Centralized quantum key relay network and key storage method thereof

Abstract

The invention provides a centralized quantum key relay network and a key storage method thereof, and the method comprises the steps: carrying out the pairwise XOR of related quantum keys at the same generation time through a relay node, so as to obtain an XOR key, and transmitting the first feature information of the XOR key to a controller; the relay node stores the feature information of the related quantum key corresponding to the XOR key, the controller sends a key use notice to the relay node on a relay path after completing the issuing of the shared key, and the used part in the XOR key used in the issuing process of the shared key is deleted; and after receiving the key use notification, the relay node deletes the used part in the corresponding quantum key according to the second feature information of the XOR key, so that the chaos caused by repeated use of the key is avoided, and the accuracy and effectiveness of the key system are ensured.

Description

Technical Field

[0001] The present invention relates to the field of quantum communication, and in particular to a centralized quantum key relay network and a key storage method thereof. Background Art

[0002] Quantum cryptography technology is based on the quantum key distribution (QKD) protocol and has achieved rapid development in recent years. Unlike traditional cryptography, quantum cryptography is based on quantum mechanics and uses quantum physics properties such as Heisenberg's uncertainty principle and the no-cloning theorem to achieve secure long-distance negotiation of symmetric keys.

[0003] Multiple quantum key distribution nodes can form a quantum key distribution network (QKDN for short). Due to the limited distance between adjacent nodes, quantum key relay distribution is required in long-distance key generation scenarios, and centralized quantum key relay networks came into being.

[0004] In a centralized quantum key relay network, the QKDN controller manages the XOR keys reported by all relay nodes. As the network runs and is used, the amount of XOR keys stored in the QKDN controller will inevitably increase and become difficult to manage. In addition, a large number of random key requests may lead to uneven consumption of keys, and the XOR keys uploaded on certain links may gradually become fragmented and unusable. Therefore, how to implement key management in a centralized quantum key relay network has become a difficult problem that technicians in this field are concerned about. Summary of the invention

[0005] The object of the present invention is to provide a centralized quantum key relay network and a key storage method thereof to improve the above-mentioned problems.

[0006] In order to achieve the above purpose, the technical solution adopted by the embodiment of the present invention is as follows:

[0007] In a first aspect, an embodiment of the present invention provides a centralized quantum key relay network, the centralized quantum key relay network comprising: a controller and a plurality of quantum key distribution nodes, the plurality of quantum key distribution nodes comprising at least one relay node, the relay node being a quantum key distribution node connected to at least two quantum links;

[0008] The relay node is used to perform XOR on related quantum keys with the same generation time in pairs to obtain an XOR key, and transmit the first characteristic information of the XOR key to the controller;

[0009] The relevant quantum key is a quantum key generated by a quantum link connected to the relay node, and the first characteristic information of the XOR key includes the XOR key, the identifier of the relay node, the identifier of the node on the quantum link related to the XOR key, and the generation time of the XOR key;

[0010] The relay node is used to store characteristic information of a related quantum key corresponding to the XOR key, where the characteristic information of the related quantum key includes the related quantum key, a peer node identifier corresponding to the related quantum key, and a generation time of the related quantum key;

[0011] The controller is used to send a key use notification to the relay node on the relay path after completing the shared key issuance, and delete the used part of the XOR key used in the process of issuing the shared key;

[0012] The key usage notification includes the second characteristic information of the XOR key used in the process of issuing the shared key, and the second characteristic information of the XOR key includes the identifier of the relay node corresponding to the XOR key, the identifier of the node on the quantum link related to the XOR key, the generation time of the XOR key, and the usage length of the XOR key;

[0013] The relay node is used to delete the used part of the corresponding quantum key according to the second characteristic information of the XOR key after receiving the key use notification.

[0014] In a second aspect, an embodiment of the present invention provides a key storage method for a centralized quantum key relay network, wherein the centralized quantum key relay network includes: a controller and a plurality of quantum key distribution nodes, wherein the plurality of quantum key distribution nodes include at least one relay node, wherein the relay node is a quantum key distribution node connected to at least two quantum links, and the method includes:

[0015] The relay node performs XOR on related quantum keys with the same generation time in pairs to obtain an XOR key, and transmits first characteristic information of the XOR key to the controller;

[0016] The relevant quantum key is a quantum key generated by a quantum link connected to the relay node, and the first characteristic information of the XOR key includes the XOR key, the identifier of the relay node, the identifier of the node on the quantum link related to the XOR key, and the generation time of the XOR key;

[0017] The relay node stores characteristic information of a related quantum key corresponding to the XOR key, where the characteristic information of the related quantum key includes the related quantum key, a peer node identifier corresponding to the related quantum key, and a generation time of the related quantum key;

[0018] After completing the sending of the shared key, the controller sends a key use notification to the relay node on the relay path, and deletes the used part of the XOR key used in the process of sending the shared key;

[0019] The key usage notification includes the second characteristic information of the XOR key used in the process of issuing the shared key, and the second characteristic information of the XOR key includes the identifier of the relay node corresponding to the XOR key, the identifier of the node on the quantum link related to the XOR key, the generation time of the XOR key, and the usage length of the XOR key;

[0020] After receiving the key use notification, the relay node deletes the used part of the corresponding quantum key according to the second characteristic information of the XOR key.

[0021] Compared with the prior art, the embodiment of the present invention provides a centralized quantum key relay network and a key storage method thereof. The relay node performs XOR on the related quantum keys of the same generation time to obtain the XOR key, and transmits the first characteristic information of the XOR key to the controller; the relay node stores the characteristic information of the related quantum key corresponding to the XOR key. After completing the issuance of the shared key, the controller sends a key use notification to the relay node on the relay path, and deletes the used part of the XOR key used in the process of issuing the shared key; after receiving the key use notification, the relay node deletes the used part of the corresponding quantum key according to the second characteristic information of the XOR key. The controller deletes the used part of the XOR key used in the process of issuing the shared key, and the relay node deletes the used part of the corresponding quantum key according to the second characteristic information of the XOR key, thereby avoiding the confusion caused by repeated use of the key and ensuring the accuracy and effectiveness of the key system.

[0022] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A schematic diagram of the architecture of a centralized quantum key relay network provided for an embodiment of the present invention.

[0025] Figure 2 One of the flow charts of the key storage method for a centralized quantum key relay network provided in an embodiment of the present invention.

[0026] Figure 3 The second flowchart of the key storage method for a centralized quantum key relay network provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0030] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0031] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0032] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0034] Please refer to Figure 1 , Figure 1 A schematic diagram of the architecture of a centralized quantum key relay network provided by an embodiment of the present invention. The centralized quantum key relay network includes: a controller (also called QKDNC) and multiple quantum key distribution nodes.

[0035] Among them, the quantum key distribution node is deployed with QKD equipment for quantum key distribution and KM equipment for managing the keys of the QKD equipment. All quantum key distribution nodes are connected to the controller to form a full network connection topology. The controller is used to control and manage the centralized quantum key relay network to achieve routing control and resource scheduling of each node and link. The controller maintains time synchronization with each quantum key distribution node.

[0036] It should be noted that Figure 1 8 quantum key distribution nodes are shown in FIG. 1 , but this is not a limitation. The number of quantum key distribution nodes can be greater or less than 8. All quantum key distribution nodes are connected to the controller in communication. Figure 1 Some connections are omitted to make the presentation clearer.

[0037] The multiple quantum key distribution nodes include at least one relay node, and the relay node is a quantum key distribution node connected to at least two quantum links.

[0038] Please refer to Figure 1 , wherein quantum key distribution node 2, quantum key distribution node 3, quantum key distribution node 4, quantum key distribution node 6 and quantum key distribution node 7 are all relay nodes. Taking quantum key distribution node 2 as an example, the quantum links connected to it include the link of quantum key distribution node 1-quantum key distribution node 2, the link of quantum key distribution node 2-quantum key distribution node 3 and the link of quantum key distribution node 2-quantum key distribution node 6.

[0039] It should be noted that the multiple quantum key distribution nodes also include user nodes, which are quantum key distribution nodes connected to the business system. The user nodes can receive communication requirements transmitted by the business system and send keys to the business system.

[0040] Figure 1 Ki(K1-K8) in represents the quantum key generated by the ith quantum link at a certain moment. The above describes the architecture of the centralized quantum key relay network in the embodiment of the present invention. The following further describes how to implement key storage in the centralized quantum key relay network. Please refer to the following.

[0041] The relay node is used to perform XOR operation on related quantum keys with the same generation time in pairs to obtain an XOR key, and transmit the first characteristic information of the XOR key to the controller.

[0042] The relevant quantum key is a quantum key generated by a quantum link connected to a relay node, and the first characteristic information of the XOR key includes the XOR key, an identifier of the relay node, an identifier of a node on the quantum link related to the XOR key, and a generation time of the XOR key. The controller is used to store the XOR key in combination with the first characteristic information of the XOR key.

[0043] It should be noted that once a quantum link is formed, it will continuously generate quantum keys. Figure 1 Taking the relay node (quantum key distribution node 2) shown as an example, at a certain moment, the relevant quantum keys corresponding to quantum key distribution node 2 are quantum key K1, quantum key K2 and quantum key K3, and the XOR keys obtained after pairwise XOR include K1⊕K2, K1⊕K3 and K2⊕K3. The generation time of the XOR key is the same as the generation time of the relevant quantum key, and the identifier of the quantum key distribution node can be but is not limited to the node ID.

[0044] Among them, the relay nodes corresponding to the XOR keys K1⊕K2, K1⊕K3 and K2⊕K3 are all quantum key distribution nodes 2. The generation time corresponding to the XOR keys K1⊕K2, K1⊕K3 and K2⊕K3 is the generation time of the quantum keys K1, K2 and K3. The nodes on the quantum link related to the XOR key K1⊕K2 are quantum key distribution nodes 1 and quantum key distribution nodes 6, the nodes on the quantum link related to the XOR key K1⊕K3 are quantum key distribution nodes 1 and quantum key distribution nodes 3, and the nodes on the quantum link related to the XOR key K2⊕K3 are quantum key distribution nodes 6 and quantum key distribution nodes 3.

[0045] The relay node is used to store characteristic information of the relevant quantum key corresponding to the XOR key, and the characteristic information of the relevant quantum key includes the relevant quantum key, the opposite node identifier corresponding to the relevant quantum key, and the generation time of the relevant quantum key.

[0046] Continue with Figure 1 Taking the relay node (quantum key distribution node 2) shown as an example, the relevant quantum keys corresponding to quantum key distribution node 2 are quantum key K1, quantum key K2 and quantum key K3. Among them, the opposite node corresponding to quantum key K1 is quantum key distribution node 1, the opposite node corresponding to quantum key K2 is quantum key distribution node 6, and the opposite node corresponding to quantum key K3 is quantum key distribution node 3.

[0047] It should be noted that when a relay node connects to a business system as a user node and needs to issue a shared key, it may need to use the quantum key it stores, so it needs to be stored.

[0048] The controller is used to send a key use notification to the relay node on the relay path after completing the shared key distribution, and delete the used part of the XOR key used in the process of sharing the key distribution.

[0049] The key usage notification includes the second characteristic information of the XOR key used in the process of issuing the shared key, and the second characteristic information of the XOR key includes the identifier of the relay node corresponding to the XOR key, the identifier of the node on the quantum link related to the XOR key, the generation time of the XOR key, and the usage length of the XOR key. The relay path is a path composed of relay nodes corresponding to the XOR key used in the process of issuing the shared key.

[0050] The relay node is used to delete the used part of the corresponding quantum key according to the second characteristic information of the XOR key after receiving the notification that the key has been used.

[0051] In the centralized quantum key relay network provided by the embodiment of the present invention, the controller deletes the used part of the XOR key used in the process of issuing the shared key, and the relay node deletes the used part of the corresponding quantum key according to the second characteristic information of the XOR key, thereby avoiding confusion caused by repeated use of the key and ensuring the accuracy and effectiveness of the key system.

[0052] Based on the foregoing, regarding how a relay node deletes the used portion of a corresponding quantum key, the embodiment of the present invention also provides an optional implementation, please refer to the following.

[0053] The relay node is used to determine the quantum key to be adjusted according to the identifier of the relay node corresponding to the XOR key in the second characteristic information of the XOR key, the identifier of the node on the quantum link related to the XOR key, and the generation time of the XOR key after receiving the notification that the key has been used.

[0054] The relay node is used to delete the content related to the used part of the XOR key in the quantum key to be adjusted according to the usage length of the XOR key in the second characteristic information of the XOR key.

[0055] In some optional scenarios, the key may not be sent through the controller. In this scenario, the embodiment of the present invention also provides an optional implementation method, please refer to the following.

[0056] When two adjacent quantum key distribution nodes distribute the quantum key corresponding to the quantum link between them to the corresponding business system, if there is a relay node between the two adjacent quantum key distribution nodes.

[0057] Please continue to refer to Figure 1, assuming that quantum key distribution node 2 is also connected to a business system. When the business system connected to quantum key distribution node 1 and the business system connected to quantum key distribution node 2 have communication needs, quantum key distribution node 1 directly sends a part of the quantum key K1 generated at a certain moment to the corresponding business system, and quantum key distribution node 2 directly sends the same part of the quantum key K1 generated at the same moment to the corresponding business system, so that the two business systems can interact based on the quantum key. This process does not go through the controller.

[0058] The relay node is used to report the key usage to the controller. The key usage includes the relay node identifier, the peer node identifier corresponding to the quantum key, the generation time of the quantum key, and the usage length of the quantum key.

[0059] The controller is used to determine the XOR key to be adjusted according to the identifier of the relay node, the identifier of the opposite node corresponding to the quantum key, and the generation time of the quantum key after receiving the key usage status.

[0060] It should be noted that there may be multiple XOR keys to be adjusted, such as XOR key K1⊕K2 and XOR key K1⊕K3.

[0061] The controller is used to delete the content related to the used part of the quantum key in the XOR key to be adjusted according to the usage length of the quantum key.

[0062] Relay nodes are also used to delete the used part of the quantum key.

[0063] On the basis of the foregoing, regarding the process of issuing a remote shared key through a controller, the embodiment of the present invention further provides an optional implementation method, please refer to the following.

[0064] The demand initiating node sends a key distribution request to the controller, and the key distribution request includes the identifier of the demand destination node.

[0065] In an optional implementation, the key distribution request also includes an XOR key of a quantum key and a quantum random number between the demand initiating node and the next node in the relay path, wherein the quantum random number is generated by the demand initiating node and is the same as the number of the demand key.

[0066] The controller determines the relay path according to the identifier of the demand initiating node and the identifier of the demand destination node, performs layer-by-layer XOR processing according to the XOR keys between adjacent quantum links on the relay path to obtain the target XOR key, and sends the target XOR key to the demand destination node. The demand destination node is used to perform XOR processing according to the target XOR key and the quantum key of the last quantum link in the relay path to obtain the shared key and complete the distribution of the shared key.

[0067] Optionally, the controller also sends the second characteristic information of the last XOR object in the target XOR key calculation process to the required destination node.

[0068] Among them, adjacent quantum links are two quantum links that share a relay node, the target XOR key is the XOR key between the shared key and the quantum key of the last quantum link in the relay path, and the last quantum link in the relay path is the quantum link between the required destination node and the last relay node in the relay path.

[0069] Please continue to refer to Figure 1 , take the demand initiating node as quantum key distribution node 1 and the demand destination node as quantum key distribution node 5 as an example. The corresponding relay paths are path 1 and path 2. Among them, path 1 is: quantum key distribution node 1-quantum key distribution node 2-quantum key distribution node 3-quantum key distribution node 4-quantum key distribution node 5; path 2 is: quantum key distribution node 1-quantum key distribution node 2-quantum key distribution node 6-quantum key distribution node 7-quantum key distribution node 4-quantum key distribution node 5.

[0070] When the key distribution request also includes the XOR key of the quantum key and the quantum random number between the initiating node and the next node in the relay path. The controller can perform layer-by-layer XOR on the key distribution request and the XOR keys between adjacent quantum links on the relay path to obtain the target XOR key. Taking path 1 as an example, assuming that the quantum random number is Kx, the key distribution request includes the XOR key Kx⊕K1. The XOR keys between adjacent quantum links on the relay path include: XOR key K1⊕K3, XOR key K3⊕K5, and XOR key K5⊕K8. After layer-by-layer XOR, the target XOR key Kx⊕K8 is obtained. Among them, the XOR key K5⊕K8 is the last XOR object in the target XOR key calculation process.

[0071] The second characteristic information of the last XOR key K5⊕K8 in the target XOR key calculation process (the identifier of the relay node corresponding to the XOR key, the identifier of the node on the quantum link related to the XOR key, the generation time of the XOR key, and the usage length of the XOR key) is sent to the required destination node. The required destination node can determine the corresponding quantum key K8, and then perform XOR here to obtain the quantum random number Kx as the shared key.

[0072] In the case where the demand initiating node does not generate a quantum random number, the controller can perform layer-by-layer XOR according to the XOR keys between adjacent quantum links on the relay path to obtain the target XOR key. Continuing with path 1 as an example, in this case, the target XOR key K1⊕K8 is obtained, and the final shared key is the quantum key K1.

[0073] It should be noted that the demand initiating node and the demand destination node will send the corresponding shared key to the corresponding business system to achieve encryption.

[0074] Based on the foregoing, in order to avoid key timeout and to prevent a large number of keys from being stored in relay nodes for too long, the embodiment of the present invention further provides an optional implementation, please refer to the following.

[0075] The relay node is also used to check whether the time difference between the generation time of the quantum key stored in it and the current time exceeds the first validity period.

[0076] If the first validity period is exceeded, the relay node is used to delete the expired quantum key and report a key expiration notification to the controller, where the key expiration notification includes an identifier of the relay node, an identifier of a peer node corresponding to the expired quantum key, and a generation time of the expired quantum key;

[0077] The controller is used to mark the XOR key corresponding to the expired quantum key as a non-dispatched state after receiving a key expiration notification. The non-dispatched state indicates that the corresponding XOR key is only used for calculations in the shared key distribution and cannot be used as the last XOR object in the target XOR key calculation process.

[0078] In an optional implementation, the controller is used to check whether the time difference between the generation time of the XOR key stored therein and the current time exceeds a second validity period.

[0079] If the second validity period is exceeded, the controller is used to delete the expired XOR key.

[0080] The second validity period is greater than or equal to the first validity period.

[0081] In an optional implementation, the relay node is further configured to, when the total data volume of the quantum keys stored in the relay node exceeds a second threshold, clear some quantum keys in order of generation time of the quantum keys so that the total data volume of the quantum keys stored in the relay node is less than the first threshold.

[0082] The second threshold is greater than or equal to the first threshold, and the second threshold can solve the capacity of the key storage space set in the relay node. Clearing part of the quantum key can be overwriting and clearing. The quantum keys are sorted according to the generation time, from the front to the back, and cleared in sequence.

[0083] Optionally, the relay node is also used to upload a key clearing notification to the controller when clearing part of the quantum key, and the key clearing notification includes the identifier of the relay node, the identifier of the opposite node corresponding to the cleared quantum key, and the generation time of the cleared quantum key.

[0084] After receiving the key clearing notification, the controller marks the XOR key corresponding to the cleared quantum key as a non-dispatching state. The non-dispatching state means that the corresponding XOR key is only used for calculations in the shared key distribution and cannot be used as the last XOR object in the target XOR key calculation process.

[0085] In the centralized quantum key relay network provided by the embodiment of the present invention, the XOR key / quantum key stored in the controller and the relay node is stored and managed, and the keys that have been consumed or timed out are cleared in time to avoid repeated use. At the same time, the controller and the relay node have different keys and different usage modes, and the keys are fully utilized as much as possible while the controller and the relay node perform key synchronization operations to avoid key waste, providing a guidance scheme for key storage in a quantum network with centralized control and key relay architecture.

[0086] The embodiment of the present invention also provides a key storage method for a centralized quantum key relay network, which is applied to the above-mentioned centralized quantum key relay network. Figure 2 , Figure 2 One of the flow diagrams of the key storage method of the centralized quantum key relay network provided by the embodiment of the present invention. The key storage method of the centralized quantum key relay network includes: S11, S12, S13 and S14, which are specifically described as follows.

[0087] S11, the relay node performs XOR on related quantum keys with the same generation time in pairs to obtain an XOR key, and transmits the first characteristic information of the XOR key to the controller.

[0088] Among them, the relevant quantum key is a quantum key generated by a quantum link connected to a relay node, and the first characteristic information of the XOR key includes the XOR key, the identifier of the relay node, the identifier of the node on the quantum link related to the XOR key, and the generation time of the XOR key.

[0089] S12, the relay node stores the characteristic information of the relevant quantum key corresponding to the XOR key.

[0090] Among them, the characteristic information of the relevant quantum key includes the relevant quantum key, the counterpart node identifier corresponding to the relevant quantum key, and the generation time of the relevant quantum key.

[0091] S13, after completing the sending of the shared key, the controller sends a key used notification to the relay node on the relay path, and deletes the used part of the XOR key used in the process of sending the shared key.

[0092] Among them, the key use notification includes the second characteristic information of the XOR key used in the process of issuing the shared key, and the second characteristic information of the XOR key includes the identifier of the relay node corresponding to the XOR key, the identifier of the node on the quantum link related to the XOR key, the generation time of the XOR key and the usage length of the XOR key.

[0093] S14, after receiving the notification that the key has been used, the relay node deletes the used part of the corresponding quantum key according to the second characteristic information of the XOR key.

[0094] Please refer to Figure 3 , Figure 3 The second flow diagram of the key storage method of the centralized quantum key relay network provided by the embodiment of the present invention. When two adjacent quantum key distribution nodes distribute the quantum key corresponding to the quantum link between the two to the corresponding business system, if there is a relay node between the two adjacent quantum key distribution nodes, the key storage method of the centralized quantum key relay network also includes: S21, S22, S23 and S24, which are specifically described as follows.

[0095] S21, the relay node reports the key usage to the controller.

[0096] Among them, the key usage includes the identifier of the relay node, the identifier of the peer node corresponding to the quantum key, the generation time of the quantum key, and the usage length of the quantum key.

[0097] S22, after receiving the key usage status, the controller determines the XOR key to be adjusted according to the identifier of the relay node, the identifier of the opposite node corresponding to the quantum key, and the generation time of the quantum key.

[0098] S23, the controller deletes the content related to the used part of the quantum key in the XOR key to be adjusted according to the usage length of the quantum key.

[0099] S24, the relay node deletes the used part of the quantum key.

[0100] It should be noted that the key storage method of the centralized quantum key relay network provided in this embodiment can perform the functional purposes shown in the above-mentioned centralized quantum key relay network embodiment to achieve the corresponding technical effects. For the sake of brief description, for the parts not mentioned in this embodiment, please refer to the corresponding contents in the above-mentioned embodiment.

[0101] In summary, the embodiment of the present invention provides a centralized quantum key relay network and a key storage method thereof. The relay node performs XOR on the related quantum keys of the same generation time to obtain the XOR key, and transmits the first characteristic information of the XOR key to the controller; the relay node stores the characteristic information of the related quantum key corresponding to the XOR key. After completing the issuance of the shared key, the controller sends a key use notification to the relay node on the relay path, and deletes the used part of the XOR key used in the process of issuing the shared key; after receiving the key use notification, the relay node deletes the used part of the corresponding quantum key according to the second characteristic information of the XOR key. The controller deletes the used part of the XOR key used in the process of issuing the shared key, and the relay node deletes the used part of the corresponding quantum key according to the second characteristic information of the XOR key, thereby avoiding the confusion caused by repeated use of the key and ensuring the accuracy and effectiveness of the key system.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0103] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A centralized quantum key relay network, characterized in that: The centralized quantum key relay network includes: a controller and a plurality of quantum key distribution nodes, wherein the plurality of quantum key distribution nodes include at least one relay node, and the relay node is a quantum key distribution node connected to at least two quantum links; The relay node is used to perform XOR on related quantum keys with the same generation time in pairs to obtain an XOR key, and transmit the first characteristic information of the XOR key to the controller; The relevant quantum key is a quantum key generated by a quantum link connected to the relay node, and the first characteristic information of the XOR key includes the XOR key, the identifier of the relay node, the identifier of the node on the quantum link related to the XOR key, and the generation time of the XOR key; The relay node is used to store characteristic information of a related quantum key corresponding to the XOR key, where the characteristic information of the related quantum key includes the related quantum key, a peer node identifier corresponding to the related quantum key, and a generation time of the related quantum key; The controller is used to send a key use notification to the relay node on the relay path after completing the shared key issuance, and delete the used part of the XOR key used in the process of issuing the shared key; The key usage notification includes the second characteristic information of the XOR key used in the process of issuing the shared key, and the second characteristic information of the XOR key includes the identifier of the relay node corresponding to the XOR key, the identifier of the node on the quantum link related to the XOR key, the generation time of the XOR key, and the usage length of the XOR key; The relay node is used to delete the used part of the corresponding quantum key according to the second characteristic information of the XOR key after receiving the key use notification.

2. The centralized quantum key relay network according to claim 1, characterized in that: The relay node is used to determine the quantum key to be adjusted according to the identifier of the relay node corresponding to the XOR key in the second characteristic information of the XOR key, the identifier of the node on the quantum link related to the XOR key, and the generation time of the XOR key after receiving the notification that the key has been used; The relay node is used to delete the content related to the used part of the XOR key in the quantum key to be adjusted according to the usage length of the XOR key in the second characteristic information of the XOR key.

3. The centralized quantum key relay network according to claim 1, characterized in that: When two adjacent quantum key distribution nodes distribute the quantum key corresponding to the quantum link between them to the corresponding business system, if there is a relay node between the two adjacent quantum key distribution nodes; The relay node is used to report key usage to the controller, where the key usage includes an identifier of the relay node, an identifier of a peer node corresponding to the quantum key, a generation time of the quantum key, and a usage length of the quantum key; The controller is used to determine the XOR key to be adjusted according to the identifier of the relay node, the identifier of the opposite node corresponding to the quantum key, and the generation time of the quantum key after receiving the key usage situation; The controller is used to delete the content related to the used part of the quantum key in the XOR key to be adjusted according to the usage length of the quantum key; The relay node is also used to delete the used part of the quantum key.

4. The centralized quantum key relay network according to claim 1, characterized in that: The process of issuing the shared key includes: The demand initiating node sends a key distribution request to the controller, wherein the key distribution request includes an identifier of the demand destination node; The controller determines the relay path according to the identifier of the demand initiating node and the identifier of the demand destination node, performs layer-by-layer XOR according to the XOR keys between adjacent quantum links on the relay path to obtain a target XOR key, and sends the target XOR key to the demand destination node. The demand destination node is used to perform XOR processing according to the target XOR key and the quantum key of the last quantum link in the relay path to obtain the shared key, and complete the distribution of the shared key; Among them, adjacent quantum links are two quantum links that share a relay node, the target XOR key is the XOR key between the shared key and the quantum key of the last quantum link in the relay path, and the last quantum link in the relay path is the quantum link between the required destination node and the last relay node in the relay path.

5. The centralized quantum key relay network according to claim 4, characterized in that: The relay node is also used to check whether the time difference between the generation time of the quantum key stored in it and the current time exceeds the first validity period; If the first validity period is exceeded, the relay node is used to delete the expired quantum key and report a key expiration notification to the controller, where the key expiration notification includes an identifier of the relay node, an identifier of a peer node corresponding to the expired quantum key, and a generation time of the expired quantum key; The controller is used to mark the XOR key corresponding to the expired quantum key as a non-dispatching state after receiving the key expiration notification, wherein the non-dispatching state indicates that the corresponding XOR key is only used for calculation in the distribution of the shared key and cannot be used as the last XOR object in the calculation process of the target XOR key.

6. The centralized quantum key relay network according to claim 5, characterized in that: The controller is used to check whether the time difference between the generation time of the XOR key stored therein and the current time exceeds the second validity period; If the second validity period is exceeded, the controller is used to delete the expired XOR key; The second validity period is greater than or equal to the first validity period.

7. The centralized quantum key relay network according to claim 1, characterized in that: The relay node is also used to, when the total data volume of the quantum keys stored in the relay node exceeds a second threshold, sort the quantum keys according to the generation time of the quantum keys and clear some of the quantum keys so that the total data volume of the quantum keys stored in the relay node is less than the first threshold.

8. The centralized quantum key relay network according to claim 7, characterized in that: The relay node is further used to upload a key clearing notification to the controller when clearing part of the quantum key, wherein the key clearing notification includes an identifier of the relay node, an identifier of a peer node corresponding to the cleared quantum key, and a generation time of the cleared quantum key; After receiving the key clearing notification, the controller marks the XOR key corresponding to the cleared quantum key as a non-dispatching state, wherein the non-dispatching state indicates that the corresponding XOR key is only used for calculation in the shared key distribution and cannot be used as the last XOR object in the target XOR key calculation process.

9. A key storage method for a centralized quantum key relay network, characterized in that: The centralized quantum key relay network includes: a controller and a plurality of quantum key distribution nodes, the plurality of quantum key distribution nodes include at least one relay node, the relay node is a quantum key distribution node connected to at least two quantum links, and the method includes: The relay node performs XOR on related quantum keys with the same generation time in pairs to obtain an XOR key, and transmits first characteristic information of the XOR key to the controller; The relevant quantum key is a quantum key generated by a quantum link connected to the relay node, and the first characteristic information of the XOR key includes the XOR key, the identifier of the relay node, the identifier of the node on the quantum link related to the XOR key, and the generation time of the XOR key; The relay node stores characteristic information of a related quantum key corresponding to the XOR key, where the characteristic information of the related quantum key includes the related quantum key, a peer node identifier corresponding to the related quantum key, and a generation time of the related quantum key; After completing the sending of the shared key, the controller sends a key use notification to the relay node on the relay path, and deletes the used part of the XOR key used in the process of sending the shared key; The key usage notification includes the second characteristic information of the XOR key used in the process of issuing the shared key, and the second characteristic information of the XOR key includes the identifier of the relay node corresponding to the XOR key, the identifier of the node on the quantum link related to the XOR key, the generation time of the XOR key, and the usage length of the XOR key; After receiving the key use notification, the relay node deletes the used part of the corresponding quantum key according to the second characteristic information of the XOR key.

10. The key storage method of a centralized quantum key relay network according to claim 9, characterized in that: When two adjacent quantum key distribution nodes distribute the quantum key corresponding to the quantum link between the two nodes to the corresponding service system, if there is a relay node between the two adjacent quantum key distribution nodes, the method further includes: The relay node reports key usage to the controller, where the key usage includes an identifier of the relay node, an identifier of a peer node corresponding to the quantum key, a generation time of the quantum key, and a usage length of the quantum key; After receiving the key usage, the controller determines the XOR key to be adjusted according to the identifier of the relay node, the identifier of the opposite node corresponding to the quantum key, and the generation time of the quantum key; The controller deletes the content related to the used part of the quantum key in the XOR key to be adjusted according to the usage length of the quantum key; The relay node deletes the used part of the quantum key.

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