Quantum communication methods, quantum communication systems and electronic devices

Abstract

The present disclosure provides a quantum communication method, quantum communication system, and electronic device. The quantum communication method includes: determining, based on a key distribution requirement of a first node, at least one second node to which the first node needs to connect and the quantum channel corresponding to each second node; controlling the first node to send a test request to the at least one second node via a negotiation channel; controlling the first node and an optical switch to enable a quantum channel from multiple quantum channels, receiving a test response signal from the second node via the enabled quantum channel; determining a channel evaluation value of the quantum channel based on the test response signal; determining a quantum channel polling queue based on the channel evaluation value of each quantum channel, and performing key distribution on the second node based on the quantum channels in the quantum channel polling queue, wherein the quantum channel polling queue includes at least one quantum channel. Embodiments of the present disclosure can improve the stability of a quantum communication system.

Description

Technical Field

[0001] The present disclosure relates to the field of quantum communication technology, and in particular to a quantum communication method, a quantum communication system, and an electronic device. Background Art

[0002] In quantum communication technology, QKD (Quantum key distribution) is a key distribution technology that uses quantum mechanics to ensure security, allowing both communicating parties to generate random and secure keys for encrypting information.

[0003] In a QKD system, a QKD receiver (also known as a QKDB node) can only connect to one QKD transmitter (also known as a QKDA node) for key distribution (also known as coding), and then switch to another QKD transmitter for key distribution.

[0004] Since the QKD system is naturally more sensitive to external factors such as channel status and device status, a short-term decline in channel quality may occur when external disturbances occur. When the QKDB node distributes keys, it will distribute keys according to the channel quality obtained when the quantum channel is energized. This will lead to a short-term decline in channel quality, causing a quantum channel to distribute keys at a low coding rate for a long time, occupying the QKDB node for a long time, affecting the key generation of other QKDA nodes, and amplifying the short-term interference to the quantum communication system, which greatly affects the communication efficiency and stability of the quantum communication system.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the Invention

[0006] The purpose of the present disclosure is to provide a quantum communication method, a quantum communication system and an electronic device for improving the stability and communication efficiency of the quantum communication system.

[0007] According to a first aspect of an embodiment of the present disclosure, a quantum communication method is provided, comprising: determining, based on a key distribution requirement of a first node, at least one second node to which the first node needs to connect and a quantum channel corresponding to each second node, wherein a first end of the quantum channel is connected to an optical switch, a second end of the quantum channel is connected to the second node, and the optical switch is connected to the first node; controlling the first node to send a test request to the at least one second node via a negotiation channel; controlling the first node and the optical switch to enable a quantum channel from a plurality of quantum channels, receiving a test response signal from the second node via the enabled quantum channel; determining a channel evaluation value of the quantum channel based on the test response signal; determining a quantum channel polling queue based on the channel evaluation value of each quantum channel, and performing key distribution on the second node based on the quantum channels in the quantum channel polling queue, wherein the quantum channel polling queue includes at least one quantum channel.

[0008] In an exemplary embodiment of the present disclosure, determining the channel evaluation value of the quantum channel according to the test response signal includes:

[0009] determining a test coding rate of the quantum channel according to the test response signal;

[0010] Determining a coding rate evaluation value corresponding to the quantum channel according to a historical coding rate corresponding to the quantum channel and the test coding rate;

[0011] Determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value;

[0012] Determine a coding rate weight corresponding to the coding rate evaluation value, and determine a channel evaluation value of the quantum channel based on the coding rate evaluation value, the coding rate weight, the at least one preset evaluation value, and the preset evaluation value weight corresponding to the preset evaluation value.

[0013] In an exemplary embodiment of the present disclosure, determining a coding rate evaluation value corresponding to the quantum channel according to a historical coding rate corresponding to the quantum channel and the test coding rate includes:

[0014] Determining an average value and a standard deviation of a historical coding rate corresponding to the quantum channel;

[0015] The coding rate evaluation value is determined according to a ratio of a difference between the test coding rate and the average value to the standard deviation.

[0016] In an exemplary embodiment of the present disclosure, the preset evaluation value includes a service priority of a second node corresponding to the quantum channel, the preset evaluation value weight includes a service weight, and determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value includes:

[0017] Determining at least one service type of the second node corresponding to the quantum channel and a service volume and a processing priority corresponding to each service type;

[0018] Determining the service priority of each service type according to the processing priority and service volume corresponding to each service type;

[0019] Determining the service priority of the second node according to the sum of the service priorities of each service type;

[0020] Determine the service weight corresponding to the quantum channel.

[0021] In an exemplary embodiment of the present disclosure, the preset evaluation value includes a distribution priority corresponding to the quantum channel, the preset evaluation value weight includes a distribution time weight, and determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value includes:

[0022] Determining a key requirement of the second node connected to the quantum channel;

[0023] Determining a key distribution speed corresponding to the quantum channel according to the test coding rate;

[0024] Determining a key replenishment time corresponding to the quantum channel according to the key demand and the key distribution speed;

[0025] Determining the distribution priority of each quantum channel according to the key replenishment time corresponding to each quantum channel, wherein the longer the key replenishment time, the greater the distribution priority;

[0026] Determine a distribution time weight corresponding to the quantum channel.

[0027] In an exemplary embodiment of the present disclosure, the preset evaluation value includes a volatility evaluation value of the quantum channel, the preset evaluation value weight includes a volatility weight, and determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value includes:

[0028] determining a fluctuation value of the quantum channel according to a ratio of a standard deviation of a historical coding rate corresponding to the quantum channel to an average value;

[0029] Determining a volatility evaluation value of the quantum channel according to a fluctuation value of the quantum channel and a test coding rate;

[0030] Determine the volatility weight corresponding to the quantum channel.

[0031] In an exemplary embodiment of the present disclosure, determining the quantum channel polling queue according to the channel evaluation value of the quantum channel corresponding to each second node includes:

[0032] Determining a key replenishment time corresponding to each of the quantum channels;

[0033] Sort the quantum channels from high to low according to the channel evaluation values, and add the first N quantum channels whose sum of key replenishment time is not greater than a preset value to the quantum channel polling queue;

[0034] After key distribution is completed according to the Nth quantum channel in the quantum channel polling queue, the first node is re-controlled to send a test request to the at least one second node through the negotiation channel.

[0035] According to a second aspect of an embodiment of the present disclosure, a quantum communication system is provided, comprising: a network controller for executing the quantum communication method as described in any one of the above items; a central node, comprising a first node and an optical switch, wherein the first node and the optical switch are both connected to the network controller, and the first node is connected to the optical switch; and a plurality of second nodes, each of the second nodes being connected to the first node via at least one quantum channel.

[0036] According to a third aspect of the present disclosure, an electronic device is provided, comprising: a memory; and a processor coupled to the memory, wherein the processor is configured to execute any one of the above methods based on instructions stored in the memory.

[0037] According to a fourth aspect of the present disclosure, a computer-readable storage medium is provided, on which a program is stored, and when the program is executed by a processor, the quantum communication method as described in any one of the above items is implemented.

[0038] The disclosed embodiment performs channel evaluation on each quantum channel before key distribution in the QKD system, and determines the quantum channel to be polled for key distribution this time based on the channel evaluation result, i.e., the channel evaluation value. This allows priority use of quantum channels with better communication quality and greater importance for key distribution, avoids key distribution using low coding rates as much as possible, improves quantum communication efficiency, and maintains the stability of the quantum communication system.

[0039] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0041] Figure 1 Schematic diagram of a quantum communication system according to the method provided in an embodiment of the present disclosure.

[0042] Figure 2 is a flow chart of a quantum communication method in an exemplary embodiment of the present disclosure.

[0043] Figure 3 The present invention is a flowchart of determining a channel estimation value in one embodiment of the present invention.

[0044] Figure 4 The present invention is a flowchart for determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value in one embodiment of the present disclosure.

[0045] Figure 5 The present invention is a flowchart for determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value in one embodiment of the present disclosure.

[0046] Figure 6 The present invention is a flowchart for determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value in one embodiment of the present disclosure.

[0047] Figure 7 This is a flowchart of distributing keys to a second node according to a quantum channel in a quantum channel polling queue in one embodiment of the present disclosure.

[0048] Figure 8 It is a schematic diagram of a channel assessment process in an application scenario in an exemplary embodiment of the present disclosure.

[0049] Figure 9 FIG. 1 is a schematic diagram of an evaluation process in one embodiment of the present disclosure. DETAILED DESCRIPTION

[0050] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the present disclosure will be more comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced while omitting one or more of the specific details, or that other methods, components, devices, steps, etc. may be employed. In other cases, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of the present disclosure.

[0051] The accompanying drawings are merely schematic illustrations of the present disclosure. Identical reference numerals in the drawings denote identical or similar components, and thus their repeated descriptions will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities that do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0052] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0053] Figure 1 Schematic diagram of a quantum communication system according to the method provided in an embodiment of the present disclosure.

[0054] refer to Figure 1 , the quantum communication system 100 may include:

[0055] A network controller 1, configured to execute the quantum communication method according to any embodiment of the present disclosure;

[0056] The central node 20 includes a first node 2 and an optical switch 3. Both the first node 2 and the optical switch 3 are connected to the network controller 1. The first node 2 is connected to the optical switch 3.

[0057] A plurality of second nodes 4 , each second node 4 is connected to the optical switch 3 via at least one quantum channel 41 .

[0058] Network controller 1 is responsible for executing the system's quantum communication methods. As the control center of the quantum key distribution (QKD) system, network controller 1 directs and schedules the operating status of each node, ensuring the security and stability of the entire quantum communication process. By manipulating other components, network controller 1 enables them to transmit and process quantum information according to predetermined methods.

[0059] The central node 20 is composed of a first node 2 and an optical switch 3, and is called a central node because it can connect to multiple second nodes 4. The first node 2 and the optical switch 3 are both connected to the network controller 1 and are also connected to each other.

[0060] The first node 2 acts as a quantum key distribution bridge (QKDB) node, whose main function is to generate and manage quantum keys. The optical switch 3 is responsible for distributing quantum signals to different channels, ensuring that the signals can be accurately transmitted to the destination. In actual applications, the first node 2 is also connected to the first key manager 21. The first key manager 21 is responsible for not only the secure storage of quantum keys but also ensures that these keys can be accurately distributed to authorized users or devices on demand. In addition, the first key manager 21 may also integrate some advanced security functions, such as key update mechanisms and intrusion detection and prevention systems, to effectively prevent potential attackers from stealing or tampering with quantum keys.

[0061] The second node 4 is a quantum key distribution application (QKDA) node, whose main function is to receive and send quantum information. It is connected to the optical switch 3 via one or more quantum channels 4. Keys and other important quantum information are transmitted to the first node 2 via quantum channel 41. Each second node 4 may have different tasks and responsibilities. In some embodiments, a second node 4 corresponds to one or more business types, each of which is, for example, an application (APP). In actual applications, each second node 4 is also connected to a second key manager 42, which is used to manage the keys of the second node 4 and can provide the number of remaining keys.

[0062] The network controller 1 is responsible for overall scheduling and control. The central node 20 is responsible for negotiating, generating, and storing symmetric keys with multiple secondary nodes. Multiple secondary nodes 4 are responsible for providing keys to users after negotiating with the central node. When a user accesses the key of a secondary node 4, it consumes the keys of all nodes on the user's end-to-end link. Therefore, the first and second nodes 2 and 4 perform a quantum key distribution process to generate symmetric keys. These keys are then added to the first key manager 21 corresponding to the central node 2 and the second key manager 42 corresponding to the secondary nodes 4 to ensure that users can access the keys normally.

[0063] In addition, the first node may link to other application nodes by connecting to other nodes similar to the first node, thereby realizing a network topology of access node (similar to the second node) - backbone node (similar to the first node) - backbone node - backbone node - access node. Since optical switches are not considered between backbone nodes, the embodiments of this disclosure do not mention other first nodes and related network topologies. Figure 1 It is only used to illustrate the embodiments of the present disclosure and is not intended to limit the network structure of a specific quantum communication system.

[0064] However, due to the different network states of different channels when supplementing keys, short-term interference will cause the key supplement process of a second node 4 to always be supplemented at the coding rate measured when the key supplement starts, resulting in a decrease in the key supplement speed and long-term occupation of the first node 2, affecting the first node 2's key supplement for other second nodes 4 and affecting the operation of the quantum communication system.

[0065] Therefore, the embodiment of the present disclosure improves the network controller so that the network controller executes the quantum communication method provided by the embodiment of the present disclosure to control the operation of the quantum communication system 100, thereby improving the key supplement efficiency and ensuring the efficient and stable operation of the quantum communication system.

[0066] Figure 2 is a flow chart of a quantum communication method in an exemplary embodiment of the present disclosure.

[0067] refer to Figure 2 , the quantum communication method 200 may include:

[0068] Step S1: Determine, based on a key distribution requirement of a first node, at least one second node to which the first node needs to be connected and a quantum channel corresponding to each second node, wherein a first end of the quantum channel is connected to an optical switch, a second end is connected to the second node, and the optical switch is connected to the first node;

[0069] Step S2, controlling the first node to send a test request to the at least one second node through a negotiation channel;

[0070] Step S3: controlling the first node and the optical switch to enable a quantum channel among the multiple quantum channels, and receiving a test response signal from the second node through the enabled quantum channel;

[0071] Step S4, determining a channel evaluation value of the quantum channel according to the test response signal;

[0072] Step S5: determining a quantum channel polling queue according to the channel evaluation value of each quantum channel, and distributing a key to the second node according to the quantum channels in the quantum channel polling queue, wherein the quantum channel polling queue includes at least one quantum channel.

[0073] The disclosed embodiment performs channel evaluation on each quantum channel before key distribution in the QKD system, and determines the quantum channel to be polled for key distribution this time based on the channel evaluation result, i.e., the channel evaluation value. This allows priority use of quantum channels with better communication quality and greater importance for key distribution, avoids key distribution using low coding rates as much as possible, improves quantum communication efficiency, and maintains the stability of the quantum communication system.

[0074] Next, each step of the quantum communication method 100 is described in detail.

[0075] In step S1, based on the key distribution requirements of a first node, at least one second node to which the first node needs to be connected and a quantum channel corresponding to each second node are determined. A first end of the quantum channel is connected to an optical switch, a second end is connected to the second node, and the optical switch is connected to the first node.

[0076] Key distribution requirements are primarily addressed by central node 20. First node 2, or QKDB, manages key distribution for multiple second nodes 4, or QKDA (Quantum Key Distribution Access) nodes, and requires timely key distribution to these nodes 4. Therefore, central node 20 determines which second nodes 4 require key distribution based on the overall network status and specific user needs.

[0077] In the disclosed embodiment, after determining the second nodes 4 to which the first node 2 needs to connect, the network controller 1 needs to determine the quantum channels between the optical switch 3 and each second node 4. It should be noted that a second node 4 may be connected to the optical switch 3 via one or more quantum channels 41, and each channel between the second node 4 and the optical switch 3 needs to be determined.

[0078] Because quantum channels 41 are implemented based on physical optical links, they always exist between each second node 2 and the optical switch 3. However, these quantum channels are in an inactive state, meaning that the optical switch 3 does not consider a particular quantum channel as a channel for current information transmission. When quantum communication requires a quantum channel, the optical switch 3 enables the channel based on its port address. This effectively connects the second node 4 connected to the quantum channel 41 to the first node 2, allowing the second node 4 to send optical signals to the first node 2.

[0079] The network controller 1 can obtain the port address of the quantum channel 41 corresponding to each second node 4 through the optical switch 3 .

[0080] Next, it is necessary to evaluate each channel between the multiple second nodes 4 and the optical switch 3 to select a suitable channel for key supplementation, so as to improve the key supplementation speed and ensure the stability of the quantum communication system.

[0081] In step S2, the first node is controlled to send a test request to the at least one second node through a negotiation channel.

[0082] The network controller 1 can send instructions to the first node 2, controlling the first node 2 to send a test request to each second node 2 to be connected via the inter-node negotiation channel. This allows each second node 2 to be ready and send a test response signal after each quantum channel 41 connected to the optical switch 3 is enabled. The test request can be defined according to a preset communication protocol, as long as the second node 2 can recognize it. This is not particularly limited in this disclosure.

[0083] In an exemplary embodiment, the test request is not sent in a unidirectional manner from the first node 2 to the second node 4. Instead, the first node 2 and the second node 4 may negotiate through a negotiation channel to produce a set of reference bases (e.g., the same measurement base) for subsequent test comparisons.

[0084] Unlike quantum channels, test requests are sent over a negotiation channel (also known as a classical channel). The negotiation channel is used to establish and maintain quantum communication protocols, transmitting control information, negotiating encryption parameters, and ensuring that both parties can effectively perform quantum key distribution (QKD). The negotiation channel is typically used to send authentication and confirmation messages, ensuring that both QKDB and QKDA parties agree on the state of the quantum channel and the key generation process.

[0085] In step S3, the first node and the optical switch are controlled to enable one quantum channel among the multiple quantum channels, and a test response signal from the second node is received through the enabled quantum channel.

[0086] Next, the quantum channels can be evaluated in any order. This evaluation is for all quantum channels corresponding to all second nodes 4 that the first node 2 needs to connect to this time.

[0087] For example, the network controller 1 may notify the first node 2 and the optical switch 3 that a channel assessment is to be performed, control the optical switch 3 to sequentially enable a quantum channel 41 according to a default order (e.g., the port address of the quantum channel), and control the first node 2 to receive a test response signal from the second node 4 connected to the quantum channel 41.

[0088] After receiving the test response signal, first node 2 calculates the coding rate of quantum channel 41 based on the test response signal, marks the calculation result as the test coding rate corresponding to quantum channel 41, and sends the test coding rate to network controller 1 for further processing by network controller 1. The coding rate of quantum channel 41 (also known as channel capacity) refers to the maximum number of quantum bits that can be reliably transmitted on the quantum channel. It is used to measure the amount of information that the quantum channel can effectively transmit per unit time and is usually expressed in bits per second (bps).

[0089] In terms of how the coding rate is calculated, for example, in step S2, the first node 2 (QKDB) and the second node 4 (QKDA) perform a series of classical signal exchanges during the test request sending phase, negotiating a set of reference bases (e.g., the same measurement base) for comparison. Then, in step S3, the first node 2 (QKDB) measures the bit value of the test response signal actually received (e.g., by monitoring the number of received photons using a photon counter), and compares it with the bits agreed to be sent by the second node 4 (QKDA), calculating the bit error rate (i.e., the proportion of error bits). In this process, the first node 2 can be regarded as the receiving end, and the second node 4 can be regarded as the sending end. Then, based on the communication protocol corresponding to the quantum channel, the bit error rate is used to calculate the coding rate. Since different communication protocols correspond to different coding rate calculation methods, this disclosure does not impose any special restrictions on how to calculate the coding rate.

[0090] Finally, the first node 2 (QKDB) sends the calculated coding rate to the network controller 1 .

[0091] In step S4, a channel evaluation value of the quantum channel is determined according to the test response signal.

[0092] The coding rate is not necessarily the most important reason for selecting a quantum channel. Whether to use a quantum channel also needs to be evaluated based on other reasons.

[0093] After receiving the coding rate of a quantum channel 41 from the first node 2, the network controller 1 regards it as a test coding rate and comprehensively determines the channel evaluation value of the quantum channel based on the historical coding rate of the quantum channel 41, that is, the coding rate calculated by the first node 2 (regardless of whether the quantum channel is ultimately used).

[0094] Figure 3 The present invention is a flowchart of determining a channel estimation value in one embodiment of the present invention.

[0095] refer to Figure 3 In an exemplary embodiment, determining a channel evaluation value of a quantum channel according to a test response signal may include:

[0096] Step S41, determining a test coding rate of the quantum channel according to the test response signal;

[0097] Step S42, determining a coding rate evaluation value corresponding to the quantum channel according to the historical coding rate corresponding to the quantum channel and the test coding rate;

[0098] Step S43, determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value;

[0099] Step S44: determining a channel evaluation value of the quantum channel according to the coding rate evaluation value, the coding rate weight, the at least one preset evaluation value, and the preset evaluation value weight corresponding to the preset evaluation value.

[0100] The coding rate evaluation value is used to assess whether the quantum channel is currently in a good or excellent communication state. At least one preset evaluation value is used to measure the influence of factors other than the coding rate on the selection of the quantum channel, namely, the urgency (or priority) of the quantum channel selection. The coding rate weight and the preset evaluation value weight are used to determine the reference value or importance of the coding rate factor and other factors in the quantum channel selection process.

[0101] In an exemplary embodiment, in step S42, the average value and standard deviation of the historical coding rate corresponding to the quantum channel may be determined, and then the coding rate evaluation value may be determined based on the ratio of the difference between the test coding rate and the average value to the standard deviation.

[0102] That is, the bit rate evaluation value Z is calculated according to the following formula:

[0103]

[0104] Where C1 is the test bitrate, μ is the average historical bitrate, and σ is the standard deviation of the historical bitrate. Formula (2), also known as the z-score, measures the degree of deviation between the test value and the average. After standardization, it can be used to determine the relative position of the test value in the population. A higher z-score indicates that the test value is further away from the average.

[0105] In addition to using the standard score of formula (2) as the coding rate evaluation value, other methods can also be used to evaluate the significance of the test coding rate for the quantum channel, such as the percentile, ranking, score level of the test coding rate in the historical coding rate, or through computational regression analysis, so as to evaluate whether the quantum channel is currently in a good or excellent communication state.

[0106] Then, the coding rate weight corresponding to the quantum channel is determined. In an exemplary embodiment, the coding rate weight corresponding to each quantum channel is the same, meaning that the coding rate is equally affected when considering whether to select it. In some embodiments, different coding rate weights can also be set for different quantum channels based on their characteristics. Generally speaking, the degree of emphasis on various factors during evaluation is relatively stable, so the coding rate weight corresponding to each quantum channel remains essentially unchanged or is updated more frequently. Therefore, each evaluation only requires reading the latest coding rate weight, eliminating the need for calculation.

[0107] In step S43, at least one preset evaluation value for the quantum channel, i.e., the selected urgency, can be determined based on various factors. For example, the quantum channel can consider the service type and volume of the second node 4 corresponding to the quantum channel, the remaining keys, the key consumption rate (how long they can be maintained), and the volatility (whether the current good state is very rare).

[0108] Figure 4 The present invention is a flowchart for determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value in one embodiment of the present disclosure.

[0109] refer to Figure 4 In an exemplary embodiment, the preset evaluation value includes a service priority of the second node corresponding to the quantum channel, the preset evaluation value weight includes a service weight, and determining at least one preset evaluation value and the preset evaluation value weight corresponding to the preset evaluation value may include:

[0110] Step S431, determining at least one service type of the second node corresponding to the quantum channel and the service volume and processing priority corresponding to each service type;

[0111] Step S432, determining the service priority of each service type based on the processing priority and service volume corresponding to each service type;

[0112] Step S433: determining the service priority of the second node according to the sum of the service priorities of each service type;

[0113] Step S434: Determine the service weight corresponding to the quantum channel.

[0114] exist Figure 4 In the illustrated embodiment, the network controller 1 can obtain, through the operator or other service users of quantum communication services, the service type (e.g., government service, civilian service, database collection service, etc.) corresponding to a second node 4, as well as the service volume of each service type (e.g., the number of requests per unit time), and the service user's processing priority setting for each service type (e.g., the processing priority of government service is higher than the processing priority of civilian service). If the service user does not provide a processing priority setting for each service type, the network controller 1 can determine the processing priority of each service type based on the preset service type processing priority.

[0115] Next, the service priority is determined based on the processing priority and traffic volume of each service type. Service priority refers to the priority of service characteristics considered during the quantum channel evaluation process. For example, if a service type has a high processing priority but a low traffic volume, its service priority may be low. Alternatively, if a service type has a low priority but a high traffic volume, its service priority may be high. The service priority corresponding to each service type needs to be comprehensively considered to determine the evaluation result of quantum channel 41 based on service factors.

[0116] For example, in order to prevent different evaluation criteria for processing priorities corresponding to different businesses, the processing priorities corresponding to each business type can be normalized or standardized first (for example, sorted by score or by standard score also known as z-score) to facilitate subsequent comparison, and then the business priority of the business type is determined based on the product of the processing priority of the normalized business type and the business volume.

[0117] If a second node 4 corresponds to multiple service types, after determining the service priorities of each service type, the service priority of the second node 4 can be determined based on the sum of the service priorities of each service type. It should be understood that the service priority corresponding to a quantum channel 41 is the service priority corresponding to the second node 4 connected to that quantum channel 41. For two quantum channels 41 connected to the same second node 4, the service priorities corresponding to both quantum channels 41 are the service priorities corresponding to that second node 4.

[0118] It should be noted that, in order to calculate together with the coding rate evaluation value later, the service priority corresponding to each second node 4 needs to be normalized or standardized. For example, after determining the service priority (absolute value) corresponding to each second node 4, the relative value of the service priority corresponding to the second node 4 can be determined according to the position of the service priority corresponding to the second node 4 in the service priority corresponding to each second node 4. For example, the standard deviation and the average value of the service priority (absolute value) corresponding to each second node 4 can be calculated, and then the relative value of the service priority corresponding to the second node 4 can be determined according to the ratio of the difference between the service priority (absolute value) corresponding to the second node 4 and the standard deviation to the average value (i.e., the standard score, also known as z-score). There are many ways to determine the relative value. In addition to using the above-mentioned z-score method, percentiles, rankings, score levels or through computational regression analysis can also be used. It is only necessary to ensure that the method for calculating the relative value is consistent with the coding rate evaluation value.

[0119] Next, the service weight corresponding to the quantum channel is determined. In an exemplary embodiment, the service weight corresponding to each quantum channel is the same, meaning that the service priority of the second node connected to the quantum channel has the same impact on its selection. In some embodiments, different service weights can be assigned to different quantum channels based on their characteristics. Generally speaking, the emphasis on various factors during evaluation is relatively stable, so the service weight corresponding to each quantum channel remains essentially unchanged or is updated more frequently. Therefore, each evaluation only requires reading the latest service weight, eliminating the need for calculation.

[0120] In addition to considering the service importance of the second node 4 connected by the quantum channel, the key supplement time of the quantum channel to the second node 4 connected thereto may also be considered.

[0121] Figure 5 The present invention is a flowchart for determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value in one embodiment of the present disclosure.

[0122] refer to Figure 5 In an exemplary embodiment, the preset evaluation value includes a distribution priority corresponding to the quantum channel, the preset evaluation value weight includes a distribution time weight, and determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value may include:

[0123] Step S435, determining the key requirement of the second node connected to the quantum channel;

[0124] Step S436, determining the key distribution speed corresponding to the quantum channel according to the test coding rate;

[0125] Step S437, determining the key replenishment time corresponding to the quantum channel according to the key demand and the key distribution speed;

[0126] Step S438: determining the distribution priority of each quantum channel according to the key replenishment time corresponding to each quantum channel, wherein the longer the key replenishment time is, the greater the distribution priority is;

[0127] Step S439: determining the distribution time weight corresponding to the quantum channel.

[0128] exist Figure 5In the illustrated embodiment, the load of each second node 4 can be monitored, and the key demand of each second node 4 can be determined based on the load of each second node 4 and historical key usage. For example, based on the corresponding relationship between the current load and the load and key consumption in the historical records, the number of keys required to be consumed per unit time by the second node 4 under the current load (consumption rate) is calculated. Then, based on the remaining number of keys in the second key manager 42 corresponding to the second node 4, the remaining amount of keys of the second node 4 can be determined (remaining consumption time). If the remaining consumption time is less than a preset time (e.g., one hour) or a maximum channel assessment period, the number of keys that must be replenished to the second node 4 before the next channel assessment is performed is calculated based on the current remaining consumption time and consumption rate so that the key quantity of the second node 4 can be used at least until the next channel assessment. It should be noted that a maximum channel assessment period can be set in advance for the channel assessment period to limit the maximum time until the next channel assessment. This maximum channel assessment period can be directly used to simplify the calculation when determining the key demand.

[0129] In addition, the key demand of a second node 4 can also be determined based on the difference between the maximum number of keys of the second key manager 42 corresponding to the second node 4 and the current number of remaining keys of the second key manager 42. The maximum number of keys and the remaining number of keys can be determined through communication between the network controller 1 and each second key manager 42.

[0130] Next, the network controller 1 can evaluate the key distribution speed of each quantum channel 41 based on the test coding rate of the quantum channel 41 corresponding to each second node 4. The higher the test coding rate, the faster the key distribution speed. Then, based on the ratio of the required key quantity to the key distribution speed, the network controller 1 determines how long it will take to replenish the required key quantity for each second node 4 via that quantum channel 41, i.e., the key replenishment time corresponding to that quantum channel 41.

[0131] It is understandable that even if two quantum channels 41 are connected to the same second node 4 and have the same key requirements, the key distribution speeds and key replenishment times corresponding to the two quantum channels 41 may not necessarily be the same.

[0132] After calculating the key replenishment time corresponding to each quantum channel 41, a distribution priority for each quantum channel can be determined based on the key replenishment time of each quantum channel. When determining the distribution priority, the longer the key replenishment time, the higher the distribution priority. This is because, to maintain the effectiveness of the evaluation, the evaluation cycle must be limited to a short period. Within this period, if key distribution requests with short key replenishment times are prioritized, key distribution requests with long key replenishment times may not be met in time, resulting in insufficient keys and affecting the stability of quantum communication. Therefore, the distribution priority of each quantum channel 41 can be set from high to low based on the key replenishment time of each quantum channel 41 in this evaluation, in descending order of key replenishment time.

[0133] It should be noted that, in order to be subsequently calculated together with the coding rate assessment value, the key replenishment time of each quantum channel 41 can be normalized or standardized when calculating the distribution priority. For example, after determining the key replenishment time of each quantum channel 41, the relative value of the key replenishment time of a quantum channel 41, i.e., the distribution priority, can be determined based on its position within the key replenishment times of all other quantum channels 41. For example, the standard deviation and average of the key replenishment times of each quantum channel 41 can be calculated. The distribution priority of the key replenishment time of a quantum channel 41 can then be determined based on the ratio of the difference between the key replenishment time of a quantum channel 41 and the standard deviation to the average value (i.e., the standard score, also known as the z-score). There are many methods for determining the distribution priority. In addition to the aforementioned z-score method, percentiles, rankings, score rankings, or regression analysis can also be used. The only requirement is to ensure that the method used to calculate the relative value is consistent with the coding rate assessment value.

[0134] Finally, the distribution time weight corresponding to the quantum channel is determined. In an exemplary embodiment, the distribution time weight corresponding to each quantum channel is the same, meaning that the time spent distributing keys via the quantum channel has the same impact on whether it is selected. In some embodiments, different distribution time weights can be assigned to different quantum channels based on their characteristics. Generally speaking, the emphasis on various factors during evaluation is relatively stable, so the distribution time weight corresponding to each quantum channel remains essentially unchanged or is updated more frequently. Therefore, each evaluation only requires reading the latest distribution time weight, eliminating the need for calculation.

[0135] In addition, the stability of the current state of the quantum channel 41 , that is, the volatility of the historical state of the quantum channel 41 , may also be considered.

[0136] Figure 6 The present invention is a flowchart for determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value in one embodiment of the present disclosure.

[0137] refer to Figure 6 In an exemplary embodiment, the preset evaluation value includes a volatility evaluation value of the quantum channel, the preset evaluation value weight includes a volatility weight, and determining at least one preset evaluation value and the preset evaluation value weight corresponding to the preset evaluation value may include:

[0138] Step S61, determining the fluctuation value of the quantum channel based on the ratio of the standard deviation of the historical coding rate corresponding to the quantum channel to the average value;

[0139] Step S62, determining a volatility assessment value of the quantum channel according to the fluctuation value of the quantum channel and the test coding rate;

[0140] Step S63: Determine the volatility weight corresponding to the quantum channel.

[0141] The larger the fluctuation value, the more unstable the current state of quantum channel 41. A good state is fleeting and needs to be utilized immediately. A volatility assessment value can be determined based on the fluctuation value and the test coding rate. When the test coding rate of the quantum channel is high and the fluctuation value is large, the volatility assessment value of the quantum channel is A. When the test coding rate of the quantum channel is high and the fluctuation value is small, the volatility assessment value of the quantum channel is B. When the test coding rate of the quantum channel is low and the fluctuation value is small, the volatility assessment value of the quantum channel is C. When the test coding rate of the quantum channel is low and the fluctuation value is large, the volatility assessment value of the quantum channel is D. A>B>C>D.

[0142] The function for determining the fluctuation evaluation value according to the fluctuation value and the test bit rate can be set by those skilled in the art as long as the above logical relationship is satisfied.

[0143] It should be noted that, in order to be subsequently calculated together with the coding rate assessment value, the volatility assessment value of each quantum channel 41 needs to be normalized or standardized. For example, after determining the volatility assessment value of each quantum channel 41, the relative value of the volatility assessment value of a quantum channel 41 can be determined based on its position within the volatility assessment values of all quantum channels 41. For example, the standard deviation and average of the volatility assessment values (absolute values) of each quantum channel 41 can be calculated. Then, the relative value of the volatility assessment value of a quantum channel 41 can be determined based on the ratio of the difference between the volatility assessment value (absolute value) of the quantum channel 41 and the standard deviation to the average value (i.e., the standard score, also known as the z-score). There are many methods for determining relative values. In addition to the aforementioned z-score method, percentiles, rankings, score rankings, or regression analysis can also be used. The only requirement is to ensure that the method used to calculate the relative value is consistent with the coding rate assessment value.

[0144] Next, the volatility weight corresponding to the quantum channel is determined. In an exemplary embodiment, the volatility weight corresponding to each quantum channel is the same, meaning that the service priority of the second node connected to the quantum channel is equally affected when considering its selection. In some embodiments, different volatility weights can be assigned to different quantum channels based on their characteristics. Generally speaking, the degree of emphasis on various factors during evaluation is relatively stable, so the volatility weight corresponding to each quantum channel remains essentially unchanged or is updated more frequently. Therefore, each evaluation only requires reading the latest volatility weight, eliminating the need for calculation.

[0145] In addition to the above examples, the channel estimation value may also be determined by considering other factors.

[0146] For example, the security of each second node 4 may be monitored. If the security of a second node 4 is threatened (for example, potential eavesdropping is detected), the channel evaluation value of the quantum channel 41 corresponding to the second node 4 may be reduced.

[0147] In addition, an alarm signal can be directly generated for quantum channels whose test coding rate is lower than a preset threshold or which pose a security threat, and the channel evaluation value of the quantum channel with the alarm signal can be directly reduced to 0, and the channel can exit the current round selection.

[0148] Finally, a channel estimation value may be formed according to a weighted sum of the various factors mentioned above and their corresponding weights.

[0149] Exemplarily, the channel evaluation value of the i-th quantum channel can be determined according to the following formula:

[0150] P i =Err i *(R i *W r +……) (2)

[0151] Among them, P i is the channel evaluation value of the i-th quantum channel, Err i is the alarm coefficient of the i-th quantum channel. When there is an alarm, Err i Err=0, when there is no alarm, Err i =1, R i is the coding rate evaluation value of the i-th quantum channel, W r is the coding rate weight of the i-th quantum channel, and the ellipsis “…” part represents the sum of the products of at least one preset evaluation value and the preset evaluation value weight corresponding to the preset evaluation value, that is, the weighted sum of various factors.

[0152] Formula (2) can also be expressed as:

[0153]

[0154] Where M is the sum of the coding rate evaluation value and the number of evaluation values of at least one preset evaluation value, that is, how many factors are considered; i is the serial number of the quantum channel, j is the serial number of the evaluation value, indicating the jth evaluation value; C ij is the jth evaluation value of the i-th channel, W ij is the weight corresponding to the jth evaluation value of the i-th channel. It should be noted that the preset evaluation values mentioned in formulas (2) and (3) are relative values after standardization, and the standardization method is consistent with the coding rate evaluation value.

[0155] In formulas (2) and (3), the alarm coefficient Err i The value of can be determined based on various information about the i-th quantum channel. For example, if the tested coding rate of the i-th quantum channel is less than the preset coding rate, or the coding rate evaluation value is less than the preset evaluation value, or if it is detected that the i-th quantum channel is potentially being monitored, the alarm coefficient Err can be set to 0, indicating that the current quantum channel may need repair and will not be included in the selection of quantum channels.

[0156] In addition to the above formula, the above evaluation values (including the coding rate evaluation value and the relative value or absolute value of at least one preset evaluation value) can also be brought into a preset channel evaluation value function, and the value of the channel evaluation value function is set as the channel evaluation value of the quantum channel 41.

[0157] There are many ways to comprehensively calculate the channel evaluation value based on various factors. Those skilled in the art can set it according to actual conditions, and this disclosure does not impose any special restrictions on this.

[0158] In step S5, a quantum channel polling queue is determined according to the channel evaluation value of each quantum channel, and key distribution is performed on the second node according to the quantum channels in the quantum channel polling queue, where the quantum channel polling queue includes at least one quantum channel.

[0159] In order to maintain the validity of each evaluation, the embodiment of the present disclosure sets a limit on the time between two evaluations. To this end, the total key replenishment time of the quantum channel selected in one evaluation is limited.

[0160] Figure 7 This is a flowchart of distributing keys to a second node according to a quantum channel in a quantum channel polling queue in one embodiment of the present disclosure.

[0161] refer to Figure 7 In an exemplary embodiment, determining a quantum channel polling queue according to a channel evaluation value of each quantum channel, and distributing a key to the second node according to the quantum channels in the quantum channel polling queue may include:

[0162] Step S51, determining the key replenishment time corresponding to each quantum channel;

[0163] Step S52, sorting the quantum channels from high to low according to the channel evaluation values, and adding the first N quantum channels whose sum of key replenishment time is not greater than a preset value to the quantum channel polling queue;

[0164] Step S53: After key distribution is completed according to the Nth quantum channel in the quantum channel polling queue, the first node is re-controlled to send a test request to the at least one second node through the negotiation channel.

[0165] exist Figure 7 In the embodiment shown, first, according to Figure 5 Steps S435 to S437 shown determine the key replenishment time corresponding to each quantum channel.

[0166] Then, the quantum channels are sorted from high to low according to their channel evaluation values, and a limited evaluation period is determined. Depending on the deployment environment of the quantum communication system 100, a maximum channel evaluation period (preset value) between two evaluations can be preset. The more stable the quantum communication environment, the larger the maximum channel evaluation period (preset value) can be. The more unstable the quantum communication environment, the more frequent the evaluation needs to be, and the smaller the maximum channel evaluation period (preset value) can be.

[0167] The first N quantum channels whose sum of key replenishment time is not greater than a preset value are selected and added to the quantum channel polling queue, so that even if the key distribution of all the selected N quantum channels is completed, the time does not exceed the above-mentioned maximum channel evaluation period (preset value). The evaluation can be started again, and a new batch of quantum channels for polling for key distribution can be selected to form a quantum channel polling queue.

[0168] There are two things to note here.

[0169] First, when selecting a quantum channel, if multiple selected quantum channels are connected to the same second node 4, only the quantum channel with the best channel evaluation value connected to the second node 4 is selected.

[0170] Second, if the sum of the key replenishment times is not greater than the preset value, the quantum channel switching time of optical switch 3 must also be considered. Each quantum channel switch can be preset to have the same duration. The total duration corresponding to the current quantum channel polling queue is determined by subtracting one from the number of selected quantum channels. For example, quantum channels A, B, C, and D are sorted from highest to lowest according to channel evaluation value, with corresponding key replenishment times of 20, 30, 10, and 20, respectively, with a preset value of 60. Each quantum channel switch consumes 5 seconds. If quantum channels A, B, and C are selected to join the quantum channel polling queue, key distribution is ultimately completed through this quantum channel polling queue, consuming a duration of 20 + 5 + 30 + 5 + 10 = 70 seconds, which is greater than the preset value of 60 and affects re-evaluation. In this case, quantum channels A and B need to be selected to join the quantum channel polling queue. Key distribution is ultimately completed through this quantum channel polling queue, consuming a duration of 20 + 5 + 30 = 55 seconds, which is less than the preset value of 60 and does not affect the channel evaluation period limit.

[0171] By limiting the channel evaluation cycle and re-evaluating each quantum channel in a timely manner, we can avoid the long-term impact of short-term fluctuations on the quantum communication system and improve the stability of the quantum communication system.

[0172] Figure 8 It is a schematic diagram of a channel assessment process in an application scenario in an exemplary embodiment of the present disclosure.

[0173] refer to Figure 8 In step S81, the network controller 1 determines to perform channel assessment and controls the first node 2 to send a test request to each second node 4 to which it needs to connect.

[0174] In step S82 , the network controller 1 controls the optical switch 3 to perform optical switching to enable a quantum channel 41 .

[0175] In step S83, the first node 2 receives the test response signal from the second node 4 through the quantum channel 41, and performs coding rate evaluation and alarm judgment.

[0176] In step S84 , the first node 2 sends the coding rate evaluation result, i.e., the test coding rate, and the alarm judgment result to the network controller 1 .

[0177] In step S85 , the network controller 1 determines whether the tests of all quantum channels 41 corresponding to this evaluation are completed. If so, the process proceeds to step S85 ; otherwise, the process returns to step S82 .

[0178] In step S86, the network controller 1 calculates the channel evaluation value of each quantum channel and determines the quantum channel polling queue for this polling according to the channel evaluation value.

[0179] In step S87 , the network controller 1 controls the optical switches of the optical switch 3 to switch in sequence, and enables one quantum channel in sequence according to the order of the quantum channels 41 in the quantum channel polling queue.

[0180] In step S88, the network controller 1 controls the first node 1 to distribute keys to the second node 4 through the enabled quantum channel.

[0181] In step S89, the network controller 1 determines whether all quantum channels in the quantum channel polling queue have been traversed. If so, it returns to step S81 for re-evaluation; otherwise, it returns to step S87 to switch quantum channels.

[0182] The following is an illustrative description of the embodiments of the present disclosure.

[0183] Figure 9 FIG. 1 is a schematic diagram of an evaluation process in one embodiment of the present disclosure. Figure 9 To simplify the illustration, the specific structure of the quantum communication system is not limited.

[0184] refer to Figure 9 , QKD-B (i.e. Figure 1 The first node 2 in the QKD receiving end is located in the center of the star network. The optical switch 3 can realize the connection of four quantum channels of three nodes. QKD-A1, QKD-A2, and QKD-A3 are the three sending ends (i.e. Figure 1 The second node 4 in the network is connected to the QKD-B of the central node 20 via a fiber quantum channel. QKD-A2 has two quantum channels connected to the QKD-B. All devices are located at the network address reachable by the network controller 1, which controls each network element through an interface.

[0185] The network controller 1 obtains the second nodes that the central node 20 needs to connect to in sequence according to the key distribution requirements, namely: QKD-A1, QKD-A2, and QKD-A3.

[0186] Network controller 1 issues a network evaluation request: requiring QKD-A1, QKD-A2, and QKD-A3 to prepare for network evaluation, and at the same time issues a quantum channel switching request to optical switch 3.

[0187] Optical switch 3 switches to quantum channel ①: QKD-A1 sends a test response signal (optical signal) through quantum channel ①. QKD-B receives and analyzes the optical signal, predicting the coding rate of quantum channel ①. The predicted result is reported as the test coding rate along with other parameters to network controller 1. Network controller 1 calculates the estimated coding rate. Assuming the test coding rate is 20 kbps, the historical average coding rate is 60 kbps, and the standard deviation is 8 kbps, the estimated coding rate Z is: Z = (20 - 60) / 8 = -5.

[0188] Optical switch 3 switches to quantum channel ②: QKD-A2 sends a test response signal (optical signal) through quantum channel ②. QKD-B receives and analyzes the optical signal, predicting the code rate of quantum channel ②. The predicted result is reported as the test code rate and other parameters to network controller 1. Network controller 1 calculates the estimated code rate. Assuming the test code rate is 40 kbps, the historical average code rate is 42 kbps, and the standard deviation is 3 kbps, Z = (40 - 42) / 3 = 0.67.

[0189] The optical switch switches to quantum channel ③: QKD-A2 sends a test response signal (optical signal) through quantum channel ③. QKD-B receives and analyzes the optical signal, predicting the code rate of quantum channel ③. The predicted result is reported as the test code rate and other parameters to network controller 1. Network controller 1 calculates the estimated code rate. Assuming the test code rate is 45 kbps, the historical average code rate is 38 kbps, and the standard deviation is 4 kbps, Z = (45 - 38) / 4 = 1.75.

[0190] The optical switch switches to quantum channel ④: QKD-A3 sends a test response signal (optical signal) through quantum channel ④. QKD-B receives and analyzes the optical signal, predicting the code rate of quantum channel ④. The predicted result is reported as the test code rate and other parameters to network controller 1. Network controller 1 calculates the estimated code rate. Assuming the test code rate is 35 kbps, the historical average code rate is 28 kbps, and the standard deviation is 6 kbps, Z = (35 - 20) / 6 = 2.5.

[0191] The network controller 1 combines the reported data from each quantum channel to calculate the channel evaluation value. The channel evaluation values are ranked from high to low based on factors such as the coding rate evaluation value, historical data, service requirements, and the remaining keys in the key pool: ④③②①.

[0192] Generate a polling queue: A quantum channel polling queue is formed based on the channel evaluation value and the sum of the key replenishment time for each quantum channel. If there are multiple quantum channels on the same node, only the quantum channel with the highest channel evaluation value is selected to enter the polling queue. That is: ④③.

[0193] Polling and Coding: Network controller 1 controls optical switch 3 to sequentially switch quantum channels and generate codes according to the quantum channel polling queue. After completing the coding process for quantum channel ③, i.e., distributing the key, the channel evaluation process is restarted, and the next batch of quantum channels to be polled is determined based on the latest channel status.

[0194] In summary, the embodiments of the present disclosure avoid the problem of network efficiency degradation and resource waste caused by long-term line occupation by low-coding-rate quantum channels by giving priority to using the time when the quantum channel state is better for coding. By analyzing the quantum channel state of all second nodes that need to be connected before coding, and then making coding polling arrangements, the waste of high-quality quantum channel resources caused by the priority coding of short-term disturbed quantum channels is avoided. Over a long period of time, the fluctuation of coding rate caused by short-term quantum channels or equipment environmental factors is avoided, and the actual coding rate of the entire network is improved. By periodically analyzing the state of all quantum channels, the response time to faults or alarms is shortened, and the reliability of the QKD network is increased. By using the network controller to calculate the channel evaluation value, priority statistics are achieved after comprehensive consideration of multiple information, avoiding problems such as some quantum channels not being coded for a long time.

[0195] It should be noted that although several modules or units of the device for action execution are mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of two or more modules or units described above can be concretized in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided into multiple modules or units to be concretized.

[0196] In an exemplary embodiment of the present disclosure, an electronic device capable of implementing the aforementioned method is also provided. The electronic device is, for example, a network controller. The electronic device includes a memory; and a processor coupled to the memory, the processor being configured to execute any of the aforementioned quantum communication methods based on instructions stored in the memory.

[0197] Those skilled in the art will appreciate that various aspects of the present invention may be implemented as systems, methods, or program products. Therefore, various aspects of the present invention may be implemented in the following forms: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or a combination of hardware and software implementations, which may be collectively referred to herein as "circuits," "modules," or "systems."

[0198] Through the description of the above embodiments, it is easy for those skilled in the art to understand that the example embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solution according to the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, and includes several instructions to enable a computing device (which can be a personal computer, a server, a terminal device, or a network device, etc.) to execute the method according to the embodiments of the present disclosure.

[0199] In exemplary embodiments of the present disclosure, a computer-readable storage medium is also provided, on which is stored a program product capable of implementing the aforementioned methods of this specification. In some possible implementations, various aspects of the present invention may also be implemented in the form of a program product comprising program code. When the program product is executed on a terminal device, the program code is configured to cause the terminal device to execute the steps according to various exemplary embodiments of the present invention described in the "Exemplary Methods" section of this specification.

[0200] The program product for implementing the above-described method according to an embodiment of the present invention may be a portable compact disc read-only memory (CD-ROM) and include program code, and may be run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited thereto. In this document, a readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0201] The program product may employ any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or component, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0202] A computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium that can transmit, propagate, or transfer a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0203] The program code embodied on the readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0204] The program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, C++, and the like, as well as conventional procedural programming languages such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a stand-alone software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving a remote computing device, the remote computing device may be connected to the user computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0205] Furthermore, the above-described figures are merely illustrative of the processes included in the method according to exemplary embodiments of the present invention and are not intended to be limiting. It is readily understood that the processes illustrated in the above-described figures do not indicate or limit the temporal order of these processes. Furthermore, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0206] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the claims.

Claims

1. A quantum communication method, characterized in that: include: Determine, based on a key distribution requirement of a first node, at least one second node to which the first node needs to be connected and a quantum channel corresponding to each second node, wherein a first end of the quantum channel is connected to an optical switch, a second end is connected to the second node, and the optical switch is connected to the first node; controlling the first node to send a test request to the at least one second node through a negotiation channel; controlling the first node and the optical switch to enable a quantum channel among the multiple quantum channels, and receiving a test response signal from the second node through the enabled quantum channel; Determine a channel evaluation value of the quantum channel according to the test response signal; determining a quantum channel polling queue according to a channel evaluation value of each quantum channel, and distributing a key to the second node according to the quantum channels in the quantum channel polling queue, wherein the quantum channel polling queue includes at least one quantum channel; The step of determining the quantum channel polling queue according to the channel evaluation value of the quantum channel corresponding to each second node includes: Determining a key replenishment time corresponding to each of the quantum channels; Sort the quantum channels from high to low according to the channel evaluation values, and add the first N quantum channels whose sum of key replenishment time is not greater than a preset value to the quantum channel polling queue; After key distribution is completed according to the Nth quantum channel in the quantum channel polling queue, the first node is re-controlled to send a test request to the at least one second node through the negotiation channel.

2. The quantum communication method according to claim 1, wherein: Determining the channel evaluation value of the quantum channel according to the test response signal includes: determining a test coding rate of the quantum channel according to the test response signal; Determining a coding rate evaluation value corresponding to the quantum channel according to a historical coding rate corresponding to the quantum channel and the test coding rate; Determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value; Determine a coding rate weight corresponding to the coding rate evaluation value, and determine a channel evaluation value of the quantum channel based on the coding rate evaluation value, the coding rate weight, the at least one preset evaluation value, and the preset evaluation value weight corresponding to the preset evaluation value.

3. The quantum communication method according to claim 2, wherein: Determining a coding rate evaluation value corresponding to the quantum channel according to a historical coding rate corresponding to the quantum channel and the test coding rate includes: Determining an average value and a standard deviation of a historical coding rate corresponding to the quantum channel; The coding rate evaluation value is determined according to a ratio of a difference between the test coding rate and the average value to the standard deviation.

4. The quantum communication method according to claim 2, wherein: The preset evaluation value includes a service priority of the second node corresponding to the quantum channel, the preset evaluation value weight includes a service weight, and determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value includes: Determining at least one service type of the second node corresponding to the quantum channel and a service volume and a processing priority corresponding to each service type; Determining the service priority of each service type according to the processing priority and service volume corresponding to each service type; Determining the service priority of the second node according to the sum of the service priorities of each service type; Determine the service weight corresponding to the quantum channel.

5. The quantum communication method according to claim 2, wherein: The preset evaluation value includes a distribution priority corresponding to the quantum channel, the preset evaluation value weight includes a distribution time weight, and determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value includes: Determining a key requirement of the second node connected to the quantum channel; Determining a key distribution speed corresponding to the quantum channel according to the test coding rate; Determining a key replenishment time corresponding to the quantum channel according to the key demand and the key distribution speed; Determining the distribution priority of each quantum channel according to the key replenishment time corresponding to each quantum channel, wherein the longer the key replenishment time, the greater the distribution priority; Determine a distribution time weight corresponding to the quantum channel.

6. The quantum communication method according to claim 2, wherein: The preset evaluation value includes a volatility evaluation value of the quantum channel, the preset evaluation value weight includes a volatility weight, and determining at least one preset evaluation value and a preset evaluation value weight corresponding to the preset evaluation value includes: determining a fluctuation value of the quantum channel according to a ratio of a standard deviation of a historical coding rate corresponding to the quantum channel to an average value; Determining a volatility evaluation value of the quantum channel according to a fluctuation value of the quantum channel and a test coding rate; Determine the volatility weight corresponding to the quantum channel.

7. A quantum communication system, characterized in that: include: A network controller, configured to execute the quantum communication method according to any one of claims 1 to 6; A central node, comprising a first node and an optical switch, wherein the first node and the optical switch are both connected to the network controller, and the first node is connected to the optical switch; A plurality of second nodes, each of the second nodes is connected to the optical switch via at least one quantum channel.

8. An electronic device, characterized in that: include: Memory; as well as A processor coupled to the memory, wherein the processor is configured to execute the method according to any one of claims 1 to 6 based on instructions stored in the memory.

9. A computer-readable storage medium having a program stored thereon, wherein when the program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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