Quantum communication method, quantum communication system and electronic equipment

Abstract

The invention provides a quantum communication method, a quantum communication system and electronic equipment. The quantum communication method comprises the following steps: determining at least one second node needing to be connected with a first node and a quantum channel corresponding to each second node according to a key distribution requirement of the first node; controlling the first node to send a test request to at least one second node through the negotiation channel; controlling the first node and the optical switch to enable one quantum channel in the plurality of quantum channels, and receiving a test response signal from the second node through the enabled quantum channel; determining a channel evaluation value of the quantum channel according to the test response signal; and a quantum channel polling queue is determined according to the channel evaluation value of each quantum channel, key distribution is performed on the second node according to the quantum channels in the quantum channel polling queue, and the quantum channel polling queue comprises at least one quantum channel. The embodiment of the invention can improve the stability of the quantum communication system.

Description

Background Art

[0002] In quantum communication technology, QKD (Quantum key distribution) is a key distribution technology that uses quantum mechanics to ensure security. It is used to enable 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 sensitive to external factors such as channel status and device status, there may be a short-term decline in channel quality when external disturbances occur. When the QKDB node distributes keys, it will distribute keys according to the channel quality obtained when the energy quantum channel is enabled, which will cause a short-term decline in channel quality and cause 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, greatly affecting 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 the 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, which are used to improve 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, according to a key distribution requirement of a first node, at least one second node to be connected to the first node 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 a 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; determining a channel evaluation value of the quantum channel according to the test response signal; determining a quantum channel polling queue according to the channel evaluation value of each quantum channel, and performing key distribution on the second node according to the quantum channel 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] Determine 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 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.

[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 the ratio of the 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] Determine 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;

[0018] Determine 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] Determine the key replenishment time corresponding to the quantum channel according to the key demand and the key distribution speed;

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

[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 the volatility value of the quantum channel and a test coding rate;

[0030] A volatility weight corresponding to the quantum channel is determined.

[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 of the second nodes 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 supplement time is not greater than a preset value to the quantum channel polling queue;

[0034] After completing key distribution according to the Nth quantum channel in the quantum channel polling queue, re-controlling the first node 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, there is provided an electronic device, comprising: a memory; and a processor coupled to the memory, wherein the processor is configured to execute any one of the methods described above 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 that needs to be polled for key distribution this time according to the channel evaluation result, i.e., the channel evaluation value. This allows the use of quantum channels with better communication quality and greater importance for key distribution to be given priority, and key distribution using low coding rates can be avoided as much as possible, thereby improving quantum communication efficiency and maintaining 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 present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings herein are incorporated into the specification 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 accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0041] Figure 1 Schematic diagram of a quantum communication system according to the method provided in the 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 for determining a channel estimation value in one embodiment of the present invention.

[0044] Figure 4The 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 The present invention is a flowchart of distributing keys to a second node according to a quantum channel in a quantum channel polling queue in an embodiment of the present invention.

[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] Fig. 9 It is a schematic diagram of the 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 being limited to the examples set forth herein; on the contrary, these embodiments are provided so that the present disclosure will be more comprehensive and complete, and the concepts of the example embodiments are fully conveyed to those skilled in the art. The described features, structures, or characteristics may be combined in one or more embodiments in any suitable manner. 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 other methods, components, devices, steps, etc. may be adopted. In other cases, known technical solutions are not shown or described in detail to avoid obscuring various aspects of the present disclosure.

[0051] In addition, the accompanying drawings are only schematic diagrams of the present disclosure, and the same reference numerals in the drawings represent the same or similar parts, so their repeated description will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities, which do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or implemented in one or more hardware modules or integrated circuits, or implemented in different networks and / or processor devices and / or microcontroller devices.

[0052] The exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0053] Figure 1 Schematic diagram of a quantum communication system according to the method provided in the 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 a 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, wherein the first node 2 and the optical switch 3 are both connected to the network controller 1, and the first node 2 is connected to the optical switch 3;

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

[0058] Among them, the network controller 1 is responsible for executing the quantum communication method in the system. As the control center of the quantum key distribution (QKD) system, the network controller 1 can command and schedule the operating status of each node to ensure the security and stability of the entire quantum communication process. The network controller 1 controls other components so that they can transmit and process quantum information according to the predetermined method.

[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 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 is a quantum key distribution bridge (QKDB) node, and its main function is to generate and manage quantum keys. The optical switch 3 is responsible for distributing quantum signals to different channels to ensure that the signals can be accurately transmitted to the destination. In practical applications, the first node 2 is also connected to the first key manager 21, which is not only responsible for 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, intrusion detection and defense systems, etc., 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 through one or more quantum channels 4. The key and other important quantum information are transmitted to the first node 2 through the 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 business type is, for example, an application (APP). In practical 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 second nodes, and multiple second nodes 4 are responsible for providing keys to users after negotiating keys with the central node. When the key of the second node 4 is called by the user, the keys of all nodes on the user's end-to-end link will be consumed. Therefore, the first node 2 and the second node 4 must perform a quantum key distribution process to generate symmetric keys, which are added to the first key manager 21 corresponding to the central node 2 and the second key manager 42 corresponding to the second node 4 to ensure that users can access the keys normally.

[0063] In addition, the first node may link other application nodes by connecting to other nodes similar to the first node, so as to realize the 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 the present 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 begins, 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, so as to improve the key supplement efficiency and ensure 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, according to the key distribution requirement of the first node, determining at least one second node to be connected to the first node and a quantum channel corresponding to each second node, wherein the first end of the quantum channel is connected to an optical switch, the 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 keys 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 that needs to be polled for key distribution this time according to the channel evaluation result, i.e., the channel evaluation value. This allows the use of quantum channels with better communication quality and greater importance for key distribution to be given priority, and key distribution using low coding rates can be avoided as much as possible, thereby improving quantum communication efficiency and maintaining 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, according to the key distribution requirements of the 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, the first end of the quantum channel is connected to an optical switch, the second end is connected to the second node, and the optical switch is connected to the first node.

[0076] The key distribution requirement is mainly proposed by the central node 20. The first node 2, namely QKDB, is responsible for managing the key distribution of multiple second nodes 4, namely QKDA (Quantum Key Distribution Access) nodes, and needs to distribute keys to the second nodes 4 in a timely manner. Therefore, the central node 20 will determine the second nodes 4 that need to be distributed with keys according to the overall network status and the specific needs of the user.

[0077] In the embodiment of the present disclosure, after determining the second node 4 to which the first node 2 needs to be connected, the network controller 1 needs to determine the quantum channel between the optical switch 3 and each second node 4. It should be noted that one 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] Since the quantum channel 41 is implemented based on a physical optical link, these quantum channels always exist between each second node 2 and the optical switch 3, but these quantum channels are all in an unenabled state, that is, the optical switch 3 does not regard a certain quantum channel as a channel for current information transmission. When quantum communication needs to be completed through a certain quantum channel, the optical switch 3 enables the quantum channel 41 according to the port address of the quantum channel 41, which is equivalent to connecting the second node 4 connected to the quantum channel 41 with the first node 2, so that the second node 4 can send an optical signal 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 to control the first node 2 to send a test request to each second node 2 that needs to be connected through the negotiation channel between nodes, so that each second node 2 is ready to 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, and the present disclosure does not impose any special restrictions on this.

[0083] In an exemplary embodiment, the test request is not sent unidirectionally from the first node 2 to the second node 4, but may be negotiated between the first node 2 and the second node 4 through a negotiation channel to negotiate a set of reference bases (for example, the same measurement base) for subsequent test comparisons.

[0084] Unlike quantum channels, test requests are sent through negotiation channels (also known as classical channels). Negotiation channels are channels used to establish and maintain quantum communication protocols, transmit control information, negotiate encryption parameters, and ensure that both parties can effectively perform quantum key distribution (QKD). Negotiation channels are usually used to send authentication and confirmation messages to ensure that both QKDB and QKDA parties agree on the state of the quantum channel used and the key generation process.

[0085] In step S3, the first node and the optical switch are controlled to enable a 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 may 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] Exemplarily, 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 in 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, the first node 2 calculates the coding rate of the quantum channel 41 according to the test response signal, marks the calculation result as the test coding rate corresponding to the quantum channel 41, and sends the test coding rate to the network controller 1 for further processing by the network controller 1. The coding rate of the quantum channel 41 (also called channel capacity) refers to the maximum number of quantum bits that can be reliably transmitted on the quantum channel, which is used to measure the amount of information that can be effectively transmitted by the quantum channel per unit time, and is usually expressed in bits per second (bps).

[0089] In terms of the calculation method of the coding rate, illustratively, in step S2, the first node 2 (QKDB) and the second node 4 (QKDA) will perform a series of classical signal exchanges during the test request sending phase, and negotiate a set of reference bases (for example, 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 (for example, by monitoring the number of photons received through a photon counter), and compares it with the bits agreed to be sent by the second node 4 (QKDA), and calculates the bit error rate (i.e., the proportion of erroneous 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, according to the communication protocol corresponding to the quantum channel, the bit error rate is used to calculate the coding rate. Since the coding rate calculation methods corresponding to different communication protocols are different, the present 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 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 all the time (regardless of whether the quantum channel is finally used).

[0094] Figure 3 The present invention is a flowchart for 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 evaluate whether the quantum channel is currently in a good or excellent communication state, and at least one preset evaluation value is used to measure the influence of other factors other than the coding rate on the selection of the quantum channel, that is, the urgency (or priority) of the selection of the quantum channel. 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 the other factors in the process of quantum channel selection.

[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 according to 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 of the historical bitrates, and σ is the standard deviation of the historical bitrates. Formula (2) is also called the standard score (z-score), which is used to measure the degree of deviation between the test value and the average value. After standardization, the relative position of the test value in the population can be determined. The higher the standard score, the greater the degree to which the test value deviates from the average value.

[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 meaning 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 by calculating 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 weights corresponding to each quantum channel are the same, that is, when considering whether to be selected, the degree of influence of the coding rate is the same. In some embodiments, different coding rate weights can also be set for different quantum channels according to the characteristics of different quantum channels. Generally speaking, the degree of emphasis on various factors during evaluation is relatively stable, so the coding rate weight corresponding to each quantum channel is basically unchanged, or the update frequency is relatively high, so each evaluation only needs to read the latest coding rate weight, without calculation.

[0107] In step S43, at least one preset evaluation value of the quantum channel, i.e., the selected urgency, can be determined according to a variety of factors. For example, the business type, business volume, remaining keys, key consumption speed (how long it can be maintained), volatility (whether the current good state is very rare), etc. of the second node 4 corresponding to the quantum channel can be considered.

[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 4In 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 according to 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, determining the service weight corresponding to the quantum channel.

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

[0115] Next, the service priority is determined according to the processing priority and service volume of each service type. The service priority is the consideration priority of service characteristics in the quantum channel evaluation process. For example, if the processing priority of a service type is very high, but its service volume is small, its service priority may be very small; or, if the priority of a service type is very low, but its service volume is large, its service priority may be very large. It is necessary to comprehensively consider the service priority corresponding to each service type to determine the evaluation result of the quantum channel 41 based on service factors.

[0116] Exemplarily, in order to prevent different services from having different evaluation criteria for processing priorities, the processing priorities corresponding to each type of service may first be normalized or standardized (for example, sorted by score or by standard score, also known as z-score) to facilitate subsequent comparisons, and then the service priority of the service type may be determined based on the product of the normalized processing priority of the service type and the service volume.

[0117] If a second node 4 corresponds to multiple service types, after determining the service priority of each service type, the service priority of the second node 4 can be determined according to the sum of the service priorities of each service type. It can be understood that the service priority corresponding to the quantum channel 41 is the service priority corresponding to the second node 4 connected to the quantum channel 41. For two quantum channels 41 connected to the same second node 4, the service priorities corresponding to the two quantum channels 41 are both the service priorities corresponding to the 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. Exemplarily, 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 a 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 a 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 calculation regression analysis can also be used, but it is necessary to ensure that the method for calculating the relative value is consistent with the coding rate evaluation value.

[0119] Next, determine the service weight corresponding to the quantum channel. In an exemplary embodiment, the service weights corresponding to each quantum channel are the same, that is, when considering whether to be selected, the service priority of the second node connected by the quantum channel has the same degree of influence. In some embodiments, different service weights can also be set for different quantum channels according to the characteristics of different quantum channels. Generally speaking, the degree of emphasis on various factors during evaluation is relatively stable, so the service weight corresponding to each quantum channel is basically unchanged, or the update frequency is relatively high, so each evaluation only needs to read the latest service weight, without calculation.

[0120] In addition to considering the business 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 5In 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 the preset evaluation value weight corresponding to the preset evaluation value may include:

[0123] Step S435, determining the key demand 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, 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 5 In 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 according to the load of each second node 4 and the historical key usage. For example, according to the corresponding relationship between the current load and the load and the key consumption in the historical record, the number of keys (consumption speed) required per unit time of the second node 4 under the current load is calculated. Then, according to the remaining number of keys of the second key manager 42 corresponding to the second node 4, it is determined how long the current number of keys of the second node 4 can be consumed (remaining consumption time). If the remaining consumption time is less than the preset time (for example, one hour) or the maximum channel assessment cycle, it is calculated according to the current remaining consumption time and consumption speed, how many keys need to be supplemented to the second node 4 before the next channel assessment so that the key amount of the second node 4 can be used at least until the next channel assessment. It should be noted that the maximum channel assessment cycle can be set in advance for the channel assessment cycle to limit the maximum time from the next channel assessment. When judging the key demand, the maximum channel assessment cycle can be directly used to simplify the calculation.

[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 according to 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, according to the ratio of the key demand to the key distribution speed, it is determined how long it takes to supplement the key of the key demand to the second node 4 through the quantum channel 41, that is, the key supplementation time corresponding to the 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 are not necessarily the same.

[0132] After calculating the key replenishment time corresponding to each quantum channel 41, the distribution priority of each quantum channel can be formed according to the key replenishment time of each quantum channel. When forming the distribution priority, the longer the key replenishment time, the greater the distribution priority. This is because, in order to maintain the effectiveness of the evaluation, it is necessary to limit the evaluation cycle to not be too long. During this cycle, if the key distribution requirements with short key replenishment time are met first, the key distribution requirements with long key replenishment time are likely to be met in time, resulting in insufficient keys and affecting the stability of quantum communication. Therefore, according to the key replenishment time of each quantum channel 41 in this evaluation, the distribution priority of each quantum channel 41 can be set from high to low according to the key replenishment time from long to short.

[0133] It should be noted that, in order to calculate together with the coding rate evaluation value later, when calculating the distribution priority, the key replenishment time of each quantum channel 41 can be normalized or standardized. Exemplarily, 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 according to the position of the key replenishment time of a quantum channel 41 in the key replenishment time of each quantum channel 41. For example, the standard deviation and the average value of the key replenishment time of each quantum channel 41 can be calculated, and then the distribution priority of the key replenishment time of the quantum channel 41 can be determined according to 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 z-score). There are many methods for determining the distribution priority. In addition to using the above-mentioned z-score method, percentiles, rankings, score levels, or through calculation regression analysis and the like can also be used, but it is necessary to ensure that the method for calculating the relative value is consistent with the coding rate evaluation 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, that is, when considering whether it is selected, the influence of the time consumed for key distribution through the quantum channel is the same. In some embodiments, different distribution time weights can also be set for different quantum channels according to the characteristics of different quantum channels. Generally speaking, the degree of emphasis on various factors during evaluation is relatively stable, so the distribution time weight corresponding to each quantum channel is basically unchanged, or the update frequency is relatively high, so each evaluation only needs to read the latest distribution time weight, without 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 according to 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 evaluation value of the quantum channel according to the volatility value of the quantum channel and the test coding rate;

[0140] Step S63, determining the volatility weight corresponding to the quantum channel.

[0141] The larger the fluctuation value, the more unstable the current state of the quantum channel 41 is, and the good state is fleeting and needs to be used immediately. The volatility evaluation value can be determined comprehensively according to the fluctuation value and the test coding rate, so that when the test coding rate of the quantum channel is high and the fluctuation value is large, the volatility evaluation 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 evaluation 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 evaluation 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 evaluation value of the quantum channel is D, and A>B>C>D.

[0142] The function for determining the fluctuation evaluation value according to the fluctuation value and the test coding 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 calculate together with the coding rate evaluation value later, the volatility evaluation value of each quantum channel 41 needs to be normalized or standardized. Exemplarily, after determining the volatility evaluation value of each quantum channel 41, the relative value of the volatility evaluation value of the quantum channel 41 can be determined according to the position of the volatility evaluation value of a quantum channel 41 in the volatility evaluation values ​​of each quantum channel 41. For example, the standard deviation and the average value of the volatility evaluation value (absolute value) of each quantum channel 41 can be calculated, and then the relative value of the volatility evaluation value of the quantum channel 41 can be determined according to the ratio of the difference between the volatility evaluation value (absolute value) of a quantum channel 41 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 calculation regression analysis and the like can also be used, but it is necessary to ensure that the method for calculating the relative value is consistent with the coding rate evaluation value.

[0144] Next, the volatility weight corresponding to the quantum channel is determined. In an exemplary embodiment, the volatility weights corresponding to each quantum channel are the same, that is, when considering whether to be selected, the influence degree of the service priority of the second node connected by the quantum channel is the same. In some embodiments, different volatility weights can also be set for different quantum channels according to the characteristics of different quantum channels. Generally speaking, the importance of various factors in evaluation is relatively stable, so the volatility weight corresponding to each quantum channel is basically unchanged, or the update frequency is relatively high, so each evaluation only needs to read the latest volatility weight, without 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, and 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 a quantum channel whose test coding rate is lower than a preset threshold or where there is a security threat, and the channel evaluation value of the quantum channel where the alarm signal appears can be directly reduced to 0, thereby exiting the current round selection.

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

[0149] Exemplarily, the channel evaluation value of the i-th quantum channel may 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 ith quantum channel, Err i is the alarm coefficient of the ith quantum channel. When there is an alarm, Err i Err=0, when there is no alarm, Err i =1, R i is the estimated value of the coding rate of the ith 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] Wherein, 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 ith channel, W ij is the weight corresponding to the jth evaluation value of the ith 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 of the ith quantum channel. For example, if the test coding rate of the ith quantum channel is less than the preset coding rate, or the coding rate evaluation value is less than the preset evaluation value, or it is detected that the ith quantum channel may be monitored, the alarm coefficient Err = 0 can be set, indicating that the current quantum channel may need to be repaired 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 the present 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 a key is distributed 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.

[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 supplement time of the quantum channel selected in one evaluation is limited.

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

[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 a second node according to a quantum channel in the quantum channel polling queue may include:

[0162] Step S51, determining the key supplement 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 supplement time is not greater than a preset value to the quantum channel polling queue;

[0164] Step S53: after completing key distribution according to the Nth quantum channel in the quantum channel polling queue, re-control the first node 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 supplement time corresponding to each quantum channel.

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

[0167] The first N quantum channels whose sum of key supplement time is not greater than a preset value are selected to join 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), and the evaluation can be started again to select a new batch of quantum channels for polling for key distribution 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, when the sum of the key supplement time is not greater than the preset value, the switching time of the optical switch 3 switching the quantum channel needs to be considered. It can be preset that each switching of the quantum channel is of the same duration, and the total duration corresponding to the current quantum channel polling queue is determined according to the number of selected quantum channels minus one. For example, quantum channels A, B, C, and D are sorted from high to low according to the channel evaluation value, and the corresponding key supplement times are 20, 30, 10, and 20 respectively, and the preset value is 60. The time consumed for each switching of the quantum channel is 5. If quantum channels A, B, and C are selected to join the quantum channel polling queue, the key distribution is finally completed through the quantum channel polling queue, and the time consumed is 20+5+30+5+10=70, which is greater than the preset value of 60, affecting the re-evaluation. At this time, it is necessary to select quantum channels A and B to join the quantum channel polling queue, and the key distribution is finally completed through the quantum channel polling queue, and the time consumed is 20+5+30=55, which is less than the preset value of 60, and does not affect the restriction on the channel evaluation cycle.

[0171] By limiting the channel evaluation cycle and timely re-evaluating each quantum channel, 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 switch 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 test of all quantum channels 41 corresponding to this evaluation is completed, if yes, it goes to step S85, otherwise, it 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 that all quantum channels in the quantum channel polling queue have been traversed. If yes, 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] Fig. 9 It is a schematic diagram of the evaluation process in one embodiment of the present disclosure. Fig. 9 To simplify the illustration, the specific structure of the quantum communication system is not limited.

[0184] refer to Fig. 9 , QKD-B (i.e. Figure 1 The first node 2 in the figure is the QKD receiving end, 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 through an optical fiber quantum channel, where QKD-A2 has two quantum channels connected to QKD-B. All devices are located at the network reachable address of the network controller 1, and the network controller 1 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 sends a network evaluation request: requiring QKD-A1, QKD-A2, and QKD-A3 to prepare for network evaluation, and at the same time sends a quantum channel switching request to light 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, predicts the coding rate of quantum channel ①, and reports the prediction result as the test coding rate and other parameters to network controller 1. Network controller 1 calculates the coding rate evaluation value. Assuming that the test coding rate here is 20kbps, the average value of the historical coding rate is 60kbps, and the standard deviation is 8kbps, the coding rate evaluation value 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, predicts the coding rate of quantum channel ②, and reports the prediction result as the test coding rate and other parameters to network controller 1. Network controller 1 calculates the coding rate evaluation value. Assume that the test coding rate here is 40kbps, the average value of the historical coding rate is 42kbps, and the standard deviation is 3kbps, 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, and QKD-B receives and analyzes the optical signal, predicts the coding rate of quantum channel ③, and reports the prediction result as the test coding rate and other parameters to network controller 1. Network controller 1 calculates the coding rate evaluation value. Assuming that the test coding rate here is 45kbps, the average value of the historical coding rate is 38kbps, and the standard deviation is 4kbps, 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, and QKD-B receives and analyzes the optical signal, predicts the coding rate of quantum channel ④, and reports the prediction result as the test coding rate and other parameters to network controller 1. Network controller 1 calculates the coding rate evaluation value. Assume that the test coding rate here is 35kbps, the average value of the historical coding rate is 28kbps, and the standard deviation is 6kbps, Z = (35-20)) / 6 = 2.5.

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

[0192] Generate polling queue: According to the channel evaluation value and the sum of the key supplement time of each quantum channel, a quantum channel polling queue is formed. In the case of 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 coding: The network controller 1 controls the optical switch 3 to switch quantum channels and code them in sequence according to the quantum channel polling queue. After the coding process of quantum channel ③ is completed, that is, the key is distributed, the channel evaluation process is restarted to determine the next batch of quantum channels to be polled based on the latest channel status.

[0194] In summary, the disclosed embodiment avoids the problem of decreased network efficiency and waste of resources caused by long-term occupation of lines 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 states 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 overall network is improved. By periodically analyzing the states of all quantum channels, the response time to faults or alarms is shortened, and the reliability of the QKD network is increased. By using a network controller to calculate the channel evaluation value, priority statistics after comprehensive consideration of multiple information are realized, avoiding the problem of some quantum channels not coding 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 above detailed description, 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 embodied in one module or unit. On the contrary, the features and functions of one module or unit described above can be further divided into multiple modules or units to be embodied.

[0196] In an exemplary embodiment of the present disclosure, an electronic device capable of implementing the above 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 above quantum communication methods based on instructions stored in the memory.

[0197] It will be appreciated by those skilled in the art that various aspects of the present invention may be implemented as a system, method or program product. Therefore, various aspects of the present invention may be specifically implemented in the following forms, namely: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or a combination of hardware and software, which may be collectively referred to herein as a "circuit", "module" or "system".

[0198] Through the description of the above implementation, it is easy for those skilled in the art to understand that the example implementation described here can be implemented by software, or by software combined with necessary hardware. Therefore, the technical solution according to the implementation 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, including 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 implementation of the present disclosure.

[0199] In an exemplary embodiment of the present disclosure, a computer-readable storage medium is also provided, on which a program product capable of implementing the above method of the present specification is stored. In some possible implementations, various aspects of the present invention can also be implemented in the form of a program product, which includes a program code, and when the program product is run on a terminal device, the program code is used to enable the terminal device to execute the steps according to various exemplary embodiments of the present invention described in the above "Exemplary Method" section of the present specification.

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

[0201] The program product may use 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 device, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with 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 of the above.

[0202] Computer readable signal media may include data signals propagated in baseband or as part of a carrier wave, in which readable program code is carried. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Readable signal media may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit 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, wired, optical cable, RF, etc., or any suitable combination of the foregoing.

[0204] 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++, etc., and 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 separate 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 through 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., through the Internet using an Internet service provider).

[0205] In addition, the above-mentioned figures are only schematic illustrations of the processes included in the method according to an exemplary embodiment of the present invention, and are not intended to be limiting. It is easy to understand that the processes shown in the above-mentioned figures do not indicate or limit the time sequence of these processes. In addition, it is also easy to understand that these processes can be performed synchronously or asynchronously, for example, in multiple modules.

[0206] Those skilled in the art will readily appreciate other embodiments of the present disclosure 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 that are not disclosed in the present disclosure. The specification and examples are to be considered exemplary only, and the true scope and concept of the present disclosure are indicated by the claims.

Claims

1. A quantum communication method, characterized in that: include: According to the key distribution requirement of the first node, determine 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; A quantum channel polling queue is determined according to a channel evaluation value of each quantum channel, and a key is distributed 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.

2. The quantum communication method according to claim 1, characterized in that: 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; Determine 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 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.

3. The quantum communication method according to claim 2, characterized in that: 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 the ratio of the difference between the test coding rate and the average value to the standard deviation.

4. The quantum communication method according to claim 2, characterized in that: The preset evaluation value includes the service priority of the second node corresponding to the quantum channel, the preset evaluation value weight includes the service weight, and determining at least one preset evaluation value and the preset evaluation value weight corresponding to the preset evaluation value includes: Determine 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; Determine 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, characterized in that: 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; Determine the key replenishment time corresponding to the quantum channel according to the key demand and the key distribution speed; Determine the distribution priority of each quantum channel according to the key replenishment time corresponding to each quantum channel, the longer the key replenishment time is, the greater the distribution priority is; Determine a distribution time weight corresponding to the quantum channel.

6. The quantum communication method according to claim 2, characterized in that: 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 the volatility value of the quantum channel and a test coding rate; A volatility weight corresponding to the quantum channel is determined.

7. The quantum communication method according to claim 1, characterized in that: Determining the quantum channel polling queue according to the channel evaluation value of the quantum channel corresponding to each of the second nodes 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 supplement time is not greater than a preset value to the quantum channel polling queue; After completing key distribution according to the Nth quantum channel in the quantum channel polling queue, re-controlling the first node to send a test request to the at least one second node through the negotiation channel.

8. 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 7; 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.

9. An electronic device, characterized in that: include: Memory; as well as A processor coupled to the memory, the processor being configured to execute the method according to any one of claims 1 to 7 based on instructions stored in the memory.

10. 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 7 is implemented.

11. 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 7 are implemented.

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