Key dynamic xor method of centralized quantum key relay network and relay node

Abstract

The application discloses a key dynamic XOR method and a relay node of a centralized quantum key relay network, and the method comprises the following steps: establishing a temporary key pool corresponding to the number of quantum links, wherein the temporary key pool is used for storing the keys generated in a current key uploading period of the corresponding quantum link; when N>2, the weights of the connected quantum links are added two by two every time the key uploading period arrives, the weight addition result is obtained and sorted, the weight of the quantum link is the key utilization rate / node utilization rate of the quantum link multiplied by the key generation efficiency of the quantum link; the keys are selected from the temporary key pools corresponding to the two quantum links with the highest weight addition result respectively for XOR; the keys are selected from the temporary key pools corresponding to any two quantum links with non-highest weight addition result respectively for XOR; and the application solves the problem of low quantum network node key XOR efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of quantum communication, in particular to a key dynamic XOR method of a centralized quantum key relay network and a relay node. BACKGROUND

[0002] Quantum cryptography technology is based on quantum key distribution (QKD) protocol and has developed rapidly in recent years. Unlike traditional cryptography, quantum cryptography is based on quantum mechanics and uses quantum physical properties such as Heisenberg uncertainty principle and no-cloning theorem to achieve secure negotiation of symmetric keys over long distances.

[0003] A plurality of quantum key distribution nodes can form a quantum key distribution network (QKDN). Due to the limited distance between adjacent nodes, quantum key relay distribution is required in the long-distance key generation scenario. A quantum network generally includes a QKD device for performing a quantum key distribution process, a KM device (Key Management) for managing the keys of the QKD device, and a QKDN controller for network control. In the current quantum network, the QKDN control has multiple forms, which are as follows: (1) a distributed control scheme, each node contains a complete QKD device, KM key management function and QKDN controller function, and the distributed routing control is used to realize distributed networking, and the key relay is realized by the KM; (2) a centralized control scheme, each node contains a QKD device and a KM function, and there is one or more centralized QKDN controllers in the network, and the routing control, resource scheduling and other functions of each node and link are controlled by the centralized QKDN controller, and the key relay is realized by the KM; (3) multi-level node centralized control, according to different roles, the network nodes, i.e. QKD nodes, are divided into user nodes, access nodes and relay nodes, wherein only the network nodes receiving quantum keys from one QKD are regarded as user nodes, the access nodes are adjacent to the user nodes, and the other network nodes are regarded as relay nodes, the access nodes are the same as the relay nodes in the relay management and control process, and the access nodes and the relay nodes receive the control of the centralized QKDN controller, and the key relay is realized by the KM; (4) centralized control and key relay, the controller function and the key relay function are centralized in the QKDN controller, and there is no key encryption transmission between the QKD nodes.

[0004] In the above QKDN networking schemes, the distributed control scheme, the centralized control scheme and the multi-level node centralized control scheme all relay the keys by the KM in each node in a chain transmission manner, and the quantum keys transmitted will pass through each relay node, so the management security of the relay nodes is required to be higher.

[0005] Centralized control and key relay schemes can reduce the connection management and authentication signaling overhead required for direct interaction between multiple relay nodes in a QKDN when performing key relay, simplify QKD node functions, and improve key relay efficiency. They are suitable for use in networks with many nodes, large range, and long relay key links. However, there is currently no specific implementation method for this scheme, and many problems remain unresolved when implementing quantum networks with a centralized scheme. For example, how to perform XOR operations on the keys of two consecutive QKD links, how to solve the problem of different keys generated by different links in the same time period, and how the QKDN controller manages the uploaded XOR keys, etc.

[0006] Some methodologies propose that when reporting XOR keys, quantum network nodes can indiscriminately XOR all keys on different links. However, this method significantly increases the upload bandwidth of each network node. The QKDN controller then faces a massive amount of keys continuously uploaded by all nodes in the network, increasing both the storage space consumption and computational management difficulty of the XOR keys. Furthermore, it fails to consider the practical realities that a node may connect to more than two other nodes, and that the number of keys generated on each link may differ.

[0007] In related technologies, patent application CN114900293A proposes that all quantum key management nodes in a quantum network establish a connection with the scheduling center. The scheduling center requests quantum key XOR information from each relay node. The relay node calculates its key XOR information and reports it. When a relay node has N neighboring nodes (i.e., N QKD links), for a relay node, when N=2, the relay node XORs the quantum keys of the two links to assemble the quantum key XOR response. When N>2, when the relay node has more than 2 neighboring nodes (i.e., more than two QKD links), the relay node uses a certain link key as the base key and XORs it with the other link keys to obtain N-1 units of quantum key XOR information, which is called direct key XOR information. However, this scheme only proposes a centralized key relay scheduling method as a methodology. Its core lies in the entire key relay process: node information reporting, central topology establishment, relay nodes uploading XOR values, forming a global XOR key table across the network, generating keys between any two points in the network, and distributing the keys. It also refines and constrains various identification information within this relay process. Its method for reducing network bandwidth is based on the XOR property: nodes with more than two connection links can upload one less XOR value, calculated by the scheduling center itself, with a greater focus on the scheduling center's scheduling approach. Summary of the Invention

[0008] This invention aims to solve the problem of low XOR efficiency when network nodes select different QKD link keys in centralized quantum key relay networks.

[0009] The application solves the above technical problems through the following technical means:

[0010] In one aspect, a key dynamic XOR method of a centralized quantum key relay network is provided, which is applied to a relay node, the number of quantum links connected to the relay node is N, and the method comprises the following steps:

[0011] A temporary key pool corresponding to the number of quantum links is established, and the temporary key pool is used to store keys generated in a current key uploading period of a corresponding quantum link;

[0012] When N>2, the weights of the connected quantum links are added two by two every time the key uploading period arrives, the weight addition results are obtained and sorted, and the weight of a quantum link is the key usage rate of the quantum link / node usage rate multiplied by the key generation efficiency of the quantum link;

[0013] Keys are selected from the temporary key pools corresponding to the two quantum links with the highest weight addition results for XOR respectively;

[0014] Keys are selected from the temporary key pools corresponding to any two quantum links with non-highest weight addition results for XOR respectively.

[0015] Further, the node usage rate is the number of times that the key of the node is used in a set time, and the link key usage rate is the number of times that the key generated on a quantum link is used in a set time;

[0016] For any relay node, V Node =∑V Link , V Node is the node usage rate, and V Link is the link key usage rate.

[0017] Further, the key generation efficiency is the ratio of the average key generation rate of each quantum link to the preset key generation reference rate.

[0018] Further, the selecting of the keys from the temporary key pools corresponding to the two quantum links with the highest weight addition results for XOR comprises the following steps:

[0019] The minimum value of the capacities of the temporary key pools corresponding to the two quantum links with the highest weight addition results is taken as the maximum XOR amount in the current period, and the same time and length of keys are selected from the two temporary key pools for XOR according to the maximum XOR amount in the current period.

[0020] Further, the selecting of the keys from the temporary key pools corresponding to any two quantum links with non-highest weight addition results for XOR comprises the following steps:

[0021] calculating a first key amount, the first key amount being P x (W A +W B ) / W max , wherein P is the maximum XOR amount in the current period, W A and W B are the weights of any two selected quantum links, and W max is the sum of the weights of the two links with the highest weights in the current period;

[0022] determining whether the minimum capacity in the temporary key pool corresponding to any two selected quantum links is greater than the first key amount;

[0023] If yes, then selecting keys from the temporary key pools corresponding to the two quantum links according to the minimum capacity for XOR operation;

[0024] If no, then selecting keys from the temporary key pools corresponding to the two quantum links according to the first key amount for XOR operation.

[0025] Further, when N = 2, every time the key uploading period arrives, selecting keys from the temporary key pools corresponding to the two quantum links according to the minimum capacity for XOR operation.

[0026] Further, after the key XOR operation, the method further comprises:

[0027] uploading the key XOR result, the IDs of the two quantum links, and the positions of the keys used in the XOR operation in the respective temporary key pools to the QKDN controller.

[0028] Further, after the key XOR operation, the method further comprises:

[0029] saving the keys used in the XOR operation and discarding all unused keys.

[0030] In a second aspect, a relay node is provided, the number of quantum links connected to the relay node being N, and the relay node comprising:

[0031] a key pool establishing module configured to establish temporary key pools corresponding to the number of quantum links, the temporary key pools being configured to store keys generated in the current key uploading period of the corresponding quantum links;

[0032] a weight calculating module configured to, when N > 2, add the weights of the connected quantum links two by two every time the key uploading period arrives, obtain the weight addition result and sort it, and the weight of a quantum link being the key usage rate of the quantum link / node usage rate x the key generation efficiency of the quantum link;

[0033] The key XOR module is configured to select keys from the temporary key pools corresponding to the two quantum links with the highest weight addition results for XOR operation, and select keys from the temporary key pools corresponding to any two quantum links with non-highest weight addition results for XOR operation.

[0034] In a third aspect, the application provides a centralized quantum key relay network system, which comprises a QKDN controller and network nodes, and the network nodes comprise user nodes and relay nodes, wherein:

[0035] The relay nodes upload the quantum keys generated by different quantum links after XOR operation to the QKDN controller according to the method as described above;

[0036] The QKDN controller receives the key request sent by the network nodes, and issues XOR keys to the service target nodes based on the key request.

[0037] In a fourth aspect, the application further provides a computer device, which comprises a memory and a processor, wherein the processor runs a program corresponding to an executable program code stored in the memory by reading the executable program code, so as to implement the key dynamic XOR method of the centralized quantum key relay network as described above.

[0038] In a fifth aspect, the application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the key dynamic XOR method of the centralized quantum key relay network as described above.

[0039] The application has the following advantages:

[0040] (1) The key dynamic XOR method of the centralized quantum key relay network combines the usage rate of the key links and the key generation rate, uploads the keys on the links with more frequent usage as much as possible, avoids the situation that there is no key available for service, and considers the key generation rate as much as possible to avoid the waste of keys on the links with more key generation, so as to solve the problem of low XOR efficiency of the quantum network node keys, and provide a guidance scheme for the XOR key selection of the quantum node in the centralized control and key relay architecture quantum network.

[0041] Additional aspects and advantages of the application will be given in part in the following description, will become apparent in part from the following description, or will be understood by those skilled in the art through practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is a centralized control and key relay quantum network architecture schematic diagram in an embodiment of the application;

[0043] Figure 2 is a flowchart of a key dynamic XOR method of a centralized quantum key relay network according to an embodiment of the present application;

[0044] Figure 3 is a structural diagram of a relay node according to an embodiment of the present application;

[0045] Figure 4 is a structural diagram of a computer device according to an embodiment of the present application. DETAILED DESCRIPTION

[0046] To make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in a clear and complete manner in conjunction with the embodiments of the present application. Obviously, the described embodiments are only some, but not all of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of the present application.

[0047] In the embodiment, the centralized control and key relay quantum network architecture is as shown in Figure 1 The network nodes in the network architecture are divided into user nodes and relay nodes according to the connection (position), the network nodes receiving quantum keys from only one QKD are regarded as user nodes, and the other network nodes are regarded as relay nodes, the relay nodes and the network nodes can be connected to user service systems and provide quantum key services to the outside, and only the relay nodes upload the quantum keys generated by different links after XOR operation. The quantum network includes a QKDN controller, which can receive the XOR keys uploaded by each node and issue the XOR keys to the service target nodes.

[0048] The QKDN controller is also responsible for calculating the optimal path for the key request in the quantum network and selecting the XOR value along the optimal path. After the path is selected each time, the QKDN controller issues a notification that the key has been used to each node on the path.

[0049] The relay nodes upload the XOR keys at regular intervals, and the period of uploading the XOR keys is referred to as a key upload period. When a quantum link is established between two nodes, the quantum link is named by the IDs of the two nodes.

[0050] When a relay node establishes quantum links with other nodes and generates quantum keys, the relay node establishes a plurality of temporary key pools for the quantum links, the number of the key pools is consistent with the number of the quantum links established by the node, each key pool stores the keys generated in the current upload period on each link, and the key pool is named by the ID of the opposite node of the link.

[0051] Specifically, as shown in Figure 2As shown, the embodiment proposes a key dynamic XOR method of a centralized quantum key relay network, applied to a relay node, the number of quantum links connected by the relay node is N, and the method comprises the following steps:

[0052] S10, a temporary key pool corresponding to the number of quantum links is established, and the temporary key pool is used to store the keys generated in the current key upload period of the corresponding quantum link;

[0053] S20, when N>2, every time the key upload period is reached, the weights of the connected quantum links are added two by two, the weight addition result is obtained and sorted, and the weight W of the quantum link is V Link / V Node ×R, V Link is the link key usage rate, V Node is the node usage rate, and R is the key generation efficiency;

[0054] S30, selecting keys from the temporary key pools corresponding to the two quantum links with the highest weight addition result for XOR respectively;

[0055] S40, selecting keys from the temporary key pools corresponding to any two quantum links with non-highest weight addition result for XOR respectively.

[0056] The embodiment combines the usage rate of the key link and the key generation rate, uploads the keys on the links with more frequent usage as much as possible, avoids the situation that there is no key available for business, and considers the key generation rate as much as possible to avoid the waste of keys on the links with more key generation, which can solve the problem of low XOR efficiency of quantum network node keys, and provides a guidance scheme for XOR key selection of quantum nodes in a centralized control and key relay architecture quantum network.

[0057] As a further preferred technical solution, the node usage rate is the number of times the key of the node is used in a set time, and the link key usage rate is the number of times the key generated on a certain quantum link is used in a set time;

[0058] For any relay node, V Node =∑V Link , V Node is the node usage rate, and V Link is the link key usage rate;

[0059] The key generation efficiency is the ratio of the average key generation rate of each quantum link to the preset key generation reference rate.

[0060] Specifically, the embodiment records the number of times of using the node key and the number of times of using the key generated on each link passing through the node in the node within a certain period of time, and records the number of times of using the node key within a certain period of time as the node usage rate V Node , and records the number of times of using the key generated on a certain link within a certain period of time as the link usage rate V Link . For any node, V Node =∑V Link ; the average key generation rate of each link passing through the node within a certain period of time is recorded in the node, and the ratio of the average key generation rate to the key generation rate benchmark preset by the system is taken as the key generation efficiency R of the link.

[0061] It should be understood that the time value mentioned in the embodiment is an empirical value defined by the user, which can be tens of minutes to several days, and the embodiment does not make specific limitations.

[0062] It should be noted that the key demand that is likely to be generated in the future is estimated according to the frequently used nodes and links in the past, and the keys generated on these nodes and links are preferentially XOR uploaded. The key generation rate on different links is evaluated, and the keys on the links with more key generation are also preferentially XOR uploaded, so as to reduce the waste of keys and avoid the generation of many unused keys. The link usage rate / node usage rate is used to identify the proportion of the key generated on a certain link connected to any node in all keys of the node. The whole formula is used to identify the importance of a certain link connected to a node.

[0063] As a further preferred technical solution, the step S30: selecting keys from the temporary key pools corresponding to the two quantum links with the highest weight addition results for XOR, specifically comprising:

[0064] The minimum capacity of the temporary key pools corresponding to the two quantum links with the highest weight addition results is taken as the maximum XOR amount within the current period, and the same time and length of keys are selected from the two temporary key pools for XOR according to the maximum XOR amount within the current period.

[0065] It should be noted that any two links need to upload XOR keys. Because the location of the long-distance key request is relatively random, the embodiment uploads keys from any two quantum links with non-highest weight addition results, specifically the step S40: selecting keys from the temporary key pools corresponding to any two quantum links with non-highest weight addition results for XOR, comprising the following steps:

[0066] S41, calculating a first key amount, the first key amount is P×(W A+W B ) / W max Where P is the maximum XOR value within the current period, and W A and W B W represents the weights of two arbitrarily chosen quantum links. max It is the sum of the weights of the two links with the highest weights in this period;

[0067] S42. Determine whether the minimum capacity of the temporary key pool corresponding to any two randomly selected quantum links is greater than the first key quantity. If yes, proceed to step S43; otherwise, proceed to step S44.

[0068] S43. Select keys from the temporary key pools corresponding to any two quantum links according to this minimum capacity and XOR them respectively;

[0069] S44. Select keys from the temporary key pools corresponding to the two randomly selected quantum links according to the first key quantity and perform XOR operation.

[0070] As a further preferred technical solution, when N=2, each time the key upload cycle is reached, keys are selected from the temporary key pools corresponding to the two quantum links according to the minimum capacity of the temporary key pools corresponding to the two quantum links and XORed.

[0071] As a further preferred technical solution, after performing the key XOR operation, the method further includes:

[0072] The XOR result of the key, the IDs of the two quantum links, and the key used for the XOR operation are uploaded to the QKDN controller at their respective temporary key pool locations.

[0073] As a further preferred technical solution, after performing the key XOR operation, the method further includes:

[0074] Save the keys used in the XOR operation and discard all unused keys.

[0075] In addition, such as Figure 3 As shown, another embodiment of the present invention also proposes a relay node, wherein the number of quantum links connected to the relay node is N, and the relay node includes:

[0076] The key pool establishment module 10 is used to establish a temporary key pool corresponding to the number of quantum links. The temporary key pool is used to store the keys generated in the current key upload cycle of the corresponding quantum link.

[0077] The weight calculation module 20 is configured to, when N>2, add the weights of the connected quantum links two by two each time the key uploading period arrives, obtain a weight addition result and perform sorting, and the weight of the quantum link is the key usage rate of the quantum link / node usage rate multiplied by the key generation efficiency of the quantum link.

[0078] The key XOR module 30 is configured to select keys from the temporary key pools corresponding to the two quantum links with the highest weight addition result respectively for XOR operation, and select keys from the temporary key pools corresponding to any two quantum links with non-highest weight addition result respectively for XOR operation.

[0079] As a further preferred technical solution, the node usage rate is the number of times that the key of the node is used within a set time, and the link key usage rate is the number of times that the key generated on a quantum link is used within a set time; for any relay node, V Node =∑V Link , V Node is the node usage rate, and V Link is the link key usage rate.

[0080] The key generation efficiency is the ratio of the average key generation rate of each quantum link to the preset key generation reference rate.

[0081] As a further preferred technical solution, the key XOR module 30 is further configured to, when N=2, select keys from the temporary key pools corresponding to the two quantum links respectively for XOR operation according to the minimum capacity in the temporary key pools corresponding to the two quantum links each time the key uploading period arrives.

[0082] As a further preferred technical solution, the relay node further comprises an XOR result uploading module configured to upload the key XOR result, the IDs of the two quantum links, and the positions of the keys in the respective temporary key pools to the QKDN controller.

[0083] In addition, an embodiment of the application further provides a centralized quantum key relay network system, which comprises a QKDN controller and network nodes, and the network nodes comprise user nodes and relay nodes, wherein:

[0084] The relay nodes upload the quantum keys generated by different quantum links after XOR operation to the QKDN controller according to the method in the above embodiment;

[0085] The QKDN controller receives the key request sent by the network nodes, and issues an XOR key to a service target node based on the key request.

[0086] Further, the system as described above can be implemented in the form of a computer program which can run on a computer device as shown in Figure 4 Figure 4 is a structural schematic block diagram of a computer device provided by an embodiment of the present application. The computer device can be a server.

[0087] The computer device comprises a processor, a memory and a network interface connected through a system bus, wherein the memory can comprise a non-volatile storage medium and an internal memory.

[0088] The non-volatile storage medium can store an operating system and a computer program. The computer program comprises program instructions which, when executed, can cause the processor to perform any one of the key dynamic XOR methods of the centralized quantum key relay network.

[0089] The processor is configured to provide computing and control capabilities to support the operation of the entire computer device.

[0090] The internal memory provides an environment for the execution of the computer program in the non-volatile storage medium, which, when executed by the processor, can cause the processor to perform any one of the key dynamic XOR methods of the centralized quantum key relay network.

[0091] The network interface is configured to perform network communication, such as sending assigned tasks, etc. Those skilled in the art can understand that, Figure 4 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can comprise more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0092] Further, the present embodiment also proposes a computer readable storage medium, which stores a computer program, and the computer program comprises program instructions. The processor executes the program instructions to implement the key dynamic XOR method of the centralized quantum key relay network provided by the above-mentioned embodiments of the present application.

[0093] ​It is to be appreciated that the above description and the examples that follow are intended to be illustrative only and that changes can be made to the description and examples without departing from the scope of the application. Note also that the use of particular brand names in the description is solely for illustration and should not be construed as an endorsement of such brands.

[0094] It should be understood that aspects of the application can be implemented in hardware, software, firmware or a combination thereof. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following technologies, known in the art, can be used: a hybrid of the technologies mentioned above, discrete logic circuitry having logic gates for implementing logic functions upon data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and so forth.

[0095] In the description of the present application, reference has been made to the use of terms such as "one embodiment", "some embodiments", "an example", "a specific example" or "some examples" means that a particular feature, structure, material or characteristic is included in at least one embodiment or example of the present application. The illustrative examples given are not necessarily to be construed as preferred or advantageous or with the exclusion of other equally valid examples that can be particularly adapted to a given application. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and operation described. Accordingly, appropriate changes are intended to be incorporated within the scope of the present application.

[0096] Furthermore, the terms "first", "second", etc. are used only for descriptive purposes and do not connote or imply relative importance or a quantity of the indicated technical features. Thus, a feature defined with "first", "second", etc. can include at least one of the features implicitly or explicitly. In the description of the present application, the meaning of "a plurality" is at least two, for example, two, three, etc., unless otherwise specifically defined.

[0097] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and that changes, modifications, substitutions and variations can be made by those skilled in the art without departing from the scope of the present application.

Claims

1. A key dynamic XOR method for centralized quantum key relay networks, characterized in that, Applied to relay nodes, wherein the number of quantum links connected to the relay node is N, the method includes: Establish a temporary key pool corresponding to the number of quantum links, the temporary key pool being used to store the keys generated within the current key upload cycle of the corresponding quantum link; When N>2, each time the key upload cycle is reached, the weights of the connected quantum links are added pairwise, and the weights are sorted. The weight of a quantum link is the key utilization rate of the quantum link / node utilization rate × key generation efficiency of the quantum link. Select keys from the temporary key pools corresponding to the two quantum links with the highest weight sum and XOR them respectively; In quantum links where the weight summation result is not the highest, perform pairwise traversal, and select keys from the temporary key pools corresponding to the two quantum links of different combinations for XOR operation. The number of selected keys is the first key quantity P × (W). A +W B ) / W max P represents the maximum XOR value within this period, selected from the temporary key pools corresponding to the two quantum links with the highest weight summation. A and W B W represents the weights of the two quantum links whose sum of weights is not the highest. max It is the sum of the weights of the two links with the highest weights in this period.

2. The key dynamic XOR method for centralized quantum key relay networks as described in claim 1, characterized in that, The node usage rate is the number of times the node's key has been used within a set time period, and the link key usage rate is the number of times the key generated on a certain quantum link has been used within a set time period. For any relay node, V satisfies Node =∑V Link V Node V represents node utilization. Link This refers to the link key utilization rate.

3. The key dynamic XOR method for centralized quantum key relay networks as described in claim 1, characterized in that, The key generation efficiency is the ratio of the average key generation rate of each quantum link to a preset key generation baseline rate.

4. The key dynamic XOR method for centralized quantum key relay networks as described in claim 1, characterized in that, The step of selecting keys from the temporary key pools corresponding to the two quantum links with the highest weight summation results and performing XOR operations includes: The minimum capacity of the temporary key pool corresponding to the two quantum links with the highest weight sum is taken as the maximum XOR value in this period. Keys of the same length are selected from the two temporary key pools according to the maximum XOR value in this period and XORed.

5. The key dynamic XOR method for centralized quantum key relay networks as described in claim 1, characterized in that, The step of selecting keys from the temporary key pools corresponding to any two quantum links whose weight addition result is not the highest and performing XOR operations includes: Determine whether the minimum capacity of the temporary key pool corresponding to any two randomly selected quantum links is greater than the first key quantity; If so, then select keys from the temporary key pools corresponding to the two randomly selected quantum links according to this minimum capacity and perform XOR operations on them; If not, then select keys from the temporary key pools corresponding to the two randomly selected quantum links according to the first key quantity and perform XOR operations on them.

6. The key dynamic XOR method for centralized quantum key relay networks as described in claim 1, characterized in that, When N=2, each time the key upload cycle is reached, the keys are selected from the temporary key pools corresponding to the two quantum links according to the minimum capacity of the temporary key pools corresponding to the two quantum links and XORed.

7. The key dynamic XOR method for centralized quantum key relay networks as described in claim 1 or 6, characterized in that, After performing the key XOR operation, the method further includes: The XOR result of the key, the IDs of the two quantum links, and the key used for the XOR operation are uploaded to the QKDN controller at their respective temporary key pool locations.

8. The key dynamic XOR method for centralized quantum key relay networks as described in claim 1, characterized in that, After performing the key XOR operation, the method further includes: Save the keys used in the XOR operation and discard all unused keys.

9. A relay node, characterized in that, The relay node is connected to N quantum links, and the relay node includes: The key pool establishment module is used to establish a temporary key pool corresponding to the number of quantum links. The temporary key pool is used to store the keys generated within the current key upload cycle of the corresponding quantum link. The weight calculation module is used to sum the weights of the connected quantum links pairwise each time the key upload cycle is reached when N>2, obtain the weight sum result and sort it. The weight of the quantum link is the key utilization rate of the quantum link / node utilization rate × key generation efficiency of the quantum link. The key XOR module is used to select keys from the temporary key pools corresponding to the two quantum links with the highest weight sum and XOR them; and to perform pairwise traversal on quantum links with non-highest weight sums, selecting keys from the temporary key pools corresponding to the two quantum links with different combinations and XORing them, with the number of selected keys being the first key quantity P × (W). A +W B ) / W max P represents the maximum XOR value within this period, selected from the temporary key pools corresponding to the two quantum links with the highest weight summation. A and W B W represents the weights of the two quantum links whose sum of weights is not the highest. max It is the sum of the weights of the two links with the highest weights in this period.

10. A centralized quantum key relay network system, characterized in that, The system includes a QKDN controller and network nodes, wherein the network nodes include user nodes and relay nodes, wherein: The relay node XORs the quantum keys generated by different quantum links and uploads them to the QKDN controller according to the method described in any one of claims 1-9; The QKDN controller receives the key request sent by the network node and issues an XOR key to the target service node based on the key request.

11. A computer device, characterized in that, The device includes a memory and a processor; wherein the processor runs a program corresponding to the executable program code by reading executable program code stored in the memory, so as to implement the method as described in any one of claims 1-8.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-8.

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