Data transmission method and system for privacy protection of power terminal equipment

Abstract

The invention belongs to a data security transmission method, and provides a data transmission method and system for privacy protection of power terminal equipment, aiming at the technical problems that the existing identity authentication method has limitation in the aspect of protecting the identity privacy of the equipment and has the risk of leaking the identity privacy of the equipment identifier. Two-way identity verification is carried out between the equipment trusted center and the equipment, the equipment initiates an access authentication request based on zero-knowledge proof to the equipment trusted center, session key negotiation and verification are carried out between the equipment trusted center and the equipment, a plaintext message transmitted between the equipment trusted center and the equipment is encrypted based on the negotiated and verified session key, and the encrypted plaintext message is sent to the equipment trusted center. And performing data transmission. And the requirements of equipment privacy protection, authentication and data security transmission for the power terminal can be met.

Description

Technical Field

[0001] The present application relates to a data security transmission method, and specifically to a data transmission method and system for privacy protection of power terminal equipment. Background Art

[0002] With the development of distributed energy and virtual power plants, terminal devices are open and interactive, and the protection boundaries are blurred. The traditional boundary security protection system based on horizontal isolation and vertical encryption has not yet covered some third-party terminals, such as distributed photovoltaic inverters, making it difficult to ensure the secure access of distributed terminals. At the same time, the scale of distributed terminal data collection is expanding, which has prompted the key to the reliable and stable operation of the system to ensure the secure access of widely distributed massive terminal devices, protect the identity information and operation data of sensitive devices from unauthorized access or use for malicious purposes, and ensure the reliability of data sources and the security of transmission.

[0003] In order to ensure the security and integrity of data transmission, identity authentication is required. However, on the one hand, the existing identity authentication methods based on Public Key Infrastructure (PKI), although providing a certain security guarantee for communication, have limitations in protecting the privacy of device identities, and public digital certificates may lead to the leakage of device identity information. On the other hand, although the current identity authentication methods based on identification bring convenience to key management and distribution, directly using the identity information of the device identification as the public key has the risk of leaking the privacy of the device identification. Summary of the invention

[0004] In view of the limitations of existing identity authentication methods in protecting device identity privacy and the technical problem of risk of leaking device identification privacy, this application provides a data transmission method and system for privacy protection of power terminal equipment.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions:

[0006] In the first aspect, the present application proposes a data transmission method for privacy protection of power terminal equipment, including:

[0007] The device trusted center publishes the system public parameters and receives the key generation authorization key generated by the key generation center;

[0008] The device trusted center generates and distributes the key generation authorization credential to the device based on the key generation authorization key and the system public parameters;

[0009] The device sends a request message containing a key generation authorization credential to the key generation center. The key generation center generates a device private identity and a device public key based on the verification result of the key generation authorization credential, and sends them to the device.

[0010] The device combines the device's private identity and the device's public key to initiate an access authentication request based on zero-knowledge proof to the device's trusted center, which then verifies the device's identity.

[0011] The device trusted center negotiates and verifies session keys with the device;

[0012] According to the session key negotiated and verified between the device trusted center and the device, the plaintext message transmitted between the device trusted center and the device is encrypted for data transmission.

[0013] Furthermore, the generation system public parameters include:

[0014] (1-1) The device trusted center selects an elliptic curve and a base point with an order of a large prime number;

[0015] (1-2) Combined with elliptic curve, multiple hash functions are determined;

[0016] (1-3) The base point, elliptic curve, large prime number and multiple hash functions are used as the public parameters of the system.

[0017] Furthermore, the generating and distributing the key generation authorization credential to the device includes:

[0018] (2-1) The device sends the ID i} is sent to the device trust center, which checks {ID i} Is it valid? If not, the registration is terminated; if valid, execute step (2-2);

[0019] (2-2) The device trusted center generates an authorization key based on the key to generate an authorization credential Cred for the device calculation key i =H4(ID DTA ,s DTA , T1), and distribute it to the device; among them, ID DTA represents the trusted center identity of the device, T1 represents the current registration timestamp of the device, H4(·) represents a hash function, s DTA Indicates the key generation authorization key generated by the key generation center;

[0020] The device sends a request message including a key generation authorization credential to a key generation center, and the key generation center generates a device privacy identity and a device public key according to a verification result of the key generation authorization credential, and sends the generated information to the device, including:

[0021] (2-3) The device sends the key generation request message {ID i , ID DTA , Cred i , T1} is sent to the key generation center;

[0022] (2-4) The key generation center verifies the freshness of the device registration timestamp T1 and calculates the key generation authorization credential verification value Cred′ i =H4(ID DTA ,s DTA , T1), then verify Cred′ i =Cred i Is it established? If the verification fails, the key generation center terminates the key generation process for the device. If the verification passes, the key generation center executes step (2-5);

[0023] (2-5) The key generation center randomly selects the device private key s i ∈F p , computing device privacy identity D i =H1(ID i ,s i ) and the device public key P i =s i G;

[0024] (2-6) The key generation center generates the device’s private identity D i and the device public key P i Send to device.

[0025] Furthermore, the device trusted center verifies the device identity, including:

[0026] (3-1) The device generates an access authentication request and sends it to the device trusted center;

[0027] (3-2) The device trusted center verifies the timestamp in the access authentication request. If it is valid, step (3-3) is executed. If it is invalid, the access authentication is terminated.

[0028] (3-3) The device trusted center calculates the random public key, random encryption factor and device privacy identity;

[0029] (3-4) The device trusted center calculates the authentication challenge value based on the random public key, random encryption factor and device privacy identity, and determines whether it is equal to the authentication challenge value in the access authentication request. If they are equal, it randomly selects a session key generation factor and calculates the session public key; if they are not equal, it terminates the access authentication.

[0030] Furthermore, the device trusted center and the device perform session key negotiation and verification, including:

[0031] The device trusted center calculates the session key, calculates the verification information based on the session key, obtains the key negotiation response message based on the verification information, and sends it to the device;

[0032] The device verifies the freshness of the key agreement response message, and calculates the session key of the device and the verification information of the device trusted center identity;

[0033] Determine whether the verification information of the device is equal to the verification information sent by the device trusted center to the device. If they are equal, the session key of the device calculated by the device is correct and the identity of the device trusted center is legal. Otherwise, terminate the key negotiation.

[0034] Furthermore, the encryption of plaintext messages transmitted between the device trusted center and the device for data transmission includes:

[0035] The device generates data source and integrity verification values ​​based on the plaintext power data to be transmitted, and calculates the ciphertext data;

[0036] The device sends the data source and integrity verification value, as well as the ciphertext data, to the device trusted center, which calculates the decrypted plaintext power data and recalculates the data encryption challenge value.

[0037] Determine whether the data encryption challenge value in the data source and integrity verification value and the recalculated data encryption challenge value are equal. If they are equal, the plaintext power data comes from a trusted device and is not damaged during transmission.

[0038] In the second aspect, the present application proposes a data transmission system for privacy protection of power terminal equipment, including a device trusted center and a key generation center, and a data processing method between the device trusted center, the key generation center and the equipment, including:

[0039] The device trusted center publishes the system public parameters and receives the key generation authorization key generated by the key generation center;

[0040] The device trusted center generates and distributes the key generation authorization credential to the device based on the key generation authorization key and the system public parameters;

[0041] The device sends a request message containing a key generation authorization credential to the key generation center. The key generation center generates a device private identity and a device public key based on the verification result of the key generation authorization credential, and sends them to the device.

[0042] The device combines the device's private identity and the device's public key to initiate an access authentication request based on zero-knowledge proof to the device's trusted center, which then verifies the device's identity.

[0043] The device trusted center negotiates and verifies session keys with the device;

[0044] According to the session key negotiated and verified between the device trusted center and the device, the plaintext message transmitted between the device trusted center and the device is encrypted for data transmission.

[0045] Furthermore, the generating and distributing the key generation authorization credential to the device includes:

[0046] (2-1) The device sends the ID i} is sent to the device trust center, which checks {ID i} Is it valid? If not, the registration is terminated; if valid, execute step (2-2);

[0047] (2-2) The device trusted center generates an authorization key based on the key to generate an authorization credential Cred for the device calculation key i =H4(ID DTA ,s DTA , T1), and distribute it to the device; among them, ID DTA represents the trusted center identity of the device, T1 represents the current registration timestamp of the device, H4(·) represents a hash function, s DTA Indicates the key generation authorization key generated by the key generation center;

[0048] The device sends a request message including a key generation authorization credential to a key generation center, and the key generation center generates a device privacy identity and a device public key according to a verification result of the key generation authorization credential, and sends the generated information to the device, including:

[0049] (2-3) The device sends the key generation request message {ID i , ID DTA , Cred i , T1} is sent to the key generation center;

[0050] (2-4) The key generation center verifies the freshness of the device registration timestamp T1 and calculates the key generation authorization credential verification value Cred′ i =H4(ID DTA ,s DTA , T1), then verify Cred′ i =Cred i Is it established? If the verification fails, the key generation center terminates the key generation process for the device. If the verification passes, the key generation center executes step (2-5);

[0051] (2-5) The key generation center randomly selects the device private key s i ∈F p , computing device privacy identity D i =H1(IDi ,s i ) and the device public key P i =s i G;

[0052] (2-6) The key generation center generates the device’s private identity D i and the device public key PPi are sent to the device.

[0053] Furthermore, the device trusted center verifies the device identity, including:

[0054] (3-1) The device generates an access authentication request and sends it to the device trusted center;

[0055] (3-2) The device trusted center verifies the timestamp in the access authentication request. If it is valid, step (3-3) is executed. If it is invalid, the access authentication is terminated.

[0056] (3-3) The device trusted center calculates the random public key, random encryption factor and device privacy identity;

[0057] (3-4) The device trusted center calculates the authentication challenge value based on the random public key, random encryption factor and device privacy identity, and determines whether it is equal to the authentication challenge value in the access authentication request. If they are equal, it randomly selects a session key generation factor and calculates the session public key; if they are not equal, it terminates the access authentication.

[0058] Furthermore, the encryption of plaintext messages transmitted between the device trusted center and the device for data transmission includes:

[0059] The device generates data source and integrity verification values ​​based on the plaintext power data to be transmitted, and calculates the ciphertext data;

[0060] The device sends the data source and integrity verification value, as well as the ciphertext data, to the device trusted center, which calculates the decrypted plaintext power data and recalculates the data encryption challenge value.

[0061] Determine whether the data encryption challenge value in the data source and integrity verification value and the recalculated data encryption challenge value are equal. If they are equal, the plaintext power data comes from a trusted device and is not damaged during transmission.

[0062] Compared with the prior art, this application has the following beneficial effects:

[0063] The present application proposes a data transmission method for privacy protection of power terminal equipment, two-way identity authentication between the device trusted center and the device, the device initiates an access authentication request based on zero-knowledge proof to the device trusted center, the device trusted center and the device negotiate and verify the session key, and encrypts the plaintext message transmitted between the device trusted center and the device based on the negotiated and verified session key to transmit data. First, the present application proposes an improved identification signature method based on zero-knowledge proof, which ensures that the device access authentication process does not expose the identity of the device and effectively protects the privacy of the device. Compared with the PKI identity authentication method, it avoids complex certificate management and is more lightweight. Second, it realizes two-way identity authentication between the device and the device trusted center, which not only ensures that the device can verify the identity of the device trusted center, but also that the device trusted center can verify the identity of the device, further enhancing the security of the system. Third, when performing data transmission, not only can the ciphertext transmission of data be realized, but also the data can be verified based on the encrypted signature to be indeed from the trusted power equipment. The authentication transmission method of the present application can resist replay attacks, modification attacks and man-in-the-middle attacks.

[0064] The present application also proposes a data transmission system for privacy protection of power terminal equipment, which has all the advantages of the above-mentioned data transmission method for privacy protection of power terminal equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0066] Figure 1 A schematic diagram of an application scenario of the data transmission method for privacy protection of power terminal equipment in this application;

[0067] Figure 2 A flowchart of a data transmission method for privacy protection of power terminal equipment in this application;

[0068] Figure 3 A schematic diagram of a principle of a data transmission method for privacy protection of power terminal equipment in this application;

[0069] Figure 4 This is a schematic diagram of the initialization phase process in the embodiment of the present application;

[0070] Figure 5 This is a flow chart of the registration and device privacy identity generation phase in the embodiment of the present application;

[0071] Figure 6 This is a schematic diagram of the access authentication process in the embodiment of the present application;

[0072] Figure 7 This is a schematic diagram of the key negotiation phase process in the embodiment of the present application;

[0073] Figure 8 This is a schematic diagram of the process flow of the data security transmission stage in the embodiment of the present application. DETAILED DESCRIPTION

[0074] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0075] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0076] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0077] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invented product is usually placed when used. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0078] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0079] In the description of the embodiments of the present application, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0080] Power terminal privacy focuses on protecting sensitive information of power terminals or devices from unauthorized access or disclosure in smart grids and power systems. These terminals usually include smart meters, distribution terminals, control units, etc., which are responsible for collecting and transmitting data about power usage, system status and operating efficiency. With the digitization and networking of power systems, it is particularly important to ensure the security of the operating data and status information of these devices and prevent possible malicious attacks and data leaks. The protection measures for power terminal privacy involve technologies such as encrypted transmission, access control, and data anonymization processing, aiming to minimize the exposure of detailed information on terminal equipment without hindering system operation and maintenance, so as to ensure the safety and reliability of the entire power supply system.

[0081] The necessity of power terminal identity privacy protection lies in that it not only ensures the safe operation of the power grid, but also maintains the privacy and data security of users. As the power grid transforms towards intelligence and digitalization, power terminals such as smart meters and distribution automation equipment are becoming more and more important. These power terminals will process and transmit a large amount of sensitive data. Implementing a privacy protection mechanism for power terminals can not only prevent unauthorized access, data leakage or tampering, and protect users' personal information from being abused, but also ensure the stable operation and security of the power grid, and avoid possible economic losses and trust crises.

[0082] With the proposal of the goal of building a new power system and the continuous development of the energy Internet, it is urgent to flexibly, safely and efficiently regulate the massive distributed resources aggregated by virtual power plants in order to establish an effective interactive mechanism. The characteristic of virtual power plants is that they can integrate numerous distributed energy resources (such as wind power, solar power generation and energy storage facilities) from different geographical locations into an optimized energy supply network. Faced with the increasing number of distributed power sources and power-consuming equipment, the scale of data collection continues to expand. At the same time, these devices need to flexibly participate in the day-ahead and intraday transactions of the power market. In this context, the following key challenges are faced:

[0083] (1) Flexible access authentication for terminal devices. Since distributed terminal devices are widely distributed in different geographical locations, the identity authentication scheme must ensure that the identity of remote devices can be securely verified to prevent unauthorized device access.

[0084] (2) The identity information and data generated by each terminal device are extremely sensitive. This information usually includes the specific location, type, production date and other identity information of the device, as well as operational data such as power output, consumption rate and device operating status. If this sensitive information falls into the hands of unauthorized third parties, it may be used for malicious attacks. For example, the identity information of the terminal device smart meter is very important for protecting the privacy of users' electricity usage information.

[0085] (3) Issues of secure transmission of terminal device data and data source verification. The user side of a virtual power plant involves a large amount of distributed terminals with sensitive information. The secure transmission of this data is the key to protecting user privacy and commercial secrets. The stable operation of a virtual power plant depends on the accurate and secure exchange of real-time data. Any security loopholes in the data transmission process may be exploited, resulting in unstable system operation or even failure. In a virtual power plant, the effectiveness of decision-making and optimization algorithms is highly dependent on the authenticity and integrity of the input data. Unverified data sources may lead to incorrect decisions and affect the efficiency and reliability of the entire system. Data source verification can prevent malicious attackers from tampering with or falsifying data and ensure system security.

[0086] The existing identity authentication methods mainly include PKI-based identity authentication methods and identification-based identity authentication methods.

[0087] Among them, the steps of the PKI-based identity authentication method are as follows: first, the device generates a key pair, and then submits a certificate issuance request: the user submits his public key and identity information to the certificate authority to request the issuance of a digital certificate. Then the certificate authority verifies the device information and issues a certificate. The certificate authority verifies the identity of the device. After confirmation, the certificate authority signs the public key and identity information of the device with the private key of the certificate authority to generate a digital certificate. This certificate effectively binds the public key of the device to its identity. Finally, the digital certificate is used for identity authentication. The device provides its digital certificate, and the certificate recipient verifies the validity of the digital certificate through the public key of the certificate authority, thereby confirming the identity of the device and the authenticity of the public key. This method does provide a powerful framework for secure communication, but it does have certain limitations for the protection of device identity privacy. In the PKI system, the identity information of the device is usually included in the digital certificate together with its public key. These digital certificates are publicly accessible, which means that any individual or entity that obtains the certificate can view the identity information contained in the certificate, such as the name of the device or other information that can identify the device. Although this method facilitates identity authentication and public key verification, it may also lead to the leakage of device identity information, especially in application scenarios where the privacy of device identity needs to be protected.

[0088] The steps of the identity authentication method based on identification are as follows: first, the initialization step, the trusted center generates system parameters and master keys. The trusted center selects a security parameter, generates global public parameters and a corresponding master key. The public parameters are shared by all participants, while the master key is managed confidentially by the trusted center. Then there is the private key generation step, generating the user's private key. The device makes a private key generation request to the trusted center and provides its unique identity information (information that will be used as the public key). The trusted center uses the device's identity information and master key to generate the device's private key through a specific algorithm and securely passes the private key to the device. Then there is the signing process, generating a signature. When the device needs to sign a message, it uses the private key and the signature algorithm to sign the message. Since the signature is based on the user's private key (the private key is generated by its identity information and the master key of the trusted center), the signature is closely related to the device's identity information. Finally, there is the verification step, verifying the signature. The device's identity information and public parameters must be used to verify the validity of the signature. If valid, the authentication is passed. This method brings convenience to key management and distribution, but because the identity information of the device identifier is directly used as the public key, there is a risk of leaking the device's identity privacy. This method of directly disclosing the device identification information as a public key requires that the identity information of the power equipment be disclosed when performing identity authentication or signature verification, which may be exposed to unnecessary third parties and is not suitable for application scenarios that require identity privacy protection.

[0089] In summary, in the face of the security protection architecture of the power network, there is an urgent need to introduce a mechanism that can provide two-way identity authentication between massive terminal devices and the upper-level master station, while providing device privacy protection, and ensuring the secure transmission of terminal device data and trusted verification of data sources. This will provide a solid foundation for the safe and efficient operation of the system. Therefore, the present application proposes a data transmission method and system for privacy protection of power terminal devices, which solves the problems of device identity privacy leakage, data source credibility, and terminal device data transmission confidentiality and integrity in existing identity authentication methods from four aspects. The present application can meet the needs of device privacy protection, authentication and secure data transmission for power terminals. In order to facilitate accurate description, the scenario is described as a scenario including a key generation center, a virtual power plant terminal device and a device trusted center.

[0090] It should be noted that the Key Generation Center (KGC) is mainly responsible for key generation and management, as well as secure storage. KGC generates public and private key pairs, and securely distributes private keys to corresponding virtual power plant terminal devices. It also makes public public keys available for use by other entities, and can ensure the secure storage of private keys to prevent unauthorized access. Through the PKI certificate system, KGC can bind private keys to the identity information of virtual power plant terminal devices, generate digital certificates, and securely distribute them to devices. Virtual power plant terminal devices are responsible for collecting power data and transmitting them to the control center through the network to ensure the security of communication with the device trust center and other virtual power plant terminal devices. In related PKI applications, digital certificates issued by PKI are used for identity authentication to ensure that the identities of both parties in communication are authentic and trustworthy. The public key is used to encrypt the transmitted data, and only the device holding the corresponding private key can decrypt it, thereby ensuring the confidentiality of the data. When sending important data or instructions, the private key is used for digital signature, and the recipient verifies the validity of the signature through the public key to ensure the integrity and non-repudiation of the data. As a certification authority (CA), the Device Trust Center (DTC) is responsible for issuing and managing digital certificates for virtual power plant terminal devices, formulating and implementing security policies, and ensuring the overall security of the virtual power plant system.

[0091] refer to Figure 1 , which is a schematic diagram of an application scenario of the data transmission method for privacy protection of power terminal equipment provided by this application. Figure 1 ,The authentication system includes three types of entities, terminal devices, device trusted ,centers and key generation centers.

[0092] like Figure 2 As shown, it is a first flow chart of a data transmission method for privacy protection of power terminal equipment in the present application, which may include:

[0093] S101, the device trusted center publishes system public parameters and receives a key generation authorization key generated by a key generation center.

[0094] It should be noted that public parameters are some security-related parameters that need to be disclosed or provided to external users during the design and implementation of cryptographic modules. The purpose is to ensure the transparency and verifiability of cryptographic modules, enable external users to understand and evaluate the security performance of cryptographic modules, and promote the standardization and interoperability of cryptographic algorithms and protocols.

[0095] S102: The device trusted center generates a key generation authorization credential based on the key generation authorization key and the system public parameters, and distributes the key generation authorization credential to the device.

[0096] In actual applications, the key generation authorization certificate usually contains information about the device identity, authorization scope, validity period, etc., and is digitally signed to ensure its authenticity and integrity.

[0097] S103, the device sends a request message including a key generation authorization certificate to the key generation center. The key generation center generates a device privacy identity and a device public key according to the verification result of the key generation authorization certificate, and sends them to the device.

[0098] The device sends a request message to KGC, which contains the key generation authorization credential. This credential is generated by the device trusted center based on the key generation authorization key and the system public parameters, and is used to authorize KGC to generate a private identity and public key for a specific device. In addition, the private identity is used to identify the device in subsequent communication processes, while protecting the device's true identity from being disclosed. The private key will be retained inside the device and used to decrypt received messages or generate digital signatures, while the public key will be made public and used to encrypt messages sent to the device or verify the device's digital signature.

[0099] S104, the device combines the device's private identity and the device's public key to initiate an access authentication request based on zero-knowledge proof to the device trusted center, and the device trusted center verifies the device's identity.

[0100] It should be noted that zero-knowledge proof allows one party (the prover) to prove to another party (the verifier) ​​that a statement is correct without revealing any information other than the correctness of the statement. The core is to be able to verify the authenticity of a certain information without sharing specific evidence, thereby protecting the privacy of the prover. Zero-knowledge proof can be applied to a variety of scenarios, including identity authentication, data security, and various applications that require a high degree of privacy protection. Relying on complex mathematical constructions and algorithmic design, the verifier can believe that a statement is true, while at the same time being unable to obtain any specific information about the statement. This unique property of zero-knowledge proof, while strengthening privacy protection, also provides new possibilities for building secure and reliable digital systems.

[0101] S105, the device trusted center and the device perform session key negotiation and verification.

[0102] It should be noted that the session key is a randomly generated encryption and decryption key to ensure a secure communication session between a user and another computer or between two computers. Communication security can be ensured through session key negotiation and verification.

[0103] S106, encrypting the plaintext message transmitted between the device trusted center and the device according to the session key negotiated and verified between the device trusted center and the device, and performing data transmission.

[0104] The advantages of the data transmission method for privacy protection of power terminal equipment in this application are comprehensively analyzed from multiple perspectives:

[0105] (1) Technical aspects: In terms of device privacy protection, authentication and data security transmission of power terminals, the security and privacy protection capabilities of the power system have been significantly improved:

[0106] ① Enhanced privacy protection: By using an improved identification signature method for device identity authentication, it is ensured that the identity information of the power terminal device is not leaked during the authentication process, thereby greatly improving the privacy protection of the device. ② Data confidentiality protection: The confidentiality of the data transmitted between the power terminal device and the device trusted center is ensured through encryption and non-interactive zero-knowledge proof, and the trusted verification and integrity of the data source are verified to prevent the data from being decoded, tampered with, and forged by a third party during the transmission process. ③ Data integrity verification: By introducing data source and integrity verification mechanisms, the integrity of the data during the transmission process is ensured, and security threats such as data tampering are effectively prevented. ④ Bidirectional authentication mechanism: Bidirectional authentication between the power terminal device and the device trusted center is realized, the security of the authentication process is enhanced, and the identities of both parties in the communication are verified. ⑤ Perfect forward security: The key negotiation mechanism in this application guarantees perfect forward security, ensuring that even if the key is cracked in the future, the previous communication records cannot be subsequently decrypted, thereby protecting the security of historical communications. ⑥ Untraceability: By generating a unique identity certificate and session key for each communication, the untraceability of the power terminal device is achieved, and the behavioral privacy of the device during use is protected. ⑦ High scalability and flexibility: Supports the addition of new equipment without affecting the security and performance of the existing system, and supports the sustainable development of the power system. ⑧ Strong applicability: The scheme based on identification keys has high key management and distribution, strong ease of use, simple deployment, and fully meets the core security mechanism requirements of terminal authentication, data transmission, etc. of massive heterogeneous terminal devices in virtual power plants.

[0107] (2) Economic benefits: Significant economic benefits have been created in three aspects: cost savings, risk prevention and enhanced competitiveness:

[0108] ① In terms of cost saving, the cost of the secure access method based on the proposed improved identification signature method is significantly lower than that of the traditional power dispatching digital certificate. In large-scale deployment, the economic benefits are significant and the cost can be greatly reduced; ② In terms of risk prevention, by strengthening the data security transmission and equipment authentication process, the economic losses caused by data leakage or malicious attacks on the system are significantly reduced. Secure data transmission and processing enable virtual power plants to collect and analyze data in real time and accurately, so as to more effectively dispatch and manage energy. This optimization can reduce energy waste and improve energy efficiency, thereby directly reducing operating costs and improving economic benefits; ③ In terms of improving competitiveness, in the energy market, especially in businesses involving user data, security and privacy protection are issues that customers are very concerned about. It can improve the performance of virtual power plants in these aspects, increase customer trust, and thus enhance market competitiveness.

[0109] (3) Social benefits: With the proposal of the goal of building a new power system and the continuous development of the energy Internet, power data, as a production factor, is a key resource for promoting the digital transformation of energy and building a new power system. On the basis of ensuring the safe access of distributed terminals such as distributed power sources to the main station, it not only provides privacy protection for distributed terminal devices but also improves the security of power data transmission, supports the flexibility and scalability of distributed terminals such as distributed power sources, ensures the reliability of operations, and contributes technical support to the development of new power systems:

[0110] First, the improvement in ensuring the secure transmission of power data and the privacy protection of terminal devices responds to the current top-level design of data security that is constantly being improved. Secondly, by providing a secure framework to promote the secure access of massive distributed terminal devices such as distributed power sources, it helps to improve the security of new energy plant access to the grid, accelerate the integration and utilization of new energy resources, thereby promoting energy transformation and contributing to the "dual carbon" goals. In addition, this application can reduce virtual power plant operation interruptions and service offlines caused by terminal access and data security issues, ensure stability and reliability, which plays a vital role in maintaining grid security and preventing large-scale power failures. At the same time, this application also helps virtual power plant operators comply with increasingly stringent data protection laws and related standards, establish best practices within the industry, promote compliance and standardization, and enhance the security and trust level of the entire industry.

[0111] The following is another example of the data transmission method for privacy protection of power terminal equipment in the present application. Figure 3 As shown in FIG. 1 , it is a schematic diagram of the principle of this embodiment, and the data transmission method can be decomposed into the following stages:

[0112] S201, initialization phase.

[0113] The device trusted center initializes system parameters and generates system public parameters. The key generation center distributes keys to the device trusted center and generates authorization keys.

[0114] like Figure 4 The figure below is a schematic diagram of the initialization phase. The following methods can be used:

[0115] S1.1, the device trusted center selects the elliptic curve (E / F p ) and a base point G of order large prime number p;

[0116] In practical applications, a series of standard elliptic curves and base points can be defined for selection and use. When selecting, the most appropriate elliptic curve and base point can be selected according to the specific application scenario and security requirements.

[0117] S1.2, the device trusted center determines a series of hash functions: H1: {0, 1}* →{0, 1} l , H2: {0, 1} * →F p ,

[0118] Where l represents the length of the privacy identity, l1 represents the length of the session key, l2 represents the length of the device authentication credential, and F p represents a finite field whose characteristic is a prime number p, and H1 to H4 represent four hash functions.

[0119] S1.3, the key generation center randomly selects a key to generate an authorization key s DTA ∈F q , and sent to the device trusted center. Among them, F q represents a finite field whose characteristic is a prime number p.

[0120] S1.4, the device trusted center publishes the public parameters pp={G, H1, H2, H3, H4} involved in this application.

[0121] 2. Registration and device privacy identity generation phase.

[0122] The virtual power plant terminal device (hereinafter referred to as the device) initiates a registration request to the device trusted center. The device trusted center verifies that the power device is valid and unregistered, and distributes a key generation authorization certificate to it. Then the power device obtains the device privacy identity D from the key generation center based on the key generation authorization certificate. i And the device master public key Pi.

[0123] like Figure 5 The figure shows the process flow of the registration and device privacy identity generation phase. Specifically, the following methods can be used to achieve this:

[0124] S2.1, the device sends the identity {ID i}Send it to the device trusted center, the power equipment trusted center checks {ID i} is valid? If not, the registration phase is terminated; if valid, proceed to step S2.2.

[0125] S2.2, the device trusted center generates an authorization key based on the key, and generates an authorization certificate Cred for the device calculation key i =H4(ID DTA ,s DTA , T1). Among them, ID DTA Indicates the trusted center identity of the device, T1 indicates the current registration timestamp of the device;

[0126] S2.3, the device sends the key generation request message {ID i , ID DTA , Credi , T1} is sent to the key generation center.

[0127] S2.4, after receiving the key generation request message from the power equipment, the key generation center first verifies the freshness of the power equipment registration timestamp T1, and then calculates the key generation authorization credential verification value Cred′ i =H4(ID DTA ,s DTA , T1), and finally verify whether Cred′ i =Cred i If the verification fails, the key generation center terminates the key generation process for the power device. If the verification passes, the key generation center executes step S2.5.

[0128] S2.5, the key generation center randomly selects the device private key s i ∈F p , computing device privacy identity D i =H1(ID i ,s i ) and the device public key P i =s i G. The key generation center generates the device privacy identity D i and the device public key P i Send to device.

[0129] 3. Access authentication phase.

[0130] The device initiates an access authentication request based on zero-knowledge proof to the device trusted center without exposing its identity, and the device trusted center verifies the identity of the power device.

[0131] like Figure 6 The figure shows a schematic diagram of the access authentication process. Specifically, the following methods can be used to implement it:

[0132] S3.1, the device calculates the temporary key factor d i =H2(ID i , T2) and temporary public key factor Y i =d i G, randomly selects a proof random value r i ∈F p And calculate the random public key E i =r i G, random encryption factor F i =r i P i , authentication response value s = r i -cd i , authentication challenge value c = H2(G, Y i , E i, F i , T2, D i ), temporary device identity The device will access the authentication request {c, s, TID i , r i , Y i , T2} is sent to the device trusted center.

[0133] S3.2, the device trusted center receives {c, s, TID i , F i , Y i , T2}, verify the validity of timestamp T2, if it is invalid, the access authentication phase is terminated, if it is valid, execute step S3.3.

[0134] S3.3, the device trusted center calculates the random public key E′ i =sG+cY i and the random encryption factor F i ′=s i E i , computing device privacy identity

[0135] S3.4, the device trusted center calculates the authentication challenge value c′=H2(G, Y i , E′ i , F′ i , T2, D′ i ), and checks whether c′=c. If so, the device trusted center randomly selects a session key generation factor x∈F p And calculate the session public key X=xG.

[0136] This application can ensure the privacy of the power equipment identity during the power equipment access authentication phase. During the registration and device privacy identity generation phase, each power equipment can obtain a device privacy identity D distributed by the key generation center. i , the device privacy identity is based on the device identity ID i and device private keys i Generated by hash function H1. Among them, the device private key s i It is randomly selected by the key generation center, which can ensure that the privacy identity of each power device is unique and unpredictable. In addition, the privacy identity D i In the subsequent communication process, it will represent the real identity of the device, without directly exposing the real identity ID of the device in the open link i .

[0137] In the access authentication phase, the non-interactive zero-knowledge proof in the proposed improved identification signature method can be used to verify the identity of the device without directly exposing its real identity ID.i and its device privacy identity D i Based on non-interactive zero-knowledge proof, the power device can generate a one-time proof each time it accesses the device trusted center. The proof can show that the power device has a valid privacy identity approved by the key generation center, and there is no need to directly show the privacy identity to it. This mechanism is suitable for scenarios where privacy protection of power equipment is required, and this mechanism simplifies the authentication process, does not require complex interactive processes, and improves the authentication efficiency of the power system.

[0138] This application also has the property of being untraceable. During the access authentication phase, the power device proves its identity to the device trusted center based on the non-interactive zero-knowledge proof in the proposed improved identification signature method. This process does not directly expose any identity of the power device. The power terminal generates a temporary and unique proof based on the current session to allow the device trusted center to verify its identity. This method ensures that even if the same device authenticates with the device trusted center multiple times, the identity proofs sent to the device trusted center for each authentication are different and unrelated, thereby ensuring the untraceability of the power device during multiple communication processes.

[0139] 4. Key negotiation phase.

[0140] The device trusted center generates a session key and sends verification information to the device. The device calculates the session key and verifies whether the obtained session key is correct through the verification information.

[0141] like Figure 7 The figure shows a schematic diagram of the key negotiation phase process. Specifically, it may include:

[0142] S4.1, the device trusted center calculates the session key K = H3(xE i , D i , T3) and verification information S = H2 (F i , K), the device trusted center sends the key agreement response message {X, S, T3} to the device, where xE i is the session key intermediate value, and X is the session public key.

[0143] S4.2, the device verifies the freshness of the key negotiation response message and calculates the device's session key K′=H3(xX, D i , T3) and the device's verification information S′=H2(F i , K′), where xX is the intermediate value of the session key; then check whether S=S′ holds. If so, the calculated session key K′ is correct and the identity of the device trusted center is legal, otherwise the key negotiation phase is terminated.

[0144] This application realizes two-way authentication between power terminal equipment and device trusted center by combining access authentication stage and key negotiation stage. In the access authentication stage, the power equipment and device trusted center use the non-interactive zero-knowledge proof calculation based on the proposed improved identification signature method to authenticate the identity. This process does not involve any exchange of forward session keys and the leakage of long-term authentication private keys, thus avoiding the risk of leakage of secret parameters. In addition, the power equipment uses the technology based on non-interactive zero-knowledge proof to prove to the device trusted center that it has a valid device privacy identity D i , without exposing any specific identity information. This process ensures that the device trusted center can verify the legitimacy of the power device, and the identity information of the power device is protected. Subsequently, in the key negotiation phase, the power device and the device trusted center construct a random and dynamically generated session key for the current session to exchange data, and the session key is calculated from temporary information such as temporary key factors and random numbers, ensuring that even if the current session key is leaked, it will not affect the session keys of other sessions. The device trusted center generates a session key and sends the verification information to the power device, and the power device confirms the correctness of the session key by verifying the information verification value. Since only a legitimate device trusted center can correctly generate the corresponding verification information, this process not only confirms the identity of the device trusted center, but also ensures the security of the session key. Through the technical implementation of these two stages, the two-way authentication between the power terminal device and the device trusted center is successfully completed, which not only ensures that the power device proves its identity to the trusted center, but also ensures that the trusted center verifies the legitimacy of the power device, providing double protection for the communication between the two parties. The session key negotiation method designed in this application is a dynamic key mechanism based on the current session context, which can provide randomness and freshness of the session key.

[0145] In summary, the present application can ensure the confidentiality and data source verification of the data transmitted between the power equipment and the equipment trusted center, and prevent the confidential power data from being tampered with or leaked during the transmission process. Among them, in the key negotiation stage, the equipment trusted center and the power equipment jointly generate a session key using parameters such as temporary key factors, temporary public key factors, and random public keys, where the session key is implemented through a secure key exchange protocol and a secure one-way hash function, ensuring that the power data is in an open channel, and the adversary cannot obtain any information about the session key. In addition, the generation of the session key relies on non-interactive zero-knowledge proof technology, and can also solve the parameter source verification problem of the key exchange process. In the data security transmission stage, the power equipment uses the session key jointly negotiated in the key negotiation stage to encrypt the power data to ensure that the power data cannot be stolen in the network. In addition, before the power equipment transmits the data, it will also calculate the data encryption temporary public key, data encryption factor, and data encryption response value. These parameters not only further enhance the data encryption effect, but also further ensure the data source verification, adding new features for confidential data transmission.

[0146] 5. Data security transmission stage.

[0147] The session key K obtained in the key negotiation phase is used to encrypt the plaintext messages transmitted between the device trusted center and the device to ensure the confidentiality and integrity of data transmission.

[0148] like Figure 8 The figure shows a flow chart of the data security transmission stage. Specifically, it may include:

[0149] S5.1, the plaintext data of electricity that the device needs to transmit is M, and the random value dr that proves safe transmission is randomly selected i ∈F p , and calculate the data encryption temporary public key DE i =dr i G, data encryption factor DF i =dr i P i , data encryption response value ds = dr i -dc·d i , data encryption challenge value dc = H2(G, Y i ,DE i , DF i , D i , M, T4), the generated data source and integrity verification value is {DE i , DF i , ds, dc, T4}.

[0150] S5.2, the device calculates the ciphertext data Among them, dr iEncrypt the random value for the data. Finally, the device sends the data source and integrity verification value {DE i , DF i , ds, dc, T4} and ciphertext data C.

[0151] S5_3, the device trusted center receives the data source and integrity verification value {DE i , DF i , ds, dc, T4} and the ciphertext data C, calculate the decrypted plaintext data Then calculate dc′=H2(G, Y i ,DE i , DF i , D i , M′, T4), where dc′ is the recalculated data encryption challenge value, and finally compare whether dc=dc′ holds. If so, the data M comes from a trusted power device and the integrity of the data is not damaged during the transmission process.

[0152] When transmitting data, the power equipment will generate data source and integrity verification values ​​based on the session key and plaintext data before sending encrypted data, and send a proof of data integrity to the recipient based on non-interactive zero-knowledge proof. When the device trusted center receives the encrypted data, data source and integrity verification value, and data integrity proof, it first decrypts the power data based on the same session key, then recalculates the data source and integrity verification value based on the decrypted data and the received parameters, and verifies the integrity proof based on the non-interactive zero-knowledge proof. By comparing the recalculated challenge value, the device trusted center can verify the integrity of the power data during transmission, ensuring that the power data has not been modified, destroyed, or forged without authorization during transmission.

[0153] Based on the above-mentioned data transmission method for privacy protection of power terminal equipment, this application also proposes a data transmission system for privacy protection of power terminal equipment, including a device trusted center and a key generation center. Among them, the data processing method between the device trusted center, the key generation center and the device includes:

[0154] The device trusted center publishes the system public parameters and receives the key generation authorization key generated by the key generation center;

[0155] The device trusted center generates and distributes the key generation authorization credential to the device based on the key generation authorization key and the system public parameters;

[0156] The device sends a request message containing a key generation authorization credential to the key generation center. The key generation center generates a device private identity and a device public key based on the verification result of the key generation authorization credential, and sends them to the device.

[0157] The device combines the device's private identity and the device's public key to initiate an access authentication request based on zero-knowledge proof to the device's trusted center, which then verifies the device's identity.

[0158] The device trusted center negotiates and verifies session keys with the device;

[0159] According to the session key negotiated and verified between the device trusted center and the device, the plaintext message transmitted between the device trusted center and the device is encrypted for data transmission.

[0160] It should be noted that the description of the relevant parts of the data transmission system for privacy protection of power terminal equipment provided in the embodiment of the present application can adopt the detailed description of the corresponding parts in the data transmission method for privacy protection of power terminal equipment provided in the embodiment of the present application, which will not be repeated here. In addition, the parts of the above-mentioned technical solutions provided in the embodiment of the present application that are consistent with the implementation principles of the corresponding technical solutions in the prior art are not described in detail to avoid excessive elaboration.

[0161] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A data transmission method for privacy protection of power terminal equipment, characterized in that: include: The device trusted center publishes the system public parameters and receives the key generation authorization key generated by the key generation center; The device trusted center generates and distributes the key generation authorization credential to the device based on the key generation authorization key and the system public parameters; The device sends a request message containing a key generation authorization credential to the key generation center. The key generation center generates a device private identity and a device public key based on the verification result of the key generation authorization credential, and sends them to the device. The device combines the device's private identity and the device's public key to initiate an access authentication request based on zero-knowledge proof to the device's trusted center, which then verifies the device's identity. The device trusted center negotiates and verifies session keys with the device; According to the session key negotiated and verified between the device trusted center and the device, the plaintext message transmitted between the device trusted center and the device is encrypted for data transmission.

2. According to claim 1, a data transmission method for privacy protection of power terminal equipment is characterized by: The generation system public parameters include: (1-1) The device trusted center selects an elliptic curve and a base point with an order of a large prime number; (1-2) Combined with elliptic curve, multiple hash functions are determined; (1-3) The base point, elliptic curve, large prime number and multiple hash functions are used as the public parameters of the system.

3. According to claim 2, a data transmission method for privacy protection of power terminal equipment is characterized by: The generating and distributing the key generation authorization credential to the device comprises: (2-1) The device sends the ID i } is sent to the device trust center, which checks {ID i } Is it valid? If not, the registration is terminated; if valid, execute step (2-2); (2-2) The device trusted center generates an authorization key based on the key to generate an authorization credential Cred for the device calculation key i =H4(ID DTA ,s DTA , T1), and distribute it to the device; among them, ID DTA represents the trusted center identity of the device, T1 represents the current registration timestamp of the device, H4(·) represents a hash function, s DTA Indicates the key generation authorization key generated by the key generation center; The device sends a request message including a key generation authorization credential to a key generation center, and the key generation center generates a device privacy identity and a device public key according to a verification result of the key generation authorization credential, and sends the generated information to the device, including: (2-3) The device sends the key generation request message {ID i , ID DTA , Cred i , T1} is sent to the key generation center; (2-4) The key generation center verifies the freshness of the device registration timestamp T1 and calculates the key generation authorization credential verification value Cred′ i =H4(ID DTA ,s DTA , T1), then verify Cred′ i =Cred i Is it established? If the verification fails, the key generation center terminates the key generation process for the device. If the verification passes, the key generation center executes step (2-5); (2-5) The key generation center randomly selects the device private key s i ∈F p , computing device privacy identity D i =H1(ID i ,s i ) and the device public key P i =s i G; (2-6) The key generation center generates the device’s private identity D i and the device public key P i Send to device.

4. According to claim 3, a data transmission method for privacy protection of power terminal equipment is characterized in that: The device trusted center verifies the device identity, including: (3-1) The device generates an access authentication request and sends it to the device trusted center; (3-2) The device trusted center verifies the timestamp in the access authentication request. If it is valid, step (3-3) is executed. If it is invalid, the access authentication is terminated. (3-3) The device trusted center calculates the random public key, random encryption factor and device privacy identity; (3-4) The device trusted center calculates the authentication challenge value based on the random public key, random encryption factor and device privacy identity, and determines whether it is equal to the authentication challenge value in the access authentication request. If they are equal, it randomly selects a session key generation factor and calculates the session public key; if they are not equal, it terminates the access authentication.

5. According to claim 4, a data transmission method for privacy protection of power terminal equipment is characterized in that: The device trusted center and the device perform session key negotiation and verification, including: The device trusted center calculates the session key, calculates the verification information based on the session key, obtains the key negotiation response message based on the verification information, and sends it to the device; The device verifies the freshness of the key agreement response message, and calculates the session key of the device and the verification information of the device trusted center identity; Determine whether the verification information of the device is equal to the verification information sent by the device trusted center to the device. If they are equal, the session key of the device calculated by the device is correct and the identity of the device trusted center is legal. Otherwise, terminate the key negotiation.

6. A data transmission method for privacy protection of power terminal equipment according to claim 5, characterized in that: The encryption of plaintext messages transmitted between the device trusted center and the device for data transmission includes: The device generates data source and integrity verification values ​​based on the plaintext power data to be transmitted, and calculates the ciphertext data; The device sends the data source and integrity verification value, as well as the ciphertext data, to the device trusted center, which calculates the decrypted plaintext power data and recalculates the data encryption challenge value. Determine whether the data encryption challenge value in the data source and integrity verification value and the recalculated data encryption challenge value are equal. If they are equal, the plaintext power data comes from a trusted device and is not damaged during transmission.

7. A data transmission system for privacy protection of power terminal equipment, comprising a device trusted center and a key generation center, characterized in that ； The data processing method between the device trusted center, the key generation center and the device includes: The device trusted center publishes the system public parameters and receives the key generation authorization key generated by the key generation center; The device trusted center generates and distributes the key generation authorization credential to the device based on the key generation authorization key and the system public parameters; The device sends a request message containing a key generation authorization credential to the key generation center. The key generation center generates a device private identity and a device public key based on the verification result of the key generation authorization credential, and sends them to the device. The device combines the device's private identity and the device's public key to initiate an access authentication request based on zero-knowledge proof to the device's trusted center, which then verifies the device's identity. The device trusted center negotiates and verifies session keys with the device; According to the session key negotiated and verified between the device trusted center and the device, the plaintext message transmitted between the device trusted center and the device is encrypted for data transmission.

8. A data transmission system for privacy protection of power terminal equipment according to claim 7, characterized in that: The generating and distributing the key generation authorization credential to the device comprises: (2-1) The device sends the ID i } is sent to the device trust center, which checks {ID i } Is it valid? If not, the registration is terminated; if valid, execute step (2-2); (2-2) The device trusted center generates an authorization key based on the key to generate an authorization credential Cred for the device calculation key i =H4(ID DTA ,s DTA , T1), and distribute it to the device; among them, ID DTA represents the trusted center identity of the device, T1 represents the current registration timestamp of the device, H4(·) represents a hash function, s DTA Indicates the key generation authorization key generated by the key generation center; The device sends a request message including a key generation authorization credential to a key generation center, and the key generation center generates a device privacy identity and a device public key according to a verification result of the key generation authorization credential, and sends the generated information to the device, including: (2-3) The device sends the key generation request message {ID i , ID DTA , Cred i , T1} is sent to the key generation center; (2-4) The key generation center verifies the freshness of the device registration timestamp T1 and calculates the key generation authorization credential verification value Cred′ i =H4(ID DTA ,s DTA , T1), then verify Cred′ i =Cred i Is it established? If the verification fails, the key generation center terminates the key generation process for the device. If the verification passes, the key generation center executes step (2-5); (2-5) The key generation center randomly selects the device private key s i ∈F p , computing device privacy identity D i =H1(ID i ,s i ) and the device public key P i =s i G; (2-6) The key generation center generates the device’s private identity D i and the device public key P i Send to device.

9. A data transmission system for privacy protection of power terminal equipment according to claim 8, characterized in that: The device trusted center verifies the device identity, including: (3-1) The device generates an access authentication request and sends it to the device trusted center; (3-2) The device trusted center verifies the timestamp in the access authentication request. If it is valid, step (3-3) is executed. If it is invalid, the access authentication is terminated. (3-3) The device trusted center calculates the random public key, random encryption factor and device privacy identity; (3-4) The device trusted center calculates the authentication challenge value based on the random public key, random encryption factor and device privacy identity, and determines whether it is equal to the authentication challenge value in the access authentication request. If they are equal, it randomly selects a session key generation factor and calculates the session public key; if they are not equal, it terminates the access authentication.

10. A data transmission system for privacy protection of power terminal equipment according to claim 9, characterized in that: The encryption of plaintext messages transmitted between the device trusted center and the device for data transmission includes: The device generates data source and integrity verification values ​​based on the plaintext power data to be transmitted, and calculates the ciphertext data; The device sends the data source and integrity verification value, as well as the ciphertext data, to the device trusted center, which calculates the decrypted plaintext power data and recalculates the data encryption challenge value. Determine whether the data encryption challenge value in the data source and integrity verification value and the recalculated data encryption challenge value are equal. If they are equal, the plaintext power data comes from a trusted device and is not damaged during transmission.

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