Quantum security cross-regional data transmission system and method

Abstract

The invention discloses a quantum security cross-regional data transmission system and method, the system comprises a first region, a second region and a third region which are connected pairwise, the first region is a data sending region, and the first region comprises a data sending end, a first boundary base station and a first data server which are connected pairwise; the second area is a data receiving area and comprises a data receiving end, a second boundary base station and a second data server which are connected in pairs; the third area is a data relay area and comprises at least one data relay server. According to the invention, the ciphertext transmission link and the key transmission link are separated, and different links are adopted for transmission, so that the data relay server cannot obtain the key information and cannot obtain the plaintext of the transmission information by intercepting the transmission data, and the security of the information in the transmission process in a cross-regional scene is ensured.

Description

Technical Field

[0001] The present application relates to the field of data transmission technology, and in particular to a quantum-secure cross-regional data transmission system and method. Background Art

[0002] In the Internet field, data is becoming the core of all services and applications. With the rapid development of the Internet, more and more service-level applications are serving users around the world. This means that the data of these application-level services may need to be transmitted to the service data center through servers deployed globally. In this business scenario, massive amounts of data need to be transmitted across regions, such as from Asia to North America, and from South America to Europe.

[0003] Cross-regional data transmission refers to data transmission between user devices located in different regions, such as data transmission between user devices located in different cities or countries. To ensure the security of cross-regional data transmission, encryption is often used in communication links for data transmission. In order to obtain data information, the data receiving end needs to decrypt the received ciphertext message. Based on this, the data receiving end and the data sending end must perform key synchronization operations. In the existing infrastructure scenario, the transmission line of the ciphertext and the transmission line of the key generally overlap, and for long-distance cross-regional data transmission, data often cannot reach the receiving end directly from the sending end, and needs to be forwarded to the receiving end through multiple relay nodes. In this case, since both the key information and the ciphertext information pass through a certain relay node, the relay node may intercept the key information and the ciphertext information, resulting in the leakage of the transmission information.

[0004] In view of this, how to ensure the security of data transmission in data transmission scenarios passing through relay nodes is a technical problem that needs to be solved urgently. Summary of the invention

[0005] Purpose of the invention: In order to solve the relevant technical problems raised in the background technology, the present invention provides a quantum-secure cross-regional data transmission method and system, which separates the ciphertext transmission link from the key transmission link and uses different links for transmission, ensuring that the data relay server does not obtain the key information, and thus cannot obtain the plaintext of the transmission information by intercepting the transmission data, thereby ensuring the security of information during transmission in cross-regional scenarios.

[0006] Technical solution: The present invention provides a quantum-secure cross-region data transmission system, which includes first to third regions connected in pairs, wherein the first region is a data sending region, and the first region includes data sending terminals connected in pairs, a first boundary base station, and a first data server; the second region is a data receiving region, and the second region includes data receiving terminals connected in pairs, a second boundary base station, and a second data server; the third region is a data relay region, and the third region includes at least one data relay server;

[0007] The data sending end is used to store and send plaintext data, and generate the transmission sequence number during the data transmission process; the first data server is used to encrypt the plaintext data to obtain the ciphertext, and calculate the hash value of the plaintext data; the first boundary base station is used to define the boundary of the first area, negotiate and transmit the encryption and decryption keys with the second boundary base station of the second area, and store and manage the keys; the data relay server is used to relay and forward the hash values ​​of the ciphertext and plaintext data; the second data server is used to decrypt the ciphertext to obtain the plaintext data, and authenticate the data integrity; the second boundary base station is used to define the boundary of the second area, negotiate and transmit the encryption and decryption keys with the first boundary base station of the first area, and store and manage the keys; the data receiving end is used to receive and store plaintext data.

[0008] The present invention also includes a method for a quantum-secure cross-region data transmission system, comprising the following steps:

[0009] (1) The first border base station determines a direct link with the second border base station;

[0010] (2) The data sending end generates a transmission sequence number NO-trans for the data transmission, sends the plaintext data data to be transmitted and the transmission sequence number NO-trans to the first data server; and sends the transmission sequence number NO-trans to the first border base station;

[0011] (3) The first data server obtains the first key k1 from the first border base station as an encryption key, and uses the encryption key k1 to encrypt the plaintext data data to be transmitted, thereby obtaining a first ciphertext DATA1 = data⊕k1;

[0012] (4) The first data server obtains a key from the first border base station to generate a hash function h p1,u1 , use this hash function to calculate the hash value of the plaintext data to be transmitted to obtain the hash value H = h p1,u1 (data), feeding back the coefficient information string str1 of the irreducible polynomial generating the hash function and the key u1 as the input random number to the first border base station;

[0013] (5) The first data server obtains the second key k2 from the first border base station, and uses the second key k2 to encrypt the first ciphertext DATA1 and the hash value H to obtain the second ciphertext DATA2 = (DATA1, H) ⊕ k2, and sends the second ciphertext DATA2 and the transmission sequence number NO-trans to the second data server via the data relay server;

[0014] (6) The first border base station sends the transmission sequence number NO-trans, the first key k1, the second key k2, the string str1 and the key u1 to the second border base station via the direct link confirmed in step (1); the second border base station associates the transmission sequence number NO-trans with the first key k1, the second key k2, the string str1 and the key u1, and uses the transmission sequence number NO-trans as an index of the first key k1, the second key k2, the string str1 and the key u1;

[0015] (7) The second data server authenticates the received hash value H. In response to successful authentication, the second data server sends the decrypted plaintext data data′ to the data receiving end. In response to failed authentication, the second data server feeds back a data reception failure to the data receiving end, and the data receiving end sends an instruction to re-transmit data to the data sending end via the second data server, the data relay server, and the first data server.

[0016] Further, the specific process of the first border base station determining the direct link with the second border base station is:

[0017] 1) The data transmitting end obtains and stores the network access IDB1 of the first border base station, and the data receiving end obtains and stores the network access IDB2 of the second border base station;

[0018] 2) The data sending end sends a query for the network access ID information of the second border base station to the data receiving end via the first data server, the data relay server and the second data server; the data receiving end responds to the query and feeds back the network access ID B2 of the second border base station to the data sending end;

[0019] 3) The data sending end receives the network entry IDB2 of the second border base station and sends it to the first border base station;

[0020] 4) The first border base station determines a direct link with the second border base station based on the access IDB2 of the second border base station.

[0021] Furthermore, the inquiry includes a timestamp t1 when the inquiry is initiated.

[0022] Further, the first border base station determines, based on the access IDB2 of the second border base station, that the direct link with the second border base station refers to:

[0023] The first border base station obtains the establishment time t2 of the direct link with the second border base station based on the access IDB2 of the second border base station, and compares the establishment time t2 with the query timestamp t1. When the establishment time t2 is earlier than the query timestamp t1, the first border base station determines that the direct link is the correct link.

[0024] Furthermore, the specific process of step (4) is as follows:

[0025] A) The first data server obtains a set of keys from the first border base station as random numbers to generate an irreducible polynomial p1(x), and feeds back a coefficient information string str1 corresponding to the irreducible polynomial to the first border base station;

[0026] B) The first data server then obtains a set of keys u1 from the first border base station as input random numbers of the hash function;

[0027] C) The first data server generates a hash function h based on the irreducible polynomial p1(x) and the key u1 as an input random number p1,u1 , use this hash function to calculate the hash value of the plaintext data to be transmitted to obtain the hash value H = h p1,u1 (data).

[0028] Furthermore, the specific process of the second data server authenticating the received hash value H is as follows:

[0029] a) The second data server uses the transmission sequence number NO-trans as an index, obtains the second key k2 as a decryption key from the second border base station, and uses the decryption key k2 to decrypt the received second ciphertext DATA2 to obtain the decrypted third ciphertext DATA1′ and the decrypted hash value H′;

[0030] b) The second data server uses the transmission sequence number NO-trans as an index, obtains the string str1 from the second border base station, and generates an irreducible polynomial p1′(x) based on the string;

[0031] c) The second data server uses the transmission sequence number NO-trans as an index, obtains the key u1 from the second border base station, and generates a hash function h′ based on the irreducible polynomial p1′(x) and the key u1 as an input random number p1,u1 ;

[0032] d) The second data server uses the transmission sequence number NO-trans as an index to obtain the first key k1 from the second border base station, and uses the first key k1 to perform a decryption operation on the decrypted third ciphertext DATA1′ again to obtain the decrypted plaintext data data′;

[0033] e) The second data server uses the generated hash function h′ p1,u1 Calculate the hash value of the decrypted plaintext data data' to obtain the hash value H" = h' p1,u1 (data′); compare the calculated hash value H″ and the decrypted hash value H′ to see if they are equal. If they are equal, the authentication is successful; if they are not equal, the authentication fails and data transmission is performed again.

[0034] Furthermore, before step (2), the method further includes: the first border base station and the second border base station synchronize the key file based on the direct link.

[0035] Beneficial effects of the present invention:

[0036] (1) The data transmission method and system of the present invention are used to separate the ciphertext transmission link from the key transmission link, and use different links for transmission, so as to ensure that the data relay server does not obtain the key information, and thus cannot obtain the plaintext of the transmission information by intercepting the transmission data, thereby ensuring the security of the information transmission process in cross-regional scenarios;

[0037] (2) Using the data transmission method and system of the present invention, the first border base station for managing keys in the sending area and the second border base station for managing keys in the receiving area are directly connected to ensure that no third party is involved in the key transmission process, thereby avoiding the risk of the key being intercepted by a third party. This method can protect the security of long-distance cross-regional data transmission, which can be extended to global cross-national data transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0039] Figure 1 A connection diagram of a data transmission system of the present invention;

[0040] Figure 2 It is a flow chart of the data transmission method of the present invention. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0042] As described in the background technology, for data transmission scenarios passing through relay nodes, the transmission paths of ciphertext data and key information are consistent, resulting in the risk of data leakage caused by relay nodes intercepting transmitted data. A system and method are needed to ensure the security of cross-regional data transmission.

[0043] In view of this, this application proposes a quantum-secure cross-region data transmission system, such as Figure 1 shown.

[0044] The system of the present invention comprises a first area 1, a second area 2 and a third area 3 connected in pairs, wherein the first area 1 is a data sending area, and the first area 1 comprises a data sending terminal 11, a first boundary base station 12 and a first data server 13 connected in pairs; the second area 2 is a data receiving area, and the second area 2 comprises a data receiving terminal 21, a second boundary base station 22 and a second data server 23 connected in pairs; the third area 3 is a data relay area, and the third area 3 comprises at least one data relay server 31;

[0045] It is understandable that the system may also include other areas where data relay servers 31 are deployed, and these other areas participate in relaying and forwarding ciphertext data. That is, the cross-region data transmission system includes at least one data relay server for data forwarding operations.

[0046] The data sending end 11 is a terminal for storing and sending plaintext data data, which is used to store and send plaintext data data, and generate the transmission sequence number during the data transmission process; the first data server 13 is used to encrypt the plaintext data data to obtain the ciphertext DATA, and calculate the hash value of the plaintext data data; the first boundary base station 12 is used to define the boundary of the first area 1, negotiate and transmit encryption and decryption keys with the second boundary base station 22 of the second area 2, and store and manage keys; the data relay server 31 is used to relay and forward the ciphertext DATA and the hash value of the plaintext data; the second data server 23 is used to decrypt the ciphertext DATA to obtain the plaintext data, and authenticate the data integrity; the second boundary base station 22 is used to define the boundary of the second area 2, negotiate and transmit encryption and decryption keys with the first boundary base station 12 of the first area 1, and store and manage keys; the data receiving end 21 is a terminal for receiving and storing plaintext data, and is used to receive and store plaintext data.

[0047] In the transmission system, each device has a unique network access ID, which can be used as the identity of each device in the transmission system.

[0048] Example 1

[0049] Based on the above system, the present invention also includes a method for a quantum secure cross-regional data transmission system, the method flow is as follows: Figure 2 As shown, the following steps are included:

[0050] (1) The first border base station 12 determines a direct link with the second border base station 22 based on the existing system connection. The specific process is as follows:

[0051] 1) The data transmitting end 11 obtains and stores the network access IDB1 of the first border base station 12, and the data receiving end 21 obtains and stores the network access IDB2 of the second border base station 22;

[0052] 2) The data transmitting end 11 confirms the network access ID information of the second border base station 22 to the data receiving end 21; that is, the data transmitting end 11 sends a query of the network access ID information of the second border base station 22 to the data receiving end 21 via the first data server 13, the data relay server 31 and the second data server 23; the data receiving end 21 responds to the query and feeds back the network access ID B2 of the second border base station 22 to the data transmitting end 11;

[0053] 3) The data transmitting end 11 receives the network access IDB2 of the second border base station 22 and sends it to the first border base station 12;

[0054] 4) The first border base station 12 determines a direct link with the second border base station 22 based on the access IDB2 of the second border base station 22 .

[0055] In the above process, the first border base station 12 can also obtain the establishment time of the direct link, and determine that the direct link is one of the links in the existing system by judging the establishment time. Specifically, when the data sending end 11 sends an inquiry to the data receiving end 21, the inquiry also includes the timestamp t1 when the inquiry is initiated; at this time, the first border base station 12 determines the direct link with the second border base station 22 based on the access IDB2 of the second border base station 22, which means: the first border base station 12 obtains the establishment time t2 of the direct link with the second border base station 22 based on the access IDB2 of the second border base station 22, compares the establishment time t2 with the inquiry timestamp t1, and only when the establishment time t2 is earlier than the inquiry timestamp t1, the first border base station 12 determines that the direct link is the correct link.

[0056] This step is to prevent bad users from intercepting the information of the network access IDB2 of the second boundary base station 22 fed back by the data receiving end, and forging a second boundary base station based on the information of the network access IDB2, and establishing a direct link between the forged second boundary base station and the first boundary base station 12. At this time, the time when the direct link is established is bound to be later than the query timestamp t1, indicating that this direct link is a new direct channel created outside the original data transmission system by the bad user after learning that the data sending end may communicate data with the data receiving end 21, in order to intercept the key information.

[0057] (2) The data transmitting end 11 generates a transmission sequence number NO-trans for the data transmission, and sends the plaintext data data to be transmitted and the transmission sequence number NO-trans to the first data server 13; and sends the transmission sequence number NO-trans to the first border base station 12;

[0058] (3) The first data server 13 obtains the first key k1 from the first border base station 12 as an encryption key, and uses the encryption key k1 to encrypt the plaintext data data to be transmitted, thereby obtaining a first ciphertext DATA1 = data⊕k1;

[0059] (4) The first data server 13 obtains a key from the first border base station 12 to generate a hash function h p1,u1 , use this hash function to calculate the hash value of the plaintext data to be transmitted to obtain the hash value H = h p1,u1 (data), feeding back the coefficient information string str1 of the irreducible polynomial generating the hash function and the key u1 as the input random number to the first border base station 12;

[0060] The specific process is:

[0061] A) The first data server 13 obtains a set of keys from the first border base station 12 as random numbers to generate an irreducible polynomial p1(x), and feeds back a coefficient information string str1 corresponding to the irreducible polynomial to the first border base station 12;

[0062] Specifically, the first data server 13 obtains a set of keys as random numbers from the first border base station 12, and uses each bit of the random number to correspond to the coefficient of each term in the polynomial except the highest term, to generate a polynomial in the GF(2) field, where the coefficient of the highest term is 1; the first data server 13 verifies whether the polynomial is an irreducible polynomial. If the verification result is "no", another set of keys is obtained from the first border base station 12 as a new random number, and the polynomial is regenerated and verified; if the verification result is "yes", the verification is stopped to obtain the irreducible polynomial p1(x), and the character string consisting of the coefficients of each term except the highest term in the irreducible polynomial p1(x) is recorded as str1.

[0063] B) The first data server 13 obtains a set of keys u1 from the first border base station 12 as input random numbers of the hash function;

[0064] C) The first data server 13 generates a hash function h based on the irreducible polynomial p1(x) and the key u1 as an input random number p1,u1 , use this hash function to calculate the hash value of the plaintext data to be transmitted to obtain the hash value H = h p1,u1 (data).

[0065] (5) The first data server 13 obtains the second key k2 from the first border base station 12, and uses the second key k2 to encrypt the first ciphertext DATA1 and the hash value H to obtain the second ciphertext DATA2 = (DATA1, H) ⊕ k2, and sends the second ciphertext DATA2 and the transmission sequence number NO-trans to the second data server 23 via the data relay server 31;

[0066] (6) The first border base station 12 sends the transmission sequence number NO-trans, the first key k1, the second key k2, the string str1 and the key u1 to the second border base station 22 via the direct link confirmed in step (1); the second border base station 22 associates the transmission sequence number NO-trans with the first key k1, the second key k2, the string str1 and the key u1, and uses the transmission sequence number NO-trans as an index of the first key k1, the second key k2, the string str1 and the key u1;

[0067] (7) The second data server 23 authenticates the received hash value H. In response to successful authentication, the second data server 23 sends the decrypted plaintext data data′ to the data receiving end 21. In response to failed authentication, the second data server 23 feeds back a data reception failure to the data receiving end 21, and the data receiving end 21 sends an instruction to retransmit data to the data sending end 11 via the second data server 23, the data relay server 31, and the first data server 13.

[0068] The specific process of the second data server 23 authenticating the received hash value H is as follows:

[0069] a) The second data server 23 uses the transmission sequence number NO-trans as an index, obtains the second key k2 as a decryption key from the second border base station 22, and uses the decryption key k2 to decrypt the received second ciphertext DATA2 to obtain the decrypted third ciphertext DATA1′ and the decrypted hash value H′;

[0070] b) The second data server 23 uses the transmission sequence number NO-trans as an index to obtain the string str1 from the second border base station 22, and generates an irreducible polynomial p1′(x) based on the string;

[0071] c) The second data server 23 uses the transmission sequence number NO-trans as an index, obtains the key u1 from the second border base station 22, and generates a hash function h′ based on the irreducible polynomial p1′(x) and the key u1 as an input random number. p1,u1 ;

[0072] d) The second data server 23 uses the transmission sequence number NO-trans as an index to obtain the first key k1 from the second border base station 22, and uses the first key k1 to perform a decryption operation on the decrypted third ciphertext DATA1′ again to obtain the decrypted plaintext data data′;

[0073] e) The second data server 23 uses the generated hash function h′ p1,u1 Calculate the hash value of the decrypted plaintext data data' to obtain the hash value H" = h' p1,u1 (data′); compare the calculated hash value H″ and the decrypted hash value H′ to see if they are equal. If they are equal, the authentication is successful; if they are not equal, the authentication fails and data transmission is performed again.

[0074] It can be seen that by adopting the data transmission method described in this embodiment, the ciphertext transmission link and the key transmission link are separated, and different links are used for transmission, ensuring that the data relay server 31 will not obtain the key information, and thus cannot obtain the plaintext of the transmission information by intercepting the transmission data, thereby ensuring the security of the information during transmission in a cross-regional scenario. In addition, the first boundary base station 12 that manages the key in the sending area and the second boundary base station 22 that manages the key in the receiving area are directly connected to ensure that there is no third party involved in the key transmission process, avoiding the risk of the key being intercepted by a third party. This method can protect the security of cross-regional data transmission, especially for long-distance cross-regional data transmission, and the cross-region here can be extended to global cross-national data transmission.

[0075] Example 2

[0076] Based on a quantum-secure cross-region data transmission method in Example 1, this Example 2 adds a key file synchronization step between step (1) and step (2) in Example 1. The key file is used for encryption and hash value calculation in subsequent data transmission processes.

[0077] That is, before step (2), the first border base station 12 and the second border base station 22 may synchronize the key file based on the direct link. In other words, the first border base station 12 and the second border base station 22 may apply for the key file from the same key center based on the direct link.

[0078] In some cases, the first area 1 and the second area 2 are two areas far away from each other, for example, the first area 1 and the second area 2 belong to two different countries. In this case, the key center may be an embedded key center deployed in the first border base station 12 or the second border base station 22. The embedded key center distributes the key file to the border base station at the other end through the direct link.

[0079] In other cases, the first area 1 and the second area 2 may be under the jurisdiction of the same key center; in this case, the key center may be an independent device that exists independently of the first border base station 12 and the second border base station 22. The first border base station 12 and the second border base station 22 negotiate key information through the direct link to ensure that the key files obtained by the first border base station 12 and the second border base station 22 from the key center are symmetrical. For example, the first border base station 12 and the second border base station 22 negotiate a common key application number NO, and the key center distributes a set of key files based on the key application number NO. Since the key application numbers NO initiated by the first border base station 12 and the second border base station 22 to the key center are the same, the key center will distribute the same set of key files to the first border base station 12 and the second border base station 22, respectively.

[0080] For example, the key file stored in the first border base station 12 is recorded as the first key file file1, and the key file stored in the second border base station 22 is recorded as the second key file file2, and file1 and file2 are symmetrical.

[0081] In view of the fact that the key file synchronization has been completed before data transmission, symmetric key files file1 and file2 are stored in the first boundary base station 12 and the second boundary base station 22. Therefore, the first boundary base station 12 can subsequently send the key index information through a direct link without sending the key. Based on the index information, the second boundary base station 22 can obtain all the keys needed from the key file file2 stored in itself.

[0082] At this time, step (6) is updated as follows: the first border base station 12 obtains the key index information (index1, index2, index3, index4) of the first key k1, the second key k2, the string str1 and the key u1 in the first key file file1 stored locally, and sends the key index information (index1, index2, index3, index4) and the transmission sequence number NO-trans to the second border base station 22 via the direct link confirmed in step (1). The second border base station 22 obtains the first key k1, the second key k2, the string str1 and the key u1 from the second key file file2 stored locally based on the received key index information for use by the second data server. The key index information may include, for example, the starting position of the key, the key length (or, the key offset value), etc.

[0083] By adopting the data transmission method described in this embodiment, before data transmission, the two boundary base stations have synchronized the symmetric key file based on the direct link between the base stations, so that in the subsequent data transmission process, there is no need to transmit keys between the base stations, but only key index information needs to be transmitted. This avoids the problem of key content transmission involved in the transmission process and completely eliminates the possibility of bad users obtaining key content during the data transmission process.

Claims

1. A quantum-secure cross-region data transmission system, characterized in that: The system includes first to third areas connected in pairs, the first area is a data sending area, the first area includes data sending terminals connected in pairs, a first boundary base station and a first data server; the second area is a data receiving area, the second area includes data receiving terminals connected in pairs, a second boundary base station and a second data server; the third area is a data relay area, the third area includes at least one data relay server; The data sending end is used to store and send plaintext data, and generate a transmission sequence number during the data transmission process; the first data server is used to perform encryption operations on the plaintext data to obtain ciphertext, and calculate the hash value of the plaintext data; The first boundary base station is used to define the boundary of the first area, negotiate and transmit encryption and decryption keys with the second boundary base station of the second area, and store and manage keys; the data relay server is used to relay and forward hash values ​​of ciphertext and plaintext data; the second data server is used to decrypt the ciphertext to obtain plaintext data, and authenticate data integrity; The second boundary base station is used to define the boundary of the second area, negotiate and transmit encryption and decryption keys with the first boundary base station of the first area, and store and manage keys; the data receiving end is used to receive and store plaintext data.

2. A method based on the quantum-secure cross-region data transmission system of claim 1, characterized in that: The following steps are involved: (1) The first border base station determines a direct link with the second border base station; (2) The data sending end generates a transmission sequence number NO-trans for the data transmission, sends the plaintext data data to be transmitted and the transmission sequence number NO-trans to the first data server; and sends the transmission sequence number NO-trans to the first border base station; (3) The first data server obtains the first key k1 from the first border base station as an encryption key, and uses the encryption key k1 to encrypt the plaintext data data to be transmitted, thereby obtaining a first ciphertext DATA1 = data⊕k1; (4) The first data server obtains a key from the first border base station to generate a hash function h p1,u1 , use this hash function to calculate the hash value of the plaintext data to be transmitted to obtain the hash value H = h p1,u1 (data), feeding back the coefficient information string str1 of the irreducible polynomial generating the hash function and the key u1 as the input random number to the first border base station; (5) The first data server obtains the second key k2 from the first border base station, and uses the second key k2 to encrypt the first ciphertext DATA1 and the hash value H to obtain the second ciphertext DATA2 = (DATA1, H) ⊕ k2, and sends the second ciphertext DATA2 and the transmission sequence number NO-trans to the second data server via the data relay server; (6) The first border base station sends the transmission sequence number NO-trans, the first key k1, the second key k2, the string str1 and the key u1 to the second border base station via the direct link confirmed in step (1); the second border base station associates the transmission sequence number NO-trans with the first key k1, the second key k2, the string str1 and the key u1, and uses the transmission sequence number NO-trans as an index of the first key k1, the second key k2, the string str1 and the key u1; (7) The second data server authenticates the received hash value H. In response to successful authentication, the second data server sends the decrypted plaintext data data′ to the data receiving end. In response to failed authentication, the second data server feeds back a data reception failure to the data receiving end, and the data receiving end sends an instruction to re-transmit data to the data sending end via the second data server, the data relay server, and the first data server.

3. The method according to claim 2, characterized in that: The specific process of the first border base station determining the direct link with the second border base station is: 1) The data transmitting end obtains and stores the network access IDB1 of the first border base station, and the data receiving end obtains and stores the network access IDB2 of the second border base station; 2) The data sending end sends a query for the network ID information of the second border base station to the data receiving end via the first data server, the data relay server and the second data server; The data receiving end responds to the inquiry and feeds back the network access IDB2 of the second border base station to the data sending end; 3) The data sending end receives the network entry IDB2 of the second border base station and sends it to the first border base station; 4) The first border base station determines a direct link with the second border base station based on the access IDB2 of the second border base station.

4. The method according to claim 3, characterized in that: The inquiry includes a timestamp t1 when the inquiry is initiated.

5. The method according to claim 4, characterized in that: The first border base station determines the direct link with the second border base station based on the access IDB2 of the second border base station, which means: The first border base station obtains the establishment time t2 of the direct link with the second border base station based on the access IDB2 of the second border base station, and compares the establishment time t2 with the query timestamp t1. When the establishment time t2 is earlier than the query timestamp t1, the first border base station determines that the direct link is the correct link.

6. The method according to claim 2, characterized in that: The specific process of step (4) is as follows: A) The first data server obtains a set of keys from the first border base station as random numbers to generate an irreducible polynomial p1(x), and feeds back a coefficient information string str1 corresponding to the irreducible polynomial to the first border base station; B) The first data server then obtains a set of keys u1 from the first border base station as input random numbers of the hash function; C) The first data server generates a hash function h based on the irreducible polynomial p1(x) and the key u1 as an input random number p1,u1 , use this hash function to calculate the hash value of the plaintext data to be transmitted to obtain the hash value H = h p1,u1 (data).

7. The method according to claim 2, characterized in that: The specific process of the second data server authenticating the received hash value H is as follows: a) The second data server uses the transmission sequence number NO-trans as an index, obtains the second key k2 as a decryption key from the second border base station, and uses the decryption key k2 to decrypt the received second ciphertext DATA2 to obtain the decrypted third ciphertext DATA1′ and the decrypted hash value H′; b) The second data server uses the transmission sequence number NO-trans as an index, obtains the string str1 from the second border base station, and generates an irreducible polynomial p1′(x) based on the string; c) The second data server uses the transmission sequence number NO-trans as an index, obtains the key u1 from the second border base station, and generates a hash function h′ based on the irreducible polynomial p1′(x) and the key u1 as an input random number p1,u1 ; d) The second data server uses the transmission sequence number NO-trans as an index to obtain the first key k1 from the second border base station, and uses the first key k1 to perform a decryption operation on the decrypted third ciphertext DATA1′ again to obtain the decrypted plaintext data data′; e) The second data server uses the generated hash function h′ p1,u1 Calculate the hash value of the decrypted plaintext data data' to obtain the hash value H" = h' p1,u1 (data′); compare the calculated hash value H″ and the decrypted hash value H′ to see if they are equal. If they are equal, the authentication is successful; if they are not equal, the authentication fails and data transmission is performed again.

8. The method according to claim 2, characterized in that: Before step (2), the method further includes: the first border base station and the second border base station synchronize the key file based on the direct link.

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