Large-scale node dynamic security networking method and system for satellite-ground convergence network

Abstract

The invention discloses a dynamic security networking method and system for large-scale nodes of a satellite-ground convergence network. The invention provides a rapid and safe networking authentication method between large-scale adjacent nodes, cross-layer nodes and cross-domain nodes for the large-scale heterogeneous node safe networking requirement in a 6G heterogeneous fusion network scene. By fusing a key management system based on a key tree and a hash chain, a trusted identity label and a block chain technology, efficient identity authentication and session key negotiation among large-scale satellite nodes can be realized, the communication overhead and the calculation overhead of multi-round interaction are reduced, the requirements of the 6G network for flexibility and dynamics can be met, and in addition, the service life of the 6G network is prolonged. Direct trust establishment among heterogeneous nodes can be promoted, and the expansibility and interoperability of the network are improved.

Description

Technical Field

[0001] This invention belongs to the field of communication technology, specifically relating to a method and system for dynamic and secure networking of large-scale nodes in a space-ground integrated network. Background Technology

[0002] With the rapid development of 6G technology, the integrated air-space-ground-sea network, as its core component, is gradually moving from concept to reality. 6G not only needs to continue the high speed, low latency, and high reliability of 5G, but also strives to break through the physical boundaries of traditional terrestrial networks. Through the deep integration of satellites, drones, high-altitude platforms, maritime nodes, and ground base stations, it aims to build a globally covering communication infrastructure supporting full-domain intelligence. In remote mountainous areas, deserts, and oceans where traditional terrestrial networks are difficult to deploy due to geographical limitations, large-scale satellite networking can leverage the wide-area coverage capabilities of satellites to extend signals, playing a crucial role in achieving seamless global 6G coverage. However, achieving large-scale secure satellite networking presents many severe challenges. On the one hand, low-Earth orbit satellites (such as the GW constellation) move at high speeds of 7.8 km / s, leading to frequent reconfiguration of inter-satellite links. Existing satellite networking protocols heavily rely on centralized ground facilities, requiring re-authentication and multiple rounds of interaction during satellite handover. Furthermore, the node-by-node interaction process of multi-hop authentication protocols causes the communication overhead of large-scale inter-satellite networking to increase exponentially, failing to meet the low-latency requirements of 6G heterogeneous converged networks. On the other hand, in cross-domain identity authentication scenarios involving multi-national satellite collaboration, traditional Public Key Infrastructure (PKI) solutions struggle to meet security requirements due to their lengthy certificate chains and single-point-of-failure risks. Existing inter-satellite networking authentication protocols typically rely on pre-shared keys, which often trigger a complete network topology reconfiguration during key updates. Therefore, they cannot support the dynamic addition and removal of massive numbers of nodes in 6G heterogeneous converged networks, nor the dynamic cluster fusion of groups. Furthermore, existing satellite networking authentication protocols are primarily designed for small-scale homogeneous networks and lack multi-domain collaboration mechanisms, preventing the establishment of direct trust between different types of heterogeneous nodes and severely limiting their scalability in 6G heterogeneous converged scenarios.

[0003] Specifically, the existing technology has the following problems: (1) Authentication problem between large-scale neighboring nodes: Existing multi-hop authentication protocols use a node-by-node interaction method when performing authentication between large-scale neighboring nodes. While this method is barely feasible in small-scale networks, it leads to an exponential increase in communication overhead in large-scale satellite networking scenarios. For example, when data needs to be transmitted between hundreds of nodes and authenticated multiple times, each node needs to perform a complete authentication process, which not only increases the communication load significantly but also significantly prolongs the data transmission latency. This latency is unacceptable in 6G heterogeneous converged networks because 6G networks require extremely low latency characteristics to support application scenarios with extremely high response speed requirements, such as real-time communication, telemedicine, and autonomous driving.

[0004] (2) Cross-layer node authentication problem: In 6G heterogeneous converged networks, nodes are divided into different layers, such as the physical layer, network layer, and application layer. Nodes at different layers differ in function and communication protocols, making it difficult for existing authentication protocols to establish an efficient authentication mechanism between these different layers. The lack of an efficient cross-layer authentication mechanism means that communication between nodes at different layers requires a complex authentication process, which not only increases communication latency but may also lead to communication interruption or data loss. For example, in the scenario of IoT and satellite network convergence, communication between IoT devices (usually located at the application layer) and satellite nodes (possibly located at the network layer or physical layer) requires authentication across multiple layers, which seriously affects communication efficiency and user experience. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, this invention provides a method and system for large-scale dynamic secure networking of nodes in a space-ground integrated network.

[0006] The technical problem to be solved by this invention is achieved through the following technical solution: This invention provides a method for large-scale dynamic secure networking of nodes in a space-ground integrated network, comprising: When a first satellite group containing multiple first satellites needs to communicate internally, the first group leader in the first satellite group and the other first satellites in the first satellite group verify each other and construct the first key tree of the first satellite group based on the trusted identity identifier, public and private keys obtained when registering with the UDM of the management domain to which they belong. The first group leader and each other first satellite determine a first session key for internal communication within the first satellite group based on the first key tree; When a target satellite in the first satellite group needs to communicate with a neighboring node of a lower-level device group, the target satellite and each device in the device group perform mutual verification and construct a second key tree based on the first preset key, the trusted identity identifier of the target satellite and the device, the identifier of the UDM of the management domain, the device identifier of the device group, and the second preset key of the device group; the first satellite group and the device group belong to the same management domain. The target first satellite and each device in the device group determine a second session key for communication with neighboring nodes based on the trusted identity of the target first satellite and the second key tree.

[0007] This invention also provides a large-scale dynamic security networking system for satellite-ground integrated networks, comprising: a first satellite group, a second satellite group, a third satellite group, and a device group; the first satellite group, the second satellite group, and the device group belong to the same management domain; the device group is a device group under the first satellite group; the first satellite group is a satellite group under the second satellite group; the third satellite group belongs to a different management domain from the first satellite group. The first satellite group is used to establish internal communication using the corresponding method in the above-mentioned large-scale node dynamic security networking method of space-ground fusion network. The first satellite group and the device group are used to establish cross-layer communication using the corresponding method in the above-mentioned large-scale node dynamic security networking method of space-ground fusion network. The first satellite group and the second satellite group are used to establish cross-layer communication using the corresponding method in the above-mentioned large-scale node dynamic security networking method of space-ground fusion network. The first satellite group and the third satellite group are used to establish cross-domain communication using the corresponding method in the above-mentioned large-scale node dynamic security networking method of space-ground fusion network.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) To address the authentication problem among large-scale neighboring nodes, this invention proposes a method for generating session keys within the same group of masters, which reduces communication overhead, lowers latency, and efficiently achieves secure networking of large-scale neighboring nodes.

[0009] (2) In response to the authentication problem between cross-layer nodes, this invention constructs an efficient cross-layer authentication mechanism by designing a fast and secure network authentication method between cross-layer nodes, which can ensure fast and secure communication between nodes at different levels.

[0010] (3) In response to the problem of cross-domain node authentication, this invention optimizes the authentication process and improves security and reliability by designing a fast and secure network authentication method for cross-domain nodes, which can adapt to complex cross-domain identity authentication scenarios.

[0011] (4) To address the issue of trust establishment between heterogeneous nodes, this invention introduces a multi-domain collaboration mechanism to achieve direct trust establishment between heterogeneous nodes, thereby improving the scalability and interoperability of the network in the 6G heterogeneous convergence scenario.

[0012] In summary, the proposed method for large-scale dynamic secure networking of satellite-ground integrated networks takes into account the dynamic topology between nodes and the high-speed movement of low-Earth orbit satellite nodes, avoiding reliance on trusted third parties on the ground and achieving efficient and rapid secure networking authentication between nodes. By integrating a key management system based on key trees and hash chains, trusted identity identification, and blockchain technology, it achieves efficient identity authentication and session key negotiation between large-scale satellite nodes, reducing the communication and computational overhead of multi-round interactions, meeting the flexibility and dynamism requirements of 6G networks, promoting direct trust establishment between heterogeneous nodes, and improving network scalability and interoperability.

[0013] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0014] Figure 1 This is a flowchart illustrating a method for dynamic and secure networking of large-scale nodes in a space-ground fusion network, as provided in an embodiment of the present invention. Figure 2 This is a flowchart of a secure network authentication process within a satellite group, provided by an embodiment of the present invention. Figure 3 This is a schematic diagram of a constructed key tree provided in an embodiment of the present invention; Figure 4 This is a flowchart of the networking authentication process between a first satellite group and a drone group provided in an embodiment of the present invention; Figure 5 This is a flowchart of the networking authentication process between a low-orbit satellite group (as the first satellite group) and a high-orbit satellite group (as the second satellite group) provided in an embodiment of the present invention. Figure 6 This is a flowchart of the cross-domain networking authentication process between the first satellite group and the third satellite group provided in an embodiment of the present invention. Detailed Implementation

[0015] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0016] The existing technology has the following problems: (1) Authentication problem between large-scale neighboring nodes: Existing multi-hop authentication protocols use a node-by-node interaction method when performing authentication between large-scale neighboring nodes. While this method is barely feasible in small-scale networks, it leads to an exponential increase in communication overhead in large-scale satellite networking scenarios. For example, when data needs to be transmitted between hundreds of nodes and authenticated multiple times, each node needs to perform a complete authentication process, which not only increases the communication load significantly but also significantly prolongs the data transmission latency. This latency is unacceptable in 6G heterogeneous converged networks because 6G networks require extremely low latency characteristics to support application scenarios with extremely high response speed requirements, such as real-time communication, telemedicine, and autonomous driving.

[0017] (2) Cross-layer node authentication problem: In 6G heterogeneous converged networks, nodes are divided into different layers, such as the physical layer, network layer, and application layer. Nodes at different layers differ in function and communication protocols, making it difficult for existing authentication protocols to establish an efficient authentication mechanism between these different layers. The lack of an efficient cross-layer authentication mechanism means that communication between nodes at different layers requires a complex authentication process, which not only increases communication latency but may also lead to communication interruption or data loss. For example, in the scenario of IoT and satellite network convergence, communication between IoT devices (usually located at the application layer) and satellite nodes (possibly located at the network layer or physical layer) requires authentication across multiple layers, which seriously affects communication efficiency and user experience.

[0018] (3) Cross-domain node authentication issues: In cross-domain identity authentication scenarios such as multi-national satellite collaboration, traditional Public Key Infrastructure (PKI) solutions have significant shortcomings. Their certificate chains are lengthy, leading to cumbersome and time-consuming authentication processes. For example, when a country's satellite system needs to communicate with another country's satellite system, both parties need to verify each other's identity through multiple layers of certificates. This not only increases authentication time but also raises the complexity of the authentication process. Furthermore, traditional PKI solutions also have a single point of failure risk. Once the Certificate Authority (CA) is compromised, the entire authentication system faces the risk of collapse, which seriously threatens the security of cross-domain communication.

[0019] (4) The dynamic nature of inter-satellite network authentication protocols: Most existing inter-satellite network authentication protocols rely on pre-shared keys. While this approach is usable in static network environments, it has significant drawbacks in dynamically changing large-scale satellite networks. When a key update is required, it typically triggers a full-network topology reconfiguration, which not only consumes a significant amount of time and resources but also leads to network service interruptions. In 6G networks, the dynamic joining and leaving of massive numbers of nodes and the dynamic merging of clusters are common phenomena. Therefore, an authentication protocol that supports dynamic key updates and flexible networking is needed to ensure stable network operation and efficient communication.

[0020] (5) Trust Establishment Issues Between Heterogeneous Nodes: Existing satellite networking authentication protocols are mainly designed for small-scale homogeneous networks and lack multi-domain collaboration mechanisms. In 6G heterogeneous converged networks, different types of nodes (such as military satellites, civilian communication satellites, and IoT devices) belong to different management domains, and their security strategies and trust models are different. This makes it difficult for heterogeneous nodes to directly establish trust relationships, requiring multiple authentications and coordinations through ground-based centralized facilities. This inefficient trust establishment method not only increases communication latency but also limits the scalability and flexibility of the network. For example, in global disaster relief scenarios, satellites and ground rescue equipment from different countries need to work together quickly, but existing technologies are unable to achieve rapid trust establishment between these heterogeneous nodes, thus affecting the efficiency of rescue operations.

[0021] To address the above problems, this invention proposes a fast and secure networking authentication method for large-scale neighboring nodes, cross-layer nodes, and cross-domain nodes. By integrating a key management system combining key trees and hash chains, trusted identity identifiers, and blockchain technology, it achieves efficient identity authentication and session key negotiation among large-scale satellite nodes, reducing the communication and computational overhead caused by multi-round interactions. This meets the flexibility and dynamism requirements of 6G networks and promotes direct trust establishment between heterogeneous nodes, improving network scalability and interoperability. Specifically, Table 1 explains the meaning of some parameters used in the method provided by this invention: Table 1

[0022] Figure 1 This is a flowchart illustrating a method for dynamic and secure networking of large-scale nodes in a space-ground integrated network, as provided in an embodiment of the present invention. Figure 1 As shown, the method includes: S101. When a first satellite group containing multiple first satellites needs to communicate internally, the first group leader in the first satellite group and the other first satellites in the first satellite group verify each other and construct the first key tree of the first satellite group based on the trusted identity identifier, public and private keys obtained when registering with the UDM of the management domain to which they belong.

[0023] Here, the first satellite group contains multiple first satellites, and the first group leader is the leader of the first satellite group, which is the most computationally powerful first satellite in the first satellite group. The first satellite group can be a low-Earth orbit (LEO), medium-Earth orbit (MEO), or high-Earth orbit (HEO) satellite group. For example, the first satellite group may be a LEO satellite group. For example, the group leader of a satellite group is elected by the UDM of its respective management domain.

[0024] S102. The first group leader and each other first satellite determine a first session key for internal communication within the first satellite group based on the first key tree.

[0025] S103. When the target first satellite in the first satellite group needs to communicate with a neighboring node of a device group in the lower layer, the target first satellite and each device in the device group perform mutual verification and construct a second key tree based on the first preset key, the trusted identity identifier of the target first satellite and the device, the identifier of the UDM of the management domain, the device identifier of the device group and the second preset key of the device group; the first satellite group and the device group belong to the same management domain.

[0026] For example, an equipment group is a drone swarm consisting of multiple drones.

[0027] S104. Each device in the target first satellite and the device group determines a second session key for communication with neighboring nodes based on the trusted identity of the target first satellite and the second key tree.

[0028] It should be noted that S101~S102 can be applied to large-scale low-Earth orbit satellite swarm networking authentication scenarios, and S101~S102 can be applied to low-Earth orbit satellite and lower-level UAV swarm networking authentication scenarios.

[0029] It should be noted that each satellite in the first satellite group has obtained its own trusted identity, its own public-private key pair, and the first satellite group's pre-set key (i.e., the first pre-set key) by registering with the UDM of its respective management domain. Each device in the device group has obtained its own trusted identity, its own public-private key pair, and the device group's pre-set key (i.e., the second pre-set key) by registering with the UDM of its respective management domain.

[0030] For example, taking the registration principle of each first satellite (i.e., the first satellite node) in the first satellite group with the UDM of its respective management domain as an example, we can illustrate how trusted identity identifiers, public-private key pairs, and preset keys are obtained: Each first satellite Register with UDM to obtain your trusted identity. Your own public and private key pairs and the initial preset key ,in, It is a pre-set key generated by UDM for legitimate satellite nodes within the first satellite group (i.e., the first satellite that has already registered). This is the private key for UDM. The security domain to which the first satellite belongs is identified. The type of equipment is identified as a low-Earth orbit satellite. Each first satellite node... storage .

[0031] The above-described S101~S104 of this invention is a large-scale network authentication process between neighboring nodes, applicable to establishing secure communication links between, for example, low-Earth orbit satellite constellations or physically adjacent heterogeneous nodes (such as low-Earth orbit satellites and lower-level devices such as drones within their coverage area). (i) For large-scale low-Earth orbit satellite constellations: The prerequisite is that during the registration phase, the UDM distributes an initial key to each satellite node within the low-Earth orbit satellite constellation. Based on a pre-set group key, bidirectional authentication between satellite nodes and the group leader node is achieved. The group leader node uses the trajectory key of each satellite member to construct a hierarchical key tree structure and distributes the corresponding path key to each member so that all satellite members derive the same key tree root key. All satellite nodes in the group (including the group leader node) use the key tree root key to derive the group's session key, thus completing the authentication and key negotiation for a large-scale low-Earth orbit satellite group. In addition, the group leader node also generates a random number to construct a pre-set hash chain for subsequent large-scale cross-layer node network authentication. (ii) For low-Earth orbit satellites and lower-layer UAV groups: The prerequisite is that UDM distributes an initial group key to each UAV node during the registration phase. The group master node of low-Earth orbit satellites uses its own initial key The initial key for deriving the drone swarm It also utilizes the trajectory keys of each drone member to construct a hierarchical drone key tree structure (similar to a large-scale low-Earth orbit satellite swarm), and uses the drone key tree to complete the session key negotiation between the low-Earth orbit satellite swarm leader and the drone swarm, as well as within the drone swarm itself.

[0032] In some embodiments, the above-mentioned S101 is implemented through steps S1011 to S1014: S1011. When a first satellite group containing multiple first satellites needs internal communication, the first group leader in the first satellite group uses the first preset key of the first satellite group. Current timestamp and your own public key and one's own trusted identity Generate the first network authentication request And it is sent to the other first satellites in the first satellite group.

[0033] For example, Figure 2 This is a flowchart of a secure network authentication process within a satellite constellation. (Example) Figure 2 As shown, the first group owner Get the current timestamp Based on a pre-set key Calculate message verification code Finally, the first group leader will send a network setup request. Send it to the other first satellites in the group. , This represents a hash operation. Indicates splicing.

[0034] S1012. Each other first satellite verifies the first network authentication request. If the verification is successful, it generates its own trajectory key and sends it to the first group leader.

[0035] Specifically, continue as follows Figure 2 As shown, each of the other first satellites Verify the first network authentication request using your current timestamp. The freshness is verified, and after the freshness verification is passed, it is based on the first pre-set key. In the first network authentication request timestamps The trusted identity identifier of the first group owner and public key Calculate the message verification code And based on the calculated message verification code For the first network authentication request Message verification code Perform verification to validate the first network authentication request. Message integrity is verified, and if successful, it is based on the first pre-set key. Your current location coordinates Your own trusted identity and your current timestamp Calculate your own trajectory key and using the first preset key Encrypt your own trajectory key , the encrypted track key and your current timestamp Send it to the first group owner.

[0036] Specifically, continue as follows Figure 2 As shown, each of the other first satellites receive First, verify the timestamp. The freshness, and then, based on The message sent by the first group admin , , Calculate the message verification code: Each of the other first satellites Both require verification of whether the verification code sent by the first group owner matches the one calculated by the group owner, i.e., whether... If they match, the group leader is considered legitimate. Then, each other first satellite calculates its own trajectory key. Ultimately, the trajectory keys of each satellite member in the group, excluding the group leader, are used as leaf nodes in the key tree to construct the key tree. Each of the other first satellites in the group uses Encrypt your own trajectory key, that is Then send To the first group leader.

[0037] S1013. The first group leader constructs a first key tree for the first satellite group based on the trajectory keys of all other first satellites, constructs a first hash chain for the first satellite group based on the first key tree, and securely stores the first hash chain for cross-group secure network authentication. Based on the first key tree, a first message containing the path key of each other first satellite is generated. And send it to the corresponding other first satellite.

[0038] Specifically, continue as follows Figure 2 As shown, the first group owner After receiving the trajectory keys from all satellite members, a first key tree is constructed to obtain the root key. Subsequently, the first group leader... Generate a random number To construct a hash chain, the expression for which is: ,in, The root key of the first key tree ,For example, This indicates that the hash chain contains 1000 hash chain key values. Afterwards, the first group leader... According to the first key tree, for each other first satellite in the first satellite group Generate path key Each of the other first satellites The path key refers to the parameter required for this satellite to generate the first key tree, and for each other first satellite... They will all be based on what they receive. The first key tree was constructed. Finally, the first group leader... Send one-to-one To each other first satellite in the group ,in This is the current timestamp of the first group owner.

[0039] Here, when the first satellite group contains X first satellites, the method by which the first group leader constructs the first key tree of the first satellite group based on the trajectory keys of all other first satellites is as follows: The first group leader uses the trajectory keys of X-1 other first satellites as X-1 leaf nodes of the first key tree. When X-1 is even, (X-1) / 2 first nodes are created, and each leaf node belongs to only one first node. Each first node is the parent node of two leaf nodes, and each first node is calculated based on the two leaf nodes. When X-1 is odd, (X-2 / 2)+1 first nodes are created, but the last first node is a leaf node of that first node. Then, using the same principle, the parent node of the obtained first node is determined to obtain the second node, and so on, layer by layer, until the root node is calculated, thus obtaining the first key tree of the first satellite group. For example, when X is 6, the constructed first key tree is as follows: Figure 3 As shown, the trajectory keys of the five other first nodes ~ There are five leaf nodes, according to and The first node can be calculated. ,according to and The first node can be calculated. , yes , and, according to and The second node can be calculated. ,according to and The root node can be calculated. (i.e., the root key), where, It is an elliptic curve generator. Specifically, the calculation process is as follows: ; ; ; ; ; .

[0040] S1014. Each first satellite verifies the first message and, upon successful verification, combines it with its own trajectory key. A first key tree is constructed, and a first hash chain is built based on the constructed first key tree. The first hash chain is then securely stored for use in cross-layer secure network authentication. The first hash chain key value is the root key of the first key tree. .

[0041] Specifically, continue as follows Figure 2 As shown, each of the other first satellites within the first group receive Then, check the timestamp. The novelty, and then, combined with one's own path key. and trajectory key Calculate the root key of the first key tree Then utilize Decrypt message get This generates a hash chain: Then, the hash chain is stored in its own security module for subsequent cross-layer secure networking authentication and key update processes.

[0042] For example, the second other first satellite in the first group For example, Path key for:{ , , },but The process of constructing the first key tree is as follows: calculate sequentially , Finally, the root key of the first key tree is calculated. .

[0043] In some embodiments, S102 is specifically implemented as follows: the first group leader generates a first session key for internal communication of the first satellite group based on the first key tree. Based on the first session key Generate a second message And broadcast the second message to all other first satellites. Each other first satellite, based on its own constructed first key tree, processes the second message. Perform verification and obtain the first session key after successful verification.

[0044] Specifically, continue as Figure 2 As shown, during the group authentication and first session key generation phase, the first group owner... Derive a new random number Generate the session key for the first satellite group. Then, the first group leader Get the current timestamp Calculate the message verification code: After the calculation was completed, the first group leader Broadcast the message to all other first satellites in the first group: Upon receiving the broadcast message, each other first satellite in the group... Based on previous calculations and the received random number calculate And the corresponding message verification code: , Each of the other first satellites Calculate itself With the first group leader Sent The comparison is performed; if they match, the verification is complete, and the secret is stored. After that, all nodes (i.e., satellites) in the group use Used as a session key to encrypt communication data.

[0045] In some embodiments, the above-mentioned S103 is specifically implemented through steps S1031 to S1034: S1031, The target first satellite is based on the first pre-set key and the trusted identity identifier of the target first satellite. Identifier of the UDM in the management domain Device identifiers for device groups Generate a second network authentication request. And send it to each device in the device group, and calculate the second preset key. .

[0046] Here, the first target satellite is the first satellite covering the equipment group.

[0047] Specifically, , It is the first target satellite Current timestamp .

[0048] S1032, Each device requests authentication for the second network group. The system will perform verification; if the verification passes, it will generate its own trajectory key. Send to the target satellite.

[0049] For example, Figure 4 This is a flowchart illustrating the network authentication process between the first satellite constellation and a drone swarm. Specifically, as shown... Figure 4 As shown, taking a drone as an example, each drone node (i.e., the drone) receive First, verify the timestamp. If the verification passes, then according to Calculate message verification code , It is important to note that... It is the UDM that securely distributes the trusted identity to the drone nodes during the drone's trusted identity generation phase. Each drone... Compare with its own calculations and Sent Whether they are consistent, that is, whether they are If they match, the drone node Get the current timestamp Calculate your own trajectory key: ,in, For current drones The location coordinates. Finally, the drone. Calculate the message verification code: Finally, drones Will Send to .

[0050] It should be noted that when verifying the timestamp, the present invention compares the difference between the timestamp to be verified and the current timestamp with a preset time difference. If the difference exceeds the preset time difference, the verification fails; if the difference does not exceed the preset time difference, the verification passes.

[0051] S1033, Target Satellite 1 based on the second pre-set key Each received message from a device is verified. If the verification passes, the trajectory keys of all devices in the device group are used. Construct a second key tree, generate a third message containing the path key for each device based on the second key tree, and send it to each device.

[0052] Specifically, continue as follows Figure 4 As shown, satellite Received each drone News Next, verify the message first. timestamps The freshness, then, using Decrypt to obtain each drone trajectory key Finally, the message verification code is calculated. To verify the drone The legitimacy of the satellite. After verification, the satellite... Construct a key tree (second key tree) based on the trajectory key of the drone node, and calculate the root node value of the second key tree. Keep it secret. Satellite Distribute the corresponding path key to each drone It should be noted that the principle for constructing the second key tree is the same as the principle for constructing the first key tree, and the principle for generating the third message is the same as the principle for generating the second message.

[0053] S1034. Each device verifies the third message and, upon successful verification, combines it with its own trajectory key. The second key tree is constructed using the contents of the third message.

[0054] Specifically, continue as follows Figure 4 As shown, each drone node Received my own Then, combined with its own trajectory key value and its own This constructs a second key tree. It should be noted that the principle of S1034 is similar to that of S1014 above, where each first satellite verifies the first message and, upon successful verification, combines it with its own trajectory key. The principle for constructing the first key tree is the same, so it will not be repeated here.

[0055] In some embodiments, the above-mentioned S104 is specifically implemented through steps S1041 to S1042: S1041, The target first satellite generates a second session key for neighboring node communication based on the second key tree. Based on the second session key Generate the fourth message It also broadcasts a fourth message to the device group.

[0056] Specifically, continue as follows Figure 4 As shown, satellite Generate a random number And calculate the group session key: Subsequently, the satellite Broadcast network authentication request message to all drones within the coverage area , It is a satellite The generated current timestamp.

[0057] S1042. Each device, based on its own constructed second key tree, processes the fourth message. Verification is performed, and a second session key is obtained upon successful verification. .

[0058] Specifically, continue as follows Figure 4 As shown, each drone verify And after successful verification, the root key of the second key tree is used. and the received random number calculate Then, through calculation To verify the integrity of the message. Once verification is successful, each drone... Secretly preserved Finally, the satellite Use between drone swarms, and within drone swarms Encrypted communication data.

[0059] This invention also provides a large-scale cross-layer node networking authentication process, applicable to networking communication between high-Earth orbit (HEO) and low-Earth orbit (LEO) satellites within the same management domain. Taking HEO-LEO cross-layer networking authentication as an example, the LEO satellite group generates a pre-set hash chain based on random numbers, and the UDM within the management domain pre-sends the corresponding hash chain key to the HEO satellite nodes. The LEO satellite group leader randomly selects a hash chain index, uses the hash chain key corresponding to that index to authenticate with the HEO satellite group leader, and derives a cross-layer group key. Here, the corresponding hash chain key is a part of the hash chain in the first hash chain generated in S1013 and S1014 above. For example, when the first hash chain is... At that time, the corresponding hash chain key can be .

[0060] Specifically, the above method also includes S201~S205: S201. When the first satellite group needs to communicate across layers with the leader of the upper-level second satellite group, the first leader starts from the first hash chain. Preset index segment Randomly select an index Based on index, index The hash chain key value corresponding to the first hash chain Your own trusted identity Your current orbit coordinates Generate a third network authentication request And send it to the second group owner; the first satellite group and the second satellite group belong to the same management domain, that is, they correspond to the same UDM; the second group owner is the group owner of the second satellite group.

[0061] It should be noted that the first satellite group can be a low-Earth orbit satellite group, and the second satellite group can be a medium-Earth orbit satellite group; or, the first satellite group can be a medium-Earth orbit satellite group, and the second satellite group can be a high-Earth orbit satellite group.

[0062] For example, Figure 5 This is a flowchart illustrating the network certification process for the low-Earth orbit satellite group (the first satellite group) and the high-Earth orbit satellite group (the second satellite group). Specifically, as shown... Figure 5As shown, when the first satellite group and the second satellite group are communicating across layers for the first time, the first group leader... Randomly select the hash chain index of the first hash chain and obtain the index. Corresponding hash chain key value and get the current timestamp And calculate the message verification code: ,in, It is an index The corresponding hash chain key value, This is the current timestamp. This refers to the current orbital coordinates of the group owner node. Finally, the first group owner... To the second group leader Send a cross-layer network authentication request: .

[0063] S202, Second group leader's authentication request to the third network Perform a freshness verification. If the freshness verification passes, then proceed based on the first group leader's current orbital coordinates. The system checks if the first group owner's location is within its coverage area. If so, the second group owner requests authentication from the third network. The message integrity is verified. If the verification passes, the second group owner proceeds according to the index. Pre-defined index segment from the first hash chain sent by UDM Find the index in the hash chain key value. Corresponding hash chain key value According to the hash chain key value Your own trusted identity And the trusted identity of the first group leader Calculate the third session key used for cross-layer communication. .

[0064] It should be noted that the preset index segment This is a sequence of indices corresponding to a hash chain key value that has not been used in previous communications between the first satellite group and the upper-level second satellite group. For example, if the first hash chain consists of 1000 hash chain key values, and each time the first satellite group communicates across layers with other satellite groups, it uses 100 consecutive hash chain key values ​​from the first hash chain, then when the first satellite group communicates across layers with the second satellite group for the first time, the sequence of indices corresponding to the first to 100th hash chain key values ​​can be used as a preset index segment. Thus, the first group leader can randomly select an index from the sequence of indices corresponding to the key values ​​of the first 100 hash chains as the index. and based on index The corresponding hash chain key value generates the third network authentication request. Correspondingly, the second group owner also possesses the sequence consisting of the first 100 hash chain key values ​​and their corresponding indices, thus enabling them to use the indices... Find the index from the first 100 hash chain keys of the first hash chain you own. The corresponding hash chain key values ​​are used to generate subsequent session keys. Thus, the first and second satellite groups can use these 1-100 hash chain key values ​​for 100 cross-layer communications. When the first and second satellite groups have exhausted these 100 hash chain key values ​​and need to conduct cross-layer communication again, the sequence of indices corresponding to the 101st to 200th hash chain key values ​​can be used as a preset index segment. Thus, the first group leader can randomly select an index from the sequence of indices corresponding to the 101st to 200th hash key values ​​in the first hash chain as the index. and based on index The corresponding hash chain key value generates the third network authentication request. Correspondingly, the second group owner also possesses the sequence consisting of the 101st to 200th hash chain key values ​​of the first hash chain and the indices corresponding to these key values. Therefore, based on the index... Find the index from the 101st to 200th hash key values ​​of the first hash chain you own. The corresponding hash chain key value is used to generate subsequent session keys, and so on.

[0065] Specifically, continue as follows Figure 5 As shown, the second group leader Received network authentication request Next, verify the timestamp. To ensure freshness and prevent replay attacks. If verification passes, then the first group leader will be tested. spatial location Whether it is within their coverage area; if the requirements are met, then the second group leader... Based on the received index Find the corresponding pre-stored key value And calculate the message verification code: ,Compare Is it consistent with the received If they agree, then the second group leader... Calculate cross-layer group key It is used for secure communication between the first and second satellite groups.

[0066] S203, The second group leader is based on the third session key. and one's own trusted identity Generate the fifth message And send it to the first group owner.

[0067] Specifically, continue as follows Figure 5 As shown, the second group leader Get the current timestamp Calculate the message verification code: And to the first group leader Send cross-layer networking authentication response message .

[0068] S204, First Group Owner's Message to the Fifth Group Perform a freshness verification. If the freshness verification passes, proceed according to the hash chain key value. Your own trusted identity The trusted identity of the second group leader Calculate the third session key And based on the calculated third session key The trusted identity of the second group leader Verify the fifth message To ensure message integrity, if verification passes, the first group owner uses the third session key. ,index The trusted identity of the second group leader Generate the sixth message And it is sent to all other first satellites in the first satellite group.

[0069] Specifically, continue as follows Figure 5 As shown, the first group owner Upon receiving the message, first verify the timestamp. The freshness, if verified, then according to Calculate the cross-level group key and message verification code: , and verify and If the data is consistent, then the verification is successful and the secure link can be established. Subsequently, the first group leader... Broadcast group authentication response message to other first satellites within the first satellite group. ,in, As the first group leader The generated current timestamp.

[0070] S205, each other first satellite to the sixth message Perform a freshness verification. If the freshness verification passes, proceed according to the sixth message. Index in From its own stored first hash chain Retrieve the corresponding hash chain key value And based on the hash chain key value And the sixth message Using other information, calculate the third session key. and using a computed third session key. The integrity of the sixth message is verified. If the verification passes, the calculated third session key is used. It serves as a key for cross-level communication with the second group leader.

[0071] Specifically, other first satellites received Afterwards, verification The freshness, if the freshness verification passes, then according to Find the corresponding hash chain key in the first hash chain stored within itself. Each other first satellite according to , and To calculate the group session key Finally, through calculation Whether or not In Consistency is used to verify the integrity of the message. If the verification passes, then... It serves as a key for cross-level communication with the second group leader.

[0072] This invention also provides a large-scale cross-domain node networking authentication process, utilizing blockchain, certificateless signature algorithms, and the Diffie-Hellman (DH) key negotiation mechanism to achieve networking communication between satellite groups within different management domains. The satellite group leader of management domain A and the satellite group leader of management domain B use a certificateless signature algorithm to achieve two-way authentication, and derive a cross-domain group session key (DH key negotiation mechanism) from the root key of both parties' key trees. The group leader node notifies the satellite members within the group via broadcast, so that all satellite members derive the same cross-domain group key. Specifically, the above method also includes steps S301-S308: S301. When the first satellite group needs to conduct cross-domain communication with the third satellite group, and the first satellite group belongs to management domain A and the third satellite group belongs to management domain B, the first group leader... Based on their own trusted identity Your own public key The public key of the UDM in domain A The root key of the first key tree and your private key Generate the fourth network authentication request And sent to the group owner of the third satellite group The UDM of Management Domain A and the UDM of Management Domain B jointly maintain a consortium blockchain. The consortium blockchain stores the public keys of the UDMs of Management Domain A and Management Domain B, the public keys and trusted identity identifiers of each registered satellite in Management Domain A and Management Domain B; the third group leader is the group leader of the third satellite group.

[0073] Here, cross-domain node secure networking authentication refers to the process of establishing secure communication between devices within different management domains. It's important to note that the UDMs in each management domain jointly maintain a consortium blockchain. This blockchain stores the public key information of each domain's UDM, as well as the public keys and trusted identity identifiers of registered legitimate satellite nodes. This consortium blockchain allows legitimate satellite nodes to obtain the public keys and trusted identity identifiers of other domain nodes through on-chain queries. Based on blockchain technology, certificateless signature algorithms, and the Diffie-Hellman (DH) key negotiation mechanism, cross-domain node networking authentication is achieved.

[0074] For example, Figure 6 This is a flowchart of the cross-domain networking authentication process between the first and third satellite groups. Specifically, as shown... Figure 6 As shown, specifically, the first group owner Get the current timestamp Generate random numbers Then calculate: , , ,in, The first group leader during the cross-domain networking process Temporary public key, As the first group leader Public keys generated based on certificateless cryptography. The public key of the UDM for domain A. Next, the first group leader Generate signature: ,in, As the first group leader The private key is generated based on a certificateless cryptographic scheme. Finally, the first group admin... Signature and timestamp Trusted identity identifier , Attached to the message After that, send The third group leader of Domain B .

[0075] S302, Third Group Leader Authentication request for the fourth network A freshness verification is performed. If the freshness verification passes, the group will proceed based on the trusted identity of the first group owner. Find the public key of the UDM in management domain A from the consortium blockchain. and the public key of the first group owner It continues to verify the fourth network authentication request. If the verification passes, it uses the root key of the third key tree of the third satellite group. The message contained in the fourth network authentication request Calculate the fourth session key used for cross-domain communication. .

[0076] It should be noted that the construction method of the third key tree is the same as that of the first key tree, and will not be repeated here.

[0077] Specifically, continue as follows Figure 6 As shown, the third group leader First, check the timestamp. The freshness, and then according to Find the public key of the management domain UDM corresponding to domain A on the blockchain. And the first group leader Corresponding public key information Calculate sequentially: , , Next, verify the first group owner. The generated signature: If this formula is true, the third group leader Get the current timestamp Calculate the cross-domain group key: .

[0078] S303, the third group leader based on the fourth session key and the message contained in the fourth network authentication request Generate the first broadcast message And it is sent to each of the other third satellites in the third satellite group.

[0079] Specifically, the third group leader Broadcast in the third satellite group of Domain B ,in, , .

[0080] S304, Each other third satellite broadcasts the first message. Verification is performed; if verification passes, the root key of the third key tree that the user possesses is used. Combined with the information in the first broadcast message, generate the fourth session key.

[0081] Specifically, each of the other third satellites received Then, based on the received ,calculate ,like Then, based on the root key value of its own key tree... and received Calculate cross-domain group key Used as a session key for secure communication between cross-domain group nodes.

[0082] S305, The third group leader relies on their own trusted identity. Your own public key Public key of domain B The root key of the third key tree and your private key Generate authentication message And send it to the first group owner.

[0083] Specifically, the third group leader Generate a new random number , using nodes Similar calculation methods are used: , , ,in, The third group leader during the cross-domain networking process Temporary public key, , , This is the public key for UDM in domain B. Finally, the third group leader... Generate signature: Continue as follows Figure 6 As shown, the third group leader Signature and timestamp Trusted identity identifier , Attached to the message After that, send a message The leader of the first satellite group in Domain A .

[0084] S306, First group owner's verification message A freshness verification is performed. If the freshness verification passes, the group will proceed based on the trusted identity of the third-party group leader. Find the public key of the UDM for management domain B in the consortium blockchain. and the public key of the third group owner It continues to verify the authentication message. If the verification passes, it uses the root key of the first key tree. Messages contained in the authentication message Calculate the fourth session key .

[0085] Specifically, continue as follows Figure 6 As shown, the first group owner First, check the timestamp. The freshness, and then according to Find the public key of UDM in domain B on the blockchain. And the third group leader Corresponding public key information Then the first group leader Calculate sequentially: , , Next, verify the node. Signature sent: If verified, the first group owner Calculate cross-domain group key .

[0086] S307, The first group leader based on the message contained in the fourth session key and authentication message. Generate a second broadcast message And it is sent to each of the other first satellites in the first satellite group.

[0087] Specifically, the first group leader Broadcast within its own domain ,in , .

[0088] S308, each other first satellite broadcasts a second message. The verification is performed. If the verification passes, the root key of the first key tree that the user possesses is used. The information in the second broadcast message is used to generate the fourth session key. At this point, the cross-domain group has been established.

[0089] Specifically, each of the other first satellites received Then, based on the received ,calculate ,like Then, based on the root key value of its own key tree... and received Calculate cross-domain group key This serves as the session key for secure communication between nodes in a cross-domain group, thus completing the establishment of the cross-domain group.

[0090] This invention proposes three networking authentication methods for dynamic networking and cross-domain communication of large-scale satellite nodes in 6G heterogeneous converged networks: a secure networking authentication method between large-scale neighboring nodes, a secure networking authentication method between large-scale cross-layer nodes, and a secure networking authentication method between large-scale cross-domain nodes. Compared with authentication methods based on symmetric keys, the three large-scale networking authentication methods proposed in this invention take into account the dynamic topology between nodes and the high-speed movement of low-Earth orbit satellite nodes, avoiding dependence on trusted third parties on the ground and achieving efficient and fast secure networking authentication between nodes. Furthermore, based on a pre-set hash chain, rapid autonomous key updates are achieved, requiring only a small number of hash operations to complete bidirectional authentication of nodes and group session key negotiation during the authentication process.

[0091] This invention also provides a large-scale dynamic security networking system for satellite-ground integrated networks, comprising: a first satellite group, a second satellite group, a third satellite group, and a device group; the first satellite group, the second satellite group, and the device group belong to the same management domain; the device group is a device group under the first satellite group; the first satellite group is a satellite group under the second satellite group; the third satellite group and the first satellite group belong to different management domains. The first satellite group is used to establish internal communication using the corresponding methods described above. The first satellite group and the device group are used to establish cross-layer communication using the corresponding methods described above. The first satellite group and the second satellite group are used to establish cross-layer communication using the corresponding methods described above. The first satellite group and the third satellite group are used to establish cross-domain communication using the corresponding methods described above.

[0092] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0093] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0094] In this specification, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. While different embodiments may describe certain measures, this does not mean that these measures cannot be combined to produce a good effect.

[0095] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for large-scale node dynamic security networking in a satellite-terrestrial integrated network, characterized in that, The method comprises the steps of: When a first satellite group comprising a plurality of first satellites needs to communicate internally, a first group master in the first satellite group and other first satellites in the first satellite group perform mutual authentication and build a first key tree of the first satellite group based on a trusted identity, a public and private key obtained when registering with a UDM of a management domain to which the first satellite group belongs, and a first preset key of the first satellite group; The first group master and each other first satellite determine a first session key for the first satellite group to communicate internally based on the first key tree; When a target first satellite in the first satellite group needs to perform proximal node communication with a device group at a lower layer, the target first satellite and each device in the device group perform mutual authentication and build a second key tree based on the first preset key, the trusted identity of the target first satellite and the device, the identity of the UDM of the management domain, the device identity of the device group, and a second preset key of the device group; The first satellite group and the device group belong to the same management domain; The target first satellite and each device in the device group determine a second session key for proximal node communication based on the trusted identity of the target first satellite and the second key tree.

2. The method of claim 1, wherein, The method comprises the steps of: The first group master in the first satellite group and other first satellites in the first satellite group perform mutual authentication and build a first key tree of the first satellite group based on a trusted identity, a public and private key obtained when registering with a UDM of a management domain to which the first satellite group belongs, and a first preset key of the first satellite group, comprising: The first group master in the first satellite group generates a first networking authentication request based on the first preset key of the first satellite group, a current timestamp, and its own public key and trusted identity, and sends the first networking authentication request to other first satellites in the first satellite group; Each other first satellite verifies the first networking authentication request, and if the verification is passed, generates its own trajectory key and sends it to the first group master; The first group master builds a first key tree of the first satellite group according to the trajectory keys of all other first satellites, builds a first hash chain of the first satellite group based on the first key tree, and securely stores the first hash chain for cross-layer secure networking authentication, generates a first message containing the path key of each other first satellite based on the first key tree, and sends the first message to the corresponding other first satellite; 3. The method of claim 2, wherein, Each first satellite verifies the first message, and after the verification is passed, builds the first key tree in combination with its own trajectory key, and builds the first hash chain based on the built first key tree, and securely stores the first hash chain for cross-layer secure networking authentication, and the first hash chain key value of the first hash chain is the root key of the first key tree. The verification of the first networking authentication request by each other first satellite, if the verification is passed, generates its own trajectory key and sends it to the first group master, comprising: Each other first satellite verifies the freshness of the first network authentication request by time stamp, and after the freshness verification passes, calculates a message authentication code based on the first preset key and the time stamp in the first network authentication request, the trusted identity and public key of the first group master, and verifies the message authentication code in the first network authentication request based on the calculated message authentication code to verify the message integrity of the first network authentication request. If the verification is successful, the trajectory key of the first satellite is calculated based on the first preset key, the current position coordinates of the first satellite, the trusted identity of the first satellite and the current time stamp of the first satellite, and the trajectory key of the first satellite is encrypted by the first preset key. The encrypted trajectory key, the current position coordinates of the first satellite and the current time stamp of the first satellite are sent to the first group master.

4. The method of claim 2, wherein, When the first satellite group contains X first satellites, the first group master constructs a first key tree of the first satellite group according to the trajectory keys of all other first satellites, including: The first group master takes the trajectory keys of X-1 other first satellites as X-1 leaf nodes of the first key tree, creates (X-1) / 2 first nodes when X-1 is even, and each leaf node belongs to only one first node, each first node is the parent node of two leaf nodes, and each first node is calculated according to two leaf nodes; (X-2 / 2)+1 first nodes are created when X-1 is odd, but the last first node is the leaf node of the first node; thereafter, the same principle is used to determine the parent nodes of the first nodes to obtain the second nodes according to the obtained first nodes, and the calculation is performed layer by layer until the root node is calculated, and the first key tree of the first satellite group is obtained.

5. The method of claim 1, wherein, The first group master and each other first satellite determine a first session key for internal communication of the first satellite group based on the first key tree, including: The first group master generates a first session key for internal communication of the first satellite group based on the first key tree, generates a second message based on the first session key, and broadcasts the second message to all other first satellites; Each other first satellite verifies the second message according to the first key tree constructed by itself, and obtains the first session key after the verification passes.

6. The method of claim 1, wherein, The target first satellite and each device in the device group perform mutual authentication and construct a second key tree based on the first preset key, the trusted identity of the target first satellite and the device, the identity of the UDM of the management domain, the device identity of the device group and the second preset key of the device group, including: The target first satellite generates a second network authentication request based on the first preset key, the trusted identity of the target first satellite, the identity of the UDM of the management domain and the device identity of the device group, and sends the second network authentication request to each device in the device group, and calculates the second preset key; Each device verifies the second group network authentication request, and if the verification is passed, generates its own track key and sends it to the target first satellite; The target first satellite verifies the received message of each device based on the second preset key, and if the verification is passed, constructs a second key tree according to the track keys of all devices in the device group, generates a third message containing the path key of each device based on the second key tree, and sends it to each device; Each device verifies the third message, and after the verification is passed, constructs the second key tree in combination with its own track key and the content in the third message; The target first satellite generates a second session key for adjacent node communication based on the second key tree, generates a fourth message based on the second session key, and broadcasts the fourth message to the device group; Each device verifies the fourth message according to the second key tree constructed by itself, and after the verification is passed, obtains the second session key.

7. The method of claim 2, wherein, The method further comprises: When the first satellite group needs to perform cross-layer communication with the group master of a second satellite group at an upper layer, the first group master randomly takes an index from a preset index segment of the first hash chain, generates a third group network authentication request based on the index, a hash chain key value corresponding to the index in the first hash chain, its own trusted identity, and its current orbit coordinate, and sends it to the second group master; the first satellite group and the second satellite group belong to the same management domain; the second group master is the group master of the second satellite group; The second group master performs freshness verification on the third group network authentication request, and if the freshness verification is passed, checks whether the spatial position of the first group master is within its coverage range according to the current orbit coordinate of the first group master, and if yes, performs message integrity verification on the third group network authentication request, and if the verification is passed, the second group master finds the hash chain key value corresponding to the index from the hash chain key values of the preset index segment of the first hash chain sent by the UDM according to the index, and calculates a third session key for cross-layer communication according to the hash chain key value, its own trusted identity, and the trusted identity of the first group master; The second group master generates a fifth message based on the third session key and its own trusted identity, and sends it to the first group master; The first group master performs freshness verification on the fifth message, and if the freshness verification is passed, calculates the third session key according to the hash chain key value, its own trusted identity, and the trusted identity of the second group master, and verifies the message integrity of the fifth message based on the calculated third session key and the trusted identity of the second group master, and if the verification is passed, the first group master generates a sixth message according to the third session key, the index, and the trusted identity of the second group master, and sends it to all other first satellites in the first satellite group; Each other first satellite performs freshness verification on the sixth message, if the freshness verification passes, obtains a corresponding hash chain key value from the first hash chain stored by itself according to the index in the sixth message, calculates the third session key according to the hash chain key value and other information in the sixth message, and verifies the message integrity of the sixth message by using the calculated third session key, if the verification passes, takes the calculated third session key as a key for cross-layer communication with the second group master.

8. The method of claim 2, wherein, The method further comprises: When the first satellite group needs to perform cross-domain communication with a third satellite group, and the first satellite group belongs to a management domain A and the third satellite group belongs to a management domain B, the first group master generates a fourth network authentication request based on a trusted identity of itself, a public key of itself, a public key of a UDM of the management domain A, a root key of the first key tree and a private key of itself, and sends the fourth network authentication request to a group master of the third satellite group; the UDM of the management domain A and the UDM of the management domain B jointly maintain a consortium chain, and the consortium chain stores the public keys of the UDMs of the management domain A and the management domain B, the public keys and trusted identities of each registered satellite in the management domain A and the management domain B; the third group master is a group master of the third satellite group; The third group master performs freshness verification on the fourth network authentication request, if the freshness verification passes, finds the public key of the UDM of the management domain A and the public key of the first group master from the consortium chain according to the trusted identity of the first group master, and continues to verify the fourth network authentication request, if the verification passes, calculates a fourth session key for cross-domain communication based on a root key of a third key tree of the third satellite group and messages contained in the fourth network authentication request; The third group master generates a first broadcast message based on the fourth session key and the messages contained in the fourth network authentication request, and sends the first broadcast message to each other third satellite in the third satellite group; Each other third satellite verifies the first broadcast message, if the verification passes, generates the fourth session key according to the root key of the third key tree and the information in the first broadcast message; The third group master generates an authentication message based on a trusted identity of itself, a public key of itself, a public key of the management domain B, a root key of the third key tree and a private key of itself, and sends the authentication message to the first group master; The first group master performs freshness verification on the authentication message, if the freshness verification passes, finds the public key of the UDM of the management domain B and the public key of the third group master from the consortium chain according to the trusted identity of the third group master, and continues to verify the authentication message, if the verification passes, calculates the fourth session key based on a root key of the first key tree and messages contained in the authentication message. The first group master generates a second broadcast message based on the fourth session key and the message contained in the authentication message and sends the second broadcast message to each other first satellite in the first satellite group; Each other first satellite verifies the second broadcast message, and if the verification is passed, generates the fourth session key according to the root key of the first key tree possessed by the satellite and the information in the second broadcast message, and the cross-domain group establishment is completed.

9. The method of claim 8, wherein, The first satellite group is a low-orbit satellite group, the device group is a UAV group, and the third satellite group is a low-orbit satellite group.

10. A satellite-ground integrated network large-scale node dynamic security networking system, characterized in that, Comprise: a first satellite group, a second satellite group, a third satellite group and a device group; The first satellite group, the second satellite group and the device group belong to the same management domain; The device group is a device group under the first satellite group, and the first satellite group is a satellite group under the second satellite group; The third satellite group and the first satellite group belong to different management domains; The first satellite group is used for establishing internal communication by the method in any one of claims 1-5, cross-layer communication between the first satellite group and the device group is established by the method in any one of claims 1-6, cross-layer communication between the first satellite group and the second satellite group is established by the method in claim 7, and cross-domain communication between the first satellite group and the third satellite group is established by the method in claim 8.

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