A lightweight network security protection method on satellite

Abstract

The application provides a kind of spaceborne lightweight network security protection method, and the spaceborne network security protection strategy is divided into control plane and data plane, control plane is responsible for policy formulation and issue, data plane focuses on real-time processing of data packet, and adopts multi-level index table, hierarchical rule base and other technologies, avoids the redundant occupation of resources, so that satellite nodes can more reasonably allocate and use computing and storage resources in a resource-limited environment, improve resource utilization efficiency, and ensure stable operation of satellite network;In terms of access authentication, satellite nodes can calculate the visible satellite set in real time according to the orbit ephemeris, generate and update the white list, and accurately adapt to the dynamic changes of satellite communication relationship;The firewall function dynamically adjusts the policy level according to the real-time data load, which can flexibly cope with normal load or high load, and ensure that network security protection does not fail due to topology change, and realize the rapid and accurate dynamic adaptation of security protection strategy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of digital data processing, in particular to a kind of starborne light-weight network security protection method. BACKGROUND

[0002] With the continuous development of satellite Internet, information security has become the focus of public attention. Network information security is an important foundation for protecting personal information security, maintaining social stability and development, and safeguarding national network security. In this context, it is important to use satellite resources reasonably and efficiently and design a network security protection method suitable for satellite Internet to maintain network information security. At the same time, it is also urgent to strengthen the protection strategy of access authentication and firewall in the field of satellite Internet information security, and to strengthen the public's awareness of information security protection and protection means.

[0003] Firewall technology is essentially a network security technology based on screening and isolation. It has a variety of hardware and software devices related to screening and isolation, which separates the internal network of the computer from the external network through screening and isolation mechanism, and is an important means to protect user data security. Firewall technology can continuously detect various security risks in the computer, and use isolation and protection measures to eliminate these risks, while recording them for subsequent monitoring to protect user data security and network stability, and maintain the integrity of user data and information. However, the traditional ground firewall technology uses five-tuple matching method, which consumes a large amount of computing resources and storage resources. The on-board router is developing towards light weight, and the computing resources and storage resources are relatively scarce, so the ground router firewall technology cannot be directly applied to the satellite.

[0004] Therefore, there is a need for a satellite network security protection method. SUMMARY

[0005] The present application is to solve the problem of insufficient storage resources and computing resources of the current on-board router, and the changeable satellite network topology leading to on-board network security problem, and provides a kind of starborne light-weight network security protection method. The access authentication technology driven by orbit prediction and dynamic white list and the hierarchical firewall strategy are used to adapt to the starborne router, realize the optimization of on-board resources and dynamic adaptation of topology; compared with ground network security technology, satellite nodes can access satellite network more safely, and the use of computing resources and storage resources is more reasonable, and it is suitable for the operation environment of low-orbit satellite.

[0006] The present application provides a kind of starborne light-weight network security protection method, comprising the following steps:

[0007] S1, the ground control station gives the control plane of each satellite node starborne router in the network to inject access authentication white list and firewall black and white list;

[0008] The content of the access authentication whitelist includes the SCID number of the legal satellite node, the access authentication whitelist valid time and the access authentication whitelist invalid time;

[0009] The firewall black and white list includes the IP address, port number, security level, maximum data flow allowed to pass of the legal satellite node and the illegal satellite node, the firewall black and white list valid time and the firewall black and white list invalid time;

[0010] S2, the control plane forwards the access authentication whitelist to the data plane of the satellite router, and the data plane updates the stored whitelist information after receiving it;

[0011] The control plane dynamically generates the firewall policy according to the firewall black and white list, stores the IP address of the legal satellite node and the illegal satellite node according to the security level, and sends the firewall policy to the data plane, the firewall policy is the firewall black and white list configuration information, and the data plane updates the stored black and white list information after receiving it;

[0012] Enter step S3 within the valid time of the access authentication whitelist and the firewall black and white list;

[0013] S3, the satellite nodes interact with each other in real time to obtain satellite orbit parameter information, the control plane of each satellite predicts the visible neighbor satellite node set within the communication window in the future ΔT within each specified time ΔT, and obtains the compressed access authentication whitelist by taking the intersection of the visible neighbor satellite node set and the SCID set of the access authentication whitelist, and sends it to the data plane for updating;

[0014] When a new satellite enters the communication window of the star, the neighbor satellite node set of the star changes, the control plane recalculates the intersection result and updates it and sends it to the data plane for updating;

[0015] S4, when the star receives an inter-satellite data packet, the data plane extracts the SCID number of the inter-satellite data frame and compares it with the SCID number in the compressed access authentication whitelist, judges whether the node SCID number of the inter-satellite data frame is in the compressed access authentication whitelist, if yes, enters the firewall function, enters step S5, if not, discards the inter-satellite data packet and reports the discarding event to the ground control station;

[0016] S5, judge whether the source IP address, source port number, destination IP address and destination port number of the inter-satellite data packet are all legal satellite nodes or illegal satellite nodes in the firewall black and white list, and the receiving or forwarding rate of the inter-satellite data packet does not exceed the maximum data flow allowed to pass, if all, receive or forward the inter-satellite data packet; if the receiving or forwarding rate exceeds the maximum data flow allowed to pass, go to step S6, if it is an illegal satellite node, discard the inter-satellite data packet and report the discarding event to the ground control station;

[0017] S6, the control plane evaluates the security of the current on-board router, and if there is no abnormal alarm, the firewall strategy is adjusted and sent to the data plane, the adjusted strategy only includes the destination IP address and the adjusted maximum data flow allowed to pass, the adjusted maximum data flow allowed to pass is greater than 100% of the bandwidth, the source IP and port check are ignored, until the receiving or forwarding rate data load returns to the normal range, the firewall strategy is restored to the data plane, and returns to step S3.

[0018] As a preferred mode of the on-board lightweight network security protection method, in step S1, the access authentication white list is generated in advance by the ground control station according to the planning and management requirements of the satellite network,

[0019] The SCID number is a unique identifier for each satellite, the access authentication white list is valid for T0, and the access authentication white list is invalid for T1, T1>T0;

[0020] The ground control station sends the access authentication white list to the control plane of each satellite node in the network through the uplink before T0;

[0021] The firewall black and white list is valid for T0, the firewall black and white list is invalid for T1, T1>T0, and the maximum data flow allowed to pass is a percentage of the bandwidth.

[0022] As a preferred mode of the on-board lightweight network security protection method, the ground control station sends the access authentication white list to the control plane of each satellite node in the network through the uplink before T0;

[0023] The maximum data flow allowed to pass is 100% of the bandwidth.

[0024] As a preferred mode of the on-board lightweight network security protection method, in step S2, when the data plane receives the access authentication list empty instruction sent by the control plane, the access authentication white list is emptied, if it is within the valid time of the access authentication white list, it is switched to the security mode, and the white list set by the satellite node factory is used for receiving and forwarding data information packets;

[0025] When the access authentication white list is invalid, then all valid data packets are received and forwarded.

[0026] The satellite lightweight network security protection method provided by the application, as a preferred mode, in step S2, the control plane stores IP addresses of high security levels in the SRAM high-speed area according to the firewall policy, and uses IP range bitmap coding for IP addresses of medium and low security levels;

[0027] The firewall policy includes IP addresses and port numbers of legal and illegal satellite nodes, and maximum data traffic allowed to pass through.

[0028] When the firewall black and white lists are valid, the data plane performs data receiving and forwarding functions according to the firewall policy.

[0029] The satellite lightweight network security protection method provided by the application, as a preferred mode, in step S3, the satellite orbit parameter information includes orbit height, inclination and ascending node right ascension;The control plane of each satellite uses an orbit mechanics model and a prediction algorithm to predict a set of visible neighbor satellite nodes within a communication window in the next 10 minutes every 10 minutes.

[0030] The satellite lightweight network security protection method provided by the application, as a preferred mode, in step S6, when the data traffic is less than 90% of the maximum data traffic allowed to pass through, the data load returns to the normal range.

[0031] The satellite lightweight network security protection method provided by the application, as a preferred mode, in step S1, the ground control station sets a sliding window counter for the control plane of each satellite node in the network at the same time, and the sliding window counter includes a default time and a count threshold N.

[0032] Steps S4 and S5 are discarded when the inter-satellite data packet is discarded, and step S7 is entered.

[0033] S7, the illegal access count of the sliding window counter is increased by 1, and when the illegal access count of the sliding window counter to the data packet of the same source SCID and IP address exceeds the threshold N within the default time, the control plane generates an alarm information and feeds back the alarm information to the ground control station.

[0034] S8, the ground control station receives the alarm information, adjusts the security policy of the access authentication white list and the firewall black and white list according to the severity and type of the alarm information, and returns to step S1.

[0035] The satellite lightweight network security protection method provided by the application, as a preferred mode, in step S1, the default time is 60 seconds, and N is 10.

[0036] The satellite-borne lightweight network security protection method provided by the application has the following advantages:

[0037] The application is a large-scale low-orbit satellite constellation network security technology.

[0038] The application has the following advantages:

[0039] (1) The application effectively improves the problem of insufficient storage and computing resources of on-board routers. By dividing the satellite-borne network security protection strategy into a control plane and a data plane, the control plane is responsible for strategy formulation and issuance, and the data plane focuses on real-time processing of data packets. By using technologies such as multi-level index table and hierarchical rule library, the application avoids redundant occupation of resources, so that the satellite node can more reasonably allocate and use computing and storage resources in a resource-limited environment, improving resource utilization efficiency and ensuring stable operation of the satellite network.

[0040] (2) In view of the variable characteristics of satellite network topology, in terms of access authentication, the satellite node calculates the visible satellite set in real time according to the orbital ephemeris, generates and updates the white list, and accurately adapts to the dynamic changes of satellite-to-satellite communication relationship; the firewall function dynamically adjusts the strategy level according to real-time data load, and can flexibly cope with both normal load and high load, ensuring that the network security protection does not fail due to changes in topology, and realizing fast and accurate dynamic adaptation of security protection strategy.

[0041] (3) The application constructs a complete network security protection system covering access authentication, firewall and abnormal alarm. Access authentication accurately filters illegal users and data packets; the firewall uses multi-dimensional protection to ensure the legality of data transmission; the abnormal alarm function uses a sliding window counter to timely discover and feedback abnormal situations. This makes the network security protection function more comprehensive, effectively resists external attacks, and improves the overall security of the satellite network. BRIEF DESCRIPTION OF DRAWINGS

[0042] Fig. 1 An access authentication method flowchart of a satellite-borne lightweight network security protection method;

[0043] Fig. 2 A firewall method flowchart of a satellite-borne lightweight network security protection method;

[0044] Fig. 3 A flowchart of a satellite-borne lightweight network security protection method;

[0045] Fig. 4 A security management function module block diagram of a satellite-borne lightweight network security protection method. DETAILED DESCRIPTION

[0046] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0047] Example 1

[0048] like Figs. 1-4 As shown, a lightweight spaceborne network security protection method is proposed. This embodiment deploys a constellation network consisting of 18 low-Earth orbit satellites, numbered SAT001-SAT18. Each satellite is equipped with an onboard router. The satellites are distributed across three orbital planes, with six satellites in each plane. Adjacent satellites communicate with each other via inter-satellite links, forming a complete satellite communication network. The orbital altitude of the satellite nodes is approximately 1000 km, the orbital inclination is 60°, the distance between adjacent satellites is approximately 1000 km, and the inter-satellite link communication bandwidth is 1 Gbps.

[0049] The spaceborne lightweight network security protection method includes the following steps:

[0050] S1. Based on the planning and management requirements of the satellite network, the ground control station pre-generates an access authentication whitelist, which includes the SCID number (a unique identifier for each satellite) of the legitimate satellite nodes, the whitelist's validity period T0, and its expiration period T0+24h. This whitelist is then sent to the control plane of each satellite node in the network via the uplink between T0 and 1h.

[0051] The ground control station simultaneously adds firewall blacklists and whitelists to each satellite node in the network. The blacklists and whitelists include the IP address, port number, security level (high, medium, low), maximum allowed data traffic (bandwidth percentage: 80%), validity period T0, and expiration period T0+24h for the legitimate satellite nodes.

[0052] The ground control station also designed a sliding window counter for the onboard routers of each satellite node in the network, setting the default time to 60 seconds and the counter to 10.

[0053] S2. The onboard router control plane sends the generated access authentication whitelist configuration information to the data plane. Upon receiving the information, the data plane updates the whitelist information it stores.

[0054] After the control plane of the satellite router receives the black and white lists, it dynamically generates a firewall strategy. IP addresses with high security levels (ground control station IP addresses: 192.0.0.0) are stored in the SRAM high-speed area, and IP addresses with general security levels (satellite SAT001-100: 192.0.0.1-192.0.0.100) are encoded using an IP range bitmap. At the same time, the firewall strategy containing IP addresses, port numbers, and the maximum data flow allowed is issued to the data plane.

[0055] After the data plane of the satellite router receives the firewall black and white list configuration information, it updates the stored black and white list information.

[0056] S3, the satellite nodes interact with each other in real time to exchange satellite orbit parameter information, including orbit height, inclination, and ascending node right ascension. Each satellite uses an orbit mechanics model and a prediction algorithm to predict a set of neighbor satellite nodes visible within a communication window in the next 10 minutes every 10 minutes, and takes an intersection of the set and a set of SCIDs annotated on the ground control station to obtain a final visible satellite access authentication white list. After the satellite SAT001 predicts for a time ΔT, the set of neighbor satellite nodes visible is {002, 003, 004}, and after taking an intersection of the set and the set of SCIDs annotated on the ground, the obtained white list is {002, 003}.

[0057] In [T0, T0+24h], when the satellite SAT005 enters the communication window of the satellite SAT001, the set of neighbor satellite nodes of the satellite SAT001 changes, the control plane recalculates the intersection result, and issues the updated white list {002, 003, 005} to the data plane, and the data plane updates the access authentication white list;

[0058] S4, at T0+500s, the satellite SAT001 receives a data packet from the satellite SAT101, and when the data plane of the satellite router receives a data packet sent by another satellite, it first extracts the SCID of the inter-satellite data frame and compares it with the SCID issued by the management plane. If the source satellite SCID number and the destination satellite SCID number do not exist in the current access authentication white list, the data packet is discarded, and the ground control station is reported of the discarding event.

[0059] In a normal load range, the satellite SAT001 receives a data packet from the satellite SAT002 at a rate of 10 Mbps, and the source satellite SCID number and the destination satellite SCID number exist in the current access authentication white list. Then the data packet enters the firewall function for further operation, and enters step S5.

[0060] S5, if the source IP address, port number, destination IP address, and port number of the data information packet exist in the firewall black and white lists, and the data receiving and forwarding rate does not exceed 80% of the link bandwidth, the data is sent on the corresponding port, and the step S3 is returned.

[0061] When the satellite SAT001 receives a data packet from the satellite SAT003 at a rate of 900 Mbps, the onboard router detects that the data load exceeds 80% of the link bandwidth, and enters step S6.

[0062] S6, the control plane evaluates the security of the current onboard router. If there is no abnormal alarm, the firewall policy is reissued to the data plane, and the adjusted policy only contains the IP address and the maximum data flow allowed (100%) to pass, ignoring the source IP and port check. When the satellite SAT001 receives the data packet from the satellite SAT003 at a rate of less than 720 Mbps, the data load returns to the normal range, and the firewall policy is restored to the data plane.

[0063] S7, within T0+560s, the onboard router of the satellite SAT001 receives more than 10 data packets from the satellite SAT101, generates an alarm information, and feeds back the alarm information to the ground control station. The alarm information includes the attack source SCID number (101), IP address (192.0.0.101), type (SCID illegal), number of times (15), first timestamp (T0+500s), and last timestamp (T0+550s).

[0064] S8, after the ground control station receives the alarm information, the security policy of the firewall black and white list and the access authentication white list is adjusted according to the severity and type of the alarm information, and the step S1 is returned.

[0065] In this embodiment, the onboard network security protection policy is divided into control plane and data plane.

[0066] The control plane is mainly responsible for receiving the security protection policy and dynamic security policy generation from the ground control station. Based on the real-time calculation of the orbit ephemeris, the visible satellite set is generated, and the compressed access authentication white list is generated. The layered firewall rules and adaptive degradation policy are formulated. The alarm information is managed, and the policy instruction is issued to the data plane.

[0067] The data plane is mainly responsible for real-time security processing of data packets. Through multi-level index table (first judging access authentication white list, then judging firewall white list), data packet filtering is realized; according to the layered rule library, flow control is executed; sliding window alarm counting is implemented, and abnormal events are fed back to the control plane.

[0068] The satellite network security protection strategy includes access authentication, firewall, and abnormal alarm function. The access authentication filters illegal users and illegal data packets through preset control strategy; the firewall sets a white list through load control routing table to realize data transmission limited to white list users and realize the function of limiting user IP+port number or MAC address; the abnormal alarm function is divided into alarm prompt and alarm information record two parts.

[0069] The access authentication function includes:

[0070] The requirements for the control plane are mainly based on real-time calculation of visible satellite set based on orbital ephemeris, generation of compressed white list, and white list configuration instruction issued to the data plane:

[0071] 1) The ground control station uploads the access authentication white list to each satellite node in the network, and the white list content includes the SCID number of the legal satellite node, the valid time and invalid time of the white list;

[0072] 2) The satellite nodes in the network interact with each other in real time to predict the neighbor satellite node set visible in the communication window in the future period ΔT based on satellite orbit parameter information, and after receiving the access authentication white list uploaded by the ground control station, the satellite node takes the intersection of the SCID set of the predicted visible satellite and the SCID set uploaded by the ground control station, and issues the intersection result to the data plane. Within the effective period of the access authentication white list uploaded on the ground, when the neighbor satellite node set changes, update the intersection result to the data plane.

[0073] The requirements for the data plane are mainly to extract the SCID of the inter-satellite data frame and compare it with the SCID issued by the management plane, and if the comparison is successful, the next step of operation is entered into the firewall function, and if it fails, the data frame is discarded and reported to the ground control station:

[0074] 1) After the data plane of the satellite router receives the access authentication white list configuration information sent by the control plane of the satellite router, the access authentication white list information stored in the data plane is updated; if the white list is enabled, only data information packets with satellite SCID numbers in the white list are received and forwarded, that is, when a data information packet is received, it is judged whether the last hop satellite SCID number and the next hop satellite SCID number of the data information packet are in the access authentication white list, if they exist, the data packet is received or forwarded, if they do not exist, the data packet is discarded, and feedback is given to the control plane;

[0075] 2) When the data plane of the satellite router receives the access authentication white list empty instruction sent by the control plane of the satellite router, the access authentication white list is emptied, and if the white list is enabled, it is switched to the security mode, and the white list set by the satellite node at the factory is used for receiving and forwarding data information packets;

[0076] 3) If the white list is not turned on, receive and forward all valid data packets.

[0077] The firewall function includes:

[0078] The requirements for the control plane are to dynamically generate a firewall policy and issue a policy configuration instruction to the data plane, to detect the load of the satellite router in real time, and to adjust the level of the firewall policy:

[0079] 1) The ground control station uploads the firewall black and white lists to each satellite node in the network, and the content of the black and white lists includes the IP addresses, port numbers, security levels, maximum data flow allowed to pass, valid time and invalid time of the black and white lists of the legal satellite nodes and illegal satellite nodes;

[0080] 2) The satellite router stores the IP addresses of high security levels in the SRAM high-speed area, and uses IP range bitmap coding for the IP addresses of general security levels, and issues the firewall policy containing the IP addresses, port numbers and maximum data flow allowed to pass to the data plane;

[0081] 3) The satellite router detects the data load in real time, and when the data load exceeds a certain threshold H, the security of the current satellite router is evaluated, and if there is no abnormal alarm, the firewall policy is reissued to the data plane, including the IP addresses and the maximum data flow allowed to pass. When the data load returns to the normal range (less than H-10% H), the firewall policy is restored to the data plane.

[0082] The requirements for the data plane are mainly to extract the IP addresses of the inter-satellite data frames and compare them with the IP addresses in the firewall black and white list issued by the control plane. If the comparison is successful within the flow range, the frame is a legal data frame, and if the comparison fails, the data frame is discarded and reported to the ground control station. If the flow range is exceeded, the speed is reduced and the data is forwarded:

[0083] 1) After receiving the firewall black and white list configuration information sent by the control plane of the satellite router, the data plane of the satellite router updates the stored firewall black and white list information. If the black and white list is turned on, the data receiving and forwarding function executes according to the policy in the black and white list;

[0084] 2) Within the normal load range of the satellite router, when a data packet is received, it is judged whether the source IP address, port number and destination IP address, port number of the data packet are in the firewall black and white list. If they exist, the data is sent on the corresponding port, and if they do not exist, the data packet is discarded. The data receiving and forwarding rate cannot exceed the flow setting in the firewall black and white list;

[0085] 3) When the satellite router exceeds the load range threshold H, it feeds back to the control plane, and after receiving the new security policy, it only checks the destination IP address of the received data packet, ignoring the source IP and port.

[0086] 4) When the data plane of the satellite router receives the firewall black and white list clearing instruction sent by the control plane of the satellite router, the firewall black and white list is cleared, and if the firewall function is enabled, the security mode is switched to, and the white list set by the satellite node at the factory is used for receiving and forwarding data packets;

[0087] 5) If the firewall function is disabled, all valid data packets are received and forwarded.

[0088] The abnormal alarm function includes:

[0089] A sliding window counter is designed for the satellite router, and the default is 60 seconds, which can be set through an instruction. The data packets of the same source SCID and IP address are counted for illegal access. When the count exceeds the threshold value N, an alarm information is generated, which includes the attack source SCID number, IP address, type (SCID illegal / IP black list), number of times, first / last time stamp, and the alarm information is fed back to the ground control station.

[0090] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art, according to the technical solution and the inventive concept of the present application, can make equivalent replacement or change within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A lightweight spaceborne network security protection method, characterized in that: Includes the following steps: S1. The ground control station adds access authentication whitelists and firewall blacklists / whitelists to the control plane of the onboard routers of each satellite node in the network. The access authentication whitelist includes the SCID number of the legitimate satellite node, the validity period of the access authentication whitelist, and the expiration period of the access authentication whitelist. The firewall blacklist and whitelist include the IP address, port number, security level, maximum allowed data traffic of legitimate and illegitimate satellite nodes, as well as the effective time and expiration time of the firewall blacklist and whitelist; S2. The control plane forwards the access authentication whitelist to the data plane of the satellite router, and the data plane updates the stored whitelist information upon receiving it. The control plane dynamically generates firewall policies based on the firewall blacklist and whitelist, stores the IP addresses of legitimate and illegitimate satellite nodes according to their security levels, and sends the firewall policies to the data plane. The firewall policies are firewall blacklist and whitelist configuration information. Upon receiving the information, the data plane updates the stored blacklist and whitelist information. The access authentication whitelist and the firewall blacklist / whitelist are valid for a period of time, then proceed to step S3; S3. Satellite orbit parameter information is exchanged between satellite nodes in real time. The control plane of each satellite predicts the set of visible neighbor satellite nodes in the communication window within a specified time ΔT, and takes the intersection of the set of visible neighbor satellite nodes and the SCID set of the access authentication whitelist to obtain a compressed access authentication whitelist, which is then sent to the data plane for updating. When a new satellite enters the local satellite's communication window, the set of neighboring satellite nodes of the local satellite changes. The control plane recalculates the intersection result and updates it before sending it to the data plane for updating. S4. When the satellite receives an inter-satellite data packet, the data plane extracts the SCID number of the inter-satellite data frame and compares it with the SCID number in the compressed access authentication whitelist to determine whether the node SCID number of the inter-satellite data frame is in the compressed access authentication whitelist. If it is, the firewall function is activated and the process proceeds to step S5. If not, the inter-satellite data packet is discarded and the discard event is reported to the ground control station. S5. Determine whether the source IP address, source port number, destination IP address, and destination port number of the inter-satellite data packet are all legitimate or illegitimate satellite nodes in the firewall's blacklist or whitelist, and whether the reception or forwarding rate of the inter-satellite data packet does not exceed the maximum allowed data traffic. If all are true, then receive or forward the inter-satellite data packet; if the reception or forwarding rate exceeds the maximum allowed data traffic, proceed to step S6. If it belongs to an illegitimate satellite node, then discard the inter-satellite data packet and report the discarding event to the ground control station. S6. The control plane evaluates the security of the current onboard router. If there are no abnormal alarms, the firewall policy is adjusted and sent to the data plane. The adjusted policy only includes the destination IP address and the adjusted maximum allowed data traffic. The adjusted maximum allowed data traffic is greater than 100% of the bandwidth. The source IP and port verification is ignored until the received or forwarded data load returns to the normal range. The firewall policy is then restored to the data plane, and the process returns to step S3.

2. The lightweight spaceborne network security protection method according to claim 1, characterized in that: In step S1, the access authentication whitelist is pre-generated by the ground control station based on the planning and management requirements of the satellite network. The SCID number is a unique identifier for each satellite. The access authentication whitelist is valid for T0 and expires for T1, where T1 > T0. The ground control station sends the access authentication whitelist to the control plane of each satellite node in the network via the uplink before T0; The firewall blacklist / whitelist is valid for T0 and expires for T1, where T1 > T0. The maximum allowed data traffic is a percentage of the bandwidth.

3. The lightweight spaceborne network security protection method according to claim 2, characterized in that: The ground control station sends the access authentication whitelist to the control plane of each satellite node in the network via the uplink before T0; The maximum allowed data traffic is 100% of the bandwidth.

4. The spaceborne lightweight network security protection method according to claim 1, characterized in that: In step S2, when the data plane receives the access authentication whitelist clearing instruction sent by the control plane, it clears the access authentication whitelist. If the access authentication whitelist is valid for a certain period of time, it switches to the security mode and uses the whitelist set by the satellite node at the factory to receive and forward data packets. When the access authentication whitelist expires, all valid data packets are received and forwarded.

5. A lightweight spaceborne network security protection method according to claim 1, characterized in that: In step S2, the control plane stores high-security IP addresses in the SRAM high-speed zone according to the firewall policy, and uses IP range bitmap encoding for medium and low-security IP addresses. The firewall policy includes the IP addresses and port numbers of legitimate and illegitimate satellite nodes, as well as the maximum allowed data traffic. When the firewall blacklist and whitelist are in effect, the data plane performs data reception and forwarding functions according to the firewall policy.

6. The lightweight spaceborne network security protection method according to claim 1, characterized in that: In step S3, the satellite orbital parameter information includes orbital altitude, inclination, and right ascension of the ascending node; the control plane of each satellite uses an orbital mechanics model and prediction algorithm to predict the set of visible neighbor satellite nodes within the communication window every 10 minutes.

7. A lightweight spaceborne network security protection method according to claim 1, characterized in that: In step S6, when the data traffic is less than 90% of the maximum allowed data traffic, the data load returns to the normal range.

8. The lightweight spaceborne network security protection method according to claim 1, characterized in that: In step S1, the ground control station simultaneously sets a sliding window counter for the control plane of each satellite node in the network. The sliding window counter includes a default time and a counting threshold N. When the inter-satellite data packets are discarded in steps S4 and S5, proceed to step S7; S7. The illegal access count of the sliding window counter is incremented by 1. When the illegal access count of the sliding window counter for data packets with the same source SCID and IP address exceeds the threshold N within the default time, the control plane generates an alarm message and feeds the alarm message back to the ground control station. S8. After receiving the alarm information, the ground control station adjusts the security policies of the access authentication whitelist and firewall blacklist / whitelist according to the severity and type of the alarm information, and returns to step S1.

9. A lightweight spaceborne network security protection method according to claim 8, characterized in that: In step S1, the default time is 60 seconds and N is 10.

10. A lightweight spaceborne network security protection method according to claim 8, characterized in that: In step S8, the alarm information includes the attack source SCID number, IP address, type, number of times, first timestamp, and last timestamp.

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