Transformer area distributed photovoltaic communication system based on improved DTLS protocol

Abstract

The invention provides a transformer area distributed photovoltaic communication system based on an improved DTLS protocol, and relates to the technical field of electric power and communication, and the system comprises a client and a server; the client and the server establish communication connection based on an improved certificateless DTLS handshake protocol; after communication connection between the client and the server is completed, distributed photovoltaic data interaction is carried out between the client and the server; wherein the improved certificateless DTLS handshake protocol is that a mechanism for allowing public key information exchange between a client and a server is expanded on an original DTLS protocol; the private keys of the client side and the server side comprise two parts, one part is generated by a private key generator according to IDs of the client side and the server side, and the other part is randomly generated by the private key generator according to system parameters. According to the scheme, the complexity of the handshake process can be reduced, and the communication transmission efficiency of the distributed photovoltaic data is improved.

Description

Technical Field

[0001] The present invention relates to the field of power and communication technology, and in particular to a distributed photovoltaic communication system in an area based on an improved DTLS protocol. Background Art

[0002] Global energy shortage and environmental pollution are becoming increasingly serious. As a safe and clean energy with huge reserves, solar energy is increasingly being utilized, among which photovoltaic power generation is the most mainstream application. Under the strategic influence of my country, distributed photovoltaic development has great potential.

[0003] Unlike centralized photovoltaics, distributed photovoltaics do not require additional land resources, have low economic costs, and are easy to install. Unlike centralized photovoltaic power stations, which can be operated and maintained by maintenance personnel on site or by monitoring electrical parameters through unified equipment, the operation and maintenance of distributed photovoltaics usually depends on the monitoring of electrical parameters. However, due to the scattered distribution of distributed photovoltaics, higher quality requirements are placed on data transmission. Therefore, ensuring the reliability and stability of distributed photovoltaic data transmission is of great significance for distributed photovoltaic power generation.

[0004] At present, in order to ensure the reliability and stability of distributed photovoltaic data transmission, the DTLS handshake protocol is introduced in the communication. DTLS is a secure transport layer protocol based on UDP, which is an extension and improvement of SSL / TLS and is suitable for scenarios where data packets may be lost or reordered. DTLS adds mechanisms such as cookie values ​​and sequence numbers to the handshake protocol to prevent denial of service attacks while ensuring the integrity and reliability of data packets.

[0005] However, currently distributed photovoltaics still need to load certificates when performing communication authentication based on DTLS, which greatly increases the complexity of the handshake process and requires a lot of time to successfully establish a communication connection, seriously restricting the communication transmission efficiency of distributed photovoltaic data. Summary of the invention

[0006] In view of this, in order to address the above shortcomings, it is necessary to propose a distributed photovoltaic communication system based on the improved DTLS protocol to reduce the complexity of the handshake process and improve the communication transmission efficiency of distributed photovoltaic data.

[0007] In a first aspect, the present invention provides a distributed photovoltaic communication system in an area based on an improved DTLS protocol, the system comprising: a client and a server; The client and server establish a communication connection based on the improved certificate-less DTLS handshake protocol; After the client and server are connected, the distributed photovoltaic data are exchanged between the client and the server; Among them, the improved certificateless DTLS handshake protocol is: a mechanism that allows the exchange of public key information between the client and the server is extended on the original DTLS protocol; the private key of the client and the server consists of two parts, one of which is generated by the private key generator according to the IDs of the two, and the other part is randomly generated by itself according to system parameters.

[0008] Preferably, when the client and the server establish a communication connection based on the improved certificateless DTLS handshake protocol, The client sends a ClientHello message to the server without a cookie value. After receiving the ClientHello message, the server replies to the client with a HelloRetryRequest message carrying the cookie value; The client extracts the cookie value from the HelloRetryRequest message, puts it into a new ClientHello message and sends it to the server, while the extension includes its own public key information; The server verifies the cookie value in the ClientHello message sent by the client, selects an encryption algorithm to generate a random number, and then sends it to the client through the ServerHello message, while carrying its own public key information in the extension; The server sends a ChangeCipherSpec message to inform the client that the cipher specification has changed, prompting the client to use the negotiated security key for secure data transmission. The server uses the negotiated algorithm and key to encrypt the Finished message and sends it to the client. After receiving the ServerHello message, ChangeCipherSpec message and Finished message sent by the server, the client calculates the corresponding session key, decrypts the Finished message and performs data verification; The client encrypts the Finished message using the negotiated algorithm and key and sends it to the server. The server decrypts and verifies the received Finished message, and after the verification is passed, the communication connection between the client and the server is established.

[0009] Preferably, when the server selects an encryption algorithm to generate a random number, it uses any one of the PKC encryption algorithm, the AES128 encryption algorithm, and the SHA512 encryption algorithm.

[0010] Preferably, after the server sends a ChangeCipherSpec message to inform the client that the cipher specification has changed, the method further includes: The server generates a pre-master key through a key exchange algorithm, and generates a master key and a session key by performing pseudo-random operations on the pre-master key and a random number.

[0011] Preferably, the pseudo-random operation is a hash function or a symmetric encryption algorithm.

[0012] Preferably, when the client performs data verification after decrypting the Finished message, if the verification passes, the client notifies the server to use the same negotiated security key for secure data transmission next by sending a ChangeCipherSpec message.

[0013] Preferably, the field introduced by the mechanism for allowing the extension to exchange public key information between the client and the server is: +publickey_share*.

[0014] In a second aspect, the present invention provides a computing device including a memory and a processor, wherein the memory stores executable code, and when the processor executes the executable code, it runs the distributed photovoltaic communication system based on the improved DTLS protocol as described in the first aspect.

[0015] In a third aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed in a computer, the computer is caused to run the distributed photovoltaic communication system in the substation area based on the improved DTLS protocol as described in the first aspect.

[0016] It can be seen from the above technical scheme that the distributed photovoltaic communication system based on the improved DTLS protocol provided by the present invention includes a client and a server. The client and the server can establish a communication connection based on the improved certificateless DTLS handshake protocol, and the improved certificateless DTLS handshake protocol is a mechanism that extends the original DTLS protocol to allow the client and the server to exchange public key information, and a part of the private key of the client and the server is generated by a private key generator according to the IDs of the two, and the other part is randomly generated by itself according to system parameters. After the communication connection between the client and the server is established, the interaction of distributed photovoltaic data between the client and the server can be realized. It can be seen that in this scheme, when the communication connection is established between the client and the server, the function of public key exchange is realized by extension, and there is no need to load certificate authentication during the entire communication construction process, thereby greatly reducing the complexity of the handshake process and the time occupied by the communication connection, thereby improving the communication transmission efficiency of distributed photovoltaic data. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a distributed photovoltaic communication system in an area based on an improved DTLS protocol provided in an embodiment of the present invention.

[0018] Figure 2 A flowchart of a client and a server establishing a communication connection based on an improved certificateless DTLS handshake protocol is provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] At present, both parties of the DTLS handshake protocol still need to load certificates when performing communication authentication, which increases the complexity of the handshake process and the time taken to successfully establish a communication connection. Therefore, in this solution, an improved certificate-free public key cryptography system is introduced in the communication of distributed photovoltaic power generation in the substation area. The improved handshake protocol can effectively avoid the process of certificate exchange and verification, reduce the amount of information that needs to be transmitted and the number of interaction rounds between the two parties in communication, and thus shorten the time to establish a communication connection. Specifically, Figure 1 As shown, the present invention provides a distributed photovoltaic communication system in a substation area based on an improved DTLS protocol, the system comprising: a client and a server; The client and server establish a communication connection based on the improved certificate-less DTLS handshake protocol; After the client and server are connected, the distributed photovoltaic data are exchanged between the client and the server; Among them, the improved certificateless DTLS handshake protocol is: a mechanism that allows the exchange of public key information between the client and the server is extended on the basis of the original DTLS protocol; the private key of the client and the server consists of two parts, one of which is generated by the private key generator according to the IDs of the two, and the other part is randomly generated by itself according to the system parameters.

[0021] In this embodiment, the client can be a collection terminal of each distributed photovoltaic system, which is used to collect photovoltaic data in real time and report it to the server. The server can be the management background of the entire distributed photovoltaic system, which is used to monitor and manage the status and operation of the entire distributed photovoltaic system.

[0022] In this embodiment, the public key exchange function is implemented through extension when establishing a communication connection between the client and the server. For example, when the mechanism that allows the exchange of public key information between the client and the server is extended, a new function or mechanism is added on the basis of the original DTLS protocol through +key_share*. Specifically, this extension allows the exchange of public key information between the client and the server to enhance the security and flexibility of the key exchange during the handshake process. The function of exchanging public key information between the client and the server extended by +key_share* can be named +publickey_share*. This protocol can better support different key generation and management strategies, thereby improving the overall communication security and efficiency. In addition, there is no need to load certificate authentication during the entire communication construction process, which can greatly reduce the complexity of the handshake process and the time occupied by the communication connection, thereby improving the communication transmission efficiency of distributed photovoltaic data.

[0023] Specifically, Figure 2 As shown, when the client and the server establish a communication connection based on the improved certificateless DTLS handshake protocol, it can be achieved through the following process: S1: The client sends a ClientHello message to the server without a cookie value. In this step, the cookie can be personal login information stored on the local terminal. The client sends a ClientHello message without a cookie value to the server to confirm that the server has been enabled.

[0024] S2: After receiving the ClientHello message, the server replies to the client with a HelloRetryRequest message carrying the cookie value; S3: The client extracts the cookie value from the HelloRetryRequest message and puts it into a new ClientHello message and sends it to the server, with its own public key information included in the extension. In this step, the extension +publickey_share* contains the public key information of the user.

[0025] S4: The server verifies the cookie value in the ClientHello message sent by the client, selects an encryption algorithm to generate a random number, and then sends it to the client through the ServerHello message, while carrying its own public key information in the extension; In this step, the server first verifies whether the cookie value in the ClientHello message sent by the client is consistent with the previous cookie value. If it is, you can select a suitable encryption algorithm and compression algorithm to generate a random number, such as PKC encryption algorithm, AES128 encryption algorithm, and SHA512 encryption algorithm, and then send it to the client through the ServerHello message. At the same time, when sending the ServerHello message to the client, the extension +publickey_share* is attached with its own public key information.

[0026] S5: The server sends a ChangeCipherSpec message to inform the client that the cipher specification has changed, prompting the client to use the negotiated security key for secure data transmission. In this step, after the server sends a ChangeCipherSpec message to inform the client that the cipher specification has changed, the server further generates a pre-master key through a key exchange algorithm, and generates a master key and a session key by performing a pseudo-random operation on the pre-master key and a random number. The pseudo-random operation may include a hash function SHA-256, a symmetric encryption algorithm AES, etc.

[0027] S6: The server uses the negotiated algorithm and key to encrypt the Finished message and sends it to the client. In this step, the server encrypts the Finished message using the negotiated algorithm and key and sends it to the client to verify whether the key exchange is successful.

[0028] S7: After receiving the ServerHello message, ChangeCipherSpec message, and Finished message sent by the server, the client calculates the corresponding session key, decrypts the Finished message, and performs data verification; In this step, after the client decrypts the Finished message and performs data verification, if the verification passes, it sends a ChangeCipherSpec message to inform the server to use the same negotiated security key to ensure secure data transmission.

[0029] S8: The client encrypts the Finished message using the negotiated algorithm and key and sends it to the server. S9: The server decrypts and verifies the received Finished message. After the verification is successful, the communication connection between the client and the server is established.

[0030] It can be seen that this scheme can effectively avoid the process of certificate exchange and verification by introducing an improved certificateless public key cryptography system into the DTLS protocol and designing a new handshake protocol, thereby reducing the amount of information that needs to be transmitted and the number of interaction rounds between the communicating parties, thereby shortening the time to establish a communication connection. Moreover, the DTLS protocol is established on the transport layer protocol and below the application layer protocol. After completing the encryption algorithm, key negotiation, and server-side authentication, the communication of the application layer protocol can be established. Therefore, the data sent by the subsequent application layer protocol will be encrypted to ensure the security of the data in the network communication. That is, this scheme not only reduces the complexity of the handshake process and improves the transmission efficiency of distributed photovoltaic data communication, but also ensures the security and stability of photovoltaic data transmission.

[0031] The present invention also provides a computing device, including a memory and a processor, wherein the memory stores executable code, and when the processor executes the executable code, it runs any of the above-mentioned distributed photovoltaic communication systems based on the improved DTLS protocol.

[0032] The present invention also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed in a computer, the computer is enabled to run any of the above-mentioned distributed photovoltaic communication systems in the substation area based on the improved DTLS protocol.

[0033] Since the device embodiment provided by the present invention is based on the same inventive concept as the system embodiment of this specification, the specific content can be found in the description of the system embodiment of this specification, and will not be repeated here.

[0034] The modules or units in the device of the embodiment of the present invention can be combined, divided and deleted according to actual needs. The above disclosure is only the preferred embodiment of the present invention, and of course it cannot be used to limit the scope of the rights of the present invention. Those skilled in the art can understand that all or part of the processes of the above embodiment are implemented, and the equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A distributed photovoltaic communication system based on an improved DTLS protocol, characterized in that: The system includes: a client and a server; The client and server establish a communication connection based on the improved certificate-less DTLS handshake protocol; After the client and server are connected, the distributed photovoltaic data are exchanged between the client and the server; Among them, the improved certificateless DTLS handshake protocol is: a mechanism that allows the exchange of public key information between the client and the server is extended on the original DTLS protocol; the private key of the client and the server consists of two parts, one of which is generated by the private key generator according to the IDs of the two, and the other part is randomly generated by itself according to system parameters.

2. The distributed photovoltaic communication system based on the improved DTLS protocol according to claim 1 is characterized in that: When the client and server establish a communication connection based on the improved certificateless DTLS handshake protocol, The client sends a ClientHello message to the server without a cookie value. After receiving the ClientHello message, the server replies to the client with a HelloRetryRequest message carrying the cookie value; The client extracts the cookie value from the HelloRetryRequest message, puts it into a new ClientHello message and sends it to the server, while the extension includes its own public key information; The server verifies the cookie value in the ClientHello message sent by the client, selects an encryption algorithm to generate a random number, and then sends it to the client through the ServerHello message, while carrying its own public key information in the extension; The server sends a ChangeCipherSpec message to inform the client that the cipher specification has changed, prompting the client to use the negotiated security key for secure data transmission. The server uses the negotiated algorithm and key to encrypt the Finished message and sends it to the client. After receiving the ServerHello message, ChangeCipherSpec message and Finished message sent by the server, the client calculates the corresponding session key, decrypts the Finished message and performs data verification; The client encrypts the Finished message using the negotiated algorithm and key and sends it to the server. The server decrypts and verifies the received Finished message, and after the verification is passed, the communication connection between the client and the server is established.

3. The distributed photovoltaic communication system based on the improved DTLS protocol according to claim 2 is characterized in that: When the server selects an encryption algorithm to generate a random number, it uses any one of the PKC encryption algorithm, the AES128 encryption algorithm, and the SHA512 encryption algorithm.

4. The distributed photovoltaic communication system based on the improved DTLS protocol according to claim 2 is characterized in that: After the server sends a ChangeCipherSpec message to inform the client that the cipher specification has changed, the method further includes: The server generates a pre-master key through a key exchange algorithm, and generates a master key and a session key by performing pseudo-random operations on the pre-master key and a random number.

5. The distributed photovoltaic communication system based on the improved DTLS protocol according to claim 4 is characterized in that: The pseudo-random operation is a hash function or a symmetric encryption algorithm.

6. The distributed photovoltaic communication system based on the improved DTLS protocol according to claim 2 is characterized in that: When the client performs data verification after decrypting the Finished message, if the verification passes, the client sends a ChangeCipherSpec message to inform the server to use the same negotiated security key for secure data transmission next.

7. The distributed photovoltaic communication system based on the improved DTLS protocol according to claim 1, characterized in that: The fields introduced by the mechanism that allows the client and the server to exchange public key information are: +publickey_share*.

8. A computing device, comprising a memory and a processor, wherein the memory stores executable code, and when the processor executes the executable code, the distributed photovoltaic communication system based on the improved DTLS protocol as described in claims 1-7 is run.

9. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, enables the computer to run the distributed photovoltaic communication system based on the improved DTLS protocol as described in claims 1-7.

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