Secure communication method and system for intelligent regulation and control terminal of distribution network

Abstract

The invention relates to the technical field of power safety regulation and control, and discloses a distribution network intelligent regulation and control terminal safety communication method and system, and the method comprises the steps: a transmitting end carries out the encryption processing of a transmission data plaintext through a homomorphic encryption algorithm, generates a new ciphertext, and adds a digital signature to the new ciphertext; carrying out encryption processing on the secret key by utilizing an improved 16-bit globefish encryption algorithm to generate a new secret key; the sending end sends the new ciphertext, the digital signature and the new key to a receiving end; after the receiving end receives the digital signature, the digital signature is decrypted, and signature authentication is carried out; if the authentication is passed, decrypting the new ciphertext and the new key; if the signature authentication is not passed, error information is returned. According to the method, the key interaction process and the sensitive data are selectively encrypted, the communication data throughput is improved, the communication time is shortened, meanwhile, the homomorphic encryption algorithm and the globefish encryption algorithm are combined to ensure the confidentiality and privacy of transmission data, and data leakage and illegal access or instruction tampering and counterfeiting are prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power safety regulation and control, and in particular to a distribution network intelligent regulation and control terminal safety communication method and system. Background Art

[0002] With the development of science and technology, the frequency of data communication between power load equipment in my country is increasing. In the interaction process between the distribution network control terminal and the main station, a large amount of data exchange and transmission is involved, including sensitive data and ordinary data.

[0003] If sensitive data is not encrypted for transmission, it may be tampered with or forged, leading to privacy leakage of power users, wrong instructions executed by power control, and illegal elements stealing data for profit. However, if all transmitted data is encrypted, it will cause problems such as large data space, high energy consumption, and low encryption and decryption efficiency. Therefore, a transmission method is needed to screen the data. During the transmission process, key sensitive data needs to be selectively encrypted to increase data throughput, reduce data transmission time, and improve data transmission efficiency while ensuring data transmission security. Summary of the invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a secure communication method and system for distribution network intelligent control terminals to solve the problems that existing transmission methods may cause data tampering or forgery, power user privacy leakage, power control execution of erroneous instructions and illegal elements stealing data for profit, as well as encryption of all transmitted data, resulting in large data space occupation, high energy consumption and low encryption and decryption efficiency.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a distribution network intelligent control terminal secure communication method, comprising:

[0008] During the interaction between the sender and the receiver, the sender encrypts the plaintext of the transmitted data using a homomorphic encryption algorithm to generate a new ciphertext, and adds a digital signature to the new ciphertext; the key is encrypted using an improved 16-bit Blowfish encryption algorithm to generate a new key;

[0009] The sending end sends the new ciphertext, digital signature and new key to the receiving end;

[0010] After receiving the digital signature, the receiving end decrypts the digital signature and performs signature authentication;

[0011] If the signature authentication passes, the new ciphertext and the new key are decrypted to obtain the correct information; if the signature authentication fails, an error message is returned;

[0012] The interaction process between the sending end and the receiving end includes a control pre-start process, a control handshake process, a control start process, and a control query process.

[0013] As a preferred solution of the secure communication method of the distribution network intelligent control terminal described in the present invention, wherein: the sending end encrypts the transmission data plaintext through a homomorphic encryption algorithm to generate a new ciphertext, including: obtaining the key information data plaintext h to be encrypted and converting it into binary;

[0014] Randomly select two prime numbers p and q and an integer r, and calculate the variable N = pq;

[0015] The plaintext H is grouped bit by bit into M={m1,m2,...m n}, each group is denoted as m i , where the subscript i represents the group number and n represents the number of groups;

[0016] If the last group digit is less than the set group length, it will be padded with 0;

[0017] Encrypt each plaintext H group to obtain the corresponding ciphertext h i , expressed as:

[0018] h i =(m i +pr)mod N

[0019] According to the grouping order, all ciphertexts are merged to obtain the new ciphertext H′ corresponding to the plaintext H.

[0020] As a preferred solution of the secure communication method of the distribution network intelligent control terminal described in the present invention, wherein: the key is encrypted using the improved 16-bit Blowfish encryption algorithm to generate a new key, including:

[0021] Initialize the first original key pbox and the second original key sbox with fixed strings;

[0022] The first original secret key pbox includes 18 16-bit subkeys, expressed as:

[0023] pbox[1], pbox[2]…pbox

[18] ;

[0024] The second original secret key sbox includes a 4×256 matrix, and each element in the matrix is ​​a 16-bit subkey.

[0025] As a preferred solution of the secure communication method of the distribution network intelligent control terminal described in the present invention, wherein: the key is encrypted using the improved 16-bit Blowfish encryption algorithm to generate a new key, and also includes:

[0026] pbox[1] in the first original key pbox is XORed with the first 16 bits of the first original key pbox, and pbox[2] is XORed with the last 16 bits of the first original key pbox, and the key bits are traversed in a loop until the entire pbox is XORed with all the bits of the key;

[0027] Encrypt a 32-bit message with all zeros using the Blowfish Encipher function. The function output replaces pbox[i+1] and pbox[i+2], where the initial value of i is 1.

[0028] Encrypt the replaced pbox[i+1] through the Blowfish Encipher function, and use the output of pbox[i+2] to replace pbox[i+3] and pbox[i+4], and repeat the replacement until all pboxes are replaced;

[0029] Use the replaced pbox

[17] and pbox

[18] as the first input, replace the second original key sbox in the same way, and generate new keys pbox' and sbox'.

[0030] As a preferred solution of the secure communication method of the distribution network intelligent control terminal of the present invention, when the master station is used as the sending end and the distribution network intelligent control terminal is used as the receiving end;

[0031] The key data sent by the master station to the distribution network intelligent control terminal include: control pre-start instructions, control handshake results, control start instructions and control query instructions.

[0032] As a preferred solution of the distribution network intelligent control terminal security communication method described in the present invention, when the distribution network intelligent control terminal acts as a sending end and the master station acts as a receiving end, the key data sent by the distribution network intelligent control terminal to the master station includes: control handshake instructions and control query results.

[0033] In a second aspect, the present invention provides a distribution network intelligent control terminal security communication system, comprising:

[0034] The encryption module is used in the process of interaction between the sending end and the receiving end. The sending end encrypts the plaintext of the transmitted data through the homomorphic encryption algorithm to generate a new ciphertext and adds a digital signature to the new ciphertext; the key is encrypted using the improved 16-bit Blowfish encryption algorithm to generate a new key;

[0035] A sending module, used for the sending end to send the new ciphertext, digital signature and new key to the receiving end;

[0036] A first decryption module, used for decrypting the digital signature and performing signature authentication after receiving the digital signature at the receiving end;

[0037] The second decryption module is used to decrypt the new ciphertext and the new key to obtain correct information if the signature authentication passes; if the signature authentication fails, an error message is returned.

[0038] As a preferred solution of the distribution network intelligent control terminal security communication system described in the present invention, the encryption module includes:

[0039] The first encryption module is used to encrypt the plaintext of the transmitted data through a homomorphic encryption algorithm to generate a new ciphertext, and to attach a digital signature to the new ciphertext;

[0040] The second encryption module is used to encrypt the key using the improved 16-bit Blowfish encryption algorithm to generate a new key.

[0041] In a third aspect, the present invention provides a computing device, comprising:

[0042] Memory and processor;

[0043] The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the method for secure communication of distribution network intelligent control terminals are implemented.

[0044] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the method for secure communication of a distribution network intelligent control terminal.

[0045] Compared with the prior art, the present invention has the following beneficial effects: the present invention aims at solving the numerous interactive data problems in the load control process of the distribution network intelligent control terminal, selectively encrypts key interactive processes and sensitive data, improves communication data throughput, shortens communication time, and adopts a hybrid data encryption method to combine homomorphic encryption with the Blowfish encryption algorithm to ensure the confidentiality, privacy, integrity and authenticity of the transmitted data, and prevents data leakage and illegal access or instruction tampering and forgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0047] Figure 1 A schematic diagram of the overall process logic of a method for secure communication of a distribution network intelligent control terminal according to an embodiment of the present invention;

[0048] Figure 2 A schematic diagram of an interactive framework structure when the master station acts as a sending end in a distribution network intelligent control terminal secure communication method according to an embodiment of the present invention;

[0049] Figure 3 A schematic diagram of an interactive framework structure when a distribution network intelligent control terminal acts as a sending end in a distribution network intelligent control terminal secure communication method according to an embodiment of the present invention;

[0050] Figure 4 The present invention is a schematic diagram of the specific flow of all interactive processes in the distribution network intelligent control terminal secure communication method described in an embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0052] Example 1, reference Figure 1-Figure 4 , is an embodiment of the present invention, and provides a distribution network intelligent control terminal secure communication method, comprising:

[0053] S100: During the interaction between the sender and the receiver, the sender encrypts the plaintext of the transmitted data using a homomorphic encryption algorithm to generate a new ciphertext, and adds a digital signature to the new ciphertext; the key is encrypted using an improved 16-bit Blowfish encryption algorithm to generate a new key;

[0054] In the embodiments of the present application, Figure 2 As shown, when the master station acts as the sending end and the distribution network intelligent control terminal acts as the receiving end, the key data sent by the master station to the distribution network intelligent control terminal include: control pre-start instructions, control handshake results, control start instructions and control query instructions.

[0055] In the embodiments of the present application, Figure 3 As shown, when the distribution network intelligent control terminal serves as a sending end and the master station serves as a receiving end, the key data sent by the distribution network intelligent control terminal to the master station includes: control handshake instructions and control query results.

[0056] In the embodiment of the present application, the sending end encrypts the plaintext of the transmitted data through a homomorphic encryption algorithm to generate a new ciphertext, including:

[0057] Obtain the key information data plaintext H to be encrypted and convert it into binary;

[0058] Randomly select two prime numbers p and q and an integer r, and calculate the variable N = pq;

[0059] Group the plaintext H into bits M = {m1,m2,...m n}, each group is denoted as m i , where the subscript i represents the group number and n represents the number of groups;

[0060] It should be noted that the length of each group can be set according to actual needs.

[0061] If the last group digit is less than the set group length, it will be padded with 0;

[0062] Encrypt each plaintext H group to obtain the corresponding ciphertext h i , expressed as:

[0063] h i =(m i +pr)mod N

[0064] According to the grouping order, all ciphertexts are merged to obtain the new ciphertext H′ corresponding to the plaintext H.

[0065] It should be noted that the homomorphic encryption method can be flexibly designed and securely perform calculations. It provides a new dimension for the storage of communication networks and also provides data confidentiality, so that the information will not be exposed in plain text at any stage, ensuring the confidentiality, privacy, integrity and authenticity of the transmitted data, and preventing data leakage and illegal access or instruction tampering and forgery.

[0066] In the embodiment of the present application, the key is encrypted using the improved 16-bit Blowfish encryption algorithm to generate a new key, including:

[0067] Initialize the first original key pbox and the second original key sbox with fixed strings;

[0068] The first original key pbox includes 18 16-bit subkeys, expressed as:

[0069] pbox[1], pbox[2]…pbox

[18] ;

[0070] The second original secret key sbox includes a 4×256 matrix, and each element in the matrix is ​​a 16-bit subkey.

[0071] Specifically, the storage space occupied by the above two key boxes is (18×16+4×256×16) bytes, that is, 2084 bytes.

[0072] In the embodiment of the present application, the key is encrypted using the improved 16-bit Blowfish encryption algorithm to generate a new key, which also includes:

[0073] pbox[1] in the first original key pbox is XORed with the first 16 bits of the first original key pbox, and pbox[2] is XORed with the last 16 bits of the first original key pbox, and the key bits are traversed in a loop until the entire pbox is XORed with all the bits of the key;

[0074] Encrypt a 32-bit message with all zeros using the Blowfish Encipher function. The function output replaces pbox[i+1] and pbox[i+2], where the initial value of i is 1.

[0075] Encrypt the replaced pbox[i+1] through the Blowfish Encipher function, and use the output of pbox[i+2] to replace pbox[i+3] and pbox[i+4], and repeat the replacement until all pboxes are replaced;

[0076] Use the replaced pbox

[17] and pbox

[18] as the first input, replace the second original secret key sbox in the same way, and generate new keys pbox' and sbox'.

[0077] It should be noted that the Blowfish encryption algorithm is used to generate secure keys, and the symmetric key block is used for decryption and encryption. The improved Blowfish encryption algorithm reduces the key to 16 bits and the effective data bits of the information to 32 bits, which can speed up the encoding and decoding speed in the encryption and decryption process; at the same time, the performance of the Blowfish encryption algorithm is inversely proportional to the size of the key. If the size of the key increases, the performance will decrease, and vice versa; it can solve security and privacy issues in the cloud.

[0078] It should also be noted that the combination of homomorphic encryption and the Blowfish encryption algorithm provides a better security technology encryption algorithm architecture in terms of data protection and secure communication in the power system, which securely encrypts and protects sensitive power data so that hackers cannot attack the data.

[0079] S200: The sending end sends the new ciphertext, digital signature and new key to the receiving end;

[0080] S300: After receiving the digital signature, the receiving end decrypts the digital signature and performs signature authentication;

[0081] S400: If the signature authentication passes, the new ciphertext and the new key are decrypted to obtain the correct information; if the signature authentication fails, an error message is returned.

[0082] Specifically, the decryption process of the new key is the same as the above-mentioned secret key encryption process. When decrypting, just use pbox[1], pbox[2]…pbox

[18] in reverse order to get the decrypted key.

[0083] Specifically, decrypt the new ciphertext to obtain the correct information, including:

[0084] Group the new ciphertext H′ by bits to obtain H′={h′1,h′2,...h′ n};

[0085] Among them, the number of groups n is the same as the encryption process;

[0086] Decrypt each new ciphertext group through the decryption function to obtain the corresponding plaintext;

[0087] The decrypted plaintext is merged to obtain the plaintext H corresponding to the new ciphertext H′.

[0088] Specifically, the decryption function can be:

[0089] m i =h i mod p

[0090] In the embodiment of the present application, the interaction process between the sending end and the receiving end includes a regulation pre-start process, a regulation handshake process, a regulation start process, and a regulation query process.

[0091] Based on the above interaction process, the specific Figure 4 As shown,

[0092] The steps of the control pre-start process are:

[0093] The master station sends the control pre-start instruction, which is encrypted with mixed data and then sent to the distribution network intelligent control terminal. The distribution network intelligent control terminal decrypts the received ciphertext.

[0094] If the decryption is successful, the distribution network intelligent control terminal generates a control handshake instruction; if the decryption is unsuccessful, the distribution network intelligent control terminal generates an error message and returns it to the master station, and the master station determines whether to abandon the control;

[0095] If the current control is abandoned, the control will be terminated; if the control is continued, the control pre-start instruction will be resent.

[0096] The steps of the control handshake process are:

[0097] The distribution network intelligent control terminal sends the control handshake command, which is encrypted with mixed data and then sent to the master station. The master station decrypts the received ciphertext.

[0098] If the decryption is successful, the master station generates a control start instruction; if the decryption is unsuccessful, it returns to the master station to determine whether to abandon the control;

[0099] If you give up this control, the control will be terminated; if you continue to control, resend the control pre-start instruction. The control start process steps are:

[0100] The control start command sent by the master station is encrypted with mixed data and then sent to the distribution network intelligent control terminal, which decrypts the received ciphertext;

[0101] If the decryption is successful, the distribution network intelligent control terminal performs control actions according to the control instructions; if the decryption is unsuccessful, the distribution network intelligent control terminal generates an error message and returns it to the master station, and the master station determines whether to abandon the control;

[0102] If the current control is abandoned, the control will be terminated; if the control is continued, the control pre-start instruction will be resent.

[0103] The steps of the control query process are:

[0104] The master station sends a control query command every certain period of time, such as 30 minutes, and then encrypts the command with mixed data and sends it to the distribution network intelligent control terminal. The distribution network intelligent control terminal decrypts the received ciphertext.

[0105] If the decryption is successful, the distribution network intelligent control terminal will send the control result to the main station after encrypting the mixed data; if the decryption is unsuccessful, the distribution network intelligent control terminal will generate an error message and return it to the main station, and the main station will determine whether to abandon the control query;

[0106] If you abandon the current control query, the query will terminate; if you continue the control query, resend the control query instruction.

[0107] The above is a schematic scheme of a distribution network intelligent control terminal secure communication method of this embodiment. It should be noted that the technical scheme of the distribution network intelligent control terminal secure communication system and the technical scheme of the distribution network intelligent control terminal secure communication method described above belong to the same concept. For details not described in detail in the technical scheme of the distribution network intelligent control terminal secure communication system in this embodiment, please refer to the description of the technical scheme of the distribution network intelligent control terminal secure communication method described above.

[0108] The distribution network intelligent control terminal security communication system in this embodiment includes:

[0109] The encryption module is used in the process of interaction between the sender and the receiver. The sender encrypts the plaintext of the transmitted data through the homomorphic encryption algorithm, generates a new ciphertext, and adds a digital signature to the new ciphertext; the key is encrypted using the improved 16-bit Blowfish encryption algorithm to generate a new key;

[0110] The sending module is used for the sending end to send the new ciphertext, digital signature and new key to the receiving end;

[0111] The first decryption module is used to decrypt the digital signature and perform signature authentication after the receiving end receives the digital signature;

[0112] The second decryption module is used to decrypt the new ciphertext and the new key to obtain the correct information if the signature authentication passes; if the signature authentication fails, an error message is returned.

[0113] Among them, the encryption module includes:

[0114] The first encryption module is used to encrypt the plaintext of the transmitted data through a homomorphic encryption algorithm, generate a new ciphertext, and add a digital signature to the new ciphertext;

[0115] The second encryption module is used to encrypt the key using the improved 16-bit Blowfish encryption algorithm to generate a new key.

[0116] This embodiment further provides a computing device, which is applicable to the case of secure communication of a distribution network intelligent control terminal, including:

[0117] Memory and processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the method for realizing secure communication of distribution network intelligent control terminals as proposed in the above embodiment.

[0118] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for realizing secure communication of a distribution network intelligent control terminal as proposed in the above embodiment is implemented.

[0119] The storage medium proposed in this embodiment and the method for realizing secure communication of distribution network intelligent control terminals proposed in the above embodiment belong to the same inventive concept. The technical details not described in detail in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0120] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course can also be implemented by hardware. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ReadOnly, Memory, ROM), random access memory (Random Access Memory, RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform the methods of various embodiments of the present invention.

[0121] Example 2

[0122] Referring to Table 1, based on the previous embodiment, this embodiment provides an application comparison case of a distribution network intelligent control terminal security communication method to illustrate the feasibility and beneficial effects of our solution.

[0123] When the distribution network intelligent control terminal exchanges key information with the controlled object, the information security requirements are high, so encryption algorithms need to be used to encrypt key data. At present, the encryption algorithms mainly include symmetric encryption algorithms and asymmetric encryption algorithms. Among them, the sender and receiver of symmetric encryption data share a key to encrypt and decrypt data. This encryption must prevent the key from being obtained by a third party; the sender and receiver of asymmetric encryption data use different keys for encryption and decryption. This encryption method is easy to be attacked by frequently updating the key when it is actually used, resulting in low security.

[0124] The mainstream symmetric encryption algorithms at present include DES, 3DES, AES and Blowfish encryption, among which Blowfish encryption is the most difficult to crack and there is no precedent for cracking it. The encryption test of 256MB size data is carried out. The operating system version and CPU main frequency of the test platform are kept consistent. The performance comparison of the four mainstream encryption algorithms and the improved Blowfish encryption algorithm is shown in Table 1.

[0125] Table 1: Performance comparison of mainstream encryption algorithms

[0126]

[0127] It can be seen from Table 1 that the encryption and decryption speed of the improved Blowfish encryption algorithm is significantly better than other algorithms, and after multiple rounds of group encryption, the comprehensive performance and security index of the improved Blowfish encryption algorithm can fully guarantee the security of key data information interaction.

[0128] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A distribution network intelligent control terminal secure communication method, characterized in that: include: During the interaction between the sender and the receiver, the sender encrypts the plaintext of the transmitted data using a homomorphic encryption algorithm to generate a new ciphertext and adds a digital signature to the new ciphertext. The key is encrypted using the improved 16-bit Blowfish encryption algorithm to generate a new key; The sending end sends the new ciphertext, digital signature and new key to the receiving end; After receiving the digital signature, the receiving end decrypts the digital signature and performs signature authentication; If the signature authentication is successful, the new ciphertext and the new key are decrypted to obtain the correct information; If the signature authentication fails, an error message is returned; The interaction process between the sending end and the receiving end includes a control pre-start process, a control handshake process, a control start process, and a control query process.

2. The method for secure communication of a distribution network intelligent control terminal according to claim 1, characterized in that: The sending end encrypts the plaintext of the transmitted data through a homomorphic encryption algorithm to generate a new ciphertext, including: Obtain the key information data plaintext H to be encrypted and convert it into binary; Randomly select two prime numbers p and q and an integer r, and calculate the variable N = pq; The plaintext H is grouped bit by bit into M={m1,m2,...m n }, each group is denoted as m i , where the subscript i represents the group number and n represents the number of groups; If the last group digit is less than the set group length, it will be padded with 0; Encrypt each plaintext H group to obtain the corresponding ciphertext h i , expressed as: h i =(m i mod N According to the grouping order, all ciphertexts are merged to obtain the new ciphertext H′ corresponding to the plaintext H.

3. The distribution network intelligent control terminal secure communication method according to claim 2, characterized in that: The method of encrypting the key using the improved 16-bit Blowfish encryption algorithm to generate a new key includes: Initialize the first original key pbox and the second original key sbox with fixed strings; The first original secret key pbox includes 18 16-bit subkeys, expressed as: pbox[1], pbox[2]…pbox[18]; The second original secret key sbox includes a 4×256 matrix, and each element in the matrix is ​​a 16-bit subkey.

4. The method for secure communication of a distribution network intelligent control terminal according to claim 3, characterized in that: The key is encrypted using the improved 16-bit Blowfish encryption algorithm to generate a new key, which also includes: pbox[1] in the first original key pbox is XORed with the first 16 bits of the first original key pbox, and pbox[2] is XORed with the last 16 bits of the first original key pbox, and the key bits are traversed in a loop until the entire pbox is XORed with all the bits of the key; Encrypt a 32-bit message with all zeros using the Blowfish Encipher function. The function output replaces pbox[i+1] and pbox[i+2], where the initial value of i is 1. Encrypt the replaced pbox[i+1] through the Blowfish Encipher function, and use the output of pbox[i+2] to replace pbox[i+3] and pbox[i+4], and repeat the replacement until all pboxes are replaced; Use the replaced pbox[17] and pbox[18] as the first input, replace the second original key sbox in the same way, and generate new keys pbox' and sbox'.

5. The method for secure communication of a distribution network intelligent control terminal according to claim 1 or 4, characterized in that: When the master station is used as the transmitter and the distribution network intelligent control terminal is used as the receiver; The key data sent by the master station to the distribution network intelligent control terminal include: control pre-start instructions, control handshake results, control start instructions and control query instructions.

6. The method for secure communication of a distribution network intelligent control terminal according to claim 1 or 4, characterized in that: When the distribution network intelligent control terminal acts as a transmitter and the master station acts as a receiver, the key data sent by the distribution network intelligent control terminal to the master station include: control handshake instructions and control query results.

7. A system using the secure communication method for distribution network intelligent control terminal according to claim 1, characterized in that: include: The encryption module is used in the process of interaction between the sending end and the receiving end. The sending end encrypts the plaintext of the transmitted data through the homomorphic encryption algorithm to generate a new ciphertext and adds a digital signature to the new ciphertext; the key is encrypted using the improved 16-bit Blowfish encryption algorithm to generate a new key; A sending module, used for the sending end to send the new ciphertext, digital signature and new key to the receiving end; A first decryption module, used for decrypting the digital signature and performing signature authentication after receiving the digital signature at the receiving end; The second decryption module is used to decrypt the new ciphertext and the new key to obtain correct information if the signature authentication passes; if the signature authentication fails, an error message is returned.

8. The distribution network intelligent control terminal security communication system according to claim 7, characterized in that: The encryption module comprises: The first encryption module is used to encrypt the plaintext of the transmitted data through a homomorphic encryption algorithm to generate a new ciphertext, and to attach a digital signature to the new ciphertext; The second encryption module is used to encrypt the key using the improved 16-bit Blowfish encryption algorithm to generate a new key.

9. An electronic device, comprising: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the distribution network intelligent control terminal secure communication method described in any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the method for secure communication of a distribution network intelligent control terminal as described in any one of claims 1 to 6.

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