WO2019128785A1

WO2019128785A1 - Quantum key relay method

Info

Publication number: WO2019128785A1
Application number: PCT/CN2018/121874
Authority: WO
Inventors: 熊英; 陈娟
Original assignee: 成都零光量子科技有限公司
Priority date: 2017-12-29
Filing date: 2018-12-19
Publication date: 2019-07-04
Also published as: CN109995515B; CN109995515A

Abstract

Disclosed by the present invention is a quantum key relay method, which mainly solves the problems of security diffusion, concurrency conflict, low efficiency and large delay of a quantum key trusted relay process in a quantum communication network; The steps of the method of the invention comprise: pre-caching quantum keys or negotiating quantum keys in real time between adjacent quantum nodes, carrying out grouping tests, and creating key identifiers; and a quantum network management server selecting a one-way concurrent relay method or a bidirectional concurrent relay method according to a relay routing table and a current state index of related quantum nodes, and securely relaying a key from a source node to a target node. The present invention may reduce the credibility requirements for a relay node, improve the efficiency of key relaying by means of a concurrent response and an optimal relay mode, and reduce the relay delay; the method and system of the present invention may be widely applied in quantum communication networks of various topological structures and have a good application prospects.

Description

A quantum key relay method

Technical field

The present invention relates to the field of communication relay technologies in a quantum communication network, and in particular, to a quantum key relay method.

Background technique

In the quantum communication network, due to the lack of concurrent quantum communication relay technology, it is impossible to construct quantum channels between any nodes in the network and direct quantum key distribution (QKD). In order to realize quantum key sharing between any nodes in the network, quantum key distribution is required by means of key relay between two nodes that cannot directly perform quantum key distribution.

In the disclosed quantum key relay scheme, since the relayed key exists in the plaintext form at the relay quantum node, any node participating in the quantum key relay knows the relay key, so security The premise is that all quantum nodes participating in the relay must be trusted. This relay quantum node is called a trusted relay quantum node. On a quantum key relay link, the nodes at both ends of the link are respectively referred to as the source node and the target node; the nodes in the middle of the link are called trusted relay quantum nodes (or trusted relay nodes). On a quantum key relay link, including two terminal quantum nodes and at least one trusted relay quantum node, each quantum node is configured with a QKD device; a quantum channel is built between adjacent nodes, and the quantum key can be directly used. Distribute and share quantum keys. Trusted relay quantum nodes are an easy-to-implement technology that relies on trusted relay quantum nodes to easily extend the service range of quantum key distribution networks. The QKD network based on trusted relay can be well compatible with various QKD technologies. Whether it is a fiber quantum key distribution system or a free space quantum key distribution system, the phase encoding system or the polarization encoding system can be easily integrated. It is the preferred solution for building quantum networks at this stage.

However, the currently disclosed single-hop forwarding trusted relay scheme has obvious security diffusion problems and scale application bottlenecks, that is, all quantum nodes participating in trusted relay can obtain the relayed key, It facilitates the secure management of the key and the information it encrypts; the trusted relay mode adopting "single-hop forwarding" has a large delay and is inefficient; in the case of scale response, there is a bottleneck problem of concurrent collision of quantum links. For the scale quantum communication network networking, overcoming the above shortcomings is very important for the security and communication efficiency of network applications.

Summary of the invention

In view of the defects in the process of trusted relay of quantum keys in the background art, the present invention discloses a method for quantum key relay, and the present invention solves the problem of security diffusion of a relay process by a novel quantum key processing method. The method for improving the key relay efficiency by the concurrent response; the present invention provides a method for quantum key relay, which comprises the following steps: (1-1) any one of the quantum service nodes in the quantum key distribution network ( Referred to as a node or a relay node, if there is a point-to-point quantum channel connection between two nodes and quantum key distribution is possible, it is called a neighboring node; the quantum key can be cached in advance between adjacent nodes or Real-time negotiation of a quantum key) pre-caches a certain amount of quantum keys with any other quantum service node connected to a point-to-point quantum channel or negotiates a certain amount of quantum keys in real time; the quantum service node pairs The quantum key is grouped and randomized for each packet, the packets passed the randomness test are cached, and a corresponding key identifier is created;

(1-2) The quantum network management server receives the request to relay a key R from the source node to the target node, and the quantum network management server according to the stored relay routing table and the current state indicator of the associated quantum service node Obtaining the number of relay nodes that are relayed from the source node to the target node, the address of each relay node, and the current state indicator, and determining that the one-way concurrent relay is used according to the number of the relay nodes and the current state indicator a method or a bidirectional concurrent relay method for relaying a key R from a source node to a target node;

(1-3) The source node and the target node perform integrity check on the relay key R, and if it fails to pass the check, re-relay; after passing the integrity check, complete the key relay The process; the nodes participating in the relay service respectively delete the used relay quantum key.

Further, the above unidirectional concurrent relay method is characterized by:

Assume that a quantum key relay service is to pass a key R from the quantum service node A (source node) through n (n is a natural number greater than 0) relay nodes and relay to the quantum service node B (target node). It is assumed that all quantum service nodes participating in the relay are sequentially recorded as A, ..., Ci, ..., B (where i is a natural number and 0 < i < n + 1, when there is a relay node, n = 1, i = 1; when there are two relay nodes, n = 2, i = 1, 2, and so on), where quantum keys are shared between any two adjacent nodes (assuming the neighbors K1, ..., Ki, ..., K(n+1) are sequentially selected as the quantum key of the relay service, wherein K1 is the shared quantum key of node A and node C1, and Ki is node C ( I-1) shared quantum key with node Ci (where i is a natural number and 1<i<n+1), K(n+1) is a shared quantum key of node Cn and node B, adjacent node a quantum key that identifies the key identifier of the used quantum key and uses the same key identifier);

The quantum network management server causes the node Ci to calculate an exclusive OR operation between the two shared quantum keys between the two adjacent nodes (denoted as

Value, ie node Ci calculation

And respectively send the calculation result Ri and its corresponding node ID to the node B (where i is a natural number and 0<i<n+1); if the node B does not receive the calculation result of some nodes within a limited time Then, the node B requests the corresponding node to resend the corresponding calculation result until the n exclusive OR operation results are received; the node B performs an exclusive OR operation on the n exclusive OR operation results together with K(n+1). That is, calculation

Thus, K1 is securely relayed from node A to node B, node B uses K1 as relay key R, or node A generates a key R and sends it to node B using K1 encryption, and node B uses K1 decryption to relay Key R.

Further, the bidirectional concurrent relay method includes a bidirectional concurrent relay method 1 and a bidirectional concurrent relay method 2, wherein:

Assume that a quantum key relay service is to pass a key R from the quantum service node A (source node) through n (n is a natural number greater than 3) relay nodes and relay to the quantum service node B (target node). It is assumed that all quantum service nodes participating in the relay are sequentially recorded as A, ..., Ci, ..., B (where i is a natural number and 0 < i < n + 1, when there is a relay node, n = 1, i = 1; when there are two relay nodes, n = 2, i = 1, 2, and so on), where quantum keys are shared between any two adjacent nodes (assuming the neighbors K1, ..., Ki, ..., K(n+1) are sequentially selected as the quantum key of the relay service, wherein K1 is the shared quantum key of node A and node C1, and Ki is node C ( I-1) shared quantum key with node Ci (where i is a natural number and 1<i<n+1), K(n+1) is a shared quantum key of node Cn and node B, adjacent node a quantum key that identifies the key identifier of the used quantum key and uses the same key identifier);

(3-1) Two-way concurrent relay method one, which is characterized by:

The quantum network management server selects and specifies the optimal relay node that provides the relay service according to the current state indicator of all the relay nodes (here assumed that node Cx, x is a certain natural number greater than 1 and less than n) Relay key R, let node Ci calculate

(i is a natural number, and 0<i<x), let node Cx calculate

And respectively, the calculation result Ri (i is a natural number, and 0 < i < x), Rx_1 and the ID of the corresponding node are sent to the node A together; if the node A does not receive the calculation result of some nodes within a limited time, Then, the node A requests the corresponding node to resend the corresponding calculation result until the x XOR operation calculation result is received; the node A performs the exclusive OR operation on the x XOR operation result together with K1, that is, the node A calculation

(i is a natural number, and 0 < i < x) and gets R;

Quantum Network Management Server Let Node Cx Calculate

Let node Ci calculate

(i is a natural number and x<i<n+1), and respectively send the calculation results Rx_2, Ri (i is a natural number and x<i<n+1) and the ID of the corresponding node to the node B; if it is limited The Node B does not receive the calculation result of some nodes in the time, and the Node B requests the corresponding node to resend the corresponding calculation result until the (n-x+1) XOR operation calculation result is received; The (n-x+1) XOR operation result is XORed with K(n+1), that is, Node B calculation

(i is a natural number and x < i < n + 1) and obtains a relay key R;

(3-2) Two-way concurrent relay method two, which is characterized by:

The quantum network management server selects and specifies an optimal relay node that provides the relay service according to the current state indicator of all the relay nodes (here assumed to be node Cx, where x is a natural number greater than 1 and less than n), Let node Ci calculate

(i is a natural number, and 0<i<x), and respectively sends the calculation result Ri (i is a natural number, and 0<i<x) and its corresponding node ID to node A (here, if x=2, Then, only need to send R1); if A does not receive the calculation result of some nodes within a limited time, node A requests the corresponding node to resend the corresponding calculation result until the (x-1) different Or calculate the calculation result; node A performs an exclusive OR operation on the (x-1) XOR operation result together with K1, that is, if x=2, then A calculation

If x=3, then node A calculates

If x>3, node A calculates

(i is a natural number, and 0 < i < x-1) and gets Kx;

Quantum Network Management Server Let Node Cx Calculate

Let node Ci calculate

(i is a natural number and x<i<n+1), and respectively send the calculation result Rx, Ri (i is a natural number and x<i<n+1) and the ID of the corresponding node to the node B; if it is limited The Node B does not receive the calculation result of some nodes in the time, and the Node B requests the corresponding node to resend the corresponding calculation result until the (n-x+1) XOR operation calculation result is received; The (n-x+1) XOR operation result is XORed with K(n+1), that is, Node B calculation

(i is a natural number and x<i<n+1) and obtains the relay key Kx; thus, Kx is securely relayed from node A to node B, node B uses Kx as relay key R, or node A generates one The key R is sent to the Node B by Kx encryption, and the Node B decrypts it by Kx to obtain the relay key R.

Further, the content included in the foregoing key identifier includes, but is not limited to, a current node ID, a neighbor node ID, a key number, and a key data length.

Further, the method for obtaining, by the quantum network management server, the address of the relay node participating in the relay service is: the quantum network management server queries the stored relay according to the address of the source node and the target node of the relay service. The routing table obtains the address of each relay quantum service node between the source node and the target node of the relay service.

Further, the foregoing relay routing table includes, but is not limited to:

(6-1) The relay routing table is composed of several records, and the contents of each record include but are not limited to: a local address, a destination address, and a next hop address;

(6-2) Each quantum service node of the quantum key distribution network stores its own relay routing table;

(6-3) a current relay routing table of each quantum service node is stored in the quantum network management server;

(6-4) After the topology of the quantum key distribution network changes, the relay routing table is also updated.

It should be noted that the relay routing table needs to consider whether adjacent nodes (if there is a point-to-point quantum channel connection between two nodes and can perform quantum key distribution, it is called adjacent nodes) Whether the quantum key is cached in advance, whether the quantum key can be negotiated in real time, and if there is a pre-cached quantum key between adjacent nodes or a quantum key can be negotiated in real time, the route between the adjacent nodes is accessible. Otherwise, it is nowhere.

Further, the current state indicator of the quantum service node described above includes, but is not limited to:

(7-1) an indicator reflecting a heavy state of a relay task currently burdened by the quantum service node, the indicator being a quantized indicator, including but not limited to a nominal quantum key distribution rate of the quantum service node How many relay tasks are currently participating and the quantum key consumption rate of each relay task;

(7-2) reflecting an indicator of the current position state of the quantum service node in the quantum key distribution network, wherein the indicator is a quantitative indicator, including but not limited to: the quantum service node and other There are effective quantum channels between the quantum service nodes and the ability to perform quantum key negotiation and hop counts between the quantum service nodes and other quantum service nodes.

Further, the quantum service node includes, but is not limited to, a quantum key relay server formed based on a single quantum key distribution terminal and a quantum key relay server formed based on a plurality of quantum key distribution terminals, wherein the quantum key distribution The terminal includes a transceiver unit of a quantum key distribution system and a transmitting end or a receiving end of the quantum key distribution system; wherein the quantum key relay server includes but is not limited to a protocol interaction module and a data encryption and decryption module, wherein the protocol The interaction module is configured to respond to the service instruction of the quantum network management server, receive relay key data sent by other nodes, or send related relay key data to other nodes according to the service instruction, and interact with the corresponding node. A data encryption/decryption module is configured to receive encrypted relay key data sent by other relay nodes, and decrypt the same using the corresponding quantum key, or encrypt the relay key sent to other relay nodes. data.

Further, the method for the XOR concurrent relay method and the bidirectional concurrent relay method in which the relay node transmits the XOR operation value of the two shared quantum keys between the relay node and the adjacent relay node includes direct transmission and encryption. Sending, wherein the encrypted transmission is encrypted by using the shared key between the relay node and the target node, and the target node decrypts by using the corresponding shared key (for example, using the data encryption standard algorithm AES for encryption and decryption, The premise of using encrypted transmission is that the communicating parties have a shared key).

Further, the foregoing quantum network management server selects and specifies an optimal method for providing a relay node of the relay service, and is characterized by:

(10-1) the quantum network management server sends an instruction to the relay node participating in the relay service, so that the relay node uploads each current state indicator to the quantum network management server;

(10-2) The quantum network management server collects the current state indicator of the relay node, and accordingly determines the trusted relay node that provides the relay service optimally in the current communication.

Further, the above quantum network management server is used for management and management of the quantum key distribution network.

Compared with the prior art, the invention has the following innovations:

(1) The present invention solves the problem of security diffusion of a relay process by a novel quantum key processing method;

(2) Improve the key relay efficiency by the concurrent response and the preferred concurrent relay mode, reduce the relay delay, and eliminate the concurrency conflict problem; the solution of the present invention is more secure and more efficient than the disclosed similar technical solutions. The relay delay is smaller; the method and system of the invention can be widely applied to quantum communication networks of various topologies, and has a good application prospect.

DRAWINGS

1 is a schematic diagram of an embodiment of a method for unidirectional concurrent relaying according to a method of the present invention;

2 is a schematic diagram of the principle of Embodiment 1 of the method for bidirectional concurrent relaying according to the method of the present invention;

3 is a schematic diagram of the principle of Embodiment 1 of the bidirectional concurrent relay method 2 of the method of the present invention;

4 is a schematic diagram showing the principle of confirming a key identifier of a used quantum key and using a quantum key identified by the same key between adjacent nodes according to an embodiment of the present invention;

5 is a schematic diagram of the principle of Embodiment 2 of the bidirectional concurrent relay method 1 of the method of the present invention;

FIG. 6 is a schematic diagram of the principle of Embodiment 2 of the bidirectional concurrent relay method 2 of the method of the present invention.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

The communication channel involved in the solution of the present invention includes: a quantum density between adjacent quantum service nodes (or quantum relay nodes, or nodes, which are used as quantum relay nodes when the equivalent sub-service nodes are used for relay nodes) The key distribution process requires the use of a quantum channel, and other communication processes use traditional network communication channels, including wired and wireless channels.

The principle of the unidirectional concurrent relay method embodiment shown in FIG. 1 and the identification symbols in FIG. 1 are the same as the corresponding descriptions in the above-mentioned "[0006] further, the method further includes a unidirectional concurrent relay method", No longer introduced. The principle of the embodiment of the bidirectional concurrent relay method shown in FIG. 2 and the identification symbols in FIG. 2 are the same as the corresponding descriptions in the above-mentioned "(3-1) bidirectional concurrent relay method one in the paragraph [0007], No longer introduced. The principle of the two-way concurrent relay method shown in FIG. 3 and the identifiers in FIG. 3 are the same as the above (3-2) bidirectional concurrent relay method (shown in FIG. 3) in the paragraph [0007]. The corresponding descriptions in the same are the same and will not be introduced here.

4 is a method embodiment of a method for confirming a key identifier of a used quantum key between adjacent nodes and using a quantum key identified by the same key, wherein the node C(i-1) is a node Ci sends the key identifier of one of the shared keys Ki between the selected two of them (process 1 in FIG. 4), and the node Ci sends a confirmation of the selection Ki to the node C(i-1) Information (Process 3 in Figure 4); Ci sends a key identification of a shared key K(i+1) in the shared key between the two selected by C(i+1) (Fig. Process 2) in 4, node C(i+1) sends confirmation information for selecting K(i+1) to node Ci (process 4 in Fig. 4); after completing the above process, node Ci calculates

(in the one-way concurrent relay method), and send Ri to the target node through the conventional network communication channel (process 5 in Fig. 4). In the two-way concurrent relay method, a similar processing method is used to confirm the shared key selected between adjacent nodes.

FIG. 5 is a schematic diagram of Embodiment 2 of a bidirectional concurrent relay method according to the method of the present invention, including three relay nodes C1, C2, and C3, and C1 calculation

C2 produces R and calculates

C1 and C2 send R1 and R2_1 to A, respectively.

C2 calculation

C3 calculation

C2 and C3 send R2_2 and R3 to B, B respectively

That is, it is achieved that the key R is relayed from A to B.

6 is a schematic diagram of Embodiment 2 of a bidirectional concurrent relay method 2 of the present invention, including three relay nodes C1, C2, and C3, and C1 calculation

C1 sends R1 to A, A calculates

C2 calculation

C3 calculation

C2 and C3 send R2 and R3 to B, B respectively

That is, it is realized that the key K2 is relayed from A to B, and K2 can be used as the relay key R, or A (or B) can generate another key R and

Issue to B (or A), B (or A) calculation

That is, it is implemented to relay the key R from A to B.

In order to reduce the credibility requirement for the relay node and reduce the risk of the third-party node obtaining the relay key, the data encryption standard algorithm may also be used to encrypt the data sent to the target node, for example, the node C2 uses the prior and the target. The work key encryption shared by the Node B (using the data encryption standard algorithm AES) R2 obtains the ciphertext R2_C and sends R2_C to B; B decrypts R2_C with the same work key and obtains R2.

The embodiments described above are only a part of the embodiments of the invention, and not all of the embodiments. Further embodiments can be obtained based on various modifications and combinations of the embodiments of the present invention, and other embodiments directly employed by those skilled in the art without the inventive work are all of the present invention. The scope of protection.

Claims

A quantum key relay method, comprising the following steps:

(1-1) Any quantum service node (referred to as a node) in a quantum key distribution network pre-caches a certain amount of quantum keys or between any adjacent quantum service nodes connected to a point-to-point quantum channel or Realizing a certain amount of quantum keys in real time, the quantum service node groups the quantum keys and performs randomness test on each packet, caches the packets through the randomness test, and creates a corresponding key identifier;

(1-2) The quantum network management server receives the request to relay a key R from the source node to the target node, and the quantum network management server according to the stored relay routing table and the current state indicator of the associated quantum service node Obtaining the number of relay nodes that are relayed from the source node to the target node, the address of each relay node, and the current state indicator, and determining that the one-way concurrent relay is used according to the number of the relay nodes and the current state indicator a method or a bidirectional concurrent relay method for relaying a key R from a source node to a target node;

(1-3) The source node and the target node perform integrity check on the relay key R, and if it fails to pass the check, re-relay; after passing the integrity check, complete the key relay The process; the nodes participating in the relay service respectively delete the used relay quantum key.
The method according to claim 1, wherein the one-way concurrent relay method is characterized by:

Assume that a quantum key relay service is to pass a key R from the quantum service node A (source node) through n (n is a natural number greater than 0) relay nodes and relay to the quantum service node B (target node). It is assumed that all quantum service nodes participating in the relay are sequentially recorded as A, ..., Ci, ..., B (where i is a natural number and 0 < i < n + 1, when there is a relay node, n = 1, i = 1; when there are two relay nodes, n = 2, i = 1, 2, and so on), where quantum keys are shared between any two adjacent nodes (assuming the neighbors K1, ..., Ki, ..., K(n+1) are sequentially selected as the quantum key of the relay service, wherein K1 is the shared quantum key of node A and node C1, and Ki is node C ( I-1) shared quantum key with node Ci (where i is a natural number and 1<i<n+1), K(n+1) is a shared quantum key of node Cn and node B, adjacent node a quantum key that identifies the key identifier of the used quantum key and uses the same key identifier);

The quantum network management server causes the node Ci to calculate an exclusive OR operation between the two shared quantum keys between the two adjacent nodes (denoted as
Value, ie node Ci calculation
And respectively send the calculation result Ri and its corresponding node ID to the node B (where i is a natural number and 0<i<n+1); if the node B does not receive the calculation result of some nodes within a limited time Then, the node B requests the corresponding node to resend the corresponding calculation result until the n exclusive OR operation results are received; the node B performs an exclusive OR operation on the n exclusive OR operation results together with K(n+1). That is, calculation
Thus, K1 is securely relayed from node A to node B, node B uses K1 as relay key R, or node A generates a key R and sends it to node B by K1 encryption, and node B decrypts it by K1. Key R.
The method according to claim 1, wherein the bidirectional concurrent relay method comprises a bidirectional concurrent relay method 1 and a bidirectional concurrent relay method 2, characterized in that:

Assume that a quantum key relay service is to pass a key R from the quantum service node A (source node) through n (n is a natural number greater than 3) relay nodes and relay to the quantum service node B (target node). It is assumed that all quantum service nodes participating in the relay are sequentially recorded as A, ..., Ci, ..., B (where i is a natural number and 0 < i < n + 1, when there is a relay node, n = 1, i = 1; when there are two relay nodes, n = 2, i = 1, 2, and so on), where quantum keys are shared between any two adjacent nodes (assuming the neighbors K1, ..., Ki, ..., K(n+1) are sequentially selected as the quantum key of the relay service, wherein K1 is the shared quantum key of node A and node C1, and Ki is node C ( I-1) shared quantum key with node Ci (where i is a natural number and 1<i<n+1), K(n+1) is a shared quantum key of node Cn and node B, adjacent node a quantum key that identifies the key identifier of the used quantum key and uses the same key identifier);

(3-1) Two-way concurrent relay method one, which is characterized by:

The quantum network management server selects and specifies the optimal relay node that provides the relay service according to the current state indicator of all the relay nodes (here assumed that node Cx, x is a certain natural number greater than 1 and less than n) Relay key R, let node Ci calculate
(i is a natural number, and 0<i<x), let node Cx calculate
And respectively, the calculation result Ri (i is a natural number, and 0 < i < x), Rx_1 and the ID of the corresponding node are sent to the node A together; if the node A does not receive the calculation result of some nodes within a limited time, Then, the node A requests the corresponding node to resend the corresponding calculation result until the x XOR operation calculation result is received; the node A performs the exclusive OR operation on the x XOR operation result together with K1, that is, the node A calculation
(i is a natural number, and 0 < i < x) and gets R;

Quantum Network Management Server Let Node Cx Calculate
Let node Ci calculate
(i is a natural number and x<i<n+1), and respectively send the calculation results Rx_2, Ri (i is a natural number and x<i<n+1) and the ID of the corresponding node to the node B; if it is limited The Node B does not receive the calculation result of some nodes in the time, and the Node B requests the corresponding node to resend the corresponding calculation result until the (n-x+1) XOR operation calculation result is received; The (n-x+1) XOR operation result is XORed with K(n+1), that is, Node B calculation

(i is a natural number and x < i < n + 1) and obtains a relay key R;

(3-2) Two-way concurrent relay method two, which is characterized by:

The quantum network management server selects and specifies an optimal relay node that provides the relay service according to the current state indicator of all the relay nodes (here assumed to be node Cx, where x is a natural number greater than 1 and less than n), Let node Ci calculate
(i is a natural number, and 0<i<x), and respectively sends the calculation result Ri (i is a natural number, and 0<i<x) and its corresponding node ID to node A (here, if x=2, Then, only need to send R1); if A does not receive the calculation result of some nodes within a limited time, node A requests the corresponding node to resend the corresponding calculation result until the (x-1) different Or calculate the calculation result; node A performs an exclusive OR operation on the (x-1) XOR operation result together with K1, that is, if x=2, then A calculation
If x=3, then node A calculates

If x>3, node A calculates
(i is a natural number, and 0 < i < x-1) and gets Kx;

Quantum Network Management Server Let Node Cx Calculate
Let node Ci calculate
(i is a natural number and x<i<n+1), and respectively send the calculation result Rx, Ri (i is a natural number and x<i<n+1) and the ID of the corresponding node to the node B; if it is limited The Node B does not receive the calculation result of some nodes in the time, and the Node B requests the corresponding node to resend the corresponding calculation result until the (n-x+1) XOR operation calculation result is received; The (n-x+1) XOR operation result is XORed with K(n+1), that is, Node B calculation

(i is a natural number and x<i<n+1) and obtains the relay key Kx; thus, Kx is securely relayed from node A to node B, node B uses Kx as relay key R, or node A generates one The key R is sent to the Node B by Kx encryption, and the Node B decrypts it by Kx to obtain the relay key R.
The method according to claim 1 or claim 2 or claim 3, wherein the content of the key identifier comprises a current node ID, a neighbor node ID, a key number, and a key data length. .
The method according to claim 1, wherein the method for the quantum network management server to obtain the address of the relay node participating in the relay service is: the quantum network management server according to the source node and the target node of the relay service The address, query the stored relay routing table, and obtain the address of each relay quantum service node between the source node and the target node of the relay service.
The method according to claim 1, wherein said relay routing table is characterized by:

(6-1) The relay routing table consists of several records, each of which includes: local address, destination address, and next hop address;

(6-2) Each quantum service node of the quantum key distribution network stores its own relay routing table;

(6-3) a current relay routing table of each quantum service node is stored in the quantum network management server;

(6-4) After the topology of the quantum key distribution network changes, the relay routing table is also updated.
The method of claim 1, the current state indicator of the quantum service node, characterized by:

(7-1) an indicator reflecting a heavy state of a relay task currently burdened by the quantum service node, the indicator being a quantized indicator, wherein the quantum service key distribution rate of the quantum service node is included, currently The number of participating relay tasks and the quantum key consumption rate of each relay task;

(7-2) an indicator reflecting the current position state of the quantum service node in the quantum key distribution network is a quantitative indicator, comprising: an effective quantum exists between the quantum service node and other quantum service nodes The number of channels and the number of quantum key negotiations and the number of hops between the quantum service node and other quantum service nodes.
The method according to claim 1, wherein said quantum service node comprises: a quantum key relay server formed based on a single quantum key distribution terminal, and a quantum key formed based on a plurality of quantum key distribution terminals Following the server, wherein the quantum key distribution terminal includes a transceiver unit of the quantum key distribution system and a transmitting end or receiving end of the quantum key distribution system.
The method according to claim 1, wherein the method for the relay node to transmit an exclusive OR operation value of two shared quantum keys between the relay node and the adjacent relay node comprises direct transmission and encrypted transmission, wherein The encrypted transmission is encrypted by using the shared key between the relay node and the target node, and the target node decrypts by using the corresponding shared key.
The method according to claim 3, wherein the method for the quantum network management server to select and specify the optimal relay node providing the relay service is:

(10-1) the quantum network management server sends an instruction to the relay node participating in the relay service, so that the relay node uploads each current state indicator to the quantum network management server;

(10-2) The quantum network management server collects the current state indicator of the relay node, and accordingly determines the trusted relay node that provides the relay service optimally in the current communication.