantum signals as reference information, determines a decoding mode according to a channel signal-to-noise ratio, decodes reference information sent by the second device, processes the reference information of each target quantum signal according to the difference between the reference information of the reference quantum signals and the decoded reference information, and sends the processed reference information to the second device; and obtaining target distribution information of each target quantum signal, and determining a quantum encryption key according to the target distribution information.

Description

Technical Field

[0001] The present invention relates to the technical field of quantum encryption communication, and particularly to a method for determining a quantum encryption key and related hardware. Background Art

[0002] With the development of information technology, the importance of data security has become increasingly prominent. The secure transfer of a large amount of data in the network has been inseparable from the support of encryption algorithms. At present, the security of some commonly used data encryption algorithms is based on the complexity of mathematical principles, and there is a possibility of being cracked in theory. Although the computing power of current computers is not yet sufficient to achieve cracking, with the development of computer technology, the computing power of future computing devices may be greatly improved, and the security of data encryption algorithms based on mathematical principles will be severely challenged. To address this issue, quantum key encryption technology based on the Heisenberg uncertainty principle of quantum mechanics can effectively cope with the security challenges brought about by the improvement of computing power.

[0003] In quantum key encryption technology, continuous-variable quantum key distribution (CV-QKD) is an encryption technology with the advantages of relatively low implementation difficulty, low cost, high reliability, etc., and has great development prospects in the field of data security. However, the current CV-QKD technology is slow and inefficient in the process of determining quantum encryption keys for both communication parties. Summary of the Invention

[0004] Embodiments of the present invention provide a method for determining a quantum encryption key and related hardware, so as to improve the efficiency of determining the quantum encryption key used by both communication parties.

[0005] In a first aspect, an embodiment of the present invention provides a method for determining a quantum encryption key, which is applied to a first device and includes:

[0006] Determine the reference information of each of a plurality of target quantum signals respectively; the plurality of target quantum signals are quantum signals carrying continuous variable information transmitted between the first device and a second device;

[0007] Receive, through a classical channel, the pending reference information of at least one reference quantum signal sent by the second device; the at least one reference quantum signal is a part of the plurality of target quantum signals;

[0008] Determine a target decoding method according to the target signal-to-noise ratio of the classical channel, and use the target decoding method to decode each of the pending reference information to obtain the actual reference information of each reference quantum signal;

[0009] Determine the information difference of each reference quantum signal respectively; wherein, for any reference quantum signal, the information difference of the reference quantum signal refers to the difference between the actual reference information of the reference quantum signal and the reference information of the reference quantum signal;

[0010] According to the information difference of each reference quantum signal, process the reference information of each target quantum signal to obtain the target distribution information of each target quantum signal;

[0011] Determine the quantum encryption key used for communication between the first device and the second device according to the target distribution information of each target quantum signal.

[0012] As an optional implementation manner, the target quantum signal is a quantum signal received from the second device, and the reference information of the target quantum signal is the observation information obtained by observing the target quantum signal.

[0013] As another optional implementation manner, the target quantum signal is a quantum signal sent to the second device, and the reference information of the target quantum signal is the modulation information for modulating the target quantum signal.

[0014] Optionally, the to-be-determined reference information is in the form of a low-density parity-check code (LDPC);

[0015] For different signal-to-noise ratios of the classical channel, different check matrices are used for decoding during the LDPC decoding process of the to-be-determined reference information;

[0016] The method of determining the target decoding method according to the target signal-to-noise ratio of the classical channel and using the target decoding method to decode the to-be-determined reference information of each reference quantum signal to obtain the actual reference information of each reference quantum signal includes:

[0017] Determine the target check matrix according to the target signal-to-noise ratio of the classical channel, and use the target check matrix to decode each to-be-determined reference information by using a soft decision algorithm to obtain the actual reference information of each reference quantum signal.

[0018] Furthermore, as an optional implementation manner, the method of determining the target check matrix according to the target signal-to-noise ratio of the classical channel includes:

[0019] Use the preset correspondence between the signal-to-noise ratio and the check matrix to determine the target check matrix corresponding to the target signal-to-noise ratio of the classical channel.

[0020] As another optional implementation manner, determine the desired node ratio of the number of check nodes m to the number of variable nodes n of the target check matrix through the following method:

[0021]

[0022] Among them, β0 is the preset coordination efficiency, B is the bandwidth of the classical channel, s is the base of the data transmitted by the classical channel, and SNR is the target signal-to-noise ratio;

[0023] Determine the target parity-check matrix corresponding to the expected node ratio according to the preset corresponding relationship between the node ratio and the parity-check matrix.

[0024] Optionally, the using the target parity-check matrix to decode each of the to-be-determined reference information by a soft-decision algorithm to obtain the actual reference information of each reference quantum signal includes:

[0025] For any to-be-determined reference information, initialize the to-be-determined reference information as the prior probability information in half-precision format corresponding to each variable node, use the prior probability information as the message value of the corresponding variable node in the first iterative decoding process, and use the target parity-check matrix to perform iterative decoding for a preset number of times by a soft-decision algorithm to obtain the actual reference information of the reference quantum signal corresponding to the to-be-determined reference information;

[0026] Among them, at the beginning of non-first iterative decoding, for any variable node, use the product of the message value transmitted by the variable node to each corresponding parity-check node determined in the previous iterative decoding and the prior probability information corresponding to the variable node as the message value of the variable node in the current iterative decoding process.

[0027] In a second aspect, based on the same inventive concept, an embodiment of the present invention further provides a method for determining a quantum encryption key, which is applied to a second device and includes:

[0028] Determine the target distribution information of each target quantum signal among a plurality of target quantum signals respectively; the plurality of target quantum signals are quantum signals carrying continuous variable information transmitted between the first device and the second device;

[0029] Determine the quantum encryption key according to the target distribution information;

[0030] Determine a target coding method according to the target signal-to-noise ratio of the classical channel, and use the target coding method to encode the actual reference information corresponding to at least one reference quantum signal into original reference information; the at least one reference quantum signal is a part of the plurality of target quantum signals; the actual reference information is the target distribution information corresponding to the reference quantum signal;

[0031] Send the original reference information to the first device through the classical channel; so that the first device determines a quantum encryption key for communicating with the second device according to the received pending reference information and the target quantum signal; the pending reference information is the information received by the first device after the original reference information is transmitted through the classical channel.

[0032] As an alternative implementation, the target quantum signal is a quantum signal sent to the first device, and the target distribution information of the target quantum signal is the modulation information for modulating the target quantum signal.

[0033] As another alternative implementation, the target quantum signal is a quantum signal received and sent by the first device, and the target distribution information of the target quantum signal is the observation information obtained by observing the target quantum signal.

[0034] Optionally, the original reference information is in LDPC format;

[0035] Different signal-to-noise ratios of the classical channel correspond to different encoding methods using different generator matrices during the LDPC encoding process of the actual reference information;

[0036] The determining the target encoding method according to the target signal-to-noise ratio of the classical channel and encoding the actual reference information corresponding to at least one reference quantum signal into the original reference information by using the target encoding method includes:

[0037] Determine a target generator matrix according to the target signal-to-noise ratio of the classical channel, and encode the actual reference information corresponding to at least one reference quantum signal by using the target generator matrix to obtain the original reference information of each reference quantum signal.

[0038] Furthermore, as an alternative implementation, the determining the target generator matrix according to the target signal-to-noise ratio of the classical channel includes:

[0039] Use the preset correspondence between the signal-to-noise ratio and the generator matrix to determine the target generator matrix corresponding to the target signal-to-noise ratio of the classical channel;

[0040] As another alternative implementation, determine the desired node ratio of the number of check nodes m to the number of variable nodes n of the target generator matrix by the following method:

[0041]

[0042] where β0 is the preset coordination efficiency, B is the bandwidth of the classical channel, s is the base of the transmission data of the classical channel, and SNR is the target signal-to-noise ratio;

[0043] Determine the target generation matrix corresponding to the expected node ratio according to the preset correspondence between the node ratio and the generation matrix.

[0044] In a third aspect, based on the same inventive concept, an embodiment of the present invention further provides a quantum encryption key determination device, including:

[0045] A quantum signal processing module, configured to respectively determine the reference information of each target quantum signal among a plurality of target quantum signals; the plurality of target quantum signals are quantum signals carrying continuous variable information transmitted between the quantum encryption key determination device and a second device;

[0046] A reference information receiving module, configured to receive the pending reference information of at least one reference quantum signal sent by the second device through a classical channel; the at least one reference quantum signal is a partial quantum signal among the plurality of target quantum signals;

[0047] A reference information decoding module, configured to determine a target decoding method according to the target signal-to-noise ratio of the classical channel, and use the target decoding method to decode each piece of pending reference information to obtain the actual reference information of each reference quantum signal;

[0048] A calibration module, configured to respectively determine the information difference of each reference quantum signal; according to the information difference of each reference quantum signal, process the reference information of each target quantum signal to obtain the target distribution information of each target quantum signal; wherein, for any reference quantum signal, the information difference of the reference quantum signal refers to the difference between the actual reference information of the reference quantum signal and the reference information of the reference quantum signal;

[0049] A quantum encryption key determination module, configured to determine the quantum encryption key used for communication between the quantum encryption key determination device and the second device according to the target distribution information of each target quantum signal.

[0050] In a fourth aspect, based on the same inventive concept, an embodiment of the present invention further provides a quantum encryption key determination device, including:

[0051] A quantum signal processing module, configured to respectively determine the target distribution information of each target quantum signal among a plurality of target quantum signals; the plurality of target quantum signals are quantum signals carrying continuous variable information transmitted between a first device and the quantum encryption key determination device;

[0052] A quantum encryption key determination module, configured to determine the quantum encryption key according to the target distribution information;

[0053] A reference information encoding module, configured to determine a target encoding method according to the target signal-to-noise ratio of a classical channel, and encode the actual reference information corresponding to at least one reference quantum signal into original reference information by using the target encoding method; the at least one reference quantum signal is a part of the multiple target quantum signals; the actual reference information is the target distribution information corresponding to the reference quantum signal.

[0054] A reference information sending module, configured to send the original reference information to the first device through the classical channel; so that the first device determines a quantum encryption key for communicating with the quantum encryption key determination device according to the received pending reference information and the target quantum signal; the pending reference information is the information received by the first device after the original reference information is transmitted through the classical channel.

[0055] In a fifth aspect, based on the same inventive concept, an embodiment of the present invention further provides an electronic device, including: a processor and a memory for storing executable instructions of the processor.

[0056] Wherein, the processor is configured to execute the instructions to implement the quantum encryption key determination method as described in the first aspect and / or the second aspect.

[0057] In a sixth aspect, based on the same inventive concept, an embodiment of the present invention further provides a readable storage medium, where the readable storage medium stores computer program code, and when the computer program code runs on a computer, the computer is enabled to implement the quantum encryption key determination method as described in the first aspect and / or the second aspect.

[0058] In a seventh aspect, based on the same inventive concept, an embodiment of the present invention further provides a computer program product, where the computer program product includes: computer program code, and when the computer program code runs on a computer, the computer is enabled to implement the quantum encryption key determination method as described in the first aspect and / or the second aspect.

[0059] The beneficial effects of the present invention are as follows:

[0060] The quantum encryption key determination method and related hardware provided by the embodiments of the present invention, in the process of negotiating the quantum encryption key between the first device and the second device, for the situation where there are differences in the target quantum signals mastered by both parties, when the second device sends the reference information for the first device to correct the target quantum signal to the first device through the classical channel, the second device encodes the reference information according to the encoding method determined by the target signal-to-noise ratio of the classical channel and then sends it to the first device. The first device decodes the received reference information according to the decoding method determined by the target signal-to-noise ratio of the classical channel. After that, the first device processes the reference information of the mastered target quantum signal based on the reference information to obtain the target distribution information. At this time, the target distribution information mastered by the first device and the second device is consistent. Furthermore, the first device and the second device determine the same quantum encryption key based on the consistent target distribution information for encrypted communication. The negotiation process of the above quantum encryption key adjusts the encoding and decoding methods of the reference information according to the target signal-to-noise ratio of the classical channel, so as to effectively select a more efficient encoding and decoding method to encode and decode the reference information according to the information transmission state of the classical channel, taking into account both the transmission efficiency of the reference information in the classical channel and the decoding and error correction efficiency of the first device for the to-be-determined reference information, thereby improving the negotiation and determination efficiency of the quantum encryption key between the communication parties. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 FIG. is a schematic structural diagram of a communication system applied to the embodiments of the present invention;

[0062] Figure 2 FIG. is one of the flowcharts of the quantum encryption key determination method provided by the embodiments of the present invention;

[0063] Figure 3 FIG. is a partial flowchart of the quantum encryption key determination method provided by the embodiments of the present invention;

[0064] Figure 4 FIG. is another flowchart of the quantum encryption key determination method provided by the embodiments of the present invention;

[0065] Figure 5 FIG. is yet another flowchart of the quantum encryption key determination method provided by the embodiments of the present invention;

[0066] Figure 6 FIG. is one of the schematic structural diagrams of the quantum encryption key determination device provided by the embodiments of the present invention;

[0067] Figure 7 FIG. is another schematic structural diagram of the quantum encryption key determination device provided by the embodiments of the present invention;

[0068] Figure 8 FIG. is a schematic structural diagram of an electronic device provided by the embodiments of the present invention. Detailed Implementation Manner

[0069] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described below with reference to the accompanying drawings and embodiments. However, the exemplary embodiments can be implemented in various forms and should not be construed as limited to the embodiments described herein; on the contrary, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings represent the same or similar structures, so the repeated description thereof will be omitted. The words expressing positions and directions described in the present invention are illustrative with reference to the drawings, but can be changed as needed, and all such changes are included in the protection scope of the present invention. The drawings of the present invention are only used to illustrate the relative position relationship and do not represent the actual proportion.

[0070] It should be noted that specific details are set forth in the following description to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific implementation manners disclosed below. The subsequent description in the specification is the preferred implementation manner for implementing the present application, but the description is for the purpose of illustrating the general principles of the present application and is not intended to limit the scope of the present application. The protection scope of the present application shall be determined by the scope defined by the appended claims.

[0071] The quantum encryption key determination method and related hardware provided by the embodiments of the present invention can be applied to a communication system as Figure 1 shown. As Figure 1 shown, the communication system includes a first device E1 and a second device E2. Among them, the first device E1 and the second device E2 communicate through a quantum channel and a classical channel respectively. The quantum channel can be implemented by means of optical fiber, etc. The classical channel can be implemented by means of wired network, wireless local area network (WLAN), Bluetooth, cellular mobile network, narrow band Internet of Things (NB-IoT), Zigbee, LoRa, etc., and the embodiments of the present invention do not make excessive limitations here. The quantum encryption key determination method and related hardware provided by the embodiments of the present invention will be specifically described below.

[0072] In a first aspect, the embodiments of the present invention provide a quantum encryption key determination method, as Figure 2 shown, including:

[0073] Among S100, multiple target quantum signals are transmitted between the first device and the second device through a quantum channel. Among them, the transmission information carried by the target quantum signal is continuous variable information.

[0074] In the specific implementation process, as Figure 2 shown, the first device can generate a target quantum signal carrying continuous variable information and send it to the second device through the quantum channel. Or, contrary to Figure 2 the situation shown, the second device can generate a target quantum signal carrying continuous variable information and send it to the first device through the quantum channel. Since noise interference, quantum signal loss, and possible eavesdropping of quantum signals may occur during the transmission of quantum signals in the quantum channel, there is a deviation between the target quantum signal obtained by the receiving device that receives the target quantum signal and the target quantum signal mastered by the sending device that sends the target quantum signal. Furthermore, there is a deviation in the transmission information carried determined by the two devices based on the target quantum signal, and the two parties cannot directly determine the quantum encryption key based on the transmission information of the target quantum signals they each master. Therefore, the steps to be described in detail later are required to achieve consensus between the two parties based on the transmission information of the target quantum signal. Furthermore, the two devices determine the same quantum encryption key based on the target distribution information obtained through consensus. Therefore, the focus of the embodiments of the present invention is not on which device generates the target quantum signal and sends it to the other device, and no further description will be given here. It should be noted that the names of the first device and the second device in this article are only used to distinguish the two devices, and do not specifically refer to the device that sends / receives the target quantum signal.

[0075] S210. The first device uses the transmission information carried by each target quantum signal as reference information.

[0076] S310. The second device uses the transmission information carried by each target quantum signal as target distribution information.

[0077] S320. The second device determines the quantum encryption key according to the target distribution information corresponding to each target quantum signal.

[0078] For the device that sends the target quantum signal, for any target quantum signal, the transmission information carried by the target quantum signal is the modulation information for the device that sends the target quantum signal to modulate the target quantum signal.

[0079] For the device that receives the target quantum signal, for any target quantum signal, the transmission information carried by the target quantum signal is the observation information obtained by the device that receives the target quantum signal for observing the target quantum signal.

[0080] In the specific implementation process, the target distribution information can be directly used as the quantum encryption key, or the target distribution information can be further processed (including operations such as privacy amplification) to obtain the quantum encryption key. The specific process can refer to the prior art implementation and will not be elaborated here.

[0081] S330. The second device determines the target encoding method according to the target signal-to-noise ratio of the classical channel, and encodes the actual reference information corresponding to at least one reference quantum signal by using the target encoding method to obtain the original reference information of each reference quantum signal. The reference quantum signal is a part of the target quantum signal. The actual reference information is the transmission information carried by the corresponding reference quantum signal, that is, the target distribution information corresponding to the corresponding reference quantum signal.

[0082] S340. The second device sends each piece of original reference information to the first device through the classical channel.

[0083] S220. The first device receives each piece of pending reference information. The pending reference information is the information after the original reference information is transmitted through the classical channel.

[0084] Since there are also situations such as noise interference and classical signal loss in the classical channel, the pending reference information received by the first device also deviates from the original reference information sent by the second device. Therefore, the first device needs to correct the pending reference information to obtain the actual reference information consistent with the second device. If the actual reference information corresponding to the reference quantum signal follows a Gaussian distribution with a mean of 0 and a variance of ∑ 2 and the noise variance of the classical channel is σ 2 . Then the original reference information follows a Gaussian distribution with a mean of 0 and a variance of ∑ 2 +σ 2 . The signal-to-noise ratio of the classical channel is where V A is the signal strength of the original reference information.

[0085] S230. The first device determines the target decoding method according to the target signal-to-noise ratio of the classical channel, and decodes each piece of pending reference information by using the target decoding method to obtain the actual reference information corresponding to each reference quantum signal.

[0086] In the specific implementation process, the target signal-to-noise ratio can be determined by using the prior art and will not be elaborated here.

[0087] S240. The first device respectively determines the information difference of each reference quantum signal. For any reference quantum signal, the information difference of the reference quantum signal refers to the difference between the actual reference information of the reference quantum signal and the reference information of the reference quantum signal.

[0088] S250. The first device determines whether it meets the security requirements based on the information differences of the reference quantum signals.

[0089] If the result of step S250 is yes, the first device executes step S260; if the result of step S250 is no, it is considered that there may be insecure hidden dangers such as eavesdropping in the transmission process of the target quantum encryption signal, the process of determining the quantum encryption key ends, and the first device abandons encrypted communication with the second device using the quantum encryption key. The security requirements can be that the ratio of the actual reference information corresponding to any reference quantum signal to the reference information belongs to a preset first numerical range, or the difference between the actual reference information corresponding to any reference quantum signal and the reference information belongs to a preset second numerical range, etc. The embodiments of the present invention do not make too many limitations.

[0090] If the target quantum signal is eavesdropped by a third party during the transmission process in the quantum channel, then according to the principles of quantum mechanics, the target quantum signal will change due to the eavesdropping behavior, resulting in the target quantum signals held by the device sending the target quantum signal and the device receiving the target quantum signal being different. Therefore, if the information differences of all the reference quantum signals are too large, it can be inferred that for all the target quantum signals, there are differences between the target quantum signals held by the receiving party and the sending party, and the quantum channel may be eavesdropped by a third party. Thus, both parties need to abandon the process of negotiating the quantum encryption key.

[0091] S260. The first device processes the reference information of each target quantum signal according to the information difference of each reference quantum signal to obtain the target distribution information corresponding to each target quantum signal.

[0092] In the specific implementation process, the process of processing the reference information of each target quantum signal according to the information difference of the reference quantum signal to obtain the target distribution information corresponding to each target quantum signal can be implemented with reference to the prior art and will not be elaborated here.

[0093] S270. The first device determines the quantum encryption key according to the target distribution information of each target quantum signal.

[0094] In the specific implementation process, the implementation process of the first device to implement step S260 is the same as the implementation process of the second device to implement step S320, so it will not be elaborated here.

[0095] After that, as shown in step S400, the first device and the second device perform encrypted communication using the quantum encryption key.

[0096] In the specific implementation process, the execution order of step S320 can be adjusted according to actual needs. For example, it can be as Figure 2The step S320 may be executed in the order shown, or at other times, as long as the execution timing of the step S320 is ensured to be after the step S310 and before the step S400.

[0097] In the above steps, if Figure 2 The first device is a device that generates and sends the target quantum signal, and the second device is a device that receives the target quantum signal. The above process is actually a reverse coordination process of the two devices for the quantum encryption key. Figure 2 In contrast to the situation shown in the figure, the second device is the device that generates and sends the target quantum signal, and the first device is the device that receives the target quantum signal. Then the above process is actually a forward coordination process of the two devices for the quantum encryption key. According to theoretical research, it is preferred to adopt Figure 2 The reverse coordination process implementation shown implements the above steps, which can more effectively improve the security of the quantum encryption key encryption transmission process between the first device and the second device.

[0098] In this way, in the embodiment of the present invention, when the first device and the second device negotiate the quantum encryption key, in the case that the target quantum signals held by both parties are different, the second device sends the reference information of the reference information used for the first device to correct the target quantum signal to the first device through the classical channel. The reference information is encoded by determining the encoding method of the reference information according to the target signal-to-noise ratio of the classical channel and then sent to the first device. The first device decodes the received reference information by determining the decoding method of the reference information according to the target signal-to-noise ratio of the classical channel. After that, the first device processes the reference information of the mastered target quantum signal based on the reference information to obtain the target distribution information. At this time, the target distribution information held by the first device and the second device is consistent, and then the first device and the second device determine the consistent quantum encryption key according to the consistent target distribution information for encrypted communication. Compared with encoding / decoding with a preset single generation matrix / check matrix, encoding / decoding with a preset single generation matrix / check matrix will reduce the error correction performance of the check matrix as the signal-to-noise ratio of the classical channel changes, thereby affecting the key rate of determining the quantum encryption key. In the method provided by the embodiment of the present invention, the above-mentioned quantum encryption key negotiation process adjusts the encoding and decoding method of the reference information according to the target signal-to-noise ratio of the classical channel, so that it can effectively select a more efficient encoding and decoding method to encode and decode the reference information according to the information transmission state of the classical channel, taking into account the transmission efficiency of the reference information in the classical channel and the efficiency of the first device in decoding and correcting errors of the reference information to be determined, thereby improving the efficiency of the quantum encryption key negotiation and determination between the communicating parties and the stability of the code rate of the quantum encryption key coordination.

[0099] Further, as an alternative implementation, the different encoding / decoding methods corresponding to different signal-to-noise ratios of the classical channel are specifically as follows: different signal-to-noise ratios of the classical channel correspond to the method of encoding the actual reference information in different encoding formats / the method of decoding the to-be-determined reference information in different decoding formats.

[0100] Then, in step S330, the second device determines a target encoding method according to the target signal-to-noise ratio of the classical channel, and encodes the actual reference information corresponding to at least one reference quantum signal into the original reference information by using the target encoding method, which specifically includes:

[0101] The second device determines a target encoding format according to the target signal-to-noise ratio of the classical channel, and encodes the actual reference information corresponding to each reference quantum signal into the original reference information in the target encoding format.

[0102] Correspondingly, in step S230, the first device determines a target decoding method according to the target signal-to-noise ratio of the classical channel, and decodes each to-be-determined reference information by using the target decoding method to obtain the actual reference information corresponding to each reference quantum signal, which specifically includes:

[0103] The first device determines a target decoding format according to the target signal-to-noise ratio of the classical channel, and decodes each to-be-determined reference information in the target decoding format to obtain the actual reference information corresponding to each reference quantum signal.

[0104] For example, the signal-to-noise ratio can be divided into two different value ranges. When the target signal-to-noise ratio belongs to the first value range with a larger value, in step S330, the second device encodes the actual reference information into the original reference information in the first encoding format; in step S230, the first device decodes the to-be-determined reference information in the first encoding format to obtain the actual reference information. When the target signal-to-noise ratio belongs to the second value range with a smaller value, in step S330, the second device encodes the actual reference information into the original reference information in the second encoding format; in step S230, the first device decodes the to-be-determined reference information in the second encoding format to obtain the actual reference information. The first encoding format can be a Low-Density Parity-Codes (LDPC), Turbo coding, etc., and the second encoding format can be a Hamming coding, etc.

[0105] As another alternative implementation, in step S330, the actual reference information can be fixedly encoded into the original reference information in the LDPC format. The different encoding / decoding methods corresponding to different signal-to-noise ratios of the classical channel are specifically as follows: different signal-to-noise ratios of the classical channel correspond to the method of encoding the actual reference information with different generating matrices of LDPC codes / the method of decoding with different parity-check matrices of LDPC codes.

[0106] Then, in step S330, the second device determines a target coding method according to the target signal-to-noise ratio of the classical channel, and encodes the actual reference information corresponding to at least one reference quantum signal into the original reference information by using the target coding method, which specifically includes:

[0107] The second device determines a target generating matrix according to the target signal-to-noise ratio of the classical channel, and encodes the actual reference information corresponding to each reference quantum signal into the original reference information by using the target generating matrix.

[0108] Correspondingly, in step S230, the first device determines a target decoding method according to the target signal-to-noise ratio of the classical channel, and decodes each to-be-determined reference information by using the target decoding method to obtain the actual reference information corresponding to each reference quantum signal, which specifically includes:

[0109] The first device determines a target parity-check matrix according to the target signal-to-noise ratio of the classical channel, and decodes each to-be-determined reference information by using the target parity-check matrix with a soft decision algorithm to obtain the actual reference information corresponding to each reference quantum signal.

[0110] In the specific implementation process, the soft decision algorithm can be implemented by using algorithms such as Belief Propagation (BP) algorithm, Sum-Product Algorithm (SPA), and Fast Hadamard Transform Belief Propagation (FHT-BP) algorithm.

[0111] In the specific implementation process, the process of the second device encoding the actual reference information into the original reference information and the first device decoding the to-be-determined reference information into the actual reference information can be implemented by using a Graphics Processing Unit (GPU), and the remaining steps are implemented by a Central Processing Unit (CPU). Thus, the overall quantum encryption key determination method is implemented by using a heterogeneous platform of CPU + GPU, and the parallel computing power of the GPU is utilized to accelerate the quantum encryption key determination process.

[0112] Further, in the process where the second device determines the target generating matrix based on the target signal-to-noise ratio of the classical channel and the first device determines the target parity-check matrix based on the target signal-to-noise ratio of the classical channel, as an alternative implementation, the corresponding relationship between the signal-to-noise ratio and the generating matrix and the parity-check matrix can be preset. For example, the signal-to-noise ratio can be divided into multiple different value ranges, and different value ranges respectively correspond to different generating matrices and parity-check matrices. In the process of encoding the original reference information / decoding the pending reference information, the target generating matrix corresponding to the target signal-to-noise ratio is determined according to the corresponding relationship between the signal-to-noise ratio and the generating matrix, and the target parity-check matrix corresponding to the target signal-to-noise ratio is determined according to the corresponding relationship between the signal-to-noise ratio and the generating matrix.

[0113] As another alternative implementation, considering that:

[0114]

[0115] where β is the coordination efficiency, R is the transmission code rate of the classical channel, C is the capacity of the classical channel, B is the bandwidth of the classical channel, s is the base of the transmission data of the classical channel, SNR is the target signal-to-noise ratio, the number of check nodes of the target generating matrix / target parity-check matrix is m, and the number of variable nodes of the target generating matrix / target parity-check matrix is n. In the specific implementation process, the classical channel mostly uses binary digital signals for transmission, so s = 2.

[0116] Then, the target generating matrix / target parity-check matrix can be determined in the following way:

[0117] The node ratio of the number of check nodes m to the number of variable nodes n of the generating matrix and the parity-check matrix can be preset and the corresponding relationship with the generating matrix and the parity-check matrix. For example, is divided into multiple different value ranges, and different value ranges respectively correspond to different generating matrices and parity-check matrices.

[0118] The desired node ratio of the number of check nodes m to the number of variable nodes n of the target generating matrix / target parity-check matrix is determined in the following way:

[0119]

[0120] where β0 is the preset coordination efficiency, B is the bandwidth of the classical channel, s is the base of the transmission data of the classical channel, and SNR is the target signal-to-noise ratio.

[0121] After that, according to the preset corresponding relationship between the node ratio and the generating matrix / parity-check matrix, the target generating matrix / target parity-check matrix corresponding to the desired node ratio is determined.

[0122] Further optionally, for the first device, in the process of decoding each pending reference information by using the target parity-check matrix and the soft-decision algorithm to obtain the actual reference information corresponding to each reference quantum signal, currently, single-precision format (32-bit floating-point number) data is defaultly used for operation. In order to improve the speed of LDPC decoding for the pending reference information, for any pending reference information, the pending reference information can be initialized as the prior probability information in the half-precision format (16-bit floating-point number) corresponding to each variable node, and the prior probability information is used as the message value of the corresponding variable node in the first iterative decoding process. Then, the soft-decision algorithm is used to perform iterative decoding for a preset number of times by using the target parity-check matrix to obtain the actual reference information of the reference quantum signal corresponding to the pending reference information.

[0123] In this way, by changing the decoding data precision of the pending reference information from single-precision to half-precision, the number of bits of the calculated data can be greatly reduced, and in theory, the key rate for determining the quantum encryption key can be increased by about one time. For the implementation manner of using the GPU to decode the pending reference information, the transfer efficiency of the decoded operation data among the GPU video memory, cache, and the Compute Unified Device Architecture (CUDA) cores can be effectively improved, and the overhead of the first device for moving and storing data can be reduced. In theory, when the data volume is the same, compared with using the single-precision format to perform LDPC decoding on the pending reference information, during the process of performing LDPC decoding on the pending reference information in the half-precision format, the data transfer and storage overhead will be smaller, and the overall throughput will be higher.

[0124] However, during the process of using the half-precision format data for decoding operation in the soft-decision algorithm, compared with using the single-precision format data for decoding operation, the accuracy is also correspondingly reduced. In order to reduce the negative impact of the decrease in the operation data precision on the decoding accuracy, correspondingly, at the beginning of the non-first iterative decoding, for any of the variable nodes, the product of the message value transmitted by the variable node to the corresponding check nodes determined in the previous iterative decoding and the prior probability information in the half-precision format corresponding to the variable node is used as the message value of the variable node in the current iterative decoding process, so as to reduce the accumulation of errors caused by the decrease in the operation data precision during multiple iterative processes. Among them, for any variable node, the check nodes corresponding to the variable node are the check nodes connected to the variable node in the Tanner graph.

[0125] Optionally, as Figure 3 shown, for any pending reference information in the LDPC format received by the first device, if the first device decodes it by using the layered BP algorithm, then the step S230 may specifically include the following steps:

[0126] S231. The first device determines the target signal-to-noise ratio of the classical channel.

[0127] S232. The first device determines the target parity-check matrix according to the target signal-to-noise ratio.

[0128] S233. The first device initializes the to-be-determined reference information as the prior probability information corresponding to each variable node.

[0129] S234. The first device converts the prior probability information corresponding to each variable node into a half-precision format.

[0130] S235. The first device determines whether the number of iterations performed has reached a preset number.

[0131] If the result of step S235 is no, execute step S236; if the result of step S235 is yes, execute step S239.

[0132] S236. The first device determines the message value corresponding to each variable node. Among them, for any variable node, in the first iteration decoding process, the message value of the variable node is the corresponding half-precision format prior probability information; in the non-first iteration decoding process, the message value of the variable node is the product of the message values transmitted by the variable node to each corresponding parity-check node in the previous iteration decoding process and the half-precision format prior probability information corresponding to the variable node.

[0133] In the specific implementation process, a kernel function can be specifically set to implement step S236.

[0134] S237. The first device determines whether all levels of decoding operations corresponding to the target parity-check matrix have been completed.

[0135] If the result of step S237 is yes, return to step S235; if the result of step S237 is no, execute step S238.

[0136] S238. The first device sequentially determines the currently decoded level of the target parity-check matrix and decodes the level.

[0137] In the specific implementation process, a kernel function can be specifically set to implement step S238.

[0138] S239. The first device determines the actual reference information corresponding to the to-be-determined reference information according to the decoding results of each iteration decoding process.

[0139] In the specific implementation process, the specific process of step S238 (such as a variable node at the current layer transmitting a message value to a corresponding check node, etc.) and the specific process of step S239 can be implemented with reference to the prior art and will not be elaborated here.

[0140] The quantum encryption key determination method provided by the embodiments of the present invention can be applied to the encryption and decryption scenarios of data collected by underlying atomic capabilities. The scenario is the requirement of real-time data collection and real-time communication, so there will be a large amount of data throughput, and thus a large number of real-time encryption communication requirements. Then, through the quantum encryption key determination method provided by the embodiments of the present invention, the first device and the second device can determine the quantum encryption key for the upper-layer quantum key management system to call. The quantum key management system provides a key usage interface to the atomic capability platform and the business system.

[0141] In a second aspect, based on the same inventive concept, the embodiments of the present invention also provide a quantum encryption key determination method, as Figure 4 shown, which is applied to the second device and includes:

[0142] S510. Transmit a plurality of target quantum signals to the first device through a quantum channel. Among them, the transmission information carried by the target quantum signal is continuous variable information.

[0143] As an optional implementation manner, the target quantum signal is a quantum signal sent to the first device.

[0144] As another optional implementation manner, the target quantum signal is a quantum signal received and sent by the first device.

[0145] S520. Determine the target distribution information of each target quantum signal respectively.

[0146] If the target quantum signal is a quantum signal sent to the first device, then for any target quantum signal, the target distribution information of the target quantum signal is the modulation information for modulating the target quantum signal.

[0147] If the target quantum signal is a quantum signal received and sent by the first device, then for any target quantum signal, the target distribution information of the target quantum signal is the observation information obtained by observing the target quantum signal.

[0148] S530. Determine the quantum encryption key according to the target distribution information.

[0149] S540. Determine the target encoding method according to the target signal-to-noise ratio of the classical channel, and use the target encoding method to encode the actual reference information corresponding to at least one reference quantum signal to obtain the original reference information of each reference quantum signal. Among them, the reference quantum signal is a part of the quantum signals of the target quantum signal. For any reference quantum signal, the actual reference information corresponding to the reference quantum signal is the target distribution information corresponding to the reference quantum signal.

[0150] S550. Send each piece of original reference information to the first device through the classical channel, so that the first device determines the quantum encryption key used for communication with the second device according to the received pending reference information and the target quantum signal. Among them, the pending reference information is the information received by the first device after the original reference information is transmitted through the classical channel.

[0151] After that, the first device and the second device perform encrypted communication using the same quantum encryption key.

[0152] As an alternative implementation manner, the different encoding methods corresponding to different signal-to-noise ratios of the classical channel are specifically: different encoding formats are used to encode the actual reference information corresponding to different signal-to-noise ratios of the classical channel.

[0153] The step S540, determining the target encoding method according to the target signal-to-noise ratio of the classical channel, and using the target encoding method to encode the actual reference information corresponding to at least one reference quantum signal to obtain the original reference information of each reference quantum signal, specifically includes:

[0154] Determine the target encoding format according to the target signal-to-noise ratio of the classical channel, and encode the actual reference information corresponding to at least one reference quantum signal in the target encoding format to obtain the original reference information corresponding to each reference quantum signal.

[0155] As another alternative implementation manner, the original reference information is in LDPC format. The different decoding methods corresponding to different signal-to-noise ratios of the classical channel are specifically: different generation matrices of LDPC codes are used to encode the actual reference information corresponding to different signal-to-noise ratios of the classical channel.

[0156] The step S540, determining the target encoding method according to the target signal-to-noise ratio of the classical channel, and using the target encoding method to encode the actual reference information corresponding to at least one reference quantum signal to obtain the original reference information of each reference quantum signal, specifically includes:

[0157] Determine the target generation matrix according to the target signal-to-noise ratio of the classical channel, and use the target generation matrix to encode the actual reference information corresponding to at least one reference quantum signal to obtain the original reference information of each reference quantum signal.

[0158] Further, as an alternative implementation, determining the target generation matrix according to the target signal-to-noise ratio of the classical channel includes:

[0159] Using the preset correspondence between the signal-to-noise ratio and the generation matrix, determine the target generation matrix corresponding to the target signal-to-noise ratio of the classical channel.

[0160] As another alternative implementation, the desired node ratio of the check node number m and the variable node number n of the target generation matrix is determined by the following method:

[0161]

[0162] where β0 is the preset coordination efficiency, B is the bandwidth of the classical channel, s is the base of the data transmitted by the classical channel, and SNR is the target signal-to-noise ratio;

[0163] According to the preset correspondence between the node ratio and the generation matrix, determine the target generation matrix corresponding to the desired node ratio.

[0164] In a third aspect, based on the same inventive concept, an embodiment of the present invention further provides a method for determining a quantum encryption key, as Figure 5 shown, applied to a first device, including:

[0165] S610. Transmit a plurality of target quantum signals to a second device through a quantum channel. Among them, the transmission information carried by the target quantum signal is continuous variable information.

[0166] As an alternative implementation, the target quantum signal is a quantum signal received and sent by the second device.

[0167] As another alternative implementation, the target quantum signal is a quantum signal sent to the second device.

[0168] S620. Respectively determine the reference information corresponding to each target quantum signal.

[0169] If the target quantum signal is a quantum signal received and sent by the second device, for any target quantum signal, the reference information of the target quantum signal is the modulation information that modulates the target quantum signal.

[0170] If the target quantum signal is a quantum signal sent to the second device, for any target quantum signal, the reference information of the target quantum signal is the observation information obtained by observing the target quantum signal.

[0171] S630. Receive the pending reference information corresponding to at least one reference quantum signal sent by the second device through a classical channel. Among them, the reference quantum signal is a part of the quantum signals in the target quantum signals.

[0172] S640. Determine a target decoding method according to the target signal-to-noise ratio of the classical channel, and use the target decoding method to decode each pending reference information to obtain the actual reference information corresponding to each reference quantum signal.

[0173] S650. Determine the information difference of each reference quantum signal respectively. For any reference quantum signal, the information difference of the reference quantum signal refers to the difference between the actual reference information of the reference quantum signal and the reference information of the reference quantum signal.

[0174] S660. Judge whether it meets the security requirements according to the information differences of the reference quantum signals.

[0175] If the result of step S660 is yes, execute step S670; if the result of step S660 is no, end the process of determining the quantum encryption key.

[0176] S670. Process the reference information corresponding to each target quantum signal according to the information difference of each reference quantum signal to obtain the target distribution information corresponding to each target quantum signal.

[0177] S680. Determine the quantum encryption key used for communication between the first device and the second device according to the target distribution information corresponding to each target quantum signal.

[0178] After that, the first device and the second device perform encrypted communication using the quantum encryption key.

[0179] As an optional implementation manner, the different decoding methods corresponding to different signal-to-noise ratios of the classical channel are specifically: different decoding formats are used to decode the pending reference information corresponding to different signal-to-noise ratios of the classical channel.

[0180] Step S640, determine a target decoding method according to the target signal-to-noise ratio of the classical channel, and use the target decoding method to decode each pending reference information to obtain the actual reference information corresponding to each reference quantum signal, specifically includes:

[0181] Determine a target decoding format according to the target signal-to-noise ratio of the classical channel, and decode each pending reference information in the target decoding format to obtain the actual reference information corresponding to each reference quantum signal.

[0182] As another optional implementation manner, the pending reference information is in LDPC format. The different decoding methods corresponding to different signal-to-noise ratios of the classical channel are specifically: different parity-check matrices of LDPC codes are used to decode the pending reference information corresponding to different signal-to-noise ratios of the classical channel.

[0183] Step S640: Determine a target decoding method according to the target signal-to-noise ratio of the classical channel, and use the target decoding method to decode each pending reference information to obtain the actual reference information of each reference quantum signal, which specifically includes:

[0184] Determine a target parity-check matrix according to the target signal-to-noise ratio of the classical channel, and use a soft-decision algorithm to decode each pending reference information by using the target parity-check matrix to obtain the actual reference information corresponding to each reference quantum signal.

[0185] In a specific implementation process, the soft-decision algorithm can be implemented by using a belief propagation (BP) algorithm.

[0186] Furthermore, as an alternative implementation manner, the determining the target parity-check matrix according to the target signal-to-noise ratio of the classical channel includes:

[0187] Use a preset correspondence relationship between the signal-to-noise ratio and the parity-check matrix to determine the target parity-check matrix corresponding to the target signal-to-noise ratio of the classical channel.

[0188] As another alternative implementation manner, determine an expected node ratio of the number m of check nodes and the number n of variable nodes of the target parity-check matrix by the following method:

[0189]

[0190] where β0 is a preset coordination efficiency, B is the bandwidth of the classical channel, s is the radix of the transmitted data of the classical channel, and SNR is the target signal-to-noise ratio;

[0191] Determine the target parity-check matrix corresponding to the expected node ratio according to a preset correspondence relationship between the node ratio and the parity-check matrix.

[0192] Furthermore, the decoding each pending reference information by using the soft-decision algorithm with the target parity-check matrix to obtain the actual reference information of each reference quantum signal includes:

[0193] For any pending reference information, initialize the pending reference information as prior probability information in a half-precision format corresponding to each variable node, convert the prior probability information as the message value of the corresponding variable node in the first iterative decoding process, and use the soft-decision algorithm with the target parity-check matrix to perform iterative decoding for a preset number of times to obtain the actual reference information of the reference quantum signal corresponding to the pending reference information;

[0194] Among them, at the beginning of the non-first iteration decoding, for any one of the variable nodes, the product of the message values respectively transmitted by the variable node to the corresponding check nodes determined in the previous iteration decoding and the prior probability information corresponding to the variable node is used as the message value of the variable node in the current iteration decoding process.

[0195] Since the quantum encryption key determination methods described in the second aspect and the third aspect are technical solutions with the same inventive concept as the quantum encryption key determination method described in the first aspect, the specific implementation processes of the second aspect and the third aspect can refer to the corresponding content of the first aspect and will not be elaborated herein.

[0196] Fourthly, based on the same inventive concept, an embodiment of the present invention further provides a quantum encryption key determination device, as Figure 6 shown, including:

[0197] A quantum signal processing module M210, configured to respectively determine the target distribution information of each target quantum signal among a plurality of target quantum signals; the plurality of target quantum signals are quantum signals carrying continuous variable information transmitted between the first device and the quantum encryption key determination device;

[0198] A quantum encryption key determination module M220, configured to determine the quantum encryption key according to the target distribution information;

[0199] A reference information encoding module M230, configured to determine a target encoding method according to the target signal-to-noise ratio of the classical channel, and encode the actual reference information corresponding to at least one reference quantum signal into the original reference information by using the target encoding method; the at least one reference quantum signal is a part of the plurality of target quantum signals; the actual reference information is the target distribution information corresponding to the reference quantum signal;

[0200] A reference information sending module M240, configured to send the original reference information to the first device through the classical channel; so that the first device determines the quantum encryption key used for communicating with the quantum encryption key determination device according to the received pending reference information and the target quantum signal; the pending reference information is the information received by the first device after the original reference information is transmitted through the classical channel.

[0201] Furthermore, if the target quantum signal is a quantum signal sent to the first device, for any target quantum signal, the target distribution information of the target quantum signal is the modulation information modulating the target quantum signal;

[0202] If the target quantum signal is the quantum signal received from the first device, for any target quantum signal, the target distribution information of the target quantum signal is the observation information obtained by observing the target quantum signal.

[0203] As an alternative implementation, the different coding methods corresponding to different signal-to-noise ratios of the classical channel are specifically: different coding formats are used for the actual reference information corresponding to different signal-to-noise ratios of the classical channel for coding.

[0204] The reference information encoding module M230 is specifically configured to:

[0205] Determine a target coding format according to the target signal-to-noise ratio of the classical channel, and encode the actual reference information corresponding to at least one reference quantum signal in the target coding format to obtain the original reference information corresponding to each reference quantum signal.

[0206] As another alternative implementation, the original reference information is in LDPC format. The different decoding methods corresponding to different signal-to-noise ratios of the classical channel are specifically: different generating matrices of LDPC codes are used for the actual reference information corresponding to different signal-to-noise ratios of the classical channel for coding.

[0207] The reference information encoding module M230 is specifically configured to:

[0208] Determine a target generating matrix according to the target signal-to-noise ratio of the classical channel, and encode the actual reference information corresponding to at least one reference quantum signal by using the target generating matrix to obtain the original reference information corresponding to each reference quantum signal.

[0209] Furthermore, as an alternative implementation, the determining the target generating matrix according to the target signal-to-noise ratio of the classical channel includes:

[0210] Determine the target generating matrix corresponding to the target signal-to-noise ratio of the classical channel by using the preset correspondence between the signal-to-noise ratio and the generating matrix.

[0211] As another alternative implementation, the expected node ratio of the check nodes number m and the variable nodes number n of the target generating matrix is determined by the following method:

[0212]

[0213] where β0 is the preset coordination efficiency, B is the bandwidth of the classical channel, s is the base of the data transmitted by the classical channel, and SNR is the target signal-to-noise ratio;

[0214] Determine the target generating matrix corresponding to the expected node ratio according to the preset correspondence between the node ratio and the generating matrix.

[0215] Fifth aspect, based on the same inventive concept, an embodiment of the present invention further provides a quantum encryption key determination device, as Figure 7 shown, including:

[0216] A quantum signal processing module M110, configured to respectively determine reference information of each target quantum signal among a plurality of target quantum signals; the plurality of target quantum signals are quantum signals carrying continuous variable information transmitted between the quantum encryption key determination device and a second device;

[0217] A reference information receiving module M120, configured to receive, through a classical channel, undetermined reference information of at least one reference quantum signal sent by the second device; the at least one reference quantum signal is a part of the plurality of target quantum signals;

[0218] A reference information decoding module M130, configured to determine a target decoding method according to a target signal-to-noise ratio of the classical channel, and use the target decoding method to decode each piece of undetermined reference information to obtain actual reference information of each reference quantum signal;

[0219] A calibration module M140, configured to respectively determine information differences of each reference quantum signal; according to the information differences of each reference quantum signal, process the reference information of each target quantum signal to obtain target distribution information of each target quantum signal; wherein, for any one reference quantum signal, the information difference of the reference quantum signal refers to the difference between the actual reference information of the reference quantum signal and the reference information of the reference quantum signal;

[0220] A quantum encryption key determination module M150, configured to determine a quantum encryption key used for communication between the quantum encryption key determination device and the second device according to the target distribution information of each target quantum signal.

[0221] Furthermore, if the target quantum signal is a quantum signal received from the second device, then for any one target quantum signal, the reference information of the target quantum signal is modulation information for modulating the target quantum signal.

[0222] If the target quantum signal is a quantum signal sent to the second device, then for any one target quantum signal, the reference information of the target quantum signal is observation information obtained by observing the target quantum signal.

[0223] As an optional implementation manner, different decoding methods corresponding to different signal-to-noise ratios of the classical channel are specifically: different signal-to-noise ratios of the classical channel correspond to a manner in which undetermined reference information is decoded using different decoding formats.

[0224] The reference information decoding module M130 is specifically configured to:

[0225] Determine the target decoding format according to the target signal-to-noise ratio of the classical channel, decode each to-be-determined reference information in the target decoding format, and obtain the actual reference information corresponding to each reference quantum signal.

[0226] As another optional implementation manner, the to-be-determined reference information is in LDPC format. The different decoding methods corresponding to different signal-to-noise ratios of the classical channel are specifically: different signal-to-noise ratios of the classical channel correspond to different decoding methods of the to-be-determined reference information using different parity-check matrices of LDPC codes.

[0227] The step reference information decoding module M130 is specifically configured to:

[0228] Determine the target parity-check matrix according to the target signal-to-noise ratio of the classical channel, and use the soft-decision algorithm to decode each to-be-determined reference information using the target parity-check matrix to obtain the actual reference information corresponding to each reference quantum signal.

[0229] In the specific implementation process, the soft-decision algorithm can be implemented using the Belief Propagation (BP) algorithm.

[0230] Furthermore, as an optional implementation manner, the determining the target parity-check matrix according to the target signal-to-noise ratio of the classical channel includes:

[0231] Use the preset correspondence between the signal-to-noise ratio and the parity-check matrix to determine the target parity-check matrix corresponding to the target signal-to-noise ratio of the classical channel.

[0232] As another optional implementation manner, determine the desired node ratio of the number of check nodes m and the number of variable nodes n of the target parity-check matrix through the following method:

[0233]

[0234] where β0 is the preset coordination efficiency, B is the bandwidth of the classical channel, s is the base of the transmission data of the classical channel, and SNR is the target signal-to-noise ratio;

[0235] According to the preset correspondence between the node ratio and the parity-check matrix, determine the target parity-check matrix corresponding to the desired node ratio.

[0236] Furthermore, the using the target parity-check matrix to decode each of the to-be-determined reference information using the soft-decision algorithm to obtain the actual reference information of each reference quantum signal includes:

[0237] For any to-be-determined reference information, initialize the to-be-determined reference information as prior probability information in half-precision format corresponding to each variable node, use the prior probability information as the message value of the corresponding variable node in the first iterative decoding process, and perform iterative decoding for a preset number of times using the target parity-check matrix with a soft decision algorithm to obtain the actual reference information of the reference quantum signal corresponding to the to-be-determined reference information;

[0238] Among them, at the beginning of non-first iterative decoding, for any of the variable nodes, use the product of the message values transmitted by the variable node to the corresponding parity-check nodes determined in the previous iterative decoding and the prior probability information corresponding to the variable node as the message value of the variable node in the current iterative decoding process.

[0239] In several embodiments provided in the present application, it should be understood that the described device embodiments are merely illustrative. For example, the division of the modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the device or module can be in electrical, mechanical or other forms. The modules described as separate components may or may not be physically separated. The components displayed as modules may or may not be physical modules, that is, they can be located in one place or distributed to multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. In addition, in each embodiment of the present application, the functional modules can be integrated in a processing module, or each module can exist physically alone, or two or more modules can be integrated in one module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can be stored in a readable storage medium.

[0240] Since the working principles of the quantum encryption key determination device described in the fourth aspect and the fifth aspect correspond to the second device and the first device in the quantum encryption key determination method described in the first aspect respectively, the specific implementation manners of the quantum encryption key determination device can refer to the corresponding contents of the first aspect to the third aspect, and will not be elaborated here.

[0241] Sixth aspect, based on the same inventive concept, the embodiments of the present application also provide an electronic device, such as Figure 8As shown, it includes: a processor 110 and a memory 120 for storing executable instructions of the processor 110; wherein, the processor 110 is configured to execute the instructions to implement the quantum encryption key determination method as described in the second aspect and / or the third aspect.

[0242] In a specific implementation process, the device may vary greatly due to configuration or performance differences, and may include one or more processors 110, a memory 120, and a computer-readable storage medium 130. One or more application programs 131 or data 132 are included in the memory 120 and / or the computer-readable storage medium 130. One or more operating systems 133, such as Windows, Mac OS, Linux, IOS, Android, Unix, FreeBSD, etc., may also be included in the memory 120 and / or the computer-readable storage medium 130. Among them, the memory 120 and the computer-readable storage medium 130 may be transient storage or persistent storage. The application program 131 may include one or more of the above-mentioned modules ( Figure 8 not shown in the figure), and each module may include a series of instruction operations. Further, the processor 110 may be set to communicate with the computer-readable storage medium 130 and execute a series of instruction operations in the computer-readable storage medium 130 on the device. The device may also include one or more power supplies ( Figure 8 not shown in the figure); one or more network interfaces 140, the network interface 140 including a wired network interface 141 and / or a wireless network interface 142; one or more input / output interfaces 143.

[0243] In a seventh aspect, based on the same inventive concept, an embodiment of the present invention provides a computer-readable storage medium storing computer program code, which, when running on a computer, causes the computer to implement the quantum encryption key determination method as described in the second aspect and / or the third aspect.

[0244] The computer-readable storage medium may be any available medium that can be stored by a computer or a data storage device such as a server or a data center that integrates one or more available media. The available medium may be a magnetic medium (such as a floppy disk, a hard disk, a USB flash drive, a magnetic tape, a read-only memory (ROM), a random access memory (RAM)), an optical medium (such as a high-definition digital video disc (DVD), a video compact disc (VCD)), or a semiconductor medium (such as a solid-state disk (SSD)), etc.

[0245] Since the principle of solving problems by the above computer-readable storage medium is the same as that of the quantum encryption key determination method described in the first to third aspects above, the implementation of the above computer-readable storage medium can refer to the implementation of the method, and the repeated parts will not be described again.

[0246] In an eighth aspect, based on the same inventive concept, an embodiment of the present application further provides a computer program product, which includes: computer program code, when the computer program code runs on a computer, enabling the computer to implement the quantum encryption key determination method described in the second aspect and / or the third aspect.

[0247] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, a computer, a server, or a data center to another website, a computer, a server, or a data center by wire (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wirelessly (such as infrared, wireless, microwave, etc.).

[0248] Since the principle of solving problems by the above computer program product is the same as that of the quantum encryption key determination method described in the first to third aspects above, the implementation of the above computer program product can refer to the implementation of the method, and the repeated parts will not be described again.

[0249] The quantum encryption key determination method and related hardware provided by the embodiments of the present invention, in the process of negotiating a quantum encryption key between a first device and a second device, for the situation where there are differences in the target quantum signals mastered by both parties, when the second device sends the reference information for the first device to correct the target quantum signal to the first device through a classical channel, the second device encodes the reference information by determining the encoding method of the reference information according to the target signal-to-noise ratio of the classical channel and then sends it to the first device. The first device decodes the received reference information by determining the decoding method of the reference information according to the target signal-to-noise ratio of the classical channel. After that, the first device processes the reference information of the mastered target quantum signal based on the reference information to obtain the target distribution information. At this time, the target distribution information mastered by the first device and the second device is consistent. Furthermore, the first device and the second device determine a consistent quantum encryption key based on the consistent target distribution information for encrypted communication. The negotiation process of the above quantum encryption key adjusts the encoding and decoding methods of the reference information according to the target signal-to-noise ratio of the classical channel, so as to be able to effectively select a more efficient encoding and decoding method to encode and decode the reference information according to the information transmission state of the classical channel, taking into account both the transmission efficiency of the reference information in the classical channel and the decoding error correction efficiency of the first device for the to-be-determined reference information, thereby improving the negotiation and determination efficiency of the quantum encryption key between the communication parties.

[0250] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0251] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0252] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-readable memory produce a manufacture including an instruction device that implements the functions specified in one or more of the processes Figure 1 one or more processes and / or blocks Figure 1 specified in the block or blocks.

[0253] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in one or more of the processes Figure 1 one or more processes and / or blocks Figure 1 specified in the block or blocks.

[0254] Obviously, those skilled in the art can make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, this application is also intended to include these changes and modifications.

Claims

1. A method for determining a quantum encryption key, characterized in that: Applied to a first device, comprising: Determining reference information of each target quantum signal in a plurality of target quantum signals respectively; the plurality of target quantum signals are quantum signals carrying continuous variable information transmitted between the first device and the second device; receiving, through a classical channel, pending reference information of at least one reference quantum signal sent by the second device; the at least one reference quantum signal is a partial quantum signal of the plurality of target quantum signals; Determining a target decoding method according to a target signal-to-noise ratio of the classical channel, and decoding each of the pending reference information using the target decoding method to obtain actual reference information of each of the reference quantum signals; Determine the information difference of each reference quantum signal respectively; wherein, for any reference quantum signal, the information difference of the reference quantum signal refers to the difference between the actual reference information of the reference quantum signal and the reference information of the reference quantum signal; According to the information difference of each reference quantum signal, the reference information of each target quantum signal is processed to obtain the target distribution information of each target quantum signal; According to the target distribution information of each target quantum signal, a quantum encryption key used by the first device to communicate with the second device is determined.

2. The method according to claim 1, characterized in that The target quantum signal is a received quantum signal sent by the second device, and the reference information of the target quantum signal is observation information obtained by observing the target quantum signal; Alternatively, the target quantum signal is a quantum signal sent to the second device, and the reference information of the target quantum signal is modulation information for modulating the target quantum signal.

3. The method according to claim 1, characterized in that The pending reference information is in a low-density parity check code LDPC format; Different signal-to-noise ratios of the classical channel correspond to the undetermined reference information in the LDPC decoding process using different check matrices for decoding; The step of determining a target decoding method according to a target signal-to-noise ratio of the classical channel, and decoding the pending reference information of each reference quantum signal using the target decoding method to obtain actual reference information of each reference quantum signal includes: A target check matrix is ​​determined according to a target signal-to-noise ratio of the classical channel, and each of the pending reference information is decoded using a soft decision algorithm using the target check matrix to obtain actual reference information of each of the reference quantum signals.

4. The method according to claim 3, characterized in that The determining a target check matrix according to a target signal-to-noise ratio of the classical channel comprises: Determine a target check matrix corresponding to the target signal-to-noise ratio of the classical channel by using a preset correspondence between the signal-to-noise ratio and the check matrix; or, The expected node ratio of the number of check nodes m and the number of variable nodes n of the target check matrix is ​​determined as follows: Among them, β0 is the preset coordination efficiency, B is the bandwidth of the classical channel, s is the number system of the transmission data of the classical channel, and SNR is the target signal-to-noise ratio; According to a preset correspondence between the node ratio and the check matrix, a target check matrix corresponding to the expected node ratio is determined.

5. The method according to claim 3, characterized in that The step of using the target check matrix to decode each of the pending reference information using a soft decision algorithm to obtain actual reference information of each of the reference quantum signals includes: For any pending reference information, the pending reference information is initialized to the prior probability information in the half-precision format corresponding to each variable node, the prior probability information is used as the message value of the corresponding variable node in the first iterative decoding process, and the target check matrix is ​​used to adopt a soft decision algorithm to perform iterative decoding for a preset number of times to obtain the actual reference information of the reference quantum signal corresponding to the pending reference information; Among them, when the non-first iterative decoding starts, for any of the variable nodes, the product of the message value transmitted by the variable node determined by the previous iterative decoding to the corresponding check nodes and the prior probability information corresponding to the variable node is used as the message value of the variable node in this iterative decoding process.

6. A method for determining a quantum encryption key, characterized in that: Applied to the second device, comprising: Determining target distribution information of each target quantum signal in a plurality of target quantum signals respectively; the plurality of target quantum signals are quantum signals carrying continuous variable information transmitted between the first device and the second device; Determining the quantum encryption key according to the target distribution information; Determine a target encoding method according to a target signal-to-noise ratio of a classical channel, and use the target encoding method to encode actual reference information corresponding to at least one reference quantum signal into original reference information; the at least one reference quantum signal is a partial quantum signal of the multiple target quantum signals; the actual reference information is target distribution information corresponding to the reference quantum signal; The original reference information is sent to the first device through the classical channel; so that the first device determines the quantum encryption key used to communicate with the second device according to the received pending reference information and the target quantum signal; the pending reference information is the information received by the first device after the original reference information is transmitted through the classical channel.

7. The method according to claim 6, characterized in that The target quantum signal is a quantum signal sent to the first device, and the target distribution information of the target quantum signal is modulation information for modulating the target quantum signal; Alternatively, the target quantum signal is a received quantum signal sent by the first device, and the target distribution information of the target quantum signal is observation information obtained by observing the target quantum signal.

8. The method according to claim 6, characterized in that The original reference information is in LDPC format; Different signal-to-noise ratios of the classical channel correspond to different generation matrices for encoding in the LDPC encoding process of actual reference information; The step of determining a target encoding method according to a target signal-to-noise ratio of a classical channel, and encoding actual reference information corresponding to at least one reference quantum signal into original reference information by using the target encoding method, comprises: A target generation matrix is ​​determined according to a target signal-to-noise ratio of a classical channel, and actual reference information corresponding to at least one reference quantum signal is encoded using the target generation matrix to obtain original reference information of each reference quantum signal.

9. The method according to claim 8, characterized in that Determining the target generation matrix according to the target signal-to-noise ratio of the classical channel includes: Determine a target generating matrix corresponding to the target signal-to-noise ratio of the classical channel by using a preset corresponding relationship between the signal-to-noise ratio and the generating matrix; or, The expected node ratio of the number of check nodes m and the number of variable nodes n of the target generator matrix is ​​determined as follows: Among them, β0 is the preset coordination efficiency, B is the bandwidth of the classical channel, s is the number system of the transmission data of the classical channel, and SNR is the target signal-to-noise ratio; According to the preset corresponding relationship between the node ratio and the generator matrix, the target generator matrix corresponding to the expected node ratio is determined.

10. A quantum encryption key determination device, characterized in that: include: A quantum signal processing module, used to respectively determine reference information of each target quantum signal among a plurality of target quantum signals; The multiple target quantum signals are quantum signals carrying continuous variable information transmitted between the quantum encryption key determination apparatus and the second device; A reference information receiving module, configured to receive, through a classical channel, pending reference information of at least one reference quantum signal sent by the second device; the at least one reference quantum signal is a partial quantum signal of the multiple target quantum signals; A reference information decoding module, used to determine a target decoding method according to a target signal-to-noise ratio of the classical channel, and use the target decoding method to decode each of the pending reference information to obtain actual reference information of each of the reference quantum signals; A correction module, used to respectively determine the information difference of each reference quantum signal; according to the information difference of each reference quantum signal, the reference information of each target quantum signal is processed to obtain the target distribution information of each target quantum signal; wherein, for any reference quantum signal, the information difference of the reference quantum signal refers to the difference between the actual reference information of the reference quantum signal and the reference information of the reference quantum signal; The quantum encryption key determination module is used to determine the quantum encryption key used by the quantum encryption key determination device to communicate with the second device according to the target distribution information of each target quantum signal.

11. A quantum encryption key determination device, characterized in that: include: a quantum signal processing module, used to respectively determine target distribution information of each target quantum signal in a plurality of target quantum signals; the plurality of target quantum signals are quantum signals carrying continuous variable information transmitted between the first device and the quantum encryption key determination device; A quantum encryption key determination module, used to determine the quantum encryption key according to the target distribution information; A reference information encoding module, used to determine a target encoding method according to a target signal-to-noise ratio of a classical channel, and to encode actual reference information corresponding to at least one reference quantum signal into original reference information using the target encoding method; The at least one reference quantum signal is a partial quantum signal of the plurality of target quantum signals; The actual reference information is the target distribution information corresponding to the reference quantum signal; A reference information sending module, configured to send the original reference information to the first device through the classical channel; so that the first device determines the quantum encryption key used for communicating with the quantum encryption key determination device according to the received pending reference information and the target quantum signal; The pending reference information is information received by the first device after the original reference information is transmitted through the classical channel.

12. An electronic device, characterized in that: include: a processor and a memory for storing instructions executable by the processor; The processor is configured to execute the instructions to implement the quantum encryption key determination method as described in any one of claims 1 to 5, and / or to implement the quantum encryption key determination method as described in any one of claims 6 to 9.

13. A readable storage medium, characterized in that: The readable storage medium stores a computer program code, and when the computer program code runs on a computer, the computer implements the quantum encryption key determination method as described in any one of claims 1 to 5, and / or implements the quantum encryption key determination method as described in any one of claims 6 to 9.

14. A computer program product, characterized in that The computer program product includes: a computer program code, which, when executed on a computer, enables the computer to implement the quantum encryption key determination method as described in any one of claims 1 to 5, and / or implement the quantum encryption key determination method as described in any one of claims 6 to 9.

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