A path verification method and device for satellite internet

Abstract

The application provides a path verification method and device for a satellite internet, constructs a global time delay gradient matrix reflecting an implicit mapping relationship between data transmission time delays and geographical distances between ground stations, detects potential risk paths through clustering analysis of abnormal values in the global time delay gradient matrix, constructs a risk criterion according to physical characteristics of path hijacking attacks in the satellite internet, and verifies the potential risk paths according to the risk criterion. The application replaces an encryption mark matching check method used by a hop-by-hop verification mechanism, avoids a large amount of overhead caused by frequent changes of paths under dynamic topology conditions of the satellite internet, and improves the performance of path verification in the satellite internet scenario.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of satellite communication, and particularly relates to a path verification method and device for satellite Internet. BACKGROUND

[0002] In recent years, the application of low-orbit mega satellite constellation provides global coverage and low-latency network services for user terminals accessing satellite Internet, and improves the user experience of user terminals accessing satellite Internet. However, a large number of inter-satellite links are deployed in the low-orbit mega satellite constellation, so that the low-orbit mega satellite constellation truly has network characteristics compared with the satellite communication system using the bent pipe mode, which means that the low-orbit mega satellite constellation faces unprecedented network attack threats. Routing hijacking attack is one of the most common network attacks in the Internet at present. Attackers modify the original forwarding path of data packets by various means, so that the data packets fall into a routing black hole or pass through an unsafe area such as a eavesdropping node, and damage the security of user data. The low-orbit mega satellite constellation also faces this problem, and compared with the secure ground node such as a data center, the global exposure characteristics of satellite nodes make them in the field of view of a large number of potential attackers. In addition, because the satellite nodes are long-term in uncontrolled areas and lack ground support facilities for measurement and control, it is difficult to timely perceive and defend in the early stage of attack. Therefore, it is particularly necessary to detect routing hijacking.

[0003] Path verification is one of the main means to detect routing hijacking, and its purpose is to enable nodes or terminals to verify whether the upstream forwarding path is consistent with the expected forwarding path, so as to detect attacks involving path tampering. Most of the existing path verification methods use hop-by-hop verification mechanism, that is, a source end is specified with an expected forwarding path under the implicit assumption that the network topology structure is stable, shared keys between nodes in the expected forwarding path are generated, an encryption mark is generated by performing a cryptographic operation on a data packet by the previous node, and the encryption mark is embedded in the packet header and followed by data forwarding. The next node proves that the data packet indeed passed through the previous node by verifying the encryption mark, and verifies the consistency between the actual forwarding path and the expected forwarding path.

[0004] However, in the satellite Internet, the network topology is in a state of rapid change due to frequent switching of the satellite-ground link at a minute level, the routing needs to be re-converged according to the new topology, and the end-to-end forwarding path is no longer stable, so when the network topology structure changes, the expected forwarding path specified for the source end with the previous network topology structure as the invisible assumption can no longer reflect the current situation, resulting in the loss of stable criteria for path verification. Each time the satellite-ground link switches, the shared key between nodes needs to be regenerated, and the hop-by-hop verification method needs to be used to verify the consistency between the actual forwarding path and the expected forwarding path; the above series of operations involve multiple signaling interactions and encryption and decryption calculations, resulting in a large amount of signaling overhead and calculation overhead. In addition, the perception of network topology changes has a certain lag, so the change of the expected forwarding path cannot be reflected in the encryption mark in time, which will lead to packet loss due to misjudgment of the path node to the data packet. Therefore, how to provide a low-overhead and high-performance path verification scheme in the satellite Internet has become a difficult problem to be solved. SUMMARY

[0005] The present application provides a path verification method and device for satellite Internet, which obtains abnormal values by clustering analysis of the implicit mapping relationship between the time delay and the geographical distance between ground stations to detect risk paths, instead of the encryption mark matching verification method used by the hop-by-hop verification mechanism, and uses the path with abnormal implicit mapping relationship between the time delay and the geographical distance searched by clustering and physical feature analysis as the path of route hijacking, thereby avoiding the large signaling overhead and calculation overhead caused by frequent changes of the path under the dynamic topology condition of the satellite Internet in the existing path verification technology.

[0006] In a first aspect, the present application provides a path verification method for satellite Internet, which comprises:

[0007] generating an inter-station distance matrix according to the geographical position information between the ground stations;

[0008] summarizing the inter-station time delay table of each ground station to obtain a global time delay matrix;

[0009] differentiating the corresponding elements of the global time delay matrix and the inter-station distance matrix to obtain a global time delay gradient matrix;

[0010] performing statistical outlier analysis on the global time delay gradient matrix, and taking the data transmission path of the ground station pair with an abnormal value as a potential risk path;

[0011] when the potential risk path meets a first condition, determining that the potential risk path is a risk path;

[0012] The inter-station time delay table of the ground station stores data transmission time delay of each target ground station to the ground station.

[0013] The first condition is that the difference between the measured value and the theoretically estimated value of the data transmission time delay is greater than the shortest data transmission time delay of one round-trip satellite-ground link.

[0014] The method for verifying a path for a satellite Internet provided by the application, and the generation process of the inter-station time delay table of the ground station, comprises the following steps:

[0015] The ground station locally creates four inter-station time delay sub-tables with the source ground station number and data transmission time delay as fields; wherein, the four inter-station time delay sub-tables correspond to four access satellite orbit directions respectively, and the four access satellite orbit directions are uplink north and downlink south, uplink north and downlink north, uplink south and downlink north, and uplink south and downlink south respectively.

[0016] In one measurement period, each target ground station is controlled to send a time delay measurement packet to the ground station at a preset time interval; wherein, the time delay measurement packet is obtained by performing header embedding of the source ground station number, the source ground station access satellite number and the sending time stamp on an IP data packet.

[0017] The ground station infers the data transmission time delay and the access satellite orbit direction of each target ground station to the ground station according to the time delay measurement packet sent by each target ground station.

[0018] Each data transmission time delay of each target ground station to the ground station is inserted into the inter-station time delay sub-table corresponding to the access satellite orbit direction of each target ground station to the ground station by taking the number of each target ground station as an index, to obtain four inter-station time delay sub-tables filled with data.

[0019] The four inter-station time delay sub-tables filled with data are combined to obtain the inter-station time delay table of the ground station.

[0020] The method for verifying a path for a satellite Internet provided by the application infers the data transmission time delay of the target ground station to the ground station according to the measurement packet sent by the target ground station, which comprises the following steps:

[0021] The time length between the sending time stamp and the receiving time of each measurement packet sent by the target ground station is listed in a first list.

[0022] The minimum value of the plurality of time lengths in the first list after filtering is obtained as the data transmission time delay of the target ground station to the ground station.

[0023] The path verification method for satellite internet provided by the application comprises the following steps:

[0024] The access satellite orbit direction of the target ground station to the ground station is determined according to the source ground station access satellite number in any measurement packet sent by the target ground station and the pre-stored two-row orbit root number information of all satellites in the constellation.

[0025] The path verification method for satellite internet provided by the application comprises the following steps:

[0026] The global delay gradient matrix is analyzed by using a preset outlier detection algorithm to select outliers greater than a safety threshold of the preset outlier detection algorithm from the global delay gradient matrix.

[0027] The preset outlier detection algorithm includes but is not limited to IQR test method and Grubbs test method.

[0028] The path verification method for satellite internet provided by the application comprises the following steps:

[0029] The determination process of the theoretical estimation value of the data transmission delay of the potential risk path comprises the following steps:

[0030] The adjacent path of the potential risk path is determined.

[0031] Elements corresponding to the ground station pair of the adjacent path are extracted from the global delay matrix to form a reference delay matrix.

[0032] The mapping relationship between the data transmission delay and the geographical distance is determined for the ground station pair in the range of the reference delay matrix by using a regression analysis method.

[0033] The theoretical estimation value of the data transmission delay of the potential risk path is determined according to the mapping relationship and the distance between the ground station pair of the potential risk path.

[0034] The path verification method for satellite internet provided by the application comprises the following steps:

[0035] The path satisfying the second condition is taken as the adjacent path of the potential risk path.

[0036] The second condition is that

[0037] a distance between the source end and a source end of the potential risk path is less than a first threshold value, and

[0038] a distance between the destination end and a destination end of the potential risk path is less than a second threshold value.

[0039] In a second aspect, the present application provides a path verification device for satellite Internet, the device comprising:

[0040] an inter-station distance matrix generating module configured to generate an inter-station distance matrix according to geographical position information between ground stations;

[0041] a global latency matrix generating module configured to aggregate an inter-station latency table of each ground station to obtain a global latency matrix;

[0042] a global latency gradient matrix generating module configured to differentiate corresponding elements of the global latency matrix and the inter-station distance matrix to obtain a global latency gradient matrix;

[0043] a potential risk path identifying module configured to perform statistical outlier analysis on the global latency gradient matrix, and identify a data transmission path of a ground station pair having an outlier value as a potential risk path;

[0044] a risk path identifying module configured to identify the potential risk path as a risk path when the potential risk path satisfies a first condition;

[0045] wherein the inter-station latency table of each ground station stores a data transmission latency of each target ground station to the ground station; the target ground station is a ground station other than the ground station;

[0046] the first condition is that a difference between a measured value and a theoretically estimated value of the data transmission latency is greater than a shortest data transmission latency of a round-trip satellite-ground link.

[0047] In a third aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor implements the path verification method for satellite Internet according to the first aspect when executing the program.

[0048] In a fourth aspect, the present application provides a non-transitory computer readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the path verification method for satellite Internet according to the first aspect.

[0049] The application provides a path verification method and device for a satellite Internet, which utilizes geographical position information between ground stations to construct an inter-station distance matrix, and utilizes measured data transmission time delays between the ground stations to construct a global time delay matrix; corresponding elements of the global time delay matrix and the inter-station distance matrix are differentiated to obtain a global time delay gradient matrix; the global time delay gradient matrix reflects an implicit mapping relationship between the data transmission time delays and the geographical distances between the ground stations, and abnormal value detection is performed on the global time delay gradient matrix from a global perspective to preliminarily screen risk paths; since the gradient abnormality is caused not only by a detour of a path hijacking attack, but also by network local congestion. In order to avoid misjudgment, and considering that an additional uplink and downlink operation is an irrepudiable attack feature of the path hijacking attack in the satellite Internet, a risk criterion is designed according to the physical features of the attack, that is, if a difference between a measured value and a theoretically estimated value of a data transmission time delay of a potential risk path is greater than a shortest data transmission time delay of a round trip of a satellite-ground link, the potential risk path is a risk path, and risk verification is performed on the potential risk path from a local perspective according to the risk criterion. The application replaces an encryption label matching check method used in a hop-by-hop verification mechanism, avoids a large amount of signaling overhead and calculation overhead caused by frequent path changes under a dynamic topology condition of the satellite Internet, and improves the performance of path verification in the satellite Internet. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0051] Figure 1 is a schematic diagram of path change caused by route hijacking provided by the prior art;

[0052] Figure 2 is a schematic diagram of expected forwarding path update caused by satellite-ground switching provided by the prior art;

[0053] Figure 3 is a flowchart of the path verification method for the satellite Internet provided by the application;

[0054] Figure 4 is a schematic diagram of IP packet header expansion provided by the application;

[0055] Figure 5 is a schematic diagram of in-band time delay measurement provided by the application;

[0056] Figure 6 is a schematic diagram of preliminary screening by the global gradient matrix provided by the application;

[0057] Figure 7 is a schematic diagram of extracting a neighboring path according to a geographical position provided by the present application;

[0058] Figure 8 is a schematic diagram of extracting a neighboring path to construct a reference delay matrix provided by the present application;

[0059] Figure 9 is a full flow example diagram provided by the present application;

[0060] Figure 10 is a structural schematic diagram of a path verification device for satellite internet provided by the present application;

[0061] Figure 11 is a structural schematic diagram of an electronic device for implementing a path verification method for satellite internet provided by the present application;

[0062] Reference signs:

[0063] 110: processor; 120: communication interface; 130: memory; 1140: communication bus. DETAILED DESCRIPTION

[0064] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0065] The path verification method and device for satellite internet of the present application will be described below in combination with Figures 1-11

[0066] The present application is applicable to a satellite internet-based ground station switching access satellite scenario, and relates to a user terminal device, a ground station and a satellite internet. The user terminal accesses the satellite internet through a ground station near the user terminal, and the satellite node is provided with an inter-satellite link. Figure 1 is a schematic diagram of path change caused by route hijacking in a satellite internet scenario, as Figure 1 ​As shown in the figure, the expected path of transmitting data in the satellite internet is R1→R2→R3→R10→R5→R6→R7; the attacker performs route hijacking on R10, deriving a downlink path from R10 to a ground station near the attacker and an uplink path from the ground station near the attacker to R10, that is, the data flow is R1→R2→R3→R10→attacker→R10→R5→R6→R7, the attacker can copy the data flow and keep it secret, which seriously damages the security of user data. Therefore, detecting route hijacking attacks is crucial for satellite internet applications.

[0067] Path verification is one of the main means to detect route hijacking, and most existing path verification methods use hop-by-hop verification mechanism to achieve it, Figure 2 is a schematic diagram of expected forwarding path update caused by satellite-ground switching, as Figure 2 As shown in the figure, when the source end switches from satellite to ground, the path planning server switches the expected path of transmitting data in the satellite internet from R1→R2→R3→R4→R5→R6→R7 to R8→R9→R10→R5→R6→R7. The shared key set up according to the expected path R1→R2→R3→R4→R5→R6→R7 and the encryption marker generated based on the shared key and embedded in the packet header are no longer applicable, and a new shared key needs to be set up according to the expected path R8→R9→R10→R5→R6→R7, and the path node encryption marker needs to be recalculated and inserted into the packet header using the new shared key. This series of operations involves multiple signaling interactions and encryption and decryption calculations, resulting in a large amount of signaling and calculation overhead.

[0068] Of course, in terms of path verification, there are also some path verification methods that rely on the expected forwarding path but are not exactly the same as the hop-by-hop verification mechanism in the background art, such as randomly selecting some satellite nodes in the expected path for verification without verifying all satellite nodes in the expected path, but these methods also face the above technical defects. The present application makes improvements to the above technical defects.

[0069] In a first aspect, the present application provides a path verification method for a satellite internet, as Figure 3 As shown in the figure, the method comprises:

[0070] S11, generating an inter-station distance matrix according to the geographical position information between ground stations;

[0071] S12, aggregating the inter-station time delay table of each ground station to obtain a global time delay matrix; wherein the inter-station time delay table of each ground station stores the data transmission time delay of each target ground station to the ground station; the target ground station is a ground station other than the ground station;

[0072] S13, differentiating corresponding elements of the global time delay matrix and the inter-station distance matrix to obtain a global time delay gradient matrix;

[0073] S14, performing statistical outlier analysis on the global time delay gradient matrix, and taking a data transmission path of a ground station pair with an outlier as a potential risk path;

[0074] S15, when the potential risk path meets a first condition, determining that the potential risk path is a risk path; wherein the first condition is that a difference between a measured value and a theoretically estimated value of a data transmission time delay is greater than a shortest data transmission time delay of a round-trip satellite-ground link.

[0075] The application provides a path verification method for a satellite Internet, which utilizes geographical position information between ground stations to construct an inter-station distance matrix, and utilizes measured data transmission time delays between the ground stations to construct a global time delay matrix; corresponding elements of the global time delay matrix and the inter-station distance matrix are differentiated to obtain a global time delay gradient matrix; the global time delay gradient matrix reflects an implicit mapping relationship between the data transmission time delays and geographical distances between the ground stations, and an outlier detection is performed on the global time delay gradient matrix from a global perspective to preliminarily screen a risk path; since the gradient outlier is caused not only by a detour of a path hijacking attack, but also by network local congestion. In order to avoid misjudgment, and considering that an additional downlink and uplink operation is an irrefutable attack feature of the path hijacking attack in the satellite Internet, a risk criterion is designed according to the physical feature of the attack, i.e., when a difference between a measured value and a theoretically estimated value of a data transmission time delay of a potential risk path is greater than a shortest data transmission time delay of a round-trip satellite-ground link, the potential risk path is a risk path, and a risk verification is performed on the potential risk path from a local perspective according to the risk criterion. The application replaces an encryption mark matching check method used in a hop-by-hop verification mechanism, avoids a large amount of signaling overhead and computing overhead caused by frequent path changes under a dynamic topology condition of the satellite Internet, and improves the performance of the path verification in the satellite Internet scenario.

[0076] Specifically, the application takes a processing center as an execution subject, the processing center is a device with computing capability, and can be a certain ground station or a special computing center. The processing center maintains geographical position information of all ground stations of a constellation and constellation characteristic information (satellite orbit height), so that, according to the geographical position information between the ground stations, the inter-station distance between the ground stations can be calculated, and the inter-station distance matrix is constructed.

[0077] Further, an element in the i-th row and the j-th column of the inter-station distance matrix represents an inter-station distance between an i-th ground station and a j-th ground station in the constellation.

[0078] Specifically, in the S12, the inter-station time delay table of each ground station is used to store the data transmission time delay from any ground station in the constellation to the local ground station. The processing center requests all ground stations to obtain their inter-station time delay tables, and constructs a global time delay matrix by taking the data transmission time delay from the source ground station to the destination ground station as the element content of the global time delay matrix. That is, the element in the i-th row and the j-th column of the global time delay matrix represents the data transmission time delay from the i-th ground station to the j-th ground station in the constellation.

[0079] The application forms a time delay measurement packet by in-band extension of the packet header, and accurately determines the data transmission time delay between the ground stations by the interval length between the transmission and reception of the time delay measurement packet between the ground stations.

[0080] That is, the generation process of the inter-station time delay table of each ground station is specifically as follows:

[0081] The ground station locally creates four inter-station time delay sub-tables with the source ground station number and the data transmission time delay as the fields; wherein the four inter-station time delay sub-tables correspond to the four access satellite orbit directions involved by the uplink of the source ground station and the downlink of the destination ground station, respectively, and the four access satellite orbit directions are uplink north and downlink south, uplink north and downlink north, uplink south and downlink north, and uplink south and downlink south, respectively.

[0082] In a measurement period, each target ground station is controlled to send a time delay measurement packet to the ground station at a preset interval; wherein the time delay measurement packet is a packet header of an IP data packet embedded with the source ground station number (Source GS ID), the source ground station access satellite number (Up Sat ID), and the sending time stamp (Send Time).

[0083] The setting of this step enables each ground station to continuously send n time delay measurement packets to other ground stations in a measurement period, avoiding the problem of inaccurate determination of the data transmission time delay between the ground stations caused by sending only one time delay measurement packet.

[0084] Figure 4 The application is intended to expand the IP packet header, and adopts a one-way measurement method based on the sending time stamp, avoiding the dependence on the transmission layer protocol and the uncertainty of the end processing.

[0085] The ground station infers the data transmission time delay and the access satellite orbit direction from each target ground station to the ground station according to the time delay measurement packet sent by each target ground station.

[0086] It should be noted that the ground station receives the time delay measurement packets from multiple target ground stations in the measurement period. Before this step, the ground station records the receiving time and parses the packet header after receiving each resolved time delay measurement packet; and then classifies the time delay measurement packets according to the source ground station number in the packet header to obtain the time delay measurement packets sent by each target ground station.

[0087] In this step, the data transmission time delay of the target ground station to the ground station is estimated according to the measurement packets sent by the target ground station, and specifically includes:

[0088] The time length between the sending time stamp and the receiving time of each measurement packet sent by the target ground station is listed in a first list;

[0089] After filtering the multiple time lengths in the first list, the minimum value is obtained, which is the data transmission time delay of the target ground station to the ground station.

[0090] Here, the purpose of filtering the multiple time lengths in the first list is to remove measurement burrs.

[0091] According to the measurement packets sent by the target ground station, the access satellite orbit direction of the target ground station to the ground station is estimated, including:

[0092] According to the source ground station access satellite number in any measurement packet sent by the target ground station and the pre-stored two-line orbit root number information of all satellites in the constellation, the access satellite orbit direction of the target ground station to the ground station is estimated. Each ground station maintains the TLE (two-line orbit root number) information of all satellites in the constellation;

[0093] It should be noted that the first line of the TLE information includes: line number (1), satellite number, security level, launch year and international launch number, TLE duration (TLE data release time year and day of the year), average motion first time derivative, average motion second time derivative, BSTAR drag modulation coefficient, ephemeris type, ephemeris number and checksum; The second line of the TLE information includes: line number (2), satellite number, orbit plane and equatorial plane angle, ascending node right ascension, orbit eccentricity, perigee amplitude, mean anomaly, average motion (number of circles around the earth per day), on-orbit number and checksum

[0094] The TLE (two-line element) information of the satellite can be used to calculate the position of the satellite at any time. Therefore, according to the satellite number accessed by the source ground station in any measurement packet sent by the target ground station and the pre-stored two-line element information of all satellites in the constellation, the running direction of the access satellite can be determined, that is, the orbit direction of the access satellite from the target ground station to the ground station is determined, so that the corresponding inter-station time delay sub-table is located,

[0095] The data transmission time delay from each target ground station to the ground station is inserted into the inter-station time delay sub-table corresponding to the orbit direction of the access satellite from each target ground station to the ground station, to obtain four inter-station time delay sub-tables filled with data.

[0096] The four inter-station time delay sub-tables filled with data are combined to obtain the inter-station time delay table of the ground station.

[0097] It should be noted that the present application assumes that the data stream between two ground stations is always transmitted through the path with the shortest time delay between them, and therefore the data transmission time delay between the two ground stations corresponds to the path with the shortest time delay.

[0098] Figure 5 It is an in-band time delay measurement schematic diagram corresponding to the generation process of the inter-station time delay table of the ground station.

[0099] Specifically, in S13, the element values in the global time delay gradient matrix reflect the relationship between the data transmission time delay and the distance between the two ground stations.

[0100] That is, the element value in the i-th row and j-th column of the global time delay gradient matrix reflects the mapping relationship between the data transmission time delay from the i-th ground station to the j-th ground station in the constellation and the distance from the i-th ground station to the j-th ground station in the constellation.

[0101] The desired forwarding path (desired path node sequence) in the dynamic network is time-varying and no longer suitable as a path verification standard. The present application uses the mapping relationship between the data transmission time delay and the geographical distance as a new verification comparison quantity, decouples from the specific access satellite, eliminates the need for recalculation of the path verification standard caused by satellite-ground switching, and avoids the large overhead caused by recalculation.

[0102] Specifically, in S14, statistical outlier analysis is performed on the global time delay gradient matrix, including:

[0103] The global time delay gradient matrix is analyzed using a preset outlier detection algorithm to select outliers greater than the safety threshold of the preset outlier detection algorithm from the global time delay gradient matrix.

[0104] The preset outlier detection algorithm includes but is not limited to IQR test method and Grubbs test method.

[0105] The application takes the implicit mapping relationship between the data transmission delay and the geographical distance of the ground station pair (i.e. source ground station-destination ground station) as the comparison quantity in the satellite internet path verification, and carries out two-stage path verification from global to local, thereby improving the performance of path verification in the satellite internet scenario. S14 is the operation step of the global verification stage (preliminary screening stage).

[0106] Figure 6 The schematic diagram of preliminary screening by the global gradient matrix is as shown in Figure 6 Based on the assumption that the attacker cannot invade most of the nodes of the satellite internet, most of the elements in the global time delay gradient matrix should satisfy the similar time delay and distance mapping relationship, therefore, the statistical outlier analysis is carried out on the global time delay gradient matrix, to preliminarily screen the gradient abnormal ground station pair (GS-GS) from the global perspective, and the data transmission path of the gradient abnormal ground station pair (GS-GS) is taken as the potential risk path.

[0107] It should be noted that the security threshold in the outlier detection algorithm is usually given according to experience.

[0108] Specifically, S15 is the local verification stage, and the gradient anomaly of the ground station pair may also be caused by network local congestion in addition to the detour caused by the path hijacking attack. For the path hijacking attack in the satellite internet, an additional downlink and uplink operation is its non-repudiable attack feature, therefore, according to the non-repudiable physical constraint that the difference between the measured value and the theoretical estimated value of the data transmission delay of the risk path is greater than the RTT (the shortest data transmission delay of the satellite-ground link for one round trip), the application constructs a verification criterion for verifying whether the potential risk path is a risk path: if the difference between the measured value and the theoretical estimated value of the data transmission delay of the potential risk path is greater than the shortest data transmission delay of the satellite-ground link for one round trip, the potential risk path is determined as a risk path, and the risk verification of the potential risk path is completed from the local perspective.

[0109] Here, the shortest data transmission delay of the satellite-ground link for one round trip is determined according to the orbital height of the satellite, and in one constellation, the application defaults that the satellites are deployed in the same layer and have the same orbital height.

[0110] The measured value of the data transmission delay of the potential risk path is the element value corresponding to the ground station pair of the potential risk path in the aforementioned global time delay matrix;

[0111] The determination process of the theoretical estimated value of the data transmission delay of the potential risk path includes:

[0112] determine the adjacent path of the potential risk path;

[0113] That is, according to the set reference distance and the geographical positions of the source ground station and the destination ground station of the potential risk path, the adjacent path of the potential risk path is screened out. Figure 7 The schematic diagram of extracting the adjacent path according to the geographical position is shown in Figure 7 As shown in the figure, the determination of the adjacent path of the potential risk path specifically includes:

[0114] The path meeting the second condition is taken as the adjacent path of the potential risk path.

[0115] The second condition is:

[0116] The distance between the source end and the source end of the potential risk path is less than the first threshold value, and

[0117] The distance between the destination end and the destination end of the potential risk path is less than the second threshold value.

[0118] It should be noted that the first threshold value and the second threshold value are determined according to experience. The potential risk path and its adjacent path are probably in a similar congestion environment.

[0119] Extract the elements corresponding to the ground station pair of the adjacent path from the global delay matrix to form a reference delay matrix;

[0120] Figure 8 The schematic diagram of extracting the adjacent path to construct the reference delay matrix is shown in the figure. The clustering characteristics of the reference delay matrix can reflect the congestion situation near the potential risk path.

[0121] For the ground station pair within the range of the reference delay matrix, the mapping relationship between the data transmission delay and the geographical distance is determined by a regression analysis method.

[0122] With the ground station pair of the adjacent path of the potential risk path as a reference, the mapping relationship between the data transmission delay and the geographical distance in the area near the potential risk path is modeled by a regression analysis method.

[0123] According to the mapping relationship and the inter-station distance of the ground station pair of the potential risk path, the theoretical estimated value of the data transmission delay of the potential risk path is determined.

[0124] The theoretical estimated value of the potential risk path is estimated by using the mapping relationship, so as to exclude the influence of the network congestion near the potential risk path on the potential risk path in the above verification criterion.

[0125] In summary, the path verification is realized by the in-band measurement and the out-of-band processing cooperative control according to the present application, as shown in Figure 9The example full flow example diagram, the ground station is the ground station at the same time, the in-band measurement mainly refers to the delay measurement packet formed when the ground station extends the packet header, and the delay measurement packet is transmitted and received between the ground stations to determine the data transmission delay between the ground stations; the out-of-band processing mainly refers to two-stage path verification from the global to the local. The method does not need to make any modification to the satellite node hardware and routing protocol, and improves the deployability of path verification in the real environment of incremental launch of nodes of a huge constellation.

[0126] In addition, the present application needs to add a delay table for storing the delay information between the ground stations to increase the information stored and maintained by the existing ground stations.

[0127] In the second aspect, the path verification device for satellite Internet provided by the present application is described, and the path verification device for satellite Internet described below can be referred to each other corresponding to the path verification method for satellite Internet described above. Figure 10 An example structure diagram of a path verification device for satellite Internet is shown in the figure, which comprises: Figure 10 As shown in the figure, the device comprises:

[0128] An inter-station distance matrix generation module 21 is configured to generate an inter-station distance matrix according to the geographical position information between the ground stations;

[0129] A global delay matrix generation module 22 is configured to collect the inter-station delay table of each ground station to obtain a global delay matrix;

[0130] A global delay gradient matrix generation module 23 is configured to differentiate the corresponding elements of the global delay matrix and the inter-station distance matrix to obtain a global delay gradient matrix;

[0131] A potential risk path identification module 24 is configured to perform statistical outlier analysis on the global delay gradient matrix, and the data transmission path of the ground station pair with an outlier is regarded as a potential risk path;

[0132] A risk path identification module 25 is configured to identify the potential risk path as a risk path when the potential risk path meets a first condition;

[0133] Wherein, the inter-station delay table of each ground station stores the data transmission delay of each target ground station to the ground station; the target ground station is a ground station other than the ground station;

[0134] The first condition is that the difference between the measured value and the theoretically estimated value of the data transmission delay is greater than the shortest data transmission delay of a round-trip satellite-ground link.

[0135] The application provides a path verification device for a satellite Internet, which uses geographical position information between ground stations to construct an inter-station distance matrix, and uses measured data transmission time delays between the ground stations to construct a global time delay matrix; corresponding elements of the global time delay matrix and the inter-station distance matrix are differentiated to obtain a global time delay gradient matrix; the global time delay gradient matrix reflects an implicit mapping relationship between the data transmission time delays and geographical distances between the ground stations, and abnormal value detection is performed on the global time delay gradient matrix from a global perspective to preliminarily screen risk paths; in addition to detours caused by path hijacking attacks, gradient abnormalities can also be caused by local network congestion. In order to avoid misjudgment and considering that an additional uplink and downlink operation is an irrepudiable attack feature of the path hijacking attack in the satellite Internet, a risk criterion is designed according to the physical characteristics of the attack, i.e., if a difference between a measured value and a theoretically estimated value of a data transmission time delay of a potential risk path is greater than a shortest data transmission time delay of a round trip of a satellite-ground link, the potential risk path is a risk path, and risk verification is performed on the potential risk path from a local perspective according to the risk criterion. The application replaces an encryption mark matching check method used in a hop-by-hop verification mechanism, avoids a large amount of signaling overhead and computing overhead caused by frequent changes of paths under a dynamic topology condition of the satellite Internet, and improves the performance of path verification in the satellite Internet scene. On the basis of the above embodiments, as an optional embodiment, the device further comprises a generation module for generating an inter-station time delay table of the ground stations.

[0136] The generation module specifically comprises:

[0137] An inter-station time delay sub-table construction unit is configured to enable the ground station to locally create four inter-station time delay sub-tables with a source end ground station number and a data transmission time delay as fields; wherein the four inter-station time delay sub-tables correspond to four satellite orbit access directions respectively, and the four satellite orbit access directions are uplink north and downlink south, uplink north and downlink north, uplink south and downlink north, and uplink south and downlink south respectively.

[0138] A time delay measurement packet sending unit is configured to control each of the target ground stations to send a time delay measurement packet to the ground station at intervals of a preset time length within a measurement period; wherein the time delay measurement packet is obtained by performing header embedding of a source end ground station number, a source end ground station satellite number and a sending time stamp on an IP data packet.

[0139] A data transmission time delay and satellite orbit access direction determination unit is configured to enable the ground station to determine the data transmission time delay and the satellite orbit access direction of each of the target ground stations to the ground station according to the time delay measurement packet sent by each of the target ground stations.

[0140] The data filling unit is configured to insert, with the number of each target ground station as an index, the data transmission time delay of each target ground station to the ground station into an inter-station time delay sub-table corresponding to the access satellite orbit direction of the target ground station to the ground station, to obtain four inter-station time delay sub-tables filled with data.

[0141] The combination unit is configured to combine the four inter-station time delay sub-tables filled with data to obtain the inter-station time delay table of the ground station.

[0142] On the basis of the above embodiments, as an optional embodiment, the data transmission time delay and access satellite orbit direction determination unit comprises a data transmission time delay determination sub-module and an access satellite orbit direction determination sub-module.

[0143] The data transmission time delay determination sub-module is configured to:

[0144] insert the time length between the sending timestamp and the receiving timestamp of each measurement packet sent by the target ground station into a first list;

[0145] obtain the data transmission time delay of the target ground station to the ground station by filtering a plurality of time lengths in the first list and taking the minimum value.

[0146] On the basis of the above embodiments, as an optional embodiment, the access satellite orbit direction determination sub-module is configured to:

[0147] deduce the access satellite orbit direction of the target ground station to the ground station according to the source ground station access satellite number in any measurement packet sent by the target ground station and the pre-stored two-row orbit root number information of all satellites in the constellation.

[0148] On the basis of the above embodiments, as an optional embodiment, the potential risk path identification module is specifically configured to:

[0149] analyze the global time delay gradient matrix by using a preset outlier detection algorithm to select an outlier greater than a safety threshold of the preset outlier detection algorithm from the global time delay gradient matrix;

[0150] The preset outlier detection algorithm includes but is not limited to an IQR test method and a Grubbs test method.

[0151] On the basis of the above embodiments, as an optional embodiment, the shortest data transmission time delay of the round-trip once satellite-ground link is determined according to the orbital height of the satellite.

[0152] The measured value of the data transmission time delay of the potential risk path is an element value corresponding to the ground station pair of the potential risk path in the global time delay matrix.

[0153] The risk path verification module comprises a unit for

[0154] The determination process comprises a determination unit for determining a theoretical estimation value of a data transmission delay of the potential risk path.

[0155] The determination unit comprises:

[0156] A first determination subunit is configured to determine a neighboring path of the potential risk path.

[0157] A reference delay matrix construction subunit is configured to extract elements corresponding to a ground station pair of the neighboring path from the global delay matrix to form a reference delay matrix.

[0158] A regression analysis subunit is configured to determine a mapping relationship between a data transmission delay and a geographical distance by a regression analysis method for a ground station pair within a range of the reference delay matrix.

[0159] A theoretical estimation value calculation subunit is configured to determine a theoretical estimation value of a data transmission delay of the potential risk path according to the mapping relationship and an inter-station distance of a ground station pair of the potential risk path.

[0160] As an optional embodiment, the first determination subunit is specifically configured to:

[0161] determine a path satisfying a second condition as the neighboring path of the potential risk path.

[0162] The second condition is:

[0163] a distance between a source end and a source end of the potential risk path is less than a first threshold value, and

[0164] a distance between a destination end and a destination end of the potential risk path is less than a second threshold value.

[0165] In a third aspect, Figure 11 An example of an entity structure diagram of an electronic device is shown in FIG. 1. Figure 11As shown, the electronic device can include a processor 1110, a communications interface 1120, a memory 1130, and a communications bus 1140, wherein the processor 1110, the communications interface 1120, and the memory 1130 complete mutual communication through the communications bus 1140. The processor 1110 can invoke a logical instruction in the memory 1130 to execute a path verification method for a satellite Internet, the method comprising: generating an inter-station distance matrix according to geographical position information between ground stations; aggregating an inter-station time delay table of each ground station to obtain a global time delay matrix; differentiating corresponding elements of the global time delay matrix and the inter-station distance matrix to obtain a global time delay gradient matrix; performing statistical outlier analysis on the global time delay gradient matrix, and taking a data transmission path of a ground station pair with an outlier as a potential risk path; when the potential risk path satisfies a first condition, identifying the potential risk path as a risk path; wherein the inter-station time delay table of each ground station stores a data transmission time delay of each target ground station to the ground station; the target ground station is a ground station other than the ground station; and the first condition is that a difference between a measured value and a theoretically estimated value of the data transmission time delay is greater than a shortest data transmission time delay of a round-trip satellite-ground link.

[0166] In addition, the logical instruction in the memory 1130 described above can be implemented in the form of a software functional unit and sold or used as an independent product, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various program code storage media.

[0167] In a fourth aspect, the present application further provides a computer program product comprising a computer program, which is stored in a non-transitory computer-readable storage medium, and when executed by a processor, the computer program enables a computer to perform the path verification method for satellite Internet provided by the above-mentioned methods, which comprises: generating an inter-station distance matrix according to geographical position information between ground stations; collecting an inter-station time delay table of each ground station to obtain a global time delay matrix; differentiating corresponding elements of the global time delay matrix and the inter-station distance matrix to obtain a global time delay gradient matrix; performing statistical outlier analysis on the global time delay gradient matrix, and taking a data transmission path of a ground station pair with an outlier as a potential risk path; and when the potential risk path satisfies a first condition, determining that the potential risk path is a risk path; wherein the inter-station time delay table of each ground station stores a data transmission time delay of each target ground station to the ground station; the target ground station is a ground station other than the ground station; and the first condition is that a difference between a measured value and a theoretically estimated value of the data transmission time delay is greater than a shortest data transmission time delay of a round-trip satellite-ground link.

[0168] In a fifth aspect, the present application further provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the computer program enables a computer to perform the path verification method for satellite Internet provided by the above-mentioned methods, which comprises: generating an inter-station distance matrix according to geographical position information between ground stations; collecting an inter-station time delay table of each ground station to obtain a global time delay matrix; differentiating corresponding elements of the global time delay matrix and the inter-station distance matrix to obtain a global time delay gradient matrix; performing statistical outlier analysis on the global time delay gradient matrix, and taking a data transmission path of a ground station pair with an outlier as a potential risk path; and when the potential risk path satisfies a first condition, determining that the potential risk path is a risk path; wherein the inter-station time delay table of each ground station stores a data transmission time delay of each target ground station to the ground station; the target ground station is a ground station other than the ground station; and the first condition is that a difference between a measured value and a theoretically estimated value of the data transmission time delay is greater than a shortest data transmission time delay of a round-trip satellite-ground link.

[0169] The device embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the present embodiment scheme according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0170] Those skilled in the art can clearly understand the technical solutions of the various embodiments from the above description of the embodiments, and the various embodiments can be implemented by means of software with the necessary general hardware platforms, and of course, can also be implemented by hardware. Based on such understanding, the above technical solutions, essentially or in other words, the part of the prior art that makes a contribution, can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, and the like, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0171] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for some technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A path verification method for satellite internet, characterized by, The method comprises: generating an inter-station distance matrix according to geographical position information between ground stations; compiling an inter-station time delay table of each ground station to obtain a global time delay matrix; differentiating corresponding elements of the global time delay matrix and the inter-station distance matrix to obtain a global time delay gradient matrix; performing statistical outlier analysis on the global time delay gradient matrix, and taking a data transmission path of a ground station pair with an outlier as a potential risk path; when the potential risk path meets a first condition, identifying the potential risk path as a risk path; wherein the inter-station time delay table of each ground station stores a data transmission time delay of each target ground station to the ground station; the target ground station is a ground station other than the ground station; the first condition is that a difference between a measured value and a theoretically estimated value of the data transmission time delay is greater than a shortest data transmission time delay of a round-trip satellite-ground link. 2.The path verification method for satellite Internet of claim 1, wherein, The generation process of the inter-station time delay table of the ground station comprises: the ground station locally creates four inter-station time delay sub-tables with a source end ground station number and a data transmission time delay as fields; wherein the four inter-station time delay sub-tables correspond to four access satellite orbit directions respectively; the four access satellite orbit directions are uplink north and downlink south, uplink north and downlink north, uplink south and downlink north, and uplink south and downlink south respectively; in a measurement period, each target ground station sends a time delay measurement packet to the ground station at a preset interval; wherein the time delay measurement packet is obtained by performing header embedding of an IP data packet with a source end ground station number, a source end ground station access satellite number, and a sending time stamp; the ground station infers a data transmission time delay and an access satellite orbit direction of each target ground station to the ground station according to the time delay measurement packet sent by each target ground station; using the number of each target ground station as an index, the data transmission time delay of each target ground station to the ground station is inserted into the inter-station time delay sub-table corresponding to the access satellite orbit direction of each target ground station to the ground station, to obtain four inter-station time delay sub-tables filled with data; combining the four inter-station time delay sub-tables filled with data to obtain the inter-station time delay table of the ground station. 3.The path verification method for satellite Internet of claim 2, wherein, inferring the data transmission time delay of the target ground station to the ground station according to the measurement packet sent by the target ground station comprises: the time length between the sending time stamp and the receiving time of each measurement packet sent by the target ground station is listed in a first list; after filtering the multiple time lengths in the first list, the minimum value is obtained as the data transmission time delay of the target ground station to the ground station. 4.The path verification method for satellite Internet of claim 3, wherein, inferring the access satellite orbit direction of the target ground station to the ground station according to the measurement packet sent by the target ground station comprises: inferring the access satellite orbit direction of the target ground station to the ground station according to the source end ground station access satellite number in any measurement packet sent by the target ground station and the pre-stored two-row orbit root number information of all satellites in the constellation.

5. The path validation method for satellite internet according to any one of claims 1-4, characterized in that, the statistical outlier analysis on the global time delay gradient matrix comprises: analyzing the global delay gradient matrix by using a preset outlier detection algorithm to select an outlier value greater than a safety threshold of the preset outlier detection algorithm from the global delay gradient matrix; the preset outlier detection algorithm includes but is not limited to IQR test method and Grubbs test method.

6. The path validation method for satellite internet according to any one of claims 1-4, characterized in that, the shortest data transmission delay of the round-trip satellite-ground link is determined according to the orbital height of the satellite, and the measured value of the data transmission delay of the potential risk path is an element value corresponding to a ground station pair of the potential risk path in the global delay matrix; the determination process of the theoretical estimation value of the data transmission delay of the potential risk path includes: determining a neighboring path of the potential risk path; extracting elements corresponding to the ground station pair of the neighboring path from the global delay matrix to form a reference delay matrix; determining a mapping relationship between the data transmission delay and the geographic distance by a regression analysis method for the ground station pair within the range of the reference delay matrix; determining the theoretical estimation value of the data transmission delay of the potential risk path according to the mapping relationship and the inter-station distance of the ground station pair of the potential risk path.

7. The path verification method for satellite internet according to claim 6, wherein, the determination of the neighboring path of the potential risk path includes: regarding a path satisfying a second condition as the neighboring path of the potential risk path; wherein the second condition is: the distance between the source end and the source end of the potential risk path is less than a first threshold, and the distance between the destination end and the destination end of the potential risk path is less than a second threshold.

8. A path verification apparatus for a satellite internet, characterized by, the device includes: an inter-station distance matrix generation module configured to generate an inter-station distance matrix according to geographic position information between ground stations; a global delay matrix generation module configured to aggregate a station-to-station delay table of each ground station to obtain a global delay matrix; a global delay gradient matrix generation module configured to differentiate corresponding elements of the global delay matrix and the inter-station distance matrix to obtain a global delay gradient matrix; a potential risk path identification module configured to perform statistical outlier analysis on the global delay gradient matrix and identify a data transmission path of a ground station pair with an outlier value as a potential risk path; a risk path identification module configured to identify the potential risk path as a risk path when the potential risk path satisfies a first condition; wherein each station-to-station delay table of each ground station stores a data transmission delay from each target ground station to the ground station; the target ground station is a ground station other than the ground station; the first condition is that the difference between the measured value and the theoretical estimation value of the data transmission delay is greater than the shortest data transmission delay of the round-trip satellite-ground link.

9. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, the processor implements the path verification method for satellite internet according to any one of claims 1 to 7 when executing the program.

10. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, the computer program implements the path verification method for satellite internet according to any one of claims 1 to 7 when executed by the processor.

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