A multi-node secure communication method and system based on quantum key distribution

Abstract

The application discloses a kind of multi-node secure communication method and system based on quantum key distribution, including, by evaluating the multidimensional parameter of quantum channel, dynamically update node reputation value, construct four-dimensional topological graph database, and generate candidate routing path based on Monte Carlo tree search algorithm;Further combined with reinforcement learning to build state-action space, optimize path selection using double Q network and priority experience replay mechanism;The application solves the defects of traditional quantum network static routing strategy through multidimensional channel evaluation and dynamic update of node reputation value, improves communication security and efficiency, and supports low-latency, high-reliable key distribution of complex quantum network.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of communication security technology, and in particular to a multi-node secure communication method and system based on quantum key distribution. BACKGROUND

[0002] With the rapid development of quantum communication technology, quantum key distribution (QKD) has shown great application potential in ensuring communication security due to its security based on quantum mechanics. In recent years, quantum key distribution technology has gradually evolved from the initial point-to-point communication mode to the multi-node networked communication mode to meet more extensive practical application needs. However, in a multi-node quantum communication network, the increase in the number of nodes and the complexity of the network topology make the quality evaluation of quantum channels, the dynamic construction of network topology, and the efficient selection of secure routing become key problems to be solved. Existing quantum key distribution networks usually adopt static or simple dynamic routing strategies, lack multi-dimensional fine evaluation of channel quality, and are difficult to effectively respond to the dynamic changes of quantum channel quality and the real-time fluctuations of node reputation, resulting in difficulty in effectively guaranteeing the overall security and communication efficiency of the network.

[0003] Specifically, the existing technology often only focuses on a single indicator in the quality evaluation of quantum channels, ignoring the comprehensive influence of multi-dimensional factors, and thus it is difficult to accurately reflect the real-time state of the channel. In addition, the existing technology lacks a dynamic updating mechanism for network node reputation values, and cannot timely identify and isolate nodes with declining reputation or potential malicious nodes, resulting in an increase in network security risks. Moreover, traditional routing selection methods mostly use simple shortest path or fixed weight algorithms, and fail to fully consider the dynamic changes of network topology and the real-time updating of node reputation values, making it difficult to quickly and accurately determine the optimal secure communication path in a complex network environment.

[0004] Therefore, how to realize multi-dimensional fine evaluation of quantum channel quality, real-time dynamic updating of node reputation values, and efficient optimization of secure routing paths has become an important technical problem to be solved in the field of multi-node secure communication based on quantum key distribution. SUMMARY

[0005] This section is intended to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification to avoid obscuring the purpose of this section, the abstract and the title, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0006] In view of the above existing problems, the present application is proposed. Therefore, the present application provides a multi-node secure communication method based on quantum key distribution to solve the problems mentioned in the background art.

[0007] To solve the above technical problems, the present application provides the following technical solutions:

[0008] In a first aspect, the present application provides a multi-node secure communication method based on quantum key distribution, comprising:

[0009] Evaluating the quality of the quantum channel, generating a multi-dimensional channel quality parameter set, and updating the reputation value of each node in the network through the multi-dimensional channel quality parameter set;

[0010] According to the updated reputation value of each node in the network and the multi-dimensional channel quality parameter set, a topology graph database of the network is constructed, and the constructed topology graph database is used as input to generate a candidate routing path by applying a Monte Carlo tree search algorithm;

[0011] The generated candidate routing path is optimized, and the final routing path is selected in combination with the real-time network state, ensuring the security of quantum key distribution in multi-node communication.

[0012] As a preferred scheme of the multi-node secure communication method based on quantum key distribution, the multi-dimensional channel quality parameter set comprises:

[0013] Photon transmission efficiency, link stability and quantum error rate dynamic change;

[0014] The basic attenuation of the quantum channel is calculated by logarithmic ratio, and the additional attenuation caused by external environmental disturbance is combined to obtain the photon transmission efficiency;

[0015] The stability factor is constructed by transmission delay and quantum error rate, and the link stability is evaluated by the stability factor;

[0016] The quantum error rate dynamic change is evaluated by the quantum error rate dynamic weight.

[0017] As a preferred scheme of the multi-node secure communication method based on quantum key distribution, the updating of the reputation value of each node in the network through the multi-dimensional channel quality parameter set comprises:

[0018] The reputation value is updated based on the relay success rate and online stability of the nodes in the network;

[0019] A reputation value interval is generated by preset high and low thresholds, and when the reputation value is less than the minimum value of the reputation value interval, a reputation verification protocol is triggered;

[0020] When the reputation value is greater than the maximum value of the reputation value interval, a fast election channel is activated.

[0021] As a preferred scheme of the multi-node secure communication method based on quantum key distribution, wherein: a topology graph database of the network is constructed, including:

[0022] The topology graph database is constructed by periodically sending entangled photon pulse sequences and synchronous detection frames.

[0023] The topology graph database is stored as a four-dimensional graph structure, including a node set, an edge set, a weight, and a time label, and the weight is based on the dynamic changes of quantum error rate and photon transmission efficiency.

[0024] As a preferred scheme of the multi-node secure communication method based on quantum key distribution, wherein: the constructed topology graph database is used as input to apply a Monte Carlo tree search algorithm to generate candidate routing paths, including:

[0025] The node state of the search tree is defined by the Monte Carlo tree search algorithm, and the node state is represented by the path cumulative cost and the remaining potential value.

[0026] The path cumulative cost is obtained by weighted summation of the weight of each edge in the topology graph database, and considering the relationship between edge weight and hop number.

[0027] The remaining potential value is obtained by calculating the minimum value of the reputation value of the node and the link stability.

[0028] As a preferred scheme of the multi-node secure communication method based on quantum key distribution, wherein: the generated candidate routing paths are optimized, including:

[0029] A state-action space is constructed using reinforcement learning.

[0030] The state space is composed of the current node identifier, the remaining hop number, and the minimum reputation value of the node in the path and the maximum quantum error rate weight of the link in the path.

[0031] The action space is composed of direct relay, cross-layer relay and emergency channel activation.

[0032] As a preferred scheme of the multi-node secure communication method based on quantum key distribution, wherein: further comprising:

[0033] The reinforcement learning uses a double Q network update mechanism and a priority experience replay.

[0034] The double Q network is the main network and the target network, and the priority experience replay is based on the time difference error to determine the sampling probability.

[0035] In a second aspect, the present application provides a multi-node secure communication system based on quantum key distribution, comprising:

[0036] A channel quality evaluation and reputation updating module is configured to evaluate the quality of a quantum channel, generate a multi-dimensional channel quality parameter set, and update the reputation values of nodes in the network through the multi-dimensional channel quality parameter set;

[0037] A topology modeling and routing planning module is configured to construct a topology graph database of the network according to the updated reputation values of nodes in the network and the multi-dimensional channel quality parameter set, and apply a Monte Carlo tree search algorithm to generate candidate routing paths using the constructed topology graph database as input;

[0038] A path optimization module is configured to optimize the generated candidate routing paths and select a final routing path in combination with real-time network states, thereby ensuring the security of quantum key distribution in multi-node communication.

[0039] In a third aspect, the present application provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and wherein the processor implements any step of the above method when executing the computer program.

[0040] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements any step of the above method.

[0041] Compared with the prior art, the present application has the following advantages:

[0042] 1. The present application solves the limitations of traditional single-index analysis by constructing a multi-dimensional parameter set through comprehensive evaluation of photon transmission efficiency, link stability, and dynamic changes in bit error rate.

[0043] 2. By constructing a four-dimensional dynamic topology graph and combining the Monte Carlo tree search algorithm to generate routing candidate paths, the present application can achieve fast convergence of the globally optimal path in complex network environments, improve routing efficiency, and reduce communication latency by real-time response to network fluctuations, thereby ensuring low bit error rate transmission and achieving high efficiency and security of the quantum key distribution network. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments description. Obviously, the drawings in the following description only represent some of the embodiments of the present application, and all other drawings can be obtained by those skilled in the art without any creative effort based on these drawings. Among them:

[0045] Figure 1 The overall flowchart of the multi-node secure communication method based on quantum key distribution according to an embodiment of the present application. DETAILED DESCRIPTION

[0046] In order to make the above-mentioned objects, features and advantages of the present application more apparent, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort should fall within the scope of protection of the present application.

[0047] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in other manners different from those described herein without departing from the scope of the present application. It will be understood by those skilled in the art that various modifications can be made to the embodiments described herein without departing from the scope of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0048] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. The "in one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an independent or alternative embodiment that excludes other embodiments.

[0049] The present application is described in detail in conjunction with the schematic diagram. In the detailed description of the embodiments of the present application, the cross-sectional view of the device structure will be partially enlarged without the general proportion for the convenience of description, and the schematic diagram is only an example, which should not limit the scope of protection of the present application herein. In addition, the three-dimensional spatial dimensions of length, width and depth should be included in the actual manufacture.

[0050] Meanwhile, in the description of the present application, it should be noted that the terms "up, down, inner and outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first, second or third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0051] Unless otherwise defined, the terms "mounting, connecting, associating" in the present application should be interpreted broadly, for example: can be fixed connection, detachable connection or integral connection; can also be mechanical connection, electrical connection or direct connection, can also be indirectly connected through intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0052] Embodiment 1

[0053] Reference Figure 1 For the first embodiment of the present application, the embodiment provides a multi-node secure communication method based on quantum key distribution, comprising:

[0054] S1, evaluating the quality of the quantum channel, generating a multi-dimensional channel quality parameter set, and updating the reputation value of each node in the network through the multi-dimensional channel quality parameter set;

[0055] It should be noted that evaluating the quality of the quantum channel is an important step to ensure the security and reliability of the quantum key distribution (QKD) network, so it is necessary to comprehensively evaluate the quantum channel through multi-dimensional parameters;

[0056] Specifically, the multi-dimensional parameters take the photon transmission efficiency, link stability and dynamic change of quantum error rate as evaluation indexes of the quality of the quantum channel;

[0057] Specifically, the photon transmission efficiency measures the channel loss, reflecting the loss degree of photons in the transmission process;

[0058] Further, at the sending end, a high-precision power meter is used to measure the power of the sending end, and at the receiving end, a single-photon detector is used to measure the power of the receiving end. The basic attenuation of the quantum channel is calculated by logarithmic ratio, and the additional attenuation caused by external environmental disturbance (such as temperature, vibration, electromagnetic interference) is considered. The basic attenuation and the additional attenuation are added to obtain the time-varying channel attenuation coefficient;

[0059] Specifically, the time-varying channel attenuation coefficient can effectively reflect the photon transmission efficiency. The time-varying channel attenuation coefficient α(t) is expressed by the formula:

[0060]

[0061] Where P t represents the power of the sending end, P r represents the power of the receiving end, represents the basic attenuation, and Δα(θ) represents the additional attenuation; t represents time;

[0062] It should be noted that, unlike traditional communication methods, the transmitting end is the source of the signal, responsible for generating and sending the signal, in quantum communication, it is usually a photon source, used to generate single photons or entangled photon pairs; its communication process is: through the transmitting end, the quantum information (quantum bits) carried in the photon is transmitted to the receiving end through the quantum channel (such as optical fiber or free space); and the receiving end is the receiving point of the signal, responsible for detecting and decoding the signal sent by the transmitting end, in quantum communication, it is usually equipped with a single photon detector, used to detect the arriving photons and extract the quantum information (quantum bits) therein; that is, the transmitting end refers to the node that sends quantum signals (photons), and the receiving end refers to the node that receives and measures quantum signals; by comparing the measurement results of the transmitting end and the receiving end, a shared key, i.e. quantum key, is generated;

[0063] Specifically, the link stability reflects the reliability of the channel in long-time operation, which includes transmission delay and quantum error rate, the quantum error rate is obtained from the quantum information transmitted in quantum communication, and is used to measure the error rate of qubit transmission;

[0064] Further, the transmitting end embeds the sending time into the frame to form a timestamped probe frame, which is then sent to the receiving end. After receiving the probe frame, the receiving end reads the timestamped probe frame and compares it with the receiving time of the receiving end to calculate the transmission time of the probe frame in the network and obtain the measurement transmission delay of the network;

[0065] It should be noted that the probe frame is a special network data packet used to test the performance or state of the network, which usually carries specific information to help the receiving end analyze network characteristics such as delay or packet loss rate, etc.

[0066] Further, a stability factor is constructed by the transmission delay and the quantum error rate.

[0067] Specifically, the formula of the stability factor is as follows:

[0068]

[0069] Where Δt represents the transmission delay, μ Δt represents the mean of the delay, represents the variance of the delay, ρ QBER,Δt represents the correlation coefficient of the quantum error rate (Quantum Bit Error Rate, QBER) and its transmission delay Δt; l represents the stability factor, if the stability factor tends to 1, the link is more stable;

[0070] It should be noted that if the dynamic change of quantum error rate is to be obtained, not only the QBER data needs to be monitored in real time, but also the critical threshold and slope factor of quantum error rate need to be defined through experiments; wherein in the QKD, the critical threshold of quantum error rate refers to the maximum error rate allowed in the quantum channel, and exceeding this value means that there is eavesdropping (Eve) in the channel, so that the security of quantum key distribution cannot be guaranteed; and the slope factor refers to the decay rate of the secure key rate with distance (or channel loss), which reflects the robustness of the system to channel loss and noise, that is, the slope factor determines the maximum safe distance of quantum key distribution; in this case, the critical threshold and slope factor of quantum error rate are used to define the dynamic weight of quantum error rate to reflect the dynamic change of quantum error rate, wherein the dynamic weight of quantum error rate QBER w is defined as follows:

[0071]

[0072] Wherein, Q th is the critical threshold of quantum error rate, and k is the slope factor of quantum error rate;

[0073] It should be noted that since the reputation value of the node reflects the reliability and performance of the node in the network, the reflected photon transmission efficiency, link stability and quantum error rate are quantified as specific numerical values, which are used as the basis for updating the reputation value of the node, so that the dynamic adjustment of the reputation value of each node in the network can be realized, which can more accurately reflect the real-time performance of the node and ensure the reliability and security of the node in the network;

[0074] Further, in addition to the reflected photon transmission efficiency, link stability and quantum error rate, the reputation value update of the node is also based on the relay success rate and online stability of the node in the network, and the reputation value of the node is obtained as follows:

[0075]

[0076] Wherein, R i (t) represents the reputation value of the i-th node, λ is a forgetting factor, which represents the weight of the historical reputation value and the current reputation value, T c represents the online stability, and C s represents the relay success rate;

[0077] It should be noted that the relay success rate includes the reflected photon transmission efficiency, link stability and quantum error rate, because the evaluation of channel quality directly affects the relay success rate of the node in the network;

[0078] Further, a preset high and low threshold is used to generate a reputation value interval, and when the reputation value is less than the minimum value of the reputation value interval, a reputation verification protocol is triggered;

[0079] It should be noted that the preset high and low threshold is set by an expert experience method, and the value is the upper and lower limits of the interval range, and the purpose is to judge the reliability of the node; when the reputation value is less than the minimum value of the reputation value interval, it means that the node is unreliable and needs additional verification; when the reputation value is greater than the maximum value of the reputation value interval, it means that the node is very reliable, so no verification is needed and it can be directly involved in network decision or resource allocation;

[0080] Specifically, the reputation verification protocol is a security protocol used to audit and verify the node when its reputation value is abnormal. The protocol can use Shamir secret sharing or Byzantine fault tolerance algorithm;

[0081] Further, when the reputation value is greater than the maximum value of the reputation value interval, a fast election channel is activated;

[0082] Specifically, the fast election channel is an optimized network decision mechanism that allows high-reputation nodes to directly participate in important decisions or resource allocation in the network, that is, high-reputation nodes can become relay nodes first, optimize the communication path, and thus improve the overall performance of the network;

[0083] S2, according to the reputation value of each node in the updated network and the multi-dimensional channel quality parameter set, a topology graph database of the network is constructed, and the constructed topology graph database is used as input to apply a Monte Carlo tree search algorithm to generate a candidate routing path;

[0084] It should be noted that since quantum key distribution (QKD) relies on the quality of the quantum channel to be secure, and in a multi-node network, the connection relationship between nodes is dynamically changing, a method is needed to monitor and record these changes in real time;

[0085] Further, a topology graph database is constructed by periodically sending entangled photon pulse sequences and synchronous detection frames;

[0086] It should be noted that the entangled photon pulse sequence is used to detect the channel state in real time, and the synchronous detection frame contains a timestamp and a topology discovery code, which is used to ensure the uniqueness of the information in the topology graph database;

[0087] Further, the topology graph database is stored as a four-dimensional graph structure, and the four-dimensional graph structure includes a node set, an edge set, a weight, and a time marker;

[0088] Specifically, the constructed topology graph database G can be represented as:

[0089] G(V,E,W,T)

[0090] wherein, V represents a node set of the network, E represents a set of edges constituted by nodes of the network, i.e. an edge set, W represents a weight of an edge in the network, and T represents a time label used to record the timeliness of information in the topology graph database;

[0091] Specifically, the weight is obtained based on dynamic changes of a quantum bit error rate and a photon transmission efficiency:

[0092] W = QBER w (i,j) x a(t)

[0093] wherein, (i,j) represents an edge of node i and node j;

[0094] Specifically, if the network is undirected, QBER w (i,j) = QBER w (j,i), otherwise QBER w (i,j) ≠ QBER w (j,i);

[0095] It needs to be explained that in a multi-node quantum communication network, due to the characteristics of the topology graph database, the topology structure thereof can change at any time, and if a traditional shortest path or fixed weight algorithm is used, limited adjustment can only be made in a static or simple dynamic scenario, and it is difficult to take into account real-time updates of multi-dimensional parameters; in addition, the search tree and simulation data of MCTS can provide rich prior information and preliminary strategies for the reinforcement learning algorithm, so that the convergence speed of the reinforcement learning on the network is faster and the effect is better;

[0096] Further, through the Monte Carlo tree search algorithm, a node state of a search tree is defined, a candidate path is generated, and a path with the minimum total cost is selected for key distribution;

[0097] Specifically, the node state represents a path cumulative cost and a remaining potential value;

[0098] Further, the path cumulative cost is obtained by weighted summation of weights of each edge in the topology graph database and consideration of a relationship between the edge weight and the hop number;

[0099] Specifically, the path cumulative cost C(s) is calculated by the following formula:

[0100]

[0101] wherein, W g is the weight of the edge g, and Δd represents a hop number increment, d maxis expressed as the maximum allowed hops; path represents the candidate path (i.e., the path sequence from the source node to the current node) currently being evaluated by the Monte Carlo Tree Search (MCTS);

[0102] It should be noted that the hop increment represents the increase in the total number of hops (usually 1) when the path is expanded from the current node to the next node; for example, if the current path already contains 3 hops (i.e., through 3 relay nodes), then after expanding to the next node, the hop increment is 1 and the total number of hops becomes 4; the maximum allowed hops is mainly used to limit the maximum length of the quantum communication path (i.e., the maximum number of relay nodes); because each additional hop requires quantum state storage, entanglement exchange, and other operations at the relay node, which cumulatively increases the transmission delay, and the quantum error rate may increase due to operational errors when passing through each relay node, so the maximum allowed hops must be limited;

[0103] Further, the remaining potential value is obtained by calculating the minimum value of the reputation value of the node and the link stability;

[0104] Specifically, the remaining potential value V(s) is calculated by the following formula:

[0105]

[0106] where v represents a candidate node in the network topology;

[0107] It should be noted that when the Monte Carlo Tree Search generates a routing path, the algorithm needs to expand from the end node of the current path (such as node C) to adjacent nodes (such as D, E, and F); for example, if the adjacent node D is not in the current path (i.e., D∉path), then it is allowed to expand to A→B→C→D, but if the adjacent node B is already in the current path (i.e., B∈path), then it is prohibited to expand to A→B→C→B (forming a loop); thus, the design of can ensure that the candidate path does not pass through the same node repeatedly, preventing the formation of a loop; in addition, since the explored nodes have been limited, the search space of the algorithm is further reduced, which improves the efficiency of the Monte Carlo Tree Search algorithm;

[0108] S3, optimizing the generated candidate routing path and selecting a final routing path in combination with the real-time network state, ensuring the security of quantum key distribution in multi-node communication;

[0109] Further, reinforcement learning is used to construct a state-action space without considering reward factors;

[0110] ​Further, the state space is composed of current node identity, remaining hop number, and minimum reputation value of nodes in the path and maximum quantum error rate weight of links in the path;

[0111] Specifically, the remaining hop number is obtained by subtracting the hop number from the maximum allowed hop number from the current node to the target node;

[0112] Specifically, the current node identity is obtained by one-hot encoding;

[0113] Further, the action space is composed of direct connection relay, cross-layer relay, and emergency channel activation;

[0114] Specifically, the direct connection relay is defined as selecting the next hop relay node directly connected to the current node;

[0115] It should be noted that if the current node has only two adjacent nodes and both have joined the routing path, the direct connection relay action is shielded, and the cross-layer or emergency channel is forced to be selected;

[0116] Specifically, the cross-layer relay is defined as skipping intermediate nodes and connecting to non-adjacent but directly reachable nodes;

[0117] It should be noted that the emergency channel activation is to enable a backup link (such as a satellite relay or a high-redundancy optical fiber), and the cost is higher, and the non-essential situation is set to not trigger the state;

[0118] Further, the reinforcement learning adopts a double Q network update mechanism and a priority experience replay;

[0119] Specifically, the double Q network is a main network and a target network, and the priority experience replay determines a sampling probability based on a time difference error;

[0120] It should be noted that the main network is updated in real time to select the action space, and the target network is periodically synchronized with the main network parameters to calculate the target Q value;

[0121] Specifically, the double Q network update mechanism is a parameter delay synchronization, that is, the main network weight is copied to the target network weight every N steps, wherein the loss function L(θ) of the main network is represented as:

[0122]

[0123] Wherein, θ represents the main network, Q(s, a; θ) represents the Q value prediction of the main network for action a under state s; and y represents the target Q value;

[0124] Specifically, the priority experience replay sets the priority according to the time difference error:

[0125] δ = |y - Q(s, a; θ)|

[0126] Wherein, δ represents the difference between the current Q value prediction and the target value, the greater the error, the higher the priority;

[0127] Specifically, the sampling probability H(i) is determined by the following formula:

[0128]

[0129] Wherein, β represents the priority intensity coefficient, taking 0 is uniform sampling, taking 1 is priority sampling; p i represents the priority;

[0130] It should be explained that by binding the action space of reinforcement learning with the physical constraints of quantum network (routing path, node reputation value and quantum error rate), invalid exploration in routing path is avoided, so that the optimal secure communication path can be quickly and accurately determined in complex network environment.

[0131] Further, the embodiment also provides a multi-node secure communication system based on quantum key distribution, comprising:

[0132] The channel quality assessment and reputation updating module is configured to assess the quality of the quantum channel, generate a multi-dimensional channel quality parameter set, and update the reputation values of the nodes in the network through the multi-dimensional channel quality parameter set;

[0133] The topology modeling and routing planning module is configured to construct a topology graph database of the network according to the updated reputation values of the nodes in the network and the multi-dimensional channel quality parameter set, and apply a Monte Carlo tree search algorithm to generate candidate routing paths by taking the constructed topology graph database as input;

[0134] The path optimization module is configured to optimize the generated candidate routing paths and select a final routing path in combination with real-time network state, thereby ensuring the security of quantum key distribution in multi-node communication.

[0135] The embodiment also provides a computer device suitable for the case of the multi-node secure communication method based on quantum key distribution, comprising:

[0136] The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions to realize the multi-node secure communication method based on quantum key distribution proposed in the above embodiment.

[0137] The computer device can be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected by a system bus. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for running the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is configured to perform wired or wireless communication with an external terminal. The wireless communication can be achieved by WIFI, an operator network, NFC (Near Field Communication) or other technologies. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer overlaid on the display screen, or a key, trackball or touchpad arranged on the shell of the computer device, or an external keyboard, touchpad or mouse.

[0138] The embodiment further provides a storage medium having a computer program stored thereon, and the computer program is executed by a processor to implement the multi-node secure communication method based on quantum key distribution as described in the above embodiment.

[0139] The storage medium provided by the embodiment belongs to the same inventive concept as the data storage method provided by the above embodiment. The technical details not described in the embodiment can be referred to the above embodiment, and the embodiment has the same beneficial effects as the above embodiment.

[0140] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can be in the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware. In addition, the present application can be in the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present application can be implemented in various computer languages, such as object-oriented programming language Java and interpreted scripting language JavaScript.

[0141] The present application is described with reference to flowcharts and / or block diagrams according to the methods, devices (systems) and computer program products of the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing devices to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices produce a machine that implements the functions described in the flowcharts and / or block diagrams.Figure 1 one or more processes and / or functions specified in the block or blocks. Figure 1 one or more processes and / or functions specified in the block or blocks.

[0142] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the Figure 1 one or more processes and / or functions specified in the block or blocks. Figure 1 one or more processes and / or functions specified in the block or blocks.

[0143] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the Figure 1 one or more processes and / or functions specified in the block or blocks. Figure 1 one or more processes and / or functions specified in the block or blocks.

[0144] While the preferred embodiments of the application have been described, additional variations and modifications can be made to the preferred embodiments by those of skill in the art once they have the benefit of the present disclosure without departing from the spirit and scope of the application. Accordingly, the appended claims are intended to encompass within their scope all such variations and modifications as are within the scope of the application.

[0145] It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application cover the modifications and variations of this application provided they come within the scope of the appended claims and their equivalents.

Claims

1. A multi-node secure communication method based on quantum key distribution, characterized in that, include: The quality of the quantum channel is evaluated, a multi-dimensional channel quality parameter set is generated, and the reputation value of each node in the network is updated using the multi-dimensional channel quality parameter set. Based on the reputation values ​​of each node in the updated network and the multi-dimensional channel quality parameter set, a network topology database is constructed. The constructed topology database is used as input, and the Monte Carlo tree search algorithm is applied to generate candidate routing paths. The network topology database includes: A topology database is constructed by periodically sending entangled photon pulse sequences and synchronous detection frames; The topology graph database is stored as a four-dimensional graph structure, which includes a node set, an edge set, weights, and a time stamp. The weights are obtained based on the dynamic changes of the quantum error rate and the photon transmission efficiency. The step of using the constructed topology database as input and applying the Monte Carlo tree search algorithm to generate candidate routing paths includes: The Monte Carlo tree search algorithm defines the node state of the search tree, which is represented by the cumulative path cost and the remaining potential value. The cumulative cost of the path is obtained by weighted summation of the weights of each edge in the topology graph database and considering the relationship between edge weights and hop count. The remaining potential value is obtained by calculating the minimum of the node's reputation value and link stability. The generated candidate routing paths are optimized, and the final routing path is selected based on the real-time network status, ensuring the security of quantum key distribution in multi-node communication.

2. The multi-node secure communication method based on quantum key distribution as described in claim 1, characterized in that, The multi-dimensional channel quality parameter set includes: Dynamic changes in photon transmission efficiency, link stability, and quantum bit error rate; The photon transmission efficiency is obtained by calculating the basic attenuation of the quantum channel using a logarithmic ratio and combining it with the additional attenuation caused by external environmental disturbances. A stability factor is constructed by measuring transmission delay and quantum bit error rate, and the stability of the link is evaluated using the stability factor. The dynamic changes in the quantum error rate are evaluated using a dynamic weighting of the quantum error rate.

3. The multi-node secure communication method based on quantum key distribution as described in claim 2, characterized in that, The reputation values ​​of each node in the network are updated using the multi-dimensional channel quality parameter set, including: The reputation value is updated based on the relay success rate and online stability of nodes in the network; A reputation value range is generated by setting high and low thresholds. When the reputation value is less than the minimum value of the reputation value range, the reputation verification protocol is triggered. When the reputation value is greater than the maximum value in the reputation value range, the fast election channel is activated.

4. The multi-node secure communication method based on quantum key distribution as described in claim 1, characterized in that, Optimize the generated candidate routes, including: Reinforcement learning is used to construct a state-action space; The state space consists of the current node identifier, the remaining hop count, the minimum reputation value of the nodes in the path, and the maximum quantum error rate weight of the links in the path. The action space consists of direct relay, cross-layer relay and emergency channel activation.

5. The multi-node secure communication method based on quantum key distribution as described in claim 4, characterized in that, Also includes: The reinforcement learning employs a dual Q-network update mechanism and priority experience replay. The dual-Q network is the master network and the target network, and the priority experience replay is based on the temporal differential error to determine the sampling probability.

6. A multi-node secure communication system based on quantum key distribution, comprising the multi-node secure communication method based on quantum key distribution as described in any one of claims 1 to 5, characterized in that, include: The channel quality assessment and reputation update module is configured to assess the quality of the quantum channel, generate a multi-dimensional channel quality parameter set, and update the reputation value of each node in the network using the multi-dimensional channel quality parameter set. The topology modeling and routing planning module is configured to construct a network topology graph database based on the reputation values ​​of each node in the updated network and the multi-dimensional channel quality parameter set, and to use the constructed topology graph database as input to generate candidate routing paths using the Monte Carlo tree search algorithm. The path optimization module is configured to optimize the generated candidate routing paths and select the final routing path based on the real-time network status, thereby ensuring the security of quantum key distribution in multi-node communication.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 5.

Images