Lightweight satellite-ground network mobile device security access method

Abstract

The invention provides a lightweight satellite-ground network mobile equipment security access method. The method comprises the following steps: a system initialization process: a network control center NCC selects a master key, initializes network parameters, generates long-term keys for each satellite AP and GS, and generates initial authentication keys for each mobile equipment ME; and an initial access and key negotiation process: when the ME requests to access the STN for the first time, the satellite AP carries out identity verification on the ME, key negotiation is carried out after the authentication is passed, and a related key is generated. By utilizing the scheme of the invention, only the trusted equipment in the STN can access the network, and session key negotiation is carried out in a safe mode, so that the security of the session is ensured.

Description

Technical Field

[0001] The present invention relates to the field of network security technology, and in particular to a lightweight satellite-to-ground network mobile device security access method. Background Art

[0002] Satellite-Terrestrial Networks (STNs) combine satellite communication systems and ground network communication systems, and achieve unified management and deployment of STNs air segments and ground segments through a variety of technologies. User equipment can access STNs through satellite-to-ground links to overcome the shortcomings of geographical restrictions in traditional wireless networks and facilitate various services. However, STNs are highly open and vulnerable to attacks such as enemy eavesdropping, counterfeiting, and information replay. In order to protect the rights and privacy of legitimate users and maintain the security of STNs, users and satellite networks need to obtain network services after two-way authentication, and the confidentiality of communication sessions should also be ensured. Therefore, reliable user terminal access and key negotiation are two key requirements in STN network security.

[0003] However, the network topology of STNs is highly heterogeneous and dynamically complex, with large transmission delays and limited network resources. These characteristics make it impossible for traditional terrestrial communication protocols to fully meet the security and performance requirements of STNs. Specifically, STNs are composed of multiple heterogeneous networks, and communication link connections are intermittent. On mobile devices such as airplanes, high-speed trains, and cruise ships, user terminals may move at extremely fast speeds, which makes it difficult to complete handover authentication within a limited time. Once authentication fails, it will affect the communication quality. At the same time, since the communication link is susceptible to interference, and due to the relative motion between Low Earth Orbit (LEO) satellites and the earth, the communication link is unstable, and the satellite coverage area is constantly changing, all of which may cause STNs communication link interruption.

[0004] In most of the existing access authentication and key negotiation technologies, satellites only act as repeaters between mobile equipment (ME) and ground facilities (such as network control centers (NCC)), and are only responsible for forwarding messages. Therefore, there are too large transmission delays and backhaul burdens in the access and key negotiation of devices. Although direct authentication technologies between terminals and satellites have also emerged, such as secure access authentication technology based on group signatures and access authentication technology based on proxy re-signatures. However, many existing technologies only target static access authentication and key negotiation scenarios of devices, and rarely consider dynamic access and switching authentication of mobile devices. If dynamic access and switching authentication are required, the initial access authentication and key negotiation need to be repeated, which is time-consuming and labor-intensive, and may also have a negative impact on business performance. Summary of the invention

[0005] The present invention provides a lightweight satellite-to-ground network mobile device security access method to ensure that only trusted devices in the STN can access the network, and perform session key negotiation in a secure manner to ensure session security.

[0006] To this end, the present invention provides the following technical solutions:

[0007] A lightweight satellite-to-ground network mobile device secure access method, the method comprising:

[0008] System initialization process: The network control center NCC selects the master key, initializes the network parameters, generates long-term keys for each satellite AP and GS, and generates initial authentication keys for each mobile device ME;

[0009] Initial access and key negotiation process: When the ME requests to access the STN for the first time, the satellite AP authenticates the ME, and after the authentication is passed, key negotiation is performed to generate relevant keys, such as the authentication key between the terminal ME and the satellite AP and the session key between the terminal ME and the ground gateway GS.

[0010] Optionally, the initializing network parameters and generating long-term keys for each satellite AP and GS includes:

[0011] Set common parameters;

[0012] Generate a pre-configuration message corresponding to each satellite AP, and send the pre-configuration information to each satellite AP; the pre-configuration information includes: the satellite AP identity, the public parameters, the satellite AP long-term key and the peer group key; the peer group key is shared by all satellite APs and is used to identify peer satellites;

[0013] Generate pre-configuration information corresponding to the GS, and send the pre-configuration information to the GS; the pre-configuration information includes: the public parameters, and the long-term key of the GS.

[0014] Optionally, generating an initial authentication key for each mobile equipment ME includes:

[0015] Receiving an offline registration request message sent by each ME, wherein the offline registration request message includes: device information of the ME; the device information includes: a long-term identity identifier and a short-term identity identifier;

[0016] The device information is verified. After the verification is successful, the NCC and the ME generate an initial authentication key of the ME according to the public parameters and the device information of the ME. The initial authentication key includes a user private key and a user public key.

[0017] Optionally, the public parameters include: a prime order group G, a generator P of the group G, an order q of the group G, three hash functions, and a parameter Y calculated based on a random value and the generator.

[0018] Optionally, when the ME requests to access the STN for the first time, the satellite AP authenticates the ME, and after the authentication is passed, performs key negotiation with the ME, and generates the relevant key, including:

[0019] The ME selects a satellite AP, generates first authentication information according to the initial authentication key, and sends the first authentication information to the satellite AP to request access; the first authentication information includes at least: a short-term identity of the ME and a first current timestamp;

[0020] After receiving the first authentication information, the satellite AP verifies the first authentication information;

[0021] If the verification fails, the access is denied;

[0022] If the verification is successful, the AP generates an authentication key and second authentication information between the AP and the ME, and sends the second authentication information to the ME; the second authentication information includes at least: a ground gateway GS identity and a second current timestamp;

[0023] The ME generates an authentication key between itself and the AP and a session key between itself and the ground gateway GS according to the second authentication information.

[0024] Optionally, the key negotiation process further includes:

[0025] After the satellite AP verifies the first authentication information, it sends the third authentication information to the GS; the third authentication information at least includes: the short-term identity of the ME and the first current timestamp;

[0026] The GS calculates the session key for this access based on the third authentication information.

[0027] Optionally, the method further includes: an interrupted communication recovery process, the interrupted communication recovery process including:

[0028] The ME sends a relink request message to the satellite AP, wherein the relink request message includes at least: a short-term identity of the ME and a third current timestamp;

[0029] The satellite AP queries the recent access record of the ME according to the short-term identity of the ME, and obtains the authentication key of the ME before the interruption and the session timestamp before the interruption;

[0030] Check whether the difference between the third current timestamp and the pre-interruption session timestamp is less than a set value, where the set value is the longest allowed interruption reconnection delay;

[0031] If yes, regenerate the authentication key corresponding to the ME according to the authentication key of the ME before the interruption, and return re-authentication information to the ME; the re-authentication information at least includes the identity of the satellite AP;

[0032] The ME regenerates the authentication key according to the re-authentication information.

[0033] Optionally, the interrupted communication recovery process further includes: if the difference between the third current timestamp and the pre-interruption session timestamp is greater than or equal to a set value, returning a re-access rejection message to the ME.

[0034] Optionally, the method further comprises:

[0035] The handover authentication process includes:

[0036] The ME sends a pre-switching request message to the current satellite AP, where the pre-switching request message includes: location information of the ME;

[0037] The current satellite AP determines the target satellite AP according to the location information of the ME, and calculates the first authentication parameter and the second authentication parameter according to the identity of the current satellite AP, the identity of the target AP, and the identity of the ME;

[0038] The current satellite AP sends handover authentication information to the target satellite AP, wherein the handover authentication information at least includes: the identity of the current satellite AP, the identity of the target AP, the identity of the ME, and the first authentication parameter; and at the same time, encrypts the second authentication parameter and the public key information of the target satellite AP with the authentication key negotiated with the ME and sends them to the ME;

[0039] The ME calculates a new authentication key and a new authentication parameter according to the second authentication parameter and the public key information of the target satellite AP, and sends the new authentication parameter to the target satellite AP;

[0040] The target satellite AP verifies the new authentication parameters according to the handover authentication information, and generates an authentication key with the ME after the verification is passed.

[0041] Optionally, the handover authentication process further includes:

[0042] If the target satellite AP fails to verify the new authentication parameters, the link is rejected.

[0043] The lightweight satellite-to-ground network mobile device secure access method provided by the present invention does not require the participation of the ground facility NCC in authentication and key negotiation, and can achieve safe and efficient device access and key negotiation, thereby reducing the total time consumption of device access and key negotiation. In addition, the protocol can also ensure that the ME can access the STN in a trusted manner to prevent network attacks such as eavesdropping, replay, and identity forgery.

[0044] Furthermore, fast reconnection of interrupted communications and access point switching can be achieved: when a communication session is interrupted, there is no need to repeat the initial access process. The mobile terminal ME and the satellite AP only need to perform a small amount of calculation and interaction operations to restore communication and update the session key, thereby reducing the reconnection overhead; at the same time, when the moving ME is about to leave the coverage of the current satellite access point, the ME can use the current satellite access point to effectively complete the pre-authentication with the peer target new satellite. Once entering the new satellite signal field, the user can immediately perform switching authentication and key negotiation with the new satellite, thereby reducing the switching delay and enhancing the robustness of the satellite communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 It is a schematic diagram of the process of LEO satellite access authentication and key negotiation based on ground facilities in the existing STN network;

[0047] Figure 2 It is a flow chart of a lightweight satellite-to-ground network mobile device secure access method provided by the present invention;

[0048] Figure 3 It is a flow chart of the initial access and key negotiation process in the lightweight satellite-to-ground network mobile device secure access method provided by the present invention;

[0049] Figure 4 It is a flow chart of the interrupted communication recovery process in the lightweight satellite-to-ground network mobile device secure access method provided by the present invention;

[0050] Figure 5 It is a flow chart of the switching authentication process in the lightweight satellite-to-ground network mobile device secure access method provided by the present invention;

[0051] Figure 6 The present invention provides a schematic diagram of a satellite-to-ground network structure used by the lightweight satellite-to-ground network mobile device secure access method provided by the present invention. DETAILED DESCRIPTION

[0052] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0053] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0054] Compared with other medium and high orbit satellites, low earth orbit (LEO) satellites are closer to the earth, have shorter launch delays, and are more suitable for providing data communications and access services. By using LEO satellites as access points, STN systems can provide mobile users with a variety of services from telephone and broadcasting to broadband and the Internet.

[0055] In order to better reflect the difference between the solution of the present invention and the prior art, the process of LEO satellite access authentication and key negotiation based on ground facilities in the existing STN network is briefly described below.

[0056] like Figure 1 FIG. 1 is a schematic diagram of the process of LEO satellite access authentication and key negotiation based on ground facilities in the existing STN network.

[0057] When a user wants to connect to STNs, the user generates an authentication request data with his terminal A and initiates an access request to the LEO satellite access point satellite B. The request data included in the access request usually includes: the identity ID of terminal A, the identity ID of satellite B, and a timestamp.

[0058] After receiving the access request, satellite B will not verify the legitimacy of the identity of terminal A, but only perform some simple preliminary verification on the format and timestamp of the above request data. If the format review is passed, satellite B will forward the request data of terminal A to the ground facility NCC for further processing.

[0059] After receiving the data forwarded by satellite B, the ground facility NCC verifies the identity of terminal A using an asymmetric or symmetric algorithm based on the information when terminal A registered and according to system regulations. If the identity verification is successful, session key negotiation parameters are generated for both terminal A and satellite B to achieve secure network access for the terminal device. If the verification fails, no key negotiation parameters are generated and the authentication result is directly returned.

[0060] Finally, if the authentication is successful and the key negotiation parameters are received, terminal A and satellite B generate a session key based on a public key negotiation technology, such as DH (Diffie-Hellman) key negotiation technology, and use the key as a symmetric encryption key for subsequent communication encryption.

[0061] In the above scheme, the satellite only acts as a repeater between the ME and the ground facilities (such as NCC) and is only responsible for forwarding messages. Authentication is implemented between the ME and the NCC, and the satellite only forwards the authentication data without participating in the actual authentication. Therefore, the authentication process needs to suffer at least several times of data transmission delay between the ground facilities and the satellite (between the user-satellite and NCC-satellite, respectively), which will lead to unacceptable access delays. In addition, as the access point of the STN system, the satellite cannot identify illegal access requests before forwarding the authentication request data to the ground facilities, and therefore cannot prevent unauthorized users from accessing the STN.

[0062] In order to reduce the delay and waiting of the backhaul link and shorten the authentication time for accessing the satellite network, there are schemes in the prior art for designing secure access to terminal devices directly on the satellite, mainly including: secure access authentication scheme based on group signature and access authentication scheme based on proxy re-signature.

[0063] In a secure access authentication scheme based on group signatures, the NCC usually plays the role of group administrator, responsible for initializing the network and generating group public / private keys. Before accessing the network, the user's ME needs to register with the NCC to obtain a group certificate and a group public key. When a user wants to access the network, the ME first generates a network access request, which contains a signature generated using the ME's group certificate, the identity ID of the satellite access point (AccessPoint, AP), a timestamp and other necessary information. Then, after receiving the ME's access request, the satellite AP uses the group public key to verify the group signature in the ME request information. If the verification is successful, the satellite AP generates response data, signs the response data with its own private key, and returns it to the ME. The ME verifies the correctness of the signature of the response data with the satellite AP's public key. If the verification is successful, the terminal AP calculates the session key and successfully accesses the satellite network.

[0064] Similar to the access authentication scheme based on group signature, the scheme based on proxy re-signature also realizes the function of each satellite with certain computing power to perform access control instead of ground facilities, thereby greatly reducing network access delay and NCC computing load. In the scheme based on proxy re-signature, only legitimate satellites that have obtained temporary proxy authorization from ground facilities can interact with ME and process ME's access authentication and key negotiation requests. In this type of scheme, ground facilities will issue proxy credentials to some legitimate satellites in advance. The credentials contain the security status of the satellite and the validity period of the temporary proxy authorization. Similarly, when a user wants to access the network, the user's ME needs to register in the system, obtain a legitimate identity and public and private keys, and generate a legitimate signature with the private key. The satellite AP determines whether to allow the user's ME to access the network by verifying the legitimacy of the user's signature. Different from the access authentication scheme based on group signature, only satellites with legitimate authorization credentials can generate signatures and key negotiation information that can be verified by ME and complete the secure access process of ME.

[0065] The LEO satellite moves very fast relative to the earth, and frequent changes in network topology make the network and communication connection unstable. However, in the direct authentication scheme between ME and satellite mentioned above, user switching between different satellites requires multiple information interactions. Users need to re-execute the initial authentication protocol when accessing a new satellite. The frequent switching caused by the rapid change of topology structure brings a heavy computing burden to users and satellite networks. In addition, in these access authentication and key negotiation schemes, the reconnection process after the satellite link is disconnected re-executes the initial authentication and key negotiation, which easily leads to a waste of computing and communication resources.

[0066] To this end, the present invention provides a lightweight satellite-to-ground network mobile device secure access method, in which authentication and key negotiation do not require the participation of ground facilities, thereby reducing the total time consumption of device access and key negotiation, and can also ensure that the ME can access the STN in a trusted manner to prevent network attacks such as eavesdropping, replay, and identity forgery.

[0067] like Figure 2 FIG. 1 is a flow chart of a lightweight satellite-to-ground network mobile device secure access method provided by the present invention, comprising the following steps:

[0068] Step 201, system initialization process, is as follows:

[0069] NCC selects the master key and initializes the network parameters. It generates long-term keys for each satellite AP and GS and initial authentication keys for each mobile device ME through an offline registration process.

[0070] During this stage, secure and reliable network initialization and entity registration can be achieved, ensuring the security of subsequent device access and communication.

[0071] Step 202, initial access and key negotiation process, is as follows:

[0072] When the ME requests to access the STN for the first time, it needs to authenticate with the satellite AP. After the authentication is passed, it negotiates keys with the satellite AP and GS to generate relevant keys.

[0073] Through the key negotiation process, the ME can use the key to encrypt the communication content in the subsequent communication process with the satellite AP and GS to ensure the security of the communication.

[0074] The following examples further illustrate the system initialization, initial access and key negotiation process in the embodiment of the present invention.

[0075] A specific example process of system initialization in an embodiment of the present invention is as follows:

[0076] (1)NCC triggers system initialization.

[0077] First, the NCC selects a master key and sets the public parameters pp.

[0078] For example, NCC selects a prime group G of order q and three hash functions H: {0,1} * →Z q ,

[0079] Among them, → represents the mapping, {0,1} * Represents a string of any length consisting of 0 or 1, Z q It is an integer group of order q consisting of (0,1,…,q-1) elements;

[0080] The hash function H represents the mapping of a string of any length consisting of 0 or 1 to an integer group Z of order q consisting of (0, 1, ..., q-1) elements. q superior;

[0081] The hash function H1 represents mapping a string of any length composed of 0 or 1 to a string of length l1 composed of 0 or 1;

[0082] The hash function H2 represents mapping a string of any length consisting of 0 or 1 into a string of length l2 consisting of 0 or 1.

[0083] Then, NCC randomly selects a value x∈Z q , use it as the private key, and calculate the public key Y = x·P;

[0084] Among them, the symbol “∈” indicates belonging to, and P is a generator of the group G.

[0085] Finally, NCC sets the public parameter pp=<G,P,q,H,H1,H2,Y> .

[0086] (2) During the satellite launch preparation phase, each satellite AP and GS sends a registration request to the NCC. Accordingly, the NCC generates pre-configuration information for each satellite AP and GS, as follows:

[0087] NCC for each satellite access point AP i Generate pre-configured information, including satellite access point AP i ID i , public parameters pp, long-term key (s i ,R i ,v i ,V i ) and the peer group key K g ;

[0088] Among them, R i =(s j -H(TID i ||R i )·x)·P;V i =v i ·P.

[0089] Among them, the peer group key K g Shared by all satellite access points and used to identify peer satellites.

[0090] Similarly, the NCC generates pre-configuration information for the GS, where the pre-configuration information includes: a public parameter pp, and a unique long-term key (s, R, v, V).

[0091] (3) Each terminal ME j Send a registration request message ReMes to the NCC, the registration request message ReMes includes ME j The device information includes: ME j Long-term ID j and short-term identification TID j .

[0092] Accordingly, NCC sends a j After successful verification, a random number r is selected. j ∈Z q , calculate the value R j =r j ·P,s j =r j +H(TID j ||R j )·x, and (Rj ,s j ) and the public parameter pp are returned to the terminal ME j .

[0093] Accordingly, the terminal ME j Randomly select a value v j ∈Z q , calculate the value V j =v j P, and store the initial authentication key (s j ,R j ,v j ,V j ) and public parameter pp. j ,v j ) as terminal ME j The private key of (R j ,V j ) as terminal ME j The public key of

[0094] It should be noted that the above-mentioned method in which the NCC generates corresponding keys for each satellite AP, GS, and each ME is only an exemplary description. In specific implementation, other key generation algorithms may also be used, which is not limited in this embodiment of the present invention.

[0095] like Figure 3 As shown, a flow chart of the initial access and key negotiation process in the lightweight satellite-to-ground network mobile device secure access method provided by the present invention is shown.

[0096] In step 301, the terminal ME j First, choose the most suitable satellite access point AP i (For example, selection based on distance or selection based on service matching), and generating first authentication information based on the initial authentication key, and sending the first authentication information to the satellite access point AP i .

[0097] For example, with the above initial authentication key (s j ,R j ,v j ,V j ) as an example, the generation process of the first information is as follows:

[0098] Terminal ME j Choose a random number a j ∈Z q ,calculate:

[0099] u j =a j +v j ;

[0100] T j =u j ·P;

[0101] e j =u j +s j +H(ID i ||TID j ||T j ||Y||TS1)·v j ;

[0102] Generate the first authentication information (TID j ,R j ,V j ,T j ,TS1), and the first authentication information (TID j ,R j ,V j ,T j ,TS1) is sent to the satellite access point AP i Request access, where TS1 is the current timestamp.

[0103] In step 302, the satellite access point AP i Receive the above first authentication information (TID j ,R j ,V j ,T j ,TS1), first verify the first authentication information, that is, verify:

[0104] e j P = T j +R j +H(TID j ||R j )·Y+H(ID i ||ID j ||T j ||Y||TS1)·V j yes

[0105] Whether established;

[0106] Among them, ID i Satellite access point AP i Identification of the

[0107] If not, the access is rejected.

[0108] Otherwise, generate the second authentication information, as follows:

[0109] Satellite Access Point AP i Choose a random number b i ∈Z q,calculate:

[0110] u i =b i +v i ;

[0111] T i =u i ·P;

[0112] K 1,i =s i ·(T j -V j )+b i ·(R j +H(TID j ∥R j )×Y);

[0113] K 2,i =b i ×(T j -V j );

[0114] Calculate the session key k i,j =H(K 1,j ∥∥K 2,j ∥∥ID i ∥TID j ∥T i ∥T j );

[0115] Then the second authentication information (R i ,V i ,T i ,V k ,ID k ,TS2) returns to the terminal ME j , where ID k Ground Gateway GS k TS2 is the current timestamp.

[0116] In addition, satellite access point AP i The third authentication information (TID j ,V j ,R j ,TS1) sent to the ground gateway GS k .

[0117] In step 303, the terminal ME j Calculate the authentication key with the AP and the authentication key with the ground gateway GS according to the second authentication information k The session keys are as follows:

[0118] K 1,j =s j·(T i -V i )+a j ·(R i +H(ID i ∥R i )×Y);

[0119] K 2,j =b j ×(T i -V i );

[0120] ME j and the AP's authentication key k j,i =H1(K 1,j ∥∥K 2,j ∥∥ID i ∥TID j ∥T i ∥T j );

[0121] ME j and GS k The session key sk j,k =H2(v j ·V k ∥ID k ∥∥TID j ∥∥Y);

[0122] Among them, V k Ground Gateway GS k The public key of

[0123] In addition, the ground gateway GS k According to the third authentication information (TID j ,V j ,R j ,TS1) calculate the session key sk for this access k,j =H2(v k ·V j ∥ID k ∥∥TID j ∥∥Y).

[0124] After the above process, the terminal ME j With Ground Gateway GS k The communication between them can be encrypted and protected using the corresponding session key, thus effectively ensuring the security of the communication.

[0125] In the process from step 301 to step 303, only hash and multiplication operations with relatively small amount of calculation are needed to achieve reliable access and key negotiation of the terminal.

[0126] In another embodiment of the method of the present invention, the method may further include a communication interruption recovery process, such as Figure 4 The figure is a flow chart of the interrupted communication recovery process in the lightweight satellite-to-ground network mobile device secure access method provided by the present invention.

[0127] Reference Figure 4 In step 401, the terminal ME j Choose a random number f j ∈Z q , calculate relink authentication parameters Then to the satellite AP i Send a reconnect message Reconnect, the reconnect message Reconnect includes: terminal ME j Short-term identity TID j , current timestamp TS3 and relink authentication parameter M j .

[0128] In step 402, the satellite access point AP i According to the terminal ME j Short-term identity TID j Query terminal ME j Recent access records of the corresponding terminal ME j The authentication key k i,j And the session timestamp TS1 before the interruption. Satellite access point AP i Check the time interval between the two timestamps TS3 and TS1 |TS1-TS3|, and determine the terminal ME based on the time interval j Whether re-access is required is as follows:

[0129] Determine whether the following is satisfied: |TS1-TS3|≤△T, where △T is the longest allowed interruption and reconnection delay;

[0130] If not satisfied, the terminal ME is rejected j To restore communication, for example, to the terminal ME j Return a re-access rejection message. Accordingly, in this case, the terminal ME j The initial access process needs to be repeated.

[0131] If satisfied, satellite access point AP i and terminal ME j Perform key negotiation and update the authentication key, as follows:

[0132] Satellite Access Point AP i Randomly select f i ∈Z q , calculate the following values:

[0133]

[0134] New authentication key k i,j ′=H1(f i ·P∥f j ′·P∥ID i ∥TID j );

[0135] Then reconnect parameter information (M i ,ID i ) is sent to the user terminal ME j .

[0136] In step 403, the terminal ME j Receive re-access parameter information (M i ,ID i ) and then, according to the re-access parameter information (M i ,ID i ) Update the authentication key as follows:

[0137]

[0138] Update the authentication key to k i,j ′=H1(f i ·P∥f j ′·P∥ID i ∥TID j ).

[0139] Through the above steps 401 to 403, based on the authentication key k before the link is disconnected i,j , which can achieve fast communication recovery within the allowed range of the interruption interval and realize secure update of authentication keys.

[0140] In another embodiment of the method of the present invention, a switching authentication process may be further included. Figure 5 FIG. 1 is a flow chart of the switching authentication process in the lightweight satellite-to-ground network mobile device secure access method provided by the present invention.

[0141] Reference Figure 5 In step 501, when the terminal ME j About to leave the current satellite access point AP i When the signal receiving area is within the range of j To the current satellite access point AP i Send a pre-switching request message CReq, in which the pre-switching request message CReq includes the terminal ME j The current location information and next moving trajectory information.

[0142] Accordingly, the current satellite access point AP i According to the terminal MEj The location information and the satellite's next trajectory information are provided to the terminal ME j Recommend the next satellite access point AP that can be connected r (i.e., the target satellite access point) and several neighboring satellite access points.

[0143] It should be noted that if the current satellite access point AP i Unable to decide on terminal ME j The next satellite access point AP that can be connected r , then the terminal ME j The current location information of the terminal ME is sent to the NCC; the NCC is the terminal ME j Select and recommend target satellite access points AP r , the target satellite access point AP r ID r Send to the current satellite access point AP i .

[0144] In step 502, the current satellite access point AP i According to the target satellite access point AP r ID r and terminal ME j Short-term identity TID j , calculate the first authentication parameter W i,1 and the second authentication parameter W i,2 , to assist AP r and ME j Establish connections quickly.

[0145] For example, in a non-limiting embodiment, the calculation method is as follows:

[0146] Choose a random number w i ∈Z q , calculate the first authentication parameter W i,1 and the second authentication parameter W i,2 :

[0147]

[0148] Towards the target satellite access point AP r Send switch authentication information (ID i ,ID r ,TID j ,W i,1 ,V i ,V j ), and at the same time the second authentication parameter W i,2 and the target satellite access point AP r The public key information (R r ,Vr ) Based on the previously negotiated authentication key k i,j Safely sent to terminal ME j .

[0149] In step 503, the terminal ME j Receive the target satellite access point AP r The public key information (R r ,V r ) and the second authentication parameter W i,2 After that, calculate and AP r New authentication key and new authentication parameters between:

[0150]

[0151] Mac j =H1(w i ′·P||v j ·V r ||ID i ||ID r ||TID j ||Y);

[0152] New authentication key sk r,j =H1(w i ′·P||v j ·V r ||ID r ||TID j ||Y);

[0153] Set new authentication parameters (ID i ,ID r ,TID j ,mac j ) and sends it to the target satellite access point AP r .

[0154] In step 504, the target satellite access point AP r Receive the handover authentication information (ID i ,ID r ,TID j ,W i,1 ,V i ,V j ) and the new authentication parameter (ID i ,ID r ,TID j ,mac j ) and then calculate and terminal ME j The authentication key k r,j .

[0155] For example, in a non-limiting embodiment, the specific calculation is as follows:

[0156]

[0157] Verify equation H1(w i ′·P∥v r ·V j ∥ID i ∥ID r ∥∥TID j ∥∥Y)=mac j Is it true? If not, the target satellite access point AP r Reject this connection; otherwise, the target satellite access point AP r Computing and Terminal ME j The authentication key k r,j =H1(w i ′·P∥v r ·V j ∥ID r ∥∥TID j ∥∥Y).

[0158] Through the above steps 501 to 504, at the current satellite network access point AP i With the help of the terminal ME j and the next target satellite access point AP r The authentication parameters can be calculated in advance, once the terminal ME j Enter the target satellite access point AP r By quickly ensuring the signal range of the wireless router, access authentication can be performed, reducing the delay of communication switching.

[0159] The lightweight satellite-to-ground network mobile device secure access method provided by the embodiment of the present invention can realize access authentication and key negotiation, communication recovery and satellite switching of mobile device network secure communication, effectively reduce the bandwidth overhead and computing overhead in satellite authentication, and provide a secure authentication and key negotiation mechanism, which has obvious advantages over the existing technology.

[0160] Refer to the following Figure 6 The satellite-to-ground network structure shown further details the process of using the method of the present invention to achieve secure access and secure communication of mobile devices in the satellite-to-ground network.

[0161] Reference Figure 6 , Network Control Center NCC, Satellite Access Point AP B , Ground Gateway GS k and owning a mobile device ME A The interaction process between users is as follows:

[0162] A. System Initialization

[0163] This phase includes three parts: NCC generates system parameters and keys, satellite and ground gateway registration, and user mobile device registration, as follows:

[0164] A1.NCC triggers system initialization, selects a prime group G of order q, and three hash functions H: {0,1} * →Z q , Among them, → represents the mapping, {0,1} * It represents a string of any length consisting of 0 or 1. q It is a q-order integer group consisting of (0,1,…,q-1) elements. The hash function H represents the mapping of a string of any length composed of 0 or 1 to a q-order integer group Z consisting of (0,1,…,q-1) elements. q In the above, the hash function H1 represents the mapping of a string of any length composed of 0 or 1 into a string of length l1 composed of 0 or 1, and the hash function H2 represents the mapping of a string of any length composed of 0 or 1 into a string of length l2 composed of 0 or 1; then, NCC randomly selects a value x∈Z q And calculate Y = x·P, where the symbol “∈” indicates belonging, and P is a generator of the group G. Finally, NCC sets the public parameter pp =<G,P,q,H,H1,H2,Y> , where P is a generator of the group G.

[0165] A2. During the satellite launch preparation phase, NCC is the satellite access point AP. B Generates a pre-configured message that includes a permanent ID B , system public parameters pp, long-term key (s B ,R B ,v B ,V B ) and the peer group key K g ∈G, where R B =(s B -H(ID B ||ID B )·x)·P,V B =v B ·P.

[0166] Similarly, NCC is the ground gateway GS k Configure the system public parameters pp and the unique long-term key (s k ,R k ,v k ,V k ).

[0167] A3. User uses his mobile device ME A Send an offline registration request message ReMes to the NCC, the offline registration request message ReMes includes the terminal ME A Long-term identification ID A and short-term identification TID A ;After NCC successfully verifies the device information, it selects a random number r A ∈Z q , calculate the value R A =r A ·P,s A =r A +H(TID A ||R A )·x, and (R A ,s A ) is returned to the terminal ME A ; Finally, the terminal ME A Randomly select a value v A ∈Z q , calculate the value V A =v A P, user settings (s A ,v A ) is the terminal ME A The private key of A ,V A ) is the public key.

[0168] B. Initial access and key negotiation

[0169] This phase includes three parts: the user generates authentication and key negotiation parameters, the satellite access point verifies the user identity and generates key negotiation parameters and authentication keys, and the user verifies the access point identity and generates session keys. The details are as follows:

[0170] B1. The user uses the terminal ME after registration A , choose the most suitable satellite access point AP B Then, the terminal ME A Choose a random number a∈Z q , calculated value u=a+v A , T A =u·P,e=u+s A +H(ID B ||TID A ||T||Y||TS1)·v A , and the first authentication information (TID A ,R A ,V A ,T A ,TS1) is sent to the satellite access point AP B, requesting access to the satellite network, where TS1 is the current timestamp.

[0171] B2. Satellite access point AP B Receive the above first authentication information (TID A ,R A ,V A ,T,TS1), first verify the equation:

[0172] e·P=T+R A +H(TID A ||R A )·Y+H(ID B ||TID A ||T||Y||TS1)·

[0173] V A whether it is established;

[0174] If not, the access is rejected.

[0175] Otherwise, the satellite access point AP B Choose a random number b∈Z q , perform the following calculations:

[0176] u B =b+v B ;

[0177] T b =u B ·P,K1=s B ·(T A -V A )+b·(R A +H(TID A ∥R A )×Y);

[0178] K2=b×(T A -V A );

[0179] Initial authentication key k B,A =H1(K1∥K2∥ID B ∥TID A ∥Y∥T A ∥T b );

[0180] Satellite Access Point AP B The second authentication information (ID B ,R b ,V B ,T B ,TS2) returns to the terminal ME A , and the third authentication information (TIDA ,V A ,R A ,TS1) sent to the ground gateway GS k , where V k For Gateway GS k The public key of

[0181] B3.Terminal ME j According to the second authentication information (ID B ,R B ,V B ,T B ,TS2) performs the following calculations:

[0182] K1′=s A ·(T B -V B )+a·(R B +H(ID B ∥R B )×Y);

[0183] K2′=a×(T B -V B );

[0184] Authentication key k A,B =H1(K1′∥K2′∥ID B ∥TID A ∥T A ∥T B );

[0185] Session key sk A,k =H2(v A ·V k ∥ID k ∥TID A ∥Y).

[0186] Ground Gateway GS k According to the third authentication information (TID A ,R A ,V A ,TS1) calculate the session key sk for this access k,j =H2(v k ·V A ∥ID k ∥∥TID j ∥∥Y).

[0187] In the above access authentication process, the satellite access point AP B The key k B,A and terminal ME j The authentication key k A,B Consistent because:

[0188] K1=s B ·(T A -V A )+b·(R A +H(TID A ∥R A )×Y)

[0189] =s B ·a·P+b·(r A ·P+H(TID A ||R A )·x·P)

[0190] =s B ·a·P+b·s A ·P

[0191] =s A ·b·P+a·(r b ·P+H(ID B ||R B )·x·P)

[0192] =s A ·(T B -V B )+a·(R B +H(ID B ∥R B )×Y)=K1′;

[0193] K2=b×(T A -V A )=b·a·P=a×(T B -V B ) = K2′;

[0194] Therefore, k A,B =k B,A =H1(K1||K2||ID B ||TID A ||T A ||T B ).

[0195] C. Restoration of interrupted communication

[0196] This phase includes the initiation of an interruption reconnection request, the access point verifying the legitimacy of the user device and updating the authentication key, and the user verifying the legitimacy of the access point and generating a new authentication key. The details are as follows:

[0197] C1.Terminal ME A Choose a random number f A ∈Z q ,calculate Then to the satellite access point APB Send a reconnect message Reconnect, which includes: short-term identity TID A , timestamp TS3 and value M B , request communication reconnection.

[0198] C2. Satellite access point AP B Query recent access records and obtain the terminal ME A The authentication key k of the last call B,A and the session timestamp TS1 before the interruption. Then, the satellite access point AP B Check whether the timestamp meets the following condition: |TS1-TS3|≤△T, where △T is the longest allowed interruption and reconnection delay; if so, the satellite access point AP B Perform the following calculations:

[0199] Randomly select f B ∈Z q ,calculate:

[0200]

[0201] New authentication key sk′=H1(f B ·P∥f A ′·P∥ID B ∥TID A ∥Y);

[0202] The re-authentication information (M B ,ID B ,TS4) sent to terminal ME A .

[0203] C3.Terminal ME A Receive re-authentication information (M B ,ID B ,TS4), calculate:

[0204]

[0205] Update the authentication key to k′=H1(f B ′·P∥f A P∥ID B ∥TID A ∥Y).

[0206] D. Communication switching

[0207] This phase includes four parts: the original satellite access point selects a new access point, the original satellite access point calculates the switching parameters, the user calculates the new session key and initiates a connection request, and the new access point verifies the user identity and calculates the session key. The details are as follows:

[0208] D1. When terminal ME A About to leave the satellite access point AP B When the signal receiving area is within the range of A Satellite access point AP B Send pre-switching request CReq and terminal ME A Location information; satellite access point AP B According to the terminal ME A The location information and satellite trajectory information of the terminal ME A Recommend the next satellite access point AP to be connected N And several (such as 4-6) nearby satellite access points. If the satellite access point AP B Unable to decide ME A The next satellite access point to be accessed will be the terminal ME A The location information is sent to NCC; NCC is the terminal ME A Select and recommend new satellite access points, and r ID r The orbit information is sent to the satellite access point AP B . Satellite access point AP B Satellite access point AP r As a terminal ME A target satellite access point.

[0209] D2. Satellite access point AP B Choose a random number w∈Z q ,calculate:

[0210] First authentication parameter

[0211] Second authentication parameter

[0212] Satellite Access Point AP B Towards the target satellite access point AP N Send switch authentication information (ID B ,ID N ,TID A ,W1,V A ), and at the same time, the second authentication parameter W2 and the target satellite access point AP N The public key information (R N ,V N ) is sent to the terminal ME through the previously negotiated secure channel A .

[0213] D3. Terminal ME AReceive the target satellite access point AP N The public key information (R N ,V N ) and the second authentication parameter W2, calculate:

[0214]

[0215] Mac A =H1(w′·P∥v A ·V N ∥ID B ∥ID N ∥TID A ∥Y);

[0216] Authentication key k new =H1(w′·P∥v A ·V N ∥ID N ∥TID A ∥Y);

[0217] Set the new authentication parameters (ID B ,TID A ,mac A ) is sent to the target satellite access point AP N .

[0218] D4. Target satellite access point AP N Receive the above switching authentication information (ID B ,ID N ,TID A ,W1,V A ) and the new authentication parameters (ID B ,ID N ,TID A ,mac A ), calculate And verify the equation H1(w′·P∥v N ·V A ∥ID B ∥ID N ∥TID A ∥Y)=mac A whether it is established;

[0219] If not, the target satellite access point AP N Reject this link;

[0220] Otherwise, the target satellite access point AP N Computing and Mobile Terminals ME A The authentication key k new =H1(w′·P∥v N ·VA ∥ID N ∥TID A ∥Y).

[0221] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0222] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0223] In several embodiments provided by the present invention, it should be understood that the disclosed device can be implemented in other ways.

[0224] The present invention also provides a storage medium, which is a computer-readable storage medium, on which a computer program is stored, and the computer program can be executed when it is run. Figure 2 or Figure 3 or Figure 4 or Figure 5 The storage medium may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc. The storage medium may also include a non-volatile memory (non-volatile) or a non-transitory memory, etc.

[0225] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented using software, the above embodiments may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired or wireless means.

[0226] The embodiments of the present invention are described in detail above. The present invention is described in detail using specific implementation methods herein. The description of the above embodiments is only used to help understand the method and system of the present invention. It is only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should belong to the scope of protection of the present invention, and the content of this specification should not be understood as limiting the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A lightweight satellite-to-ground network mobile device secure access method, characterized in that: The method comprises: System initialization process: The network control center NCC selects the master key, initializes the network parameters, generates long-term keys for each satellite AP and GS, and generates initial authentication keys for each mobile device ME; Initial access and key negotiation process: When the ME requests to access the STN for the first time, the satellite AP authenticates the ME, and after the authentication is passed, key negotiation is performed to generate relevant keys, such as the authentication key between the terminal ME and the satellite AP and the session key between the terminal ME and the ground gateway GS.

2. The lightweight satellite-to-ground network mobile device secure access method according to claim 1, characterized in that: Initializing network parameters and generating long-term keys for each satellite AP and GS includes: Set common parameters; Generate a pre-configuration message corresponding to each satellite AP, and send the pre-configuration information to each satellite AP; the pre-configuration information includes: the satellite AP identity, the public parameters, the satellite AP long-term key and the peer group key; the peer group key is shared by all satellite APs and is used to identify peer satellites; Generate pre-configuration information corresponding to the GS, and send the pre-configuration information to the GS; the pre-configuration information includes: the public parameters, and the long-term key of the GS.

3. The lightweight satellite-to-ground network mobile device secure access method according to claim 2, characterized in that: Generating an initial authentication key for each mobile equipment ME comprises: Receiving an offline registration request message sent by each ME, wherein the offline registration request message includes: device information of the ME; the device information includes: a long-term identity identifier and a short-term identity identifier; The device information is verified. After the verification is successful, the NCC and the ME generate an initial authentication key of the ME according to the public parameters and the device information of the ME. The initial authentication key includes a user private key and a user public key.

4. The lightweight satellite-to-ground network mobile device secure access method according to claim 2, characterized in that: The public parameters include: a prime order group G, a generator P of the group G, the order q of the group G, three hash functions, and a parameter Y calculated based on a random value and the generator.

5. The lightweight satellite-to-ground network mobile device secure access method according to claim 1, characterized in that: When the ME requests to access the STN for the first time, the satellite AP authenticates the ME, and after the authentication is passed, performs key negotiation with the ME, and generates the relevant key including: The ME selects a satellite AP, generates first authentication information according to the initial authentication key, and sends the first authentication information to the satellite AP to request access; the first authentication information includes at least: a short-term identity of the ME and a first current timestamp; After receiving the first authentication information, the satellite AP verifies the first authentication information; If the verification fails, the access is denied; If the verification is successful, the AP generates an authentication key and second authentication information between the AP and the ME, and sends the second authentication information to the ME; the second authentication information includes at least: a ground gateway GS identity and a second current timestamp; The ME generates an authentication key between itself and the AP and a session key between itself and the ground gateway GS according to the second authentication information.

6. The lightweight satellite-to-ground network mobile device secure access method according to claim 5, characterized in that: The key negotiation process further includes: After the satellite AP verifies the first authentication information, it sends the third authentication information to the GS; the third authentication information at least includes: the short-term identity of the ME and the first current timestamp; The GS calculates the session key for this access based on the third authentication information.

7. The lightweight satellite-to-ground network mobile device secure access method according to any one of claims 1 to 6, characterized in that: The method further comprises: The interrupted communication recovery process includes: The ME sends a relink request message to the satellite AP, wherein the relink request message includes at least: a short-term identity of the ME and a third current timestamp; The satellite AP queries the recent access record of the ME according to the short-term identity of the ME, and obtains the authentication key of the ME before the interruption and the session timestamp before the interruption; Check whether the difference between the third current timestamp and the pre-interruption session timestamp is less than a set value, where the set value is the longest allowed interruption reconnection delay; If yes, regenerate the authentication key corresponding to the ME according to the authentication key of the ME before the interruption, and return re-authentication information to the ME; the re-authentication information at least includes the identity of the satellite AP; The ME regenerates the authentication key according to the re-authentication information.

8. The lightweight satellite-to-ground network mobile device secure access method according to claim 7, characterized in that: The interrupted communication recovery process also includes: If the difference between the third current timestamp and the pre-interruption session timestamp is greater than or equal to a set value, a re-access rejection message is returned to the ME.

9. The lightweight satellite-to-ground network mobile device secure access method according to any one of claims 1 to 6, characterized in that: The method further comprises: The handover authentication process includes: The ME sends a pre-switching request message to the current satellite AP, where the pre-switching request message includes: location information of the ME; The current satellite AP determines the target satellite AP according to the location information of the ME, and calculates the first authentication parameter and the second authentication parameter according to the identity of the current satellite AP, the identity of the target AP, and the identity of the ME; The current satellite AP sends handover authentication information to the target satellite AP, wherein the handover authentication information at least includes: the identity of the current satellite AP, the identity of the target AP, the identity of the ME, and the first authentication parameter; and at the same time, encrypts the second authentication parameter and the public key information of the target satellite AP with the authentication key negotiated with the ME and sends them to the ME; The ME calculates a new authentication key and a new authentication parameter according to the second authentication parameter and the public key information of the target satellite AP, and sends the new authentication parameter to the target satellite AP; The target satellite AP verifies the new authentication parameters according to the handover authentication information, and generates an authentication key with the ME after the verification is passed.

10. The lightweight satellite-to-ground network mobile device secure access method according to claim 9, characterized in that: The switching authentication process also includes: If the target satellite AP fails to verify the new authentication parameters, the link is rejected.

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