Deployment method and device of inter-domain quantum key distribution equipment

Abstract

The invention provides a deployment method of inter-domain quantum key distribution equipment. The deployment method specifically comprises the following steps: step 1, querying inter-domain path information; 2, processing chain segments of inter-domain paths; further calculating and determining chain segment information on each inter-domain path by combining the inter-domain path information inquired in the step 1, wherein a chain segment can cover one link or a plurality of links connected in series; and step 3, carrying out device deployment oriented to cross-domain interconnection. The invention discloses a deployment device of inter-domain quantum key distribution equipment. The deployment device comprises a master control module, an inter-domain path information query module, a chain segment processing module and an equipment deployment module, the general control module is responsible for controlling the operation of the whole device, and the inter-domain path information query module is used for querying related information of each inter-domain path; the chain segment processing module is used for processing chain segments on each inter-domain path; and the equipment deployment module is used for completing QKD equipment deployment on each inter-domain path. According to the invention, the problem of low cost performance of the existing inter-domain QKD equipment deployment method is solved, so that the key code rate requirement of the cross-domain QKD service is met with high cost performance.

Description

Technical Field

[0001] The present invention relates to the field of quantum communication, and in particular to a method and apparatus for deploying an inter-domain quantum key distribution device. Background Art

[0002] Quantum Key Distribution (QKD) can provide theoretically "unconditionally secure" symmetric keys between communicating parties, enabling information-theoretically secure key distribution. Currently, a variety of high-performance QKD protocols are in use within metropolitan areas, but most metropolitan quantum networks are based on a single QKD protocol. Given the varying characteristics and applicable scenarios of different QKD protocols, a multi-domain quantum network may consist of multiple metropolitan quantum networks based on different QKD protocols. In a multi-domain quantum network, cross-domain interconnection between metropolitan quantum networks requires the deployment of QKD equipment on the corresponding inter-domain paths to meet the key coding rate requirements of cross-domain QKD services. QKD equipment can generally be divided into QKD transmitters (QTx) and QKD receivers (QRx). Inter-domain QKD equipment deployment methods vary. For example, QTx and QRx can be deployed at different node locations, and there are multiple options for the QKD protocol used for the QTx and QRx connections. In particular, differences in QKD equipment costs and available key encoding rates for different protocols lead to significant differences in the cost-effectiveness of different inter-domain QKD equipment deployment methods. Therefore, a cost-effective inter-domain QKD equipment deployment method is key to achieving low-cost and efficient interconnection between various metropolitan quantum networks in a multi-domain quantum network.

[0003] Currently, the deployment of inter-domain QKD equipment in quantum networks is relatively simple. Most metropolitan quantum networks interconnect using a single QKD protocol, ignoring the performance and cost differences between different QKD protocols. Furthermore, existing solutions typically deploy QKD equipment hop-by-hop at optical nodes along the inter-domain path, requiring a QKD device at every optical node. This results in high inter-domain QKD deployment costs and a lack of flexibility. With the evolution of large-scale quantum networks, the development of QKD protocols, and the continued expansion of user base, individual metropolitan quantum networks may adopt different QKD protocols. The provision of inter-domain QKD services between metropolitan quantum networks will rely on inter-domain QKD equipment. Therefore, the lack of cost-effective inter-domain QKD equipment deployment methods will result in high inter-domain interconnection costs and weak inter-domain QKD service capabilities, making it impossible to meet the diverse secure communication needs of end-to-end users. Furthermore, the core issue of metropolitan quantum network interconnection lies in how to rationally segment and deploy appropriate QKD equipment. Summary of the Invention

[0004] To address these issues, the present invention discloses a method and apparatus for deploying inter-domain quantum key distribution equipment. This method, based on determining the key coding rate requirements for cross-domain QKD services, comprehensively considers segment length, the available key coding rate for each segment, and the cost of the QKD equipment used in each segment to select a cost-effective inter-domain QKD equipment deployment method. This method and apparatus enables low-cost and efficient interconnection between metropolitan quantum networks in a multi-domain quantum network. This method and apparatus can be adjusted and adapted based on the key coding rate requirements for cross-domain QKD services and the actual scenarios of multi-domain quantum networks, avoiding the problems of high cross-domain interconnection costs and low flexibility.

[0005] A method for deploying an inter-domain quantum key distribution device comprises the following steps: Step 1: Query inter-domain path information; Step 2: Processing inter-domain path segments: Combined with the inter-domain path information queried in Step 1, further calculation and determination of segment information on each inter-domain path are performed. A segment can cover a single link or multiple serially connected links. Step 3: Device deployment for cross-domain interconnection.

[0006] Furthermore, the step 1 specifically includes: Step 1.1: Query the node and link information on each inter-domain path; the node types specifically include edge nodes and optical nodes; Step 1.2: Query the QKD protocols allowed on each inter-domain path and the cost of the corresponding QKD equipment. When deploying inter-domain QKD equipment, select a QKD protocol and equipment based on the "transmitter→receiver" model. The corresponding QKD equipment cost is the cost of a set of QKD equipment including a transmitter and a receiver.

[0007] Step 1.3: Query the cross-domain QKD services carried on each inter-domain path and their key coding rate requirements; the key coding rate requirements of the cross-domain QKD services will accumulate on the inter-domain paths through which the cross-domain QKD services pass. When the accumulated key coding rate requirements increase, the number of QKD devices that need to be deployed on the inter-domain paths will also increase, thereby increasing the deployment cost.

[0008] Furthermore, the step 2 specifically includes the following steps: Step 2.1: Determine the segment information that can be constructed on each inter-domain path and add the segment on the inter-domain path to the candidate segment set. The segment information specifically includes the links covered by the segment and the corresponding nodes. Step 2.2: Determine the length of each segment on each inter-domain path. The length of each segment is obtained by summing the lengths of all links covered by the segment. Step 2.3: Determine the key coding rate that each segment on each inter-domain path can provide under different QKD protocols. Combined with the length of each segment, determine the key coding rate that each segment can provide under different QKD protocols based on the key coding rate-distance formula.

[0009] Furthermore, the step 3 specifically includes the following steps: Step 3.1: Calculate the total key coding rate requirement of the cross-domain QKD services accumulated on each inter-domain path. The total key coding rate requirement accumulated on each inter-domain path is obtained by adding up the key coding rate requirements of all cross-domain QKD services carried by the inter-domain path queried in step 1.3.

[0010] Step 3.2: Calculate the key coding rate distance product of each segment on each inter-domain path under different available QKD protocols. The key coding rate distance product of each segment under the used QKD protocol = segment length × key coding rate available with the QKD protocol used for the segment. Step 3.3: Calculate the cost-performance ratio of each segment on each inter-domain path under different available QKD protocols. The cost-performance ratio of each segment under the used QKD protocol = the key coding rate distance product / the cost of a set of QKD equipment corresponding to the used QKD protocol; Step 3.4: Find and select the segment with the highest cost-effectiveness and the corresponding QKD protocol from the set of candidate segments on each inter-domain path, and add this segment to the set of selected segments. Since each segment may have one or more available QKD protocols, the segment with the highest cost-effectiveness among the combinations of the segments and the corresponding available QKD protocols is selected here. If the same cost-effectiveness exists, a random selection is made. Step 3.5: Based on the total key coding rate requirement accumulated on each inter-domain path, calculate the number of QKD devices corresponding to the protocol to be deployed on the selected segment, where the number of QKD devices to be deployed = Indicates rounding up; Step 3.6: Delete the selected segment and all segments that share any of the same links as the selected segment from the candidate segment set to avoid link overlap in subsequent segment selection. Step 3.7: Determine whether all segments in the selected segment set can cover the entire inter-domain path. If not, then loop through steps 3.4-3.7. Otherwise, it means that all segments in the selected segment set on each current inter-domain path can cover the entire inter-domain path. Step 3.8: Deploy the corresponding QKD devices based on the number of QKD devices corresponding to the protocol used by each segment in the selected segment set on each inter-domain path; Step 3.9: Connect each inter-domain path through the QKD devices deployed on each chain segment. At this point, the inter-domain QKD device deployment is complete.

[0011] Furthermore, when calculating the cost-effectiveness of each segment on each inter-domain path under different available QKD protocols in step 3.3, the units of each parameter should be kept consistent.

[0012] A deployment device for the inter-domain quantum key distribution device, mainly comprising a master control module, an inter-domain path information query module, a segment processing module, and a device deployment module; the master control module is responsible for controlling the operation of the entire device, and the inter-domain path information query module is used to query relevant information of each inter-domain path, and specifically includes a node and link query unit, a protocol and device query unit, and a service key coding rate query unit; The segment processing module is used to process the segments on each inter-domain path, specifically including a segment information determination unit, a segment length determination unit, and a key coding rate determination unit; The device deployment module is used to complete the QKD device deployment on each inter-domain path, specifically including a demand calculation unit, a key coding rate distance product calculation unit, a cost-effectiveness calculation unit, a segment search and selection unit, a device quantity calculation unit, a segment set update unit, a judgment unit, a device deployment unit, and a path connectivity unit.

[0013] Furthermore, the node and link query unit in the inter-domain path information query module is mainly used to query the node and link information on each inter-domain path; the protocol and device query unit is mainly used to query the QKD protocol allowed to be used on each inter-domain path and the cost of the QKD device corresponding to the protocol; the service key coding rate query unit is mainly used to query the cross-domain QKD service carried on each inter-domain path and its key coding rate requirements.

[0014] Furthermore, the segment information determination unit in the segment processing module is used to determine the segment information that can be constructed on each inter-domain path, and add the segments on the inter-domain path to the candidate segment set; the segment length determination unit is used to determine the length of each segment on each inter-domain path; and the key coding rate determination unit is used to determine the key coding rate that can be supplied by each segment on each inter-domain path under different QKD protocols.

[0015] Furthermore, the demand calculation unit in the device deployment module is used to calculate the total key coding rate requirement of the cross-domain QKD service accumulated on each inter-domain path; The key coding rate distance product calculation unit is used to calculate the key coding rate distance product of each segment on each inter-domain path under different available QKD protocols; The cost-performance calculation unit is used to calculate the cost-performance of each segment on each inter-domain path under different available QKD protocols; The segment search and selection unit is used to search and select the segment with the highest cost-effectiveness and the corresponding QKD protocol from the candidate segment set on each inter-domain path, and add the segment to the selected segment set; The device quantity calculation unit is used to calculate the number of QKD devices corresponding to the protocol to be deployed on the selected segment based on the total key coding rate requirements accumulated on each inter-domain path; The segment set updating unit is used to delete the selected segment and all segments that cover any of the same links as the selected segment from the candidate segment set; The judging unit is used to judge whether all segments in the selected segment set can cover the entire inter-domain path; The device deployment unit is used to deploy corresponding QKD devices according to the number of QKD devices corresponding to the protocol used by each segment in the selected segment set on each inter-domain path; The path connectivity unit is used to connect each inter-domain path through the QKD devices deployed on each segment.

[0016] Beneficial effects of the present invention: 1. Aiming at the key coding rate requirements accumulated by cross-domain QKD services on the inter-domain path, the present invention deploys QKD equipment based on the boundary nodes and optical nodes on the inter-domain path, and comprehensively considers the segment length, the key coding rate that the segment can supply, and the cost of the QKD equipment used in the segment to evaluate and compare the cost-effectiveness of different segments and protocols, providing a solution for realizing cross-domain interconnection between metropolitan area quantum networks.

[0017] 2. The inter-domain QKD device deployment method proposed in the present invention is realized by querying inter-domain path information, segment processing of inter-domain paths and device deployment for cross-domain interconnection, and the inter-domain QKD device deployment method is realized in a centralized manner using the proposed inter-domain QKD device deployment device.

[0018] 3. The present invention can flexibly adapt to the diverse secure communication needs of end-to-end users, reduce the cost of cross-domain interconnection between metropolitan quantum networks to a certain extent, and solve the problem of low cost-effectiveness of existing inter-domain QKD equipment deployment methods, thereby cost-effectively meeting the key coding rate requirements of cross-domain QKD services. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 , a schematic diagram of a method for deploying inter-domain QKD equipment according to the present invention; Figure 2 , a schematic diagram of a deployment device for an inter-domain QKD device according to the present invention; Figure 3 , a schematic diagram of a specific embodiment of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, and the terms "inward" and "outward" refer to directions toward or away from the geometric center of a particular component, respectively.

[0021] This embodiment provides a method for deploying an inter-domain quantum key distribution device. The corresponding flowchart of this method is as follows: Figure 1 As shown, it mainly includes the following three steps: Step 1: Query inter-domain path information - (1.1) Query the node and link information on each inter-domain path, including node type, link parameters (such as link length, link attenuation), etc. Node types specifically include border nodes and optical nodes.

[0022] (1.2) Query the QKD protocols allowed for use on each inter-domain path and the cost of the QKD equipment corresponding to that protocol. The QKD protocols allowed for use on each inter-domain path (i.e., the available QKD protocols) can be determined based on the actual network environment. For example, from the perspective of protocol compatibility within a metropolitan quantum network, the QKD protocol used by the two metropolitan quantum networks connected by an inter-domain path can be used as the QKD protocol allowed for use on that inter-domain path. Alternatively, from the perspective of the entire network, a different QKD protocol can be selected by comprehensively considering the performance and availability of different QKD protocols. In addition, to achieve the goal of high cost-effectiveness in inter-domain device deployment, the costs of QKD equipment corresponding to different protocols also need to be queried. Because the present invention selects QKD protocols and equipment based on the "transmitter → receiver" model when deploying inter-domain QKD equipment, the QKD equipment cost queried here refers to the cost of a set of QKD equipment including a transmitter and a receiver.

[0023] (1.3) Query the cross-domain QKD services carried on each inter-domain path and their key coding rate requirements. The key coding rate requirements of the cross-domain QKD services will accumulate on the inter-domain paths through which the cross-domain QKD services pass. When the accumulated key coding rate requirements increase, the number of QKD devices that need to be deployed on the inter-domain paths will also increase, thereby increasing the deployment cost.

[0024] Step 2: Processing inter-domain path segments—Combined with the inter-domain path information queried in step 1, the segment information on each inter-domain path can be further calculated and determined. A segment can cover one link or multiple serial links.

[0025] (2.1) Determine the segment information that can be constructed on each inter-domain path, and add the segment on the inter-domain path to the candidate segment set. The segment information specifically includes the links covered by the segment and the corresponding nodes.

[0026] (2.2) Determine the length of each segment on each inter-domain path. The length of each segment is obtained by summing the lengths of all links covered by the segment.

[0027] (2.3) Determine the key coding rate that each segment on each inter-domain path can provide under different QKD protocols. Combined with the length of each segment, the key coding rate that each segment can provide under different QKD protocols can be determined based on the key coding rate-distance formula.

[0028] Step 3: Device deployment for cross-domain interconnection - (3.1) Calculate the total key coding rate requirement of the cross-domain QKD services accumulated on each inter-domain path. The total key coding rate requirement accumulated on each inter-domain path is obtained by summing the key coding rate requirements of all cross-domain QKD services carried by the inter-domain path queried in step 1.3.

[0029] (3.2) Calculate the key coding rate distance product of each segment on each inter-domain path under different available QKD protocols. The key coding rate distance product of each segment under the used QKD protocol = segment length × key coding rate that can be provided by the QKD protocol used in the segment.

[0030] (3.3) Calculate the cost-performance ratio of each segment on each inter-domain path under the various available QKD protocols. The cost-performance ratio of each segment under the used QKD protocol is calculated as: the key coding rate / distance product / the cost of the QKD equipment corresponding to the used QKD protocol. This cost-performance ratio comprehensively considers the segment length, the available key coding rate of the segment, and the cost of the QKD equipment used in the segment. A larger value indicates a higher cost-performance ratio for the QKD equipment deployed for that protocol. It is important to note that when calculating the cost-performance ratio of each segment on each inter-domain path under the various available QKD protocols, the units of all parameters should be consistent. For example, the unit of length (distance) should be set to km, the unit of key coding rate should be set to kbps, and the unit of QKD equipment cost should be set to the normalized unit (unit). This ensures a fair comparison of cost-performance ratios.

[0031] (3.4) Find and select the segment with the highest cost-effectiveness and the corresponding QKD protocol from the set of candidate segments on each inter-domain path, and add the segment to the set of selected segments. Since each segment may have one or more available QKD protocols, the segment selected here is the one with the highest cost-effectiveness after combining the segments and the corresponding available different QKD protocols. If the same value for cost-effectiveness exists, a random selection can be made.

[0032] (3.5) Based on the total key coding rate requirement accumulated on each inter-domain path, calculate the number of QKD devices corresponding to the protocol used that need to be deployed on the selected segment, where the number of QKD devices required to be deployed = Indicates rounding up;

[0033] (3.6) Delete the selected segment and all segments that share any of the same links as the selected segment from the candidate segment set. This step is to avoid link overlap when selecting subsequent segments.

[0034] (3.7) Determine whether all segments in the selected segment set can cover the entire inter-domain path. If not, loop through steps 3.4-3.7. Otherwise, it means that all segments in the selected segment set on each current inter-domain path can cover the entire inter-domain path.

[0035] (3.8) Deploy the corresponding QKD devices based on the number of QKD devices corresponding to the protocol used by each segment in the set of selected segments on each inter-domain path.

[0036] (3.9) Each inter-domain path is connected through the QKD devices deployed on each chain segment. At this point, the inter-domain QKD device deployment is complete.

[0037] The above-mentioned inter-domain QKD device deployment method can be implemented based on a centralized QKD device deployment device, such as Figure 2 The device primarily comprises a master control module, an inter-domain path information query module, a segment processing module, and a device deployment module. The master control module is responsible for controlling the operation of the entire device, while the inter-domain path information query module, segment processing module, and device deployment module respectively execute steps 1 to 3 of the inter-domain QKD device deployment method.

[0038] The inter-domain path information query module is used to query the relevant information of each inter-domain path. It specifically includes a node and link query unit, a protocol and device query unit, and a service key coding rate query unit. Among them, the node and link query unit is mainly used to query the node and link information on each inter-domain path; the protocol and device query unit is mainly used to query the QKD protocols allowed on each inter-domain path and the cost of the corresponding QKD equipment; the service key coding rate query unit is mainly used to query the cross-domain QKD services carried on each inter-domain path and their key coding rate requirements.

[0039] The segment processing module is used to process the segments on each inter-domain path. It specifically includes a segment information determination unit, a segment length determination unit, and a key coding rate determination unit. The segment information determination unit is used to determine the segment information that can be constructed on each inter-domain path and add the segments on the inter-domain path to the candidate segment set; the segment length determination unit is used to determine the length of each segment on each inter-domain path; and the key coding rate determination unit is used to determine the key coding rate that can be provided by each segment on each inter-domain path under different QKD protocols.

[0040] The device deployment module is used to complete the QKD device deployment on each inter-domain path, and specifically includes a demand calculation unit, a key coding rate distance product calculation unit, a cost-effectiveness calculation unit, a segment search and selection unit, a device quantity calculation unit, a segment set update unit, a judgment unit, a device deployment unit, and a path connectivity unit. The demand calculation unit is used to calculate the total key coding rate demand of the cross-domain QKD business accumulated on each inter-domain path; the key coding rate distance product calculation unit is used to calculate the key coding rate distance product of each segment on each inter-domain path under different available QKD protocols; the cost-effectiveness calculation unit is used to calculate the cost-effectiveness of each segment on each inter-domain path under different available QKD protocols; the segment search and selection unit is used to find and select the segment with the highest cost-effectiveness and the corresponding QKD protocol in the set of candidate segments on each inter-domain path, and add the segment to the selected segment set; the device quantity calculation unit is used to calculate the cost-effectiveness of each segment on each inter-domain path according to the cost-effectiveness of each segment. The total key coding rate requirements accumulated are used to calculate the number of QKD devices corresponding to the protocol used and need to be deployed on the selected segment; the segment set update unit is used to delete the selected segment and all segments that cover any of the same links as the selected segment from the candidate segment set; the judgment unit is used to judge whether all segments in the selected segment set can cover the entire inter-domain path; the device deployment unit is used to deploy corresponding QKD devices according to the number of QKD devices corresponding to the protocol used by each segment in the selected segment set on each inter-domain path; the path connection unit is used to connect each inter-domain path through the QKD devices deployed on each segment.

[0041] Given that the inter-domain QKD device deployment method proposed in the present invention is a centralized deployment method, the inter-domain QKD device deployment device can be implemented in the centralized control system of the quantum network. The specific process is as follows: the cross-domain QKD service in the quantum network generates a key coding rate requirement and sends it to the centralized control system. The centralized control system triggers the inter-domain QKD device deployment device and executes the inter-domain QKD device deployment method to achieve cost-effective deployment of the inter-domain QKD device and meet the key coding rate requirements of the cross-domain QKD service. Finally, after the inter-domain QKD device is successfully deployed, the corresponding inter-domain path is connected.

[0042] Figure 3 The specific embodiments of the inter-domain QKD device deployment method and apparatus proposed in the present invention are given as follows: Figure 3In the three metropolitan quantum networks shown, cross-domain QKD services exist between the GG02 and BB84 domains, and between the BB84 and COW domains. Following the inter-domain QKD device deployment method, the node and link information on each inter-domain path is first queried (inter-domain path 1 includes boundary nodes A and E, optical nodes B, C, and D, and links 1, 2, 3, and 4 are 20 km, 25 km, 25 km, and 20 km long, respectively; inter-domain path 2 includes boundary nodes J and F, optical nodes I, H, and G, and links 5, 6, 7, and 8 are 20 km, 25 km, 20 km, and 30 km long, respectively). Query the QKD protocols allowed on each inter-domain path and the cost of the corresponding QKD equipment (based on the protocol compatibility of the metropolitan quantum network, inter-domain path 1 allows the use of the GG02 protocol and the BB84 protocol, and inter-domain path 2 allows the use of the BB84 protocol and the COW protocol. After querying, the cost of the GG02 device is 1 unit, and the cost of the BB84 and COW devices is 2 units each); Query the cross-domain QKD services carried on each inter-domain path and their key coding rate requirements (inter-domain path 1 carries 10 cross-domain QKD services, with key coding rate requirements of 45 kbps, 55 kbps, 56 kbps, 44 kbps, 43 kbps, 57 kbps, 45 kbps, 55 kbps, 50 kbps, and 50 kbps respectively; inter-domain path 2 carries 12 cross-domain QKD services, with key coding rate requirements of 45 kbps, 55 kbps, 56 kbps, 44 kbps, 43 kbps, 57 kbps, 45 kbps, 55 kbps, 50 kbps, 50 kbps, 45 kbps, and 55 kbps respectively).

[0043] Determine the segment information that can be constructed on each inter-domain path and add the segment on the inter-domain path to the candidate segment set (inter-domain path 1 can construct 10 segments, namely AB, BC, CD, DE, AC, BD, CE, AD, BE, and AE; inter-domain path 2 can construct 10 segments, namely FG, GH, HI, IJ, FH, GI, HJ, FI, GJ, and FJ). Determine the length of each segment on each inter-domain path (the lengths of the segments on inter-domain path 1 are 20 km, 25 km, 25 km, 20 km, 45 km, 50 km, 45 km, 70 km, 70 km, and 90 km; the lengths of the segments on inter-domain path 2 are 20 km, 25 km, 20 km, 30 km, 45 km, 45 km, 50 km, 65 km, 75 km, and 95 km). Determine the key coding rates that can be provided by each segment on each inter-domain path under different QKD protocols (on inter-domain path 1, the key coding rates that can be provided by segments AB, BC, CD, DE, AC, BD, CE, AD, BE, and AE under the GG02 protocol are 80 kbps, 20 kbps, 20 kbps, 80 kbps, 4 kbps, 2 kbps, 4 kbps, 0 kbps, 0 kbps, and 0 kbps; and the key coding rates that can be provided under the BB84 protocol are 60 kbps, 50 kbps, 50 kbps, 60 kbps, 35 kbps, 30kbps, 35 kbps, 20 kbps, 20 kbps, and 10 kbps; On inter-domain path 2, the key coding rates that can be provided by segments FG, GH, HI, IJ, FH, GI, HJ, FI, GJ, and FJ under the BB84 protocol are 60 kbps, 50 kbps, 60 kbps, 40 kbps, 35 kbps, 35 kbps, 25 kbps, 21 kbps, 15 kbps, and 5 kbps. The key coding rates that can be provided under the COW protocol are 55 kbps, 45 kbps, 55 kbps, 35 kbps, 30 kbps, 30 kbps, 26 kbps, 23 kbps, 20 kbps, and 10 kbps.

[0044] Calculate the total key coding rate requirement for cross-domain QKD services accumulated on each inter-domain path (the total key coding rate requirement for cross-domain QKD services accumulated on inter-domain path 1 is 500 kbps, and the total key coding rate requirement for cross-domain QKD services accumulated on inter-domain path 2 is 600 kbps). Calculate the key coding rate distance product of each segment on each inter-domain path under different available QKD protocols (on inter-domain path 1, the key coding rate distance products of segments AB, BC, CD, DE, AC, BD, CE, AD, BE, and AE under the GG02 protocol are 1600 km•kbps, 500 km•kbps, 500 km•kbps, 1600 km•kbps, 180 km•kbps, 100 km•kbps, 180 km•kbps, 0 km•kbps, 0 km•kbps, and 0 km•kbps respectively; the key coding rate distance products of segments AB, BC, CD, DE, AC, BD, CE, AD, BE, and AE under the BB84 protocol are 1200 km•kbps, 1250 km•kbps, 1250 km•kbps, 1200 km•kbps, 1575 km•kbps, and 1500 km•kbps respectively). km•kbps, 1575 km•kbps, 1400km•kbps, 1400 km•kbps, 900 km•kbps; On inter-domain path 2, the key-coding rate-distance products of segments FG, GH, HI, IJ, FH, GI, HJ, FI, GJ, and FJ under the BB84 protocol are 1200 km•kbps, 1250 km•kbps, 1200 km•kbps, 1200 km•kbps, 1575 km•kbps, 1575 km•kbps, 1250 km•kbps, 1365 km•kbps, 1125 km•kbps, and 475 km•kbps, respectively. Their key-coding rate-distance products under the COW protocol are 1100 km•kbps, 1125 km•kbps, 1100 km•kbps, 1050 km•kbps, 1350 km•kbps, 1350 km•kbps, 1300 km•kbps, 1495 km•kbps, and 1500 km•kbps, respectively. km•kbps, 950 km•kbps); Calculate the cost-performance of each segment on each inter-domain path under different available QKD protocols (on inter-domain path 1, the cost-performance of segments AB, BC, CD, DE, AC, BD, CE, AD, BE, and AE under the GG02 protocol are 1600 km•kbps / unit, 500 km•kbps / unit, 500 km•kbps / unit, 1600 km•kbps / unit, 180 km•kbps / unit, 100 km•kbps / unit, 180 km•kbps / unit, 0 km•kbps / unit, 0 km•kbps / unit, and 0 km•kbps / unit; the cost-performance of segments AB, BC, CD, DE, AC, BD, CE, AD, BE, and AE under the BB84 protocol are 600 km•kbps / unit, 625 km•kbps / unit, 625 km•kbps / unit, and 600 km•kbps / unit, respectively). km·kbps / unit, 787.5km·kbps / unit, 750 km·kbps / unit, 787.5 km·kbps / unit, 700 km·kbps / unit, 700 km·kbps / unit, 450 km·kbps / unit; On inter-domain path 2, the cost-performance ratios of segments FG, GH, HI, IJ, FH, GI, HJ, FI, GJ, and FJ under the BB84 protocol are 600 km•kbps / unit, 625 km•kbps / unit, 600 km•kbps / unit, 600 km•kbps / unit, 787.5 km•kbps / unit, 787.5 km•kbps / unit, 625 km•kbps / unit, 682.5 km•kbps / unit, 562.5 km•kbps / unit, and 237.5 km•kbps / unit, respectively. Their key coding rate-distance products under the COW protocol are 550 km•kbps / unit, 562.5 km•kbps / unit, 550 km•kbps / unit, 525 km•kbps / unit, 675 km•kbps / unit, 675 km•kbps / unit, and 237.5 km•kbps / unit, respectively. km·kbps / unit, 747.5 km·kbps / unit, 750 km·kbps / unit, 475 km·kbps / unit); Find and select the segment with the highest cost-effectiveness and the corresponding QKD protocol from the candidate segment set on each inter-domain path, and add the segment to the selected segment set (on inter-domain path 1, the segments with the highest cost-effectiveness are segments AB and DE under the GG02 protocol. These two segments have the highest cost-effectiveness and the same value. Segment AB is added to the selected segment set by random selection; on inter-domain path 2, the segments with the highest cost-effectiveness are segments FH and GI under the BB84 protocol. These two segments have the highest cost-effectiveness and the same value. Segment FH is added to the selected segment set by random selection).

[0045] Based on the total key coding rate requirements accumulated on each inter-domain path, calculate the number of QKD devices corresponding to the protocol to be deployed on the selected segment (segment AB on inter-domain path 1 requires 7 sets of GG02 devices, and segment FH on inter-domain path 2 requires 18 sets of BB84 devices). Delete the selected segment and all segments that share any link with the selected segment from the candidate segment set (on inter-domain path 1, delete segment AB and segments AC, AD, and AE that share the same link with segment AB from the candidate segment set; on inter-domain path 2, delete segment FH and segments FG, GH, GI, FI, GJ, and FJ that share the same link with segment FH from the candidate segment set); Determine whether all segments in the selected segment set can cover the entire inter-domain path (all segments in the selected segment set of the current inter-domain paths 1 and 2 cannot cover the entire inter-domain path); execute in a loop Figure 2 Steps 3.4-3.7 in the previous section: Find and select the segment with the highest cost-effectiveness and the corresponding QKD protocol from the set of candidate segments on each inter-domain path, and add that segment to the set of selected segments (on inter-domain path 1, the segment with the highest cost-effectiveness is segment DE under the GG02 protocol, so segment DE is added to the set of selected segments; on inter-domain path 2, the segment with the highest cost-effectiveness is segment HJ under the COW protocol, so segment HJ is added to the set of selected segments). Based on the total key coding rate requirements accumulated on each inter-domain path, calculate the number of QKD devices corresponding to the protocol that needs to be deployed on the selected segment (segment DE on inter-domain path 1 requires 7 sets of GG02 devices, and segment HJ on inter-domain path 2 requires 24 sets of COW devices). Delete the selected segment and all segments that share any of the same links as the selected segment from the candidate segment set (on inter-domain path 1, delete segment DE and segments BE and CE that share the same link as segment DE from the candidate segment set; on inter-domain path 2, delete segment HJ and segments HI and IJ that share the same link as segment HJ from the candidate segment set). Determine whether all segments in the selected segment set can cover the entire inter-domain path (all segments in the selected segment set of the current inter-domain path 1 cannot cover the entire inter-domain path, and all segments in the selected segment set of the inter-domain path 2 can cover the entire inter-domain path); execute in a loop Figure 2 Steps 3.4-3.7: Find and select the most cost-effective segment and corresponding QKD protocol from the candidate segments set on each inter-domain path, and add that segment to the selected segment set (on inter-domain path 1, the most cost-effective segment is segment BD under the BB84 protocol, so segment BD is added to the selected segment set). Based on the total key coding rate requirements accumulated on each inter-domain path, calculate the number of QKD devices corresponding to the protocol used that need to be deployed on the selected segment (segment BD on inter-domain path 1 requires 17 sets of BB84 devices). Delete the selected segment and all segments that share any link with the selected segment from the candidate segment set. (On inter-domain path 1, delete segment BD and segments BC and CD that share the same link with segment BD.) Determine whether all segments in the selected segment set can cover the entire inter-domain path. (For inter-domain paths 1 and 2, all segments in the selected segment set can cover the entire inter-domain path.)

[0046] According to the number of QKD devices corresponding to the protocol used by each segment in the selected segment set on each inter-domain path, the corresponding QKD devices are deployed (on inter-domain path 1, 7 sets of GG02 devices are deployed on segment AB, 17 sets of BB84 devices are deployed on segment BD, and 7 sets of GG02 devices are deployed on segment DE; on inter-domain path 2, 18 sets of BB84 devices are deployed on segment FH, and 24 sets of COW devices are deployed on segment HJ); each inter-domain path is connected through the QKD devices deployed on each segment (connecting inter-domain paths 1 and 2).

[0047] In summary, the deployment cost of inter-domain path 1 using the proposed method is 48 units, with an average cost-performance ratio of 1134.9 km•kbps / unit per QKD device. In contrast, the deployment cost under the existing solution (i.e., deploying BB84 devices hop-by-hop at each optical node) is 76 units, with an average cost-performance ratio of 613.2 km•kbps / unit per QKD device. Therefore, the deployment cost of inter-domain path 1 is reduced by 36.8% and the cost-performance ratio is improved by 85.1% under the proposed method. The deployment cost of inter-domain path 2 using the proposed method is 60 units, with an average cost-performance ratio of 708.9 km•kbps / unit per QKD device. In contrast, the deployment cost under the existing solution (i.e., deploying BB84 devices hop-by-hop at each optical node) is 94 units, with an average cost-performance ratio of 606.4 km•kbps / unit per QKD device. Therefore, the deployment cost of inter-domain path 2 using the proposed method is reduced by 36.2%, with an average cost-performance ratio improvement of 16.9%.

[0048] The technical means disclosed in the solution of the present invention are not limited to the technical means disclosed in the above-mentioned embodiment, but also include technical solutions composed of any combination of the above technical features.

Claims

1. A method for deploying an inter-domain quantum key distribution device, characterized by: The specific steps include: Step 1: Query inter-domain path information; Step 2: Processing inter-domain path segments: Combined with the inter-domain path information queried in step 1, further calculation and determination of segment information on each inter-domain path are performed. A segment covers one link or multiple serially connected links. Step 3: Device deployment for cross-domain interconnection.

2. The method for deploying an inter-domain quantum key distribution device according to claim 1, characterized in that: The step 1 specifically includes: Step 1.1: Query the node and link information on each inter-domain path; the node types specifically include edge nodes and optical nodes; Step 1.2: Query the QKD protocols allowed on each inter-domain path and the cost of the corresponding QKD equipment. When deploying inter-domain QKD equipment, select a QKD protocol and equipment based on the "transmitter → receiver" model. The corresponding QKD equipment cost is the cost of a set of QKD equipment including one transmitter and one receiver. Step 1.3: Query the cross-domain QKD services carried on each inter-domain path and their key coding rate requirements; the key coding rate requirements of the cross-domain QKD services will accumulate on the inter-domain paths through which the cross-domain QKD services pass. When the accumulated key coding rate requirements increase, the number of QKD devices that need to be deployed on the inter-domain paths will also increase, thereby increasing the deployment cost.

3. The method for deploying an inter-domain quantum key distribution device according to claim 1, characterized in that: The step 2 specifically includes the following steps: Step 2.1: Determine the segment information that can be constructed on each inter-domain path and add the segment on the inter-domain path to the candidate segment set. The segment information specifically includes the links covered by the segment and the corresponding nodes. Step 2.2: Determine the length of each segment on each inter-domain path. The length of each segment is obtained by summing the lengths of all links covered by the segment. Step 2.3: Determine the key coding rate that each segment on each inter-domain path can provide under different QKD protocols. Combined with the length of each segment, determine the key coding rate that each segment can provide under different QKD protocols based on the key coding rate-distance formula.

4. The method for deploying an inter-domain quantum key distribution device according to claim 1, wherein: The step 3 specifically includes the following steps: Step 3.1: Calculate the total key coding rate requirement for cross-domain QKD services accumulated on each inter-domain path. The total key coding rate requirement accumulated on each inter-domain path is obtained by summing the key coding rate requirements of all cross-domain QKD services carried by the inter-domain path queried in step 1.

3. Step 3.2: Calculate the key coding rate distance product of each segment on each inter-domain path under different available QKD protocols. The key coding rate distance product of each segment under the used QKD protocol = segment length × key coding rate available with the QKD protocol used for the segment. Step 3.3: Calculate the cost-performance ratio of each segment on each inter-domain path under different available QKD protocols. The cost-performance ratio of each segment under the used QKD protocol = the key coding rate distance product / the cost of a set of QKD equipment corresponding to the used QKD protocol; Step 3.4: Find and select the segment with the highest cost-effectiveness and the corresponding QKD protocol from the set of candidate segments on each inter-domain path, and add this segment to the set of selected segments. Since each segment may have one or more available QKD protocols, the segment with the highest cost-effectiveness among the combinations of the segments and the corresponding available QKD protocols is selected here. If the same cost-effectiveness exists, a random selection is made. Step 3.5: Based on the total key coding rate requirement accumulated on each inter-domain path, calculate the number of QKD devices corresponding to the protocol to be deployed on the selected segment, where the number of QKD devices to be deployed = Indicates rounding up; Step 3.6: Delete the selected segment and all segments that share any of the same links as the selected segment from the candidate segment set to avoid link overlap in subsequent segment selection. Step 3.7: Determine whether all segments in the selected segment set can cover the entire inter-domain path. If not, then loop through steps 3.4-3.

7. Otherwise, it means that all segments in the selected segment set on each current inter-domain path can cover the entire inter-domain path. Step 3.8: Deploy the corresponding QKD devices based on the number of QKD devices corresponding to the protocol used by each segment in the selected segment set on each inter-domain path; Step 3.9: Connect each inter-domain path through the QKD devices deployed on each chain segment. At this point, the inter-domain QKD device deployment is complete.

5. The method for deploying an inter-domain quantum key distribution device according to claim 1, wherein: When calculating the cost-effectiveness of each segment on each inter-domain path under different available QKD protocols in step 3.3, the units of each parameter should be kept consistent.

6. The apparatus for deploying an inter-domain quantum key distribution device according to claim 1, characterized in that: The device mainly includes a master control module, an inter-domain path information query module, a segment processing module, and a device deployment module. The master control module is responsible for controlling the operation of the entire device. The inter-domain path information query module is used to query the relevant information of each inter-domain path. It specifically includes a node and link query unit, a protocol and device query unit, and a service key coding rate query unit. The segment processing module is used to process the segments on each inter-domain path, specifically including a segment information determination unit, a segment length determination unit, and a key coding rate determination unit; The device deployment module is used to complete the QKD device deployment on each inter-domain path, specifically including a demand calculation unit, a key coding rate distance product calculation unit, a cost-effectiveness calculation unit, a segment search and selection unit, a device quantity calculation unit, a segment set update unit, a judgment unit, a device deployment unit, and a path connectivity unit.

7. The deployment device for an inter-domain quantum key distribution device according to claim 6, characterized in that: The node and link query unit in the inter-domain path information query module is mainly used to query the node and link information on each inter-domain path; the protocol and device query unit is mainly used to query the QKD protocol allowed to be used on each inter-domain path and the cost of the QKD device corresponding to the protocol; The service key coding rate query unit is mainly used to query the cross-domain QKD services carried on each inter-domain path and their key coding rate requirements.

8. The deployment device for an inter-domain quantum key distribution device according to claim 6, characterized in that: The segment information determination unit in the segment processing module is used to determine the segment information that can be constructed on each inter-domain path and add the segments on the inter-domain path to the candidate segment set; the segment length determination unit is used to determine the length of each segment on each inter-domain path; The key coding rate determination unit is used to determine the key coding rate that can be provided by each segment on each inter-domain path under different QKD protocols.

9. The deployment device for an inter-domain quantum key distribution device according to claim 6, characterized in that: The demand calculation unit in the device deployment module is used to calculate the total key coding rate requirement of the cross-domain QKD service accumulated on each inter-domain path; The key coding rate distance product calculation unit is used to calculate the key coding rate distance product of each segment on each inter-domain path under different available QKD protocols; The cost-performance calculation unit is used to calculate the cost-performance of each segment on each inter-domain path under different available QKD protocols; The segment search and selection unit is used to search and select the segment with the highest cost-effectiveness and the corresponding QKD protocol from the candidate segment set on each inter-domain path, and add the segment to the selected segment set; The device quantity calculation unit is used to calculate the number of QKD devices corresponding to the protocol to be deployed on the selected segment based on the total key coding rate requirements accumulated on each inter-domain path; The segment set updating unit is used to delete the selected segment and all segments that cover any of the same links as the selected segment from the candidate segment set; The judging unit is used to judge whether all segments in the selected segment set can cover the entire inter-domain path; The device deployment unit is used to deploy corresponding QKD devices according to the number of QKD devices corresponding to the protocol used by each segment in the selected segment set on each inter-domain path; The path connectivity unit is used to connect each inter-domain path through the QKD devices deployed on each segment.

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