Pmu communication access control system

Abstract

The application relates to a PMU communication access control system, which comprises a PMU terminal, a cloud server, a security evaluation device and a PDC terminal. The PMU terminal is used for sending encrypted data, a first encryption key and a second encryption key to the cloud server. The security evaluation device is used for performing first verification on PDC information of the PDC terminal, re-encrypting a PDC public key of the PDC terminal to obtain a third encryption key, and sending the third encryption key to the cloud server in the case that the first verification is passed. The cloud server is used for re-encrypting the first encryption key, the second encryption key and the third encryption key to obtain a fourth encryption key in the case that the third encryption key is received, and sending the fourth encryption key and the encrypted data to the PDC terminal. The PDC terminal is used for decrypting the fourth encryption key to obtain a decryption key, decrypting the encrypted data by using the decryption key to obtain decrypted data corresponding to the encrypted data. The system can guarantee PMU communication security.

Description

Technical Field

[0001] This application relates to the field of information security technology, and in particular to a PMU communication access control system. Background Technology

[0002] State estimation, monitoring, control, and protection of smart grids can be accomplished through wide-area monitoring and control systems based on PMUs (Phasor Measurement Units). By periodically recording dynamic parameters of the power system, such as voltage and current phasors, frequency, and RoCoF (Rate of Change of Frequency), voltage instability in the smart grid can be monitored. The PMU can also act as an electrical parameter collector, sending the collected electrical parameters along with GPS synchronization timestamps to the PDC (Phasor Data Concentrator) for subsequent processing and analysis.

[0003] During data transmission from the Power Management Unit (PMU) to the Power Distribution Center (PDC), information leakage can easily lead to power system instability and untimely data monitoring, as well as power system threats caused by information tampering. Furthermore, there is a possibility of individuals impersonating the PDC to receive data, resulting in security vulnerabilities in PMU communication and compromising the normal operation of the power system. Traditional technologies employ firewalls, antivirus software, and intrusion detection systems for protection. However, due to the persistent, combined, cross-domain, and targeted nature of unknown threats faced by power industry control systems, traditional protection measures are insufficient to effectively prevent internal attacks and emerging threats, and are also inadequate to counter attacks exploiting logical flaws.

[0004] Therefore, there is currently a problem that makes it difficult to guarantee the security of data transmission between PMU and PDC. Summary of the Invention

[0005] Therefore, it is necessary to provide a PMU communication access control system, method, computer device, and computer-readable storage medium that can ensure data transmission security in response to the above-mentioned technical problems.

[0006] In a first aspect, this application provides a PMU communication access control system. The system includes a PMU terminal, a cloud server, a security assessment device, and a PDC terminal;

[0007] The PMU terminal is used to send encrypted data, a first encryption key, and a second encryption key to the cloud server.

[0008] The security assessment device is used to perform a first verification on the PDC information of the PDC terminal. If the first verification is successful, the PDC public key of the PDC terminal is re-encrypted to obtain a third encryption key, and the third encryption key is sent to the cloud server.

[0009] The cloud server is configured to, upon receiving the third encryption key, re-encrypt the first encryption key, the second encryption key, and the third encryption key to obtain a fourth encryption key, and then send the fourth encryption key and the received encrypted data to the PDC terminal.

[0010] The PDC terminal is used to decrypt the received fourth encryption key to obtain a decryption key, and use the decryption key to decrypt the received encrypted data to obtain the decrypted data corresponding to the encrypted data.

[0011] In one embodiment, the PDC terminal is further configured to send the PDC certificate, PDC public key, and PDC information to the cloud server.

[0012] In one embodiment, the cloud server is further configured to send the received PDC certificate to a certificate verification device for a second verification, and if the second verification is successful, send the received PDC information to the security assessment device for the first verification.

[0013] In one embodiment, the security assessment device is further configured to extract terminal information of the PDC terminal from the PDC information, and determine that the PDC terminal passes the first verification if the terminal information matches preset reference information.

[0014] In one embodiment, the PMU terminal is further configured to generate an original key and segment the original key to obtain a first segment key and a second segment key.

[0015] In one embodiment, the security assessment device is further configured to receive the first segment key and the second segment key sent by the PMU terminal, encrypt the first segment key and the second segment key respectively to obtain the first encryption key and the second encryption key, and return the first encryption key and the second encryption key to the PMU terminal.

[0016] In one embodiment, the PMU terminal is further configured to encrypt the data to be sent using the original key to obtain the encrypted data.

[0017] In one embodiment, the PDC terminal is further configured to decrypt the fourth encryption key using the PDC private key to obtain the first segment key and the second segment key, combine the first segment key and the second segment key to obtain the original key, and use the original key to decrypt the encrypted data to obtain the decrypted data.

[0018] In one embodiment, there is at least one PMU terminal, and each PMU terminal is connected to the cloud server.

[0019] In one embodiment, there is at least one PDC terminal, and each PDC terminal corresponds to the same timestamp.

[0020] Secondly, this application provides a PMU communication access control method. The method includes:

[0021] Receive encrypted data, a first encryption key, and a second encryption key sent by the PMU terminal;

[0022] Upon receiving the third encryption key sent by the security assessment device, the first encryption key, the second encryption key, and the third encryption key are re-encrypted to obtain a fourth encryption key; the third encryption key is obtained by re-encrypting the PDC public key when the security assessment device passes the first verification of the PDC information.

[0023] The fourth encryption key and the received encrypted data are sent to the PDC terminal so that the PDC terminal can decrypt the fourth encryption key to obtain a decryption key, and use the decryption key to decrypt the encrypted data to obtain decrypted data.

[0024] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to perform the following steps:

[0025] Receive encrypted data, a first encryption key, and a second encryption key sent by the PMU terminal;

[0026] Upon receiving the third encryption key sent by the security assessment device, the first encryption key, the second encryption key, and the third encryption key are re-encrypted to obtain a fourth encryption key; the third encryption key is obtained by re-encrypting the PDC public key when the security assessment device passes the first verification of the PDC information.

[0027] The fourth encryption key and the received encrypted data are sent to the PDC terminal so that the PDC terminal can decrypt the fourth encryption key to obtain a decryption key, and use the decryption key to decrypt the encrypted data to obtain decrypted data.

[0028] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, performs the following steps:

[0029] Receive encrypted data, a first encryption key, and a second encryption key sent by the PMU terminal;

[0030] Upon receiving the third encryption key sent by the security assessment device, the first encryption key, the second encryption key, and the third encryption key are re-encrypted to obtain a fourth encryption key; the third encryption key is obtained by re-encrypting the PDC public key when the security assessment device passes the first verification of the PDC information.

[0031] The fourth encryption key and the received encrypted data are sent to the PDC terminal so that the PDC terminal can decrypt the fourth encryption key to obtain a decryption key, and use the decryption key to decrypt the encrypted data to obtain decrypted data.

[0032] The aforementioned PMU communication access control system, method, computer equipment, and storage medium allow the PMU terminal to send encrypted data, a first encryption key, and a second encryption key to a cloud server. A security assessment device performs a first verification of the PDC information of the PDC terminal. If the first verification passes, the PDC terminal's PDC public key is re-encrypted to obtain a third encryption key, which is then sent to the cloud server. Upon receiving the third encryption key, the cloud server re-encrypts the first, second, and third encryption keys to obtain a fourth encryption key, which, along with the received encrypted data, is sent to the PDC terminal. The PDC terminal decrypts the received fourth encryption key to obtain a decryption key, which is then used to decrypt the received encrypted data to obtain the decrypted data corresponding to the encrypted data. The encrypted data sent by the PMU terminal can be stored on the cloud server. If the security assessment device verifies the PDC terminal, the cloud server is allowed to transmit the encrypted data sent by the PMU terminal to the PDC terminal, thus achieving access control over the PDC terminal and ensuring secure data transmission between the PMU terminal and the PDC terminal. Attached Figure Description

[0033] Figure 1 This is a block diagram of the PMU communication access control system in one embodiment;

[0034] Figure 2 This is a schematic diagram of the framework of a PMU communication access control system based on cloud storage and trusted computing in one embodiment.

[0035] Figure 3 This is a schematic diagram of the PDC identity access control process in one embodiment;

[0036] Figure 4 This is a schematic diagram of a trusted computing-based measurement mechanism for a security assessment center in one embodiment;

[0037] Figure 5 This is a flowchart illustrating a PMU communication access control method based on cloud storage and trusted computing in one embodiment.

[0038] Figure 6 This is a flowchart illustrating a PMU communication access control method in one embodiment;

[0039] Figure 7 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0041] In one embodiment, such as Figure 1 As shown, a PMU communication access control system is provided, including a PMU terminal 110, a cloud server 120, a security assessment device 130, and a PDC terminal 140.

[0042] PMU terminal 110 is used to send encrypted data, a first encryption key and a second encryption key to cloud server 120;

[0043] The security assessment device 130 is used to perform a first verification on the PDC information of the PDC terminal 140. If the first verification is successful, the PDC public key of the PDC terminal 140 is re-encrypted to obtain a third encryption key, and the third encryption key is sent to the cloud server 120.

[0044] The cloud server 120 is used to re-encrypt the first encryption key, the second encryption key and the third encryption key when it receives the third encryption key to obtain the fourth encryption key, and send the fourth encryption key and the received encrypted data to the PDC terminal 140.

[0045] PDC terminal 140 is used to decrypt the received fourth encryption key to obtain the decryption key, and use the decryption key to decrypt the received encrypted data to obtain the decrypted data corresponding to the encrypted data.

[0046] The PMU terminal can be a terminal equipped with a phasor measurement unit. The PDC terminal can be a terminal equipped with a phasor data concentrator. The terminal can be, but is not limited to, various personal computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. IoT devices can include smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, etc. Portable wearable devices can include smartwatches, smart bracelets, head-mounted devices, etc.

[0047] The cloud service can be a cloud server of a CSP (Cloud Service Provider), which can be implemented using a standalone server or a server cluster composed of multiple servers.

[0048] Among them, safety assessment equipment can be equipment used by safety assessment centers (SAs) to conduct safety assessments.

[0049] In specific implementation, the PMU terminal can generate a key K, split the key K into a first segment key K0 and a second segment key K1, and send the first segment key K0 and the second segment key K1 to the security assessment device. After receiving the first segment key K0 and the second segment key K1, the security assessment device can encrypt the first segment key K0 into a first encryption key K. S0 Encrypt the second segment key K1 into the second encryption key K. S1 , the first encryption key K S0 Second encryption key K S1 The data is returned to the PMU terminal; the PMU terminal can also use the unsplit key K to encrypt the data to be sent, obtaining encrypted data E_M, and then combine the encrypted data E_M with the first encryption key K. S0 Second encryption key K S1The PDC terminal can send its PDC certificate (PDC_crt), public key (PDC_pub), and PDC information to the cloud server. The cloud server can then send the received PDC certificate to a CA (Certification Authority) for secondary verification. If verification fails, PMU communication is terminated, and the cloud server can send the PDC information corresponding to the current PDC certificate to the security assessment device for recording. Otherwise, if verification succeeds, the cloud server can send the PDC information to the security assessment device for further verification. If verification succeeds, the PDC device is allowed to access data. The security assessment device can obtain the PDC public key from the cloud server, re-encrypt the PDC public key to obtain the third encryption key Kr_SA→PDC, and return the third encryption key Kr_SA→PDC to the cloud server. Upon receiving the third encryption key Kr_SA→PDC, the cloud server can process the first encryption key Kr_SA→PDC. S0 Second encryption key K S1 The third encryption key Kr_SA→PDC is re-encrypted to obtain the fourth encryption key {E(K PDC ,K0),E(K PDC ,K1)}, where K PDC This represents the PDC key; the cloud server can use the fourth encryption key {E(K)}. PDC ,K0),E(K PDC The PDC terminal receives the fourth encryption key {E(K1)} and encrypted data E_M. PDC ,K0),E(K PDC After encrypting the data E_M and K1), the fourth encryption key {E(K)} can be decrypted using the PDC private key PDC_key. PDC ,K0),E(K PDC ,K1)}, obtain the decryption key, which may include the first segment key K0 and the second segment key K1 of the PMU device, combine the first segment key K0 and the second segment key K1 into key K, and use key K to decrypt the encrypted data E_M to obtain the decrypted data.

[0050] The aforementioned PMU communication access control system involves the PMU terminal sending encrypted data, a first encryption key, and a second encryption key to the cloud server. A security assessment device performs a first verification of the PDC information of the PDC terminal. If the first verification passes, the PDC terminal's PDC public key is re-encrypted to obtain a third encryption key, which is then sent to the cloud server. Upon receiving the third encryption key, the cloud server re-encrypts the first, second, and third encryption keys to obtain a fourth encryption key, which, along with the received encrypted data, is sent to the PDC terminal. The PDC terminal decrypts the received fourth encryption key to obtain a decryption key, which is then used to decrypt the received encrypted data, yielding the decrypted data. The encrypted data sent by the PMU terminal can be stored on the cloud server. If the security assessment device verifies the PDC terminal's identity, the cloud server is allowed to transmit the encrypted data sent by the PMU terminal to the PDC terminal, thus achieving access control over the PDC terminal and ensuring secure data transmission between the PMU and PDC terminals.

[0051] In one embodiment, the aforementioned PDC terminal is further configured to send the PDC certificate, PDC public key, and PDC information to the cloud server.

[0052] The PDC certificate can be a CA certificate stored on the PDC terminal.

[0053] The PDC public key can be the public key stored on the PDC terminal.

[0054] The PDC information may include information about the PDC terminal, such as at least one of the following: the PDC terminal's address, device number, device name, access path, encoding, digest value, and signature.

[0055] In practice, the PDC terminal can store the PDC certificate, PDC public key, and PDC information. The PDC terminal can send the stored PDC certificate, PDC public key, and PDC information to the cloud server. The PDC terminal can also send data access schemes to the cloud server.

[0056] In this embodiment, the PDC terminal sends the PDC certificate, PDC public key, and PDC information to the cloud server. This enables the cloud server to effectively verify the identity of the PDC terminal based on the PDC certificate, PDC public key, and PDC information, and to perform access control on the PDC terminal based on the authentication result, thereby preventing unauthorized PDCs from receiving power data and ensuring the security of the power system.

[0057] In one embodiment, the cloud server is further configured to send the received PDC certificate to a certificate verification device for second verification, and if the second verification is successful, send the received PDC information to a security assessment device for first verification.

[0058] Among them, certificate verification equipment can be the equipment used by a CA (Certificate Authority) to verify certificates.

[0059] In practice, after receiving the PDC certificate, PDC public key, and PDC information from the PDC terminal, the cloud server can send the PDC certificate to the certificate verification device for verification. If the verification fails, the PMU communication is terminated, and the cloud server sends the PDC terminal's PDC information to the SA for recording. For example, the cloud server can send the PDC terminal's IP address and other identity information to the SA for recording. Otherwise, if the verification passes, the cloud server sends the PDC terminal's PDC information to the SA. The SA can then verify the PDC terminal again based on the received PDC information. If the verification fails, the PDC terminal is deemed illegitimate, access is denied, and PMU communication is terminated. Otherwise, if the verification passes, the PDC terminal is deemed legitimate, data access is allowed, and the encrypted data from the PMU terminal can be sent to the PDC terminal.

[0060] In practical applications, the SA (Security Controller) can use trusted computing to measure the trustworthiness of PDC (Personal Data Center) terminals. When the SA receives a verification request from the CSP (Content Provider Service), it executes the interface of the trusted computing module. First, it extracts the information of the information access user and queries a whitelist database. This whitelist database stores information such as the address, device number (device name), access path, encoding, digest value, and signature of allowed devices. The whitelist database is used to control the scheduling of devices such as PDCs, verifying their identity and legitimacy. Unknown devices are prohibited from accessing data. If it is scheduler code, the integrity and legitimacy of the program can be verified during code loading or startup, rejecting the execution of unknown code, thus achieving proactive defense through static libraries. If the SA determines that the PDC's identity is legitimate, it allows data access.

[0061] In this embodiment, the cloud server sends the received PDC certificate to the certificate verification device for a second verification. If the second verification is successful, the received PDC information is sent to the security assessment device for a first verification. The certificate verification device and the security assessment device can be used to perform two verifications on the access to the PDC terminal, which can effectively prevent PDC intrusion and fake PDC terminals from impersonating PDC to receive power data, thus ensuring the security of the power system.

[0062] In one embodiment, the aforementioned security assessment device is further configured to extract terminal information of the PDC terminal from the PDC information, and determine that the PDC terminal has passed the first verification if the terminal information matches the preset reference information.

[0063] The terminal information can be the device information of the PDC terminal, which may include at least one of the following: device address, device number, device name, access path, encoding, digest value, and signature.

[0064] The preset reference information can be a list of allowed access devices pre-stored in the security assessment device, which contains information about all allowed access devices.

[0065] In practice, the cloud server can send a verification request to the security assessment device. When the security assessment device receives the verification request, it can receive the PDC information sent by the cloud server and extract the terminal information of the PDC terminal from the received PDC information. The security assessment device can pre-store a list of allowed access devices. If the terminal information of the PDC terminal can be found in the list of allowed access devices, the PDC terminal is determined to have passed the first verification. Otherwise, if the terminal information of the PDC terminal cannot be found in the list of allowed access devices, the PDC terminal is determined to have failed the first verification.

[0066] In this embodiment, the security assessment device extracts the terminal information of the PDC terminal from the PDC information. If the terminal information matches the preset reference information, it determines that the PDC terminal has passed the first verification. The security assessment device can then verify the access of the PDC terminal again, effectively preventing PDC intrusion and fake PDC terminals from impersonating PDC to receive power data, thus ensuring the safety of the power system.

[0067] In one embodiment, the PMU terminal is further configured to generate an original key and segment the original key to obtain a first segment key and a second segment key.

[0068] The original key can be a key generated by the PMU terminal.

[0069] In a specific implementation, the PMU terminal can generate an original key K, and then divide the original key K into a first segment key K0 and a second segment key K1.

[0070] For example, the PMU terminal can use the SM2 algorithm (a public-key cryptography algorithm) to generate an asymmetric key, use the asymmetric key as the original key K, and divide the original key K into segment keys K0 and K1.

[0071] In this embodiment, the PMU terminal generates an original key and splits it into a first segment key and a second segment key. By splitting the original key, the security of the key is increased, thereby ensuring the security of PMU communication.

[0072] In one embodiment, the security assessment device is further configured to receive a first segment key and a second segment key sent by the PMU terminal, encrypt the first segment key and the second segment key respectively to obtain a first encryption key and a second encryption key, and return the first encryption key and the second encryption key to the PMU terminal.

[0073] In practice, the PMU terminal can send the first segment key K0 and the second segment key K1 to the security assessment device. After receiving the first segment key K0 and the second segment key K1, the security assessment device can use its own key to encrypt the first segment key K0 to obtain the first encryption key K. S0 You can also use your own key to encrypt the second segment key K1 to obtain the second encryption key K. S1 and the first encryption key K S0 Second encryption key K S1 Return to the PMU terminal.

[0074] In this embodiment, the security assessment device receives the first segment key and the second segment key sent by the PMU terminal, encrypts the first segment key and the second segment key respectively to obtain the first encryption key and the second encryption key, and returns the first encryption key and the second encryption key to the PMU terminal. This can encrypt the first segment key and the second segment key, increase the security of the segment key, and thus ensure the security of PMU communication.

[0075] In one embodiment, the aforementioned PMU terminal is further configured to encrypt the data to be sent using the original key to obtain encrypted data.

[0076] The data to be sent can be the data that is expected to be transmitted from the PMU terminal to the PDC terminal.

[0077] In the specific implementation, after generating the original key K, the PMU terminal can use the original key K to encrypt the data to be sent, and obtain the encrypted data E_M.

[0078] In this embodiment, the PMU terminal uses the original key to encrypt the data to be sent, thus obtaining encrypted data, which can ensure the secure transmission of the data to be sent.

[0079] In one embodiment, the PDC terminal is further configured to use the PDC private key to decrypt the fourth encryption key to obtain the first segment key and the second segment key, combine the first segment key and the second segment key to obtain the original key, and use the original key to decrypt the encrypted data to obtain the decrypted data.

[0080] The PDC private key can be the private key stored on the PDC terminal.

[0081] In specific implementation, the PDC terminal receives the fourth encryption key {E(K PDC ,K0),E(K PDC After encrypting the data E_M and K1), the PDC private key can be used to encrypt the fourth encryption key {E(K)}. PDC ,K0),E(K PDC The PDC terminal can decrypt the encrypted data E_M by combining the first segment key K0 and the second segment key K1. The PDC terminal can then use the original key K to decrypt the encrypted data E_M, thus obtaining the decrypted data.

[0082] In this embodiment, the PDC terminal uses the PDC private key to decrypt the fourth encryption key to obtain the first segment key and the second segment key. The first segment key and the second segment key are combined to obtain the original key. The original key is used to decrypt the encrypted data to obtain the decrypted data. The encrypted data can be decrypted at the PDC terminal to obtain the data that is expected to be transmitted from the PMU terminal to the PDC terminal, thus ensuring the secure transmission of power system data.

[0083] In one embodiment, there is at least one PMU terminal, and each PMU terminal is connected to the cloud server.

[0084] In practice, there can be one PMU terminal connected to the cloud server, or there can be multiple PMU terminals connected to one cloud server, sharing the same cloud server.

[0085] In this embodiment, there is at least one PMU terminal, and each PMU terminal is connected to a cloud server. A cloud server can provide data transmission services for multiple PMU terminals, thereby improving the efficiency of the PMU communication system.

[0086] In one embodiment, there is at least one PDC terminal, and each PDC terminal corresponds to the same timestamp.

[0087] In practice, there can be one PDC terminal connected to a cloud server, or there can be multiple PDC terminals connected to one cloud server, which can simultaneously request data access from that cloud server.

[0088] In this embodiment, there is at least one PDC terminal, and each PDC terminal corresponds to the same timestamp. This can avoid the situation where one PDC terminal obtains data from a designated PMU terminal while other PDC terminals wait, thereby improving the efficiency of the PMU communication system.

[0089] To facilitate a deeper understanding of the embodiments of this application by those skilled in the art, a specific example will be used for illustration below.

[0090] Access control is a crucial information security technology applied across various fields. It refers to the methods by which a system restricts the access of individuals and their predefined policy groups to data resources. Access control is used by system administrators to control user network resources. Mainstream access control models include: Discretionary Access Control (DAC), Mandatory Access Control (MAC), Role-Based Access Control (RBAC), and Attribute-Based Access Control (ABAC). In the RBAC model, users are associated with one or more roles, and user roles are configured and activated as needed. Roles are relatively stable and do not change frequently, making implementation very easy and leading to its widespread use. However, the coarse-grained authorization of RBAC makes it unsuitable for complex technical environments. The ABAC model uses fine-grained access control and is widely used in large-scale distributed environments, web service systems, grid computing, and message sharing and management. However, it also suffers from excessive complexity and ineffective management, limiting its practical application scenarios.

[0091] Trusted computing is gradually becoming a core technology. Trusted computing architecture treats trusted protection nodes as independent, proactive control and defense nodes, sharing a single hardware and software computing platform with resource nodes. Based on a domestically developed cryptographic system, with trusted platform control software at its core, and a trusted network as the link, it ensures the security of the application execution environment and network environment. Trusted computing 3.0 technology, based on the computational complexity theory of cryptography and trusted verification, is particularly suitable for providing security for critical information infrastructure and important information systems. In the future, it can be applied and promoted in fields such as public communication and information services, supporting the transformation of industrial internet security facilities and driving the growth of the industrial internet security market and the information technology innovation industry.

[0092] To address the vulnerabilities of existing PMU and PDC communication to malicious attacks and data theft, and considering data storage issues within power systems, this application proposes a PMU communication identity access control method based on cloud storage and trusted computing. By introducing cloud service providers and security assessment centers into traditional data communication, PMU data storage and PDC access control are achieved, while effectively verifying the PDC's identity information. This enhances the security of information transmission between the phasor measurement device and the phasor data concentrator, enables the system to store information, and avoids power system instability and untimely data monitoring caused by information leakage, as well as potential threats to the power system caused by information tampering, thus ensuring the normal operation of power equipment.

[0093] Figure 2 A schematic diagram of a PMU communication access control system framework based on cloud storage and trusted computing is provided. Figure 2 The system architecture is mainly divided into four parts. Multiple PMU devices, acting as power terminals, can simultaneously send data to the CSP in real time, i.e., data upload. Simultaneously, the PMU devices encrypt keys with the security assessment center, i.e., the information recording center. The CSP, as a storage platform, can communicate with multiple PDC devices simultaneously and verify the legitimacy of their certificates. After verification, the CSP hands the information over to the SA for trusted computation to ultimately determine whether the target PDC is qualified to access the data in the CSP.

[0094] Figure 3 A diagram illustrating the PDC identity access control process is provided. According to... Figure 3 PDC identity access control may specifically include the following steps:

[0095] 1. The PMU generates a key K using a supported encryption algorithm. In practice, the SM2 national cryptographic algorithm can be used to generate an asymmetric key. The generated key K is then divided into two segments, K0 and K1, and sent by the PMU to the SA. Simultaneously, the PMU also sends the information retrieval scheme S used by the PDC, which serves as the cryptographic protocol for data transmission from the PMU to the PDC. Upon receiving K0 and K1, the SA encrypts them using its own key to form K. S0 and K S1 Resend to PMU.

[0096] 2. After receiving the data to be sent, the PMU encrypts the data using the unsplit key K to generate E_M. Then, it combines E_M and K... S0 K S1 The data is packaged together with S and sent to the Cloud Service Center (CSP). The CSP does not have permission to decrypt E_M, so storing it in the CSP will protect the data from CSP attacks.

[0097] 3. The PDC sends its certificate PDC_crt, public key PDC_pub, and data access scheme S to the CSP. The data access scheme S can be the cryptographic protocol by which the PDC accesses the PMU to transmit data.

[0098] 4. After receiving the PDC's certificate (PDC_crt), the CSP verifies the PDC_crt with a trusted CA. If verification fails, communication is immediately terminated, and the CSP sends the PDC's IP address and other identity information to the SA. The SA records the received identity information. If verification succeeds, the CSP sends the PDC's information to the SA, which then uses trusted computing technology to measure the trust level of its identity.

[0099] Figure 4 A schematic diagram of a security assessment center's measurement mechanism based on trusted computing is provided. According to... Figure 4 Upon receiving a verification request from the CSP, the SA executes the trusted computing module's interface. First, it extracts the information of the information access user and queries the whitelist database. The whitelist database stores information such as the address, device ID (or device name), access path, encoding, digest value, and signature of allowed access devices. The whitelist database is used to control the scheduling of devices such as PDCs, verifying their identity and legitimacy, and prohibiting unknown devices from accessing data. If it is scheduler code, the integrity and legitimacy of the program can also be verified during code loading or startup, rejecting the execution of unknown code, thus achieving proactive defense through static libraries.

[0100] If the SA determines that the PDC's identity is illegitimate and data access is not permitted, communication is terminated. Otherwise, if the SA determines that the PDC's identity is legitimate and data access is permitted, it will generate Kr_SA→PDC using the PDC's public key and a re-encryption algorithm. The SA sends Kr_SA→PDC to the CSP, and the CSP will re-encrypt Kr_SA→PDC and Kr_SA→PDC using the re-encryption algorithm. S1 and K S0 The generated encryption result is E(K) PDC ,K r ), where Kr is divided into K0 and K1. CSP will combine the PMU's encrypted data E_M and re-encrypted information E(K). PDC ,K r Send to the PDC terminal.

[0101] 5. The PDC receives the encrypted data E_M and the re-encryption information E(K). PDC ,K r Then use your private key PDC_key to decrypt E(K) PDC ,K rObtain the PMU keys K0 and K1, and combine K0 and K1 to generate K. Finally, use K to decrypt E_M to obtain the target information.

[0102] The aforementioned PDC identity access control process, by introducing a cloud service provider as an intermediate data storage provider and performing initial verification of the PDC's identity, and further verifying identity through a security assessment center based on trusted computing, enables the system to acquire historical data storage capabilities and ensures that data is not eavesdropped on, forged, or tampered with during transmission from the PMU to the PDC. First, the PMU segments the initialization key and performs a first-level re-encryption of the key via the SA, sending it along with the encrypted data to the CSP. Second, the PDC requests data access from the CSP. Third, the CSP verifies the PDC's identity information with the CA, and the SA performs a second-level verification of the PDC's identity. After successful verification, the PDC can access the data. This achieves the goal of ensuring that data is not eavesdropped on, forged, or tampered with during transmission from the PMU to the PDC while introducing cloud storage.

[0103] Figure 5 A flowchart illustrating a PMU communication access control method based on cloud storage and trusted computing is provided. Figure 5 The PMU communication access control method based on cloud storage and trusted computing can specifically include the following steps:

[0104] Step S210: PMU key initialization, negotiating with the Security Assessment Center (SA) to generate an encryption key.

[0105] During the key initialization process, the PMU can use the national cryptographic algorithm and decompose the key into two parts before sending them to the security assessment center for encryption.

[0106] Specifically, the PMU key is initialized, a key K is generated, and K is decomposed into K0 and K1. The Security Assessment Center (SA) will use its own key to encrypt the keys K0 and K1 sent by the PMU and transmit them back to the PMU device terminal.

[0107] In step S220, the PMU sends the encryption information, key, and encryption scheme to the cloud storage service provider (CSP).

[0108] Specifically, the PMU uses key K to encrypt the data and decomposes the SA-encrypted key (K). s0 K s1 The PMU sends encrypted data and the specified PDC access scheme S to the cloud storage service provider CSP. The PMU has absolute trust in the CSP, and the CSP can store historical data. Multiple PMU terminals share a single CSP cloud storage center.

[0109] Step S230: PDC requests access data from CSP.

[0110] Specifically, the PDC sends its certificate (PDC_crt) and access scheme (S) to the CSP. Multiple PDCs can simultaneously request data access from the CSP, resolving the issue of one PDC obtaining data from a specific PMU while other PDCs wait, thus significantly increasing system efficiency.

[0111] In step S240, CSP and SA verify the identity of PDC and evaluate the security level of PDC, and re-encrypt the key.

[0112] Specifically, after receiving the PDC's information, the CSP verifies the authenticity of its certificate with the CA. If the certificate is found to be fake, communication is blocked and information such as the address is recorded to the SA. Once the certificate verification is successful, the information is sent to the SA, which uses trusted computing technology for identity verification. In this process, the CSP uses traditional certificate authentication technology for first-level authentication, while the SA uses trusted computing technology for deep authentication of the PDC's identity information. This solves the problem of counterfeit PDCs possessing genuine certificates and obtaining real information.

[0113] In step S250, the PDC decrypts the re-encrypted key to obtain a key that can decrypt the encrypted information and extracts the encrypted data.

[0114] Specifically, after successful verification, the CSP sends the encrypted information and re-encryption key to the PDC. The PDC uses its private key to decrypt the data to obtain the PMU encryption key K and extract the encrypted data.

[0115] The aforementioned PMU communication access control method based on cloud storage and trusted computing significantly enhances communication efficiency by introducing cloud service providers for data storage. Furthermore, it employs trusted computing technology to implement access control over the PC's identity, strengthening the security of PMU data transmission compared to existing communication access control schemes while simultaneously gaining data storage capabilities. This method prevents intrusion into PDCs and fake PDC terminals from impersonating PDCs to receive power data, thus avoiding situations where proactive defense is impossible during attacks or proactive control is lacking. It provides crucial technical support for the security defense of the power system's intranet and has profound significance for accelerating the construction of substation monitoring and control and secure access PMU devices.

[0116] In one embodiment, such as Figure 6 As shown, a PMU communication access control method is provided, which is applied to... Figure 1 Taking the cloud server as an example, the explanation includes the following steps:

[0117] Step S310: Receive encrypted data, a first encryption key, and a second encryption key sent by the PMU terminal;

[0118] Step S320: Upon receiving the third encryption key sent by the security assessment device, the first encryption key, the second encryption key, and the third encryption key are re-encrypted to obtain a fourth encryption key; the third encryption key is obtained by the security assessment device re-encrypting the PDC public key when the first verification of the PDC information is passed.

[0119] Step S330: Send the fourth encryption key and the received encrypted data to the PDC terminal so that the PDC terminal can decrypt the fourth encryption key to obtain a decryption key, and use the decryption key to decrypt the encrypted data to obtain decrypted data.

[0120] In specific implementation, the PMU terminal can generate a key K, divide the key K into a first segment key K0 and a second segment key K1, and send the first segment key K0 and the second segment key K1 to the security assessment device for encryption, obtaining the first encryption key K returned by the security assessment device. S0 Second encryption key K S1 The PMU terminal can also use the unsplit key K to encrypt the data to be sent, obtaining encrypted data E_M, and then combine the encrypted data E_M with the first encryption key K. S0 Second encryption key K S1 The PDC terminal can send the PDC certificate (PDC_crt), PDC public key (PDC_pub), and PDC information to the cloud server. The cloud server sends the received PDC certificate to the CA authority for second verification. If the second verification fails, the PMU communication is terminated; otherwise, if the verification passes, the cloud server can send the PDC information to the security assessment device for first verification. If the first verification passes, the security assessment device can re-encrypt the PDC public key obtained from the cloud server to obtain the third encryption key Kr_SA→PDC, and return the third encryption key Kr_SA→PDC to the cloud server. Upon receiving the third encryption key Kr_SA→PDC, the cloud server can process the first encryption key Kr_SA→PDC. S0 Second encryption key K S1 The third encryption key Kr_SA→PDC is re-encrypted to obtain the fourth encryption key {E(K PDC ,K0),E(K PDC ,K1)}, and the fourth encryption key {E(K PDC ,K0),E(K PDC The PDC terminal sends the received fourth encryption key {E(K1)} and encrypted data E_M together. The PDC terminal can use the PDC private key PDC_key to process the received fourth encryption key {E(K1)}. PDC ,K0),E(K PDCDecrypt the received encrypted data E_M using the decryption key, and then use the decryption key to decrypt the encrypted data.

[0121] Since the cloud server's processing procedure has been described in detail in the aforementioned embodiments, it will not be repeated here.

[0122] In this embodiment, by receiving encrypted data, a first encryption key, and a second encryption key sent by the PMU terminal, and upon receiving a third encryption key sent by the security assessment device, the first, second, and third encryption keys are re-encrypted to obtain a fourth encryption key. The fourth encryption key and the received encrypted data are then sent to the PDC terminal. The encrypted data sent by the PMU terminal can be stored on a cloud server. If the security assessment device verifies the PDC terminal, the cloud server is allowed to transmit the encrypted data sent by the PMU terminal to the PDC terminal, thus realizing access control over the PDC terminal and ensuring the security of data transmission between the PMU terminal and the PDC terminal.

[0123] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0124] Based on the same inventive concept, this application also provides a PMU communication access control device for implementing the PMU communication access control method described above. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations in one or more PMU communication access control device embodiments provided below can be found in the limitations of the PMU communication access control method described above, and will not be repeated here.

[0125] In one embodiment, a PMU communication access control device is provided, comprising: a receiving module, an encryption module, and a transmitting module, wherein:

[0126] The receiving module is used to receive encrypted data, a first encryption key, and a second encryption key sent by the PMU terminal.

[0127] The encryption module is used to re-encrypt the first encryption key, the second encryption key, and the third encryption key upon receiving a third encryption key from the security assessment device to obtain a fourth encryption key; the third encryption key is obtained by re-encrypting the PDC public key when the security assessment device passes the first verification of the PDC information.

[0128] The sending module is used to send the fourth encryption key and the received encrypted data to the PDC terminal, so that the PDC terminal can decrypt the fourth encryption key to obtain a decryption key, and use the decryption key to decrypt the encrypted data to obtain decrypted data.

[0129] Each module in the aforementioned PMU communication access control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.

[0130] In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 7 As shown, the computer device includes a processor, memory, and a network interface connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores PMU communication access control data. The network interface communicates with external terminals via a network connection. When executed by the processor, the computer program implements a PMU communication access control method.

[0131] Those skilled in the art will understand that Figure 7 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0132] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0133] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0134] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0135] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0136] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0137] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A PMU communication access control system, characterized in that, The system includes a PMU terminal, a cloud server, a security assessment device, and a PDC terminal; The PMU terminal is used to generate an original key, split the original key to obtain a first segment key and a second segment key, and send the first segment key and the second segment key to the security assessment device. The security assessment device is used to receive the first segment key and the second segment key sent by the PMU terminal, encrypt the first segment key and the second segment key respectively using its own key to obtain a first encryption key and a second encryption key, and return the first encryption key and the second encryption key to the PMU terminal. The PMU terminal is also used to encrypt the data to be sent using the original key to obtain encrypted data, and send the encrypted data, the first encryption key and the second encryption key to the cloud server. The PDC terminal is used to send the PDC certificate, PDC public key, and PDC information to the cloud server; the PDC information includes at least one of the following: PDC terminal address, device number, device name, access path, encoding, digest value, and signature. The cloud server is used to send the received PDC certificate to the certificate verification device for a second verification, and if the second verification is successful, send the received PDC information to the security assessment device. The security assessment device is also used to extract the terminal information of the PDC terminal from the PDC information. If the terminal information can be found in the pre-stored list of allowed access devices, the PDC terminal is determined to have passed the first verification. If the first verification is passed, the PDC public key of the PDC terminal is re-encrypted to obtain a third encryption key, and the third encryption key is sent to the cloud server. The cloud server is also used to, upon receiving the third encryption key, re-encrypt the first encryption key, the second encryption key, and the third encryption key to obtain a fourth encryption key, and send the fourth encryption key and the received encrypted data to the PDC terminal; The PDC terminal is further configured to decrypt the received fourth encryption key to obtain a decryption key, and use the decryption key to decrypt the received encrypted data to obtain decrypted data corresponding to the encrypted data.

2. The system according to claim 1, characterized in that, The security assessment device is also used to measure the trust level of the PDC terminal's identity through trusted computing.

3. The system according to claim 2, characterized in that, The security assessment device is also used to extract information from information visitors and query a whitelist database, which stores the address, device number, device name, access path, code, digest value, and signature of devices that are allowed to access them.

4. The system according to claim 3, characterized in that, The security assessment device is also used to control the scheduling of the PDC terminal through the whitelist database to verify the legitimacy of the PDC terminal's identity.

5. The system according to claim 1, characterized in that, The PDC terminal is further configured to use the PDC private key to decrypt the fourth encryption key to obtain the first segment key and the second segment key, combine the first segment key and the second segment key to obtain the original key, and use the original key to decrypt the encrypted data to obtain the decrypted data.

6. The system according to claim 1, characterized in that, There is at least one PMU terminal, and each PMU terminal is connected to the cloud server.

7. The system according to claim 6, characterized in that, There is at least one PDC terminal, and each PDC terminal corresponds to the same timestamp.

8. The system according to claim 1, characterized in that, The PDC certificate is a CA certificate stored on the PDC terminal.

9. The system according to claim 1, characterized in that, The PDC public key is the public key stored on the PDC terminal.

10. The system according to claim 1, characterized in that, The data to be sent is the data that is expected to be transmitted from the PMU terminal to the PDC terminal.

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