Secure and reliable NC-Link agent, control method, device and terminal

Abstract

This invention belongs to the field of communications technology and discloses a secure and trusted NC-Link agent, control method, device, and terminal. The invention integrates the NC-Link protocol with a national secret algorithm to implement an NC-Link numerical control communication agent, performing identity authentication and providing transmission encryption and integrity protection. The invention also integrates the NC-Link protocol with attribute access control, embedding identity and attribute certificates into NC-Link to achieve permission control for uplink and downlink operations of the numerical control system. A distributed deployment solution is provided through message routing and bridging of the NC-Link agent. Customized security policies enable trusted network connectivity and active immunization capabilities of the agent. The invention supports a trusted and interoperable numerical control equipment interconnection protocol, implements security reinforcement of the NC-Link protocol based on a national secret algorithm, organically integrates secure and trusted technologies with the numerical control system, and utilizes an NC-Link agent server for distributed deployment.

Description

Technical Field

[0001] The present invention belongs to the field of communication technology, and in particular relates to a safe and reliable NC-Link agent, a control method, a device and a terminal. Background Art

[0002] As the wave of industrial intelligence upgrades sweeps the globe, traditional manufacturing is undergoing fundamental changes. The shift from digital manufacturing to intelligent manufacturing is an inevitable trend in manufacturing development. One of the key research areas in intelligent manufacturing is the digital workshop, and the core of digital workshop research lies in the interconnectivity of equipment.

[0003] Currently, research on interconnection and communication technologies in open CNC systems focuses primarily on the intercommunication and interoperability layers, which are essential for addressing the fusion and application of multi-source, heterogeneous big data. Among existing CNC system intercommunication protocols, the primary international standards for heterogeneous system interoperability are MT-Connect and OPC-UA. Other existing standards include umati and NC-Link. While MT-Connect and OPC-UA provide interoperability between heterogeneous systems, both protocols have varying degrees of limitations. OPC UA is a typical intercommunication layer communication protocol, while MT-Connect, umati, and NC-Link are typical interoperability protocols.

[0004] The MT-Connect protocol transmits a large amount of data, which is a severe test for network bandwidth. It can only be used for one-way reading of device status to implement monitoring functions and cannot be used for two-way control.

[0005] The OPC-UA protocol model definition language is too complex and inconvenient to use.

[0006] Neither MT-Connect nor OPC-UA protocols can meet the requirements for high-frequency data acquisition. However, intelligent applications for CNC machine tools, such as vibration analysis, temperature measurement, and compensation, require high-frequency signals as input. Therefore, data acquisition adapters based on these two protocols also inherit this limitation.

[0007] OPC UA is a widely used communication protocol for interconnecting CNC systems, providing a platform-independent interoperability standard for data and information transmission between factory floors and enterprises. Through OPC UA, all required information is available to every authorized application and every authorized person at any time and anywhere, independent of the manufacturer's original application, programming language, and operating system. In the context of Industry 4.0, OPC UA is not intended to replace the deterministic communication methods already in common use within mechanical devices. Instead, it provides a unified communication method for modeling data collection between complete sets of equipment, machinery, and components produced by different manufacturers, while also making communication between the factory floor and the enterprise more secure and reliable. It officially became a recommended standard in China on September 5, 2017. The key features of OPC UA technology include: unified access, effectively integrating existing OPC specifications (Data Access (DC), Alarms and Events (A&E), Historical Data Access (HDA), commands, complex data, and object types) into the current OPC UA specification; a standard security model, clearly defined in the OPC UA access specification, which improves interoperability while reducing maintenance and configuration costs; and platform-spanning. OPC UA software development is no longer restricted to any specific operating platform and can be implemented on platforms such as Windows, Linux, Unix, and Mac.

[0008] The NC-Link protocol is a CNC machine tool interconnection communication protocol standard with independent intellectual property rights, developed by the "CNC Machine Tool Interoperability Industry Alliance" (hereinafter referred to as the "Alliance"). Led by the China Machine Tool Builders' Association, the Alliance currently includes 22 enterprises, institutions, research institutes, and universities, including Wuhan Huazhong CNC Co., Ltd. and Huazhong University of Science and Technology. The Alliance aims to create a machine tool interconnection communication standard with independent intellectual property rights in China and provide an interconnection communication protocol more suitable for CNC machine tools. The NC-Link protocol provides standardized interfaces and data structures, supports multi-source heterogeneous data acquisition, integration, and feedback control, and enables data exchange between individual CNC equipment, intelligent production lines, and smart factories, as well as interconnection and communication between multiple cloud data centers. Its main features are as follows:

[0009] (1) Unique CNC equipment information model. The CNC equipment model defined by the NC-Link protocol uses a JSON tree-structured model file, which can accurately reflect the logical relationship between the machine tool and its various functional components. JSON has a rich data type that can fully cover the description requirements of various types of CNC machine tool information. Therefore, the NC-Link information model can describe more equipment data and output more equipment and production information.

[0010] (2) Support for custom combined data. NC-Link supports combining a set of data generated in the same time period (or other forms of alignment) into a set of data blocks on the CNC equipment side using multiple standards. The data is naturally aligned within the data block, which greatly improves data transmission efficiency and provides a basis for data correlation analysis.

[0011] (3) Lightweight data exchange format. Using weakly typed JSON (Java script notation) for model description and data transmission, it reduces bandwidth pressure and provides strong real-time performance, which determines the real-time bidirectional control characteristics of NC-Link.

[0012] (4) High compatibility with heterogeneous devices or platforms. The NC-Link information model is highly flexible and scalable, and is compatible with existing mainstream industrial interconnection data interaction protocols, including OPC UA, MTConnect, and umati.

[0013] (5) Unique security design. The NC-Link protocol supports end-to-end secure communication of CNC equipment, access security, permission control, and data transmission security between devices and terminals, and implements strict permission control and identity authorization for data operation permissions on the device side.

[0014] The NC-Link protocol has entered the application verification phase and has achieved interoperability with communication protocols such as MTConnect, OPC UA, and iport. It supports CNC systems from companies such as Huazhong CNC, i5, Guangzhou CNC, Kede CNC, Beckhoff, FANUC, and SIEMENS. Applicable devices include CNC machine tools, robots, AGVs, and PLC modules. For example, iNC Cloud, an industrial internet platform implemented by Wuhan Huazhong CNC using the NC-Link protocol, aggregates and processes hundreds of millions of data points daily, collecting information on thousands of points in CNC equipment, including equipment status, alarm information, machining piece counts, sampling data, and other operating conditions. This platform establishes a traceability system for the entire lifecycle of physical equipment. The iNC Cloud platform utilizes the NC-Link protocol to open up data, providing data services for predictive analysis, remote fault diagnosis, and process parameter evaluation. It also optimizes equipment production processes through NC-Link-based feedback control, enabling interoperability across the entire data exchange system.

[0015] Identity authentication is a crucial technology for ensuring data security. Its primary purpose is to verify the true identity of the other end of a communication and prevent forgery and impersonation. The primary technical methods for identity authentication are cryptographic methods, including symmetric encryption algorithms, public key cryptography algorithms, and digital signature algorithms.

[0016] In addition, in order to improve the secure communication and privacy protection issues of IoT devices, some researchers have applied the IBE-based cryptographic mechanism to the identity authentication of IoT, improved the CSAS authentication scheme, and proposed the IBE-VF scheme to build a two-way identity authentication scheme for IoT terminal devices at the network layer. Finally, the IBE-VF authentication scheme was integrated with the network security protocol TLS to realize the identity authentication of IoT devices before encrypted communication.

[0017] Access control technology prevents unauthorized access to any resource, thereby limiting the use of computer systems within legal boundaries. This technology limits user access to certain information items or the use of certain control functions based on user identity and the group to which they belong. For example, the UniNAC network access control system is based on this technology.

[0018] To address the privacy and security issues surrounding access to networked resource data, scholars have primarily employed access control mechanisms to prevent unauthorized users from attempting to access data. Existing access control technologies primarily include discretionary access control (DAC), mandatory access control (MAC), role-based access control, attribute-based access control, intent-based access control, risk-based access control, lineage-based access control, sensitivity-based access control, content-based access control, and behavior-based access control. These technologies are employed in different ways. Discretionary access control allows file owners to determine which users can access and use their files. Mandatory access control involves assigning fixed security attributes to both subjects and objects, preventing arbitrary changes to their access rights and other security attributes. Role-based access control involves establishing multiple roles within a system and assigning corresponding access rights to objects. Specifically, the system assigns access rights to each role based on the user's role. Attribute-based access control (ABAC) involves assigning a set of relevant attributes to legitimate users and using access control policies to determine which attributes can access which objects. Attribute-based access control is a logical access control model that controls access between objects based on the attributes of entries, operations, and the associated environment. ABAC first extracts the attributes of users (subjects), resources (objects), permissions, and the environment. It then flexibly combines the relationships between these attributes and transforms permission management into attribute management, providing a fine-grained, dynamic access management approach.

[0019] Through the above analysis, the problems and defects of the existing technology are as follows:

[0020] (1) OPC UA has limitations in real-time communication and is not suitable for industrial field-level data interoperability. OPC UA and the currently widely used industrial interconnection protocols MTConnect and umati are not self-controlled protocols. Furthermore, the protocols are not fully compatible with each other and cannot effectively guarantee data access security, transmission security, and permission control security between end-to-end CNC equipment and between devices and terminals. The identity authentication scheme used in the protocol, which is based on public key infrastructure as the communication entity, faces problems such as complex certificate management and maintenance and difficulty in scalability.

[0021] (2) Symmetric encryption algorithms use the same key for encryption and decryption operations. Therefore, the security of symmetric encryption algorithms depends on the preservation of the encryption key. If the shared key is stolen or intercepted by a third-party attacker, the communication session can be easily cracked and all previous traffic can be cracked. When distributing keys, the sender establishes a secure channel. The secure and efficient delivery of the key to the receiver is the weak point of the symmetric encryption system. The distribution process of symmetric keys is often cumbersome and requires a high cost. The key volume is large and difficult to manage. When multiple devices use symmetric encryption algorithms for confidential communication, the complexity of key management will be greatly increased. In addition, symmetric encryption algorithms have difficulty solving the problem of non-repudiation. Both communicating parties can deny receiving or sending information, making it difficult to distinguish between true and false.

[0022] (3) Traditional access control methods, including autonomous access control (DAC) and identity-based access control (IBAC), are mainly centralized in design and have disadvantages such as difficulty in scalability, poor reliability, and low throughput. However, devices in industrial Internet scenarios may belong to different organizations or users and may have mobility and limited performance, which makes it difficult for centralized access control to meet the access control requirements in the industrial Internet environment. In addition, in decentralized access control, existing distributed access control technologies do not elaborate much on anonymity and cross-network and cross-domain aspects, nor do they elaborate on detailed information such as the hierarchy of roles. Summary of the Invention

[0023] In response to the problems existing in the prior art, the present invention provides a secure and reliable NC-Link agent, control method, device and terminal, and in particular relates to a secure and reliable NC-Link agent, control method, medium, device and terminal based on the national secret algorithm.

[0024] The present invention is implemented as follows: a secure and reliable NC-Link agent control method, which includes: integrating the NC-Link protocol with the national secret algorithm to realize the NC-Link numerical control communication agent, performing identity authentication and providing transmission encryption and integrity protection; integrating the NC-Link protocol with attribute access control, and realizing the permission control of the upstream and downstream operations of the numerical control system by embedding identity and attribute certificates into NC-Link; providing a distributed deployment solution through message routing and bridging of the NC-Link agent; and realizing the trusted network connection and active immunity function of the agent through customized security policies.

[0025] Furthermore, the safe and reliable NC-Link agent control method includes the following steps:

[0026] Step 1: Implement identity authentication and access control based on trusted identity and attribute certificate services;

[0027] Step 2: Perform transmission encryption and integrity protection on the NC system communication protocol NC-Link.

[0028] Furthermore, the implementation of identity authentication and access control in step 1 includes:

[0029] Authentication protocols and access control technologies are constructed under the Trusted Computing 3.0 network architecture to simplify the identity authentication and permission verification process and improve the efficiency of secure access. Identity authentication and access control functions are based on trusted identity and attribute certificate services. Based on the X.509 standard, the dynamic policy configuration of attribute-based access control is used to overcome the mismatch between the lifecycles of identity certificates and attribute certificates, realize the merging and binding of identity certificates and attribute certificates, and simplify certificate storage and interaction times. Combined with the NC-Link protocol, identity and attribute certificate application, review, issuance, release and cancellation services are provided to users, processes and device entities. Based on the TPCM and trusted cryptographic services of Trusted Computing 3.0, a multi-level key management mechanism is implemented in the certificate service, including key separation, master key derivation encryption key, encryption protection data key and session key capabilities, forming lifecycle protection for keys at all levels and realizing lightweight identity and attribute certificate services.

[0030] Attribute-based encryption (ABE) is based on fuzzy identity-based encryption (IBE). ABE associates ciphertext and keys with attribute sets and access structures. Decryption is successful only when the attribute sets satisfy the access structure. Based on these pairwise correspondences, ABE is categorized into two types: key-policy attribute-based encryption (KP-ABE) and ciphertext-policy attribute-based encryption (CP-ABE).

[0031] KP-ABE is an access structure and / or access policy implied in the user's key, corresponding to a set of attributes in the ciphertext. Decryption is successful if and only if the attribute set of the ciphertext satisfies the access structure of the user's key. The user is the subject, and only specific ciphertexts can be matched with them for decryption.

[0032] CP-ABE is a set of attributes corresponding to the user's key. The ciphertext contains the access structure and / or access policy. The user decrypts successfully if and only if the user's attribute set satisfies the ciphertext's access structure. The ciphertext is the main body, and only a specific key can match it and thus decrypt it. With CP-ABE, the data owner in CP-ABE defines the appropriate access structure according to his or her needs.

[0033] Furthermore, the transmission encryption and integrity protection in step 2 includes:

[0034] Communication between the NC-Link agent and application systems, between the NC-Link agent and CNC equipment, and through trusted identity and attribute certificate services is based on the NC-Link protocol. This protocol, a domestically produced CNC system communication protocol, is reinforced using domestic cryptographic algorithms, generating a nationally encrypted secure channel for secure data transmission. NC-Link CNC communication, based on nationally encrypted TLS, ensures trusted identities while also protecting the confidentiality and integrity of communications.

[0035] TLS (Transport Layer Security) is a security protocol that provides security and data integrity for network communications. TLS encrypts network connections at the transport layer. Traditional TLS protocols utilize two methods: one-way authentication and two-way authentication. One-way authentication involves the client verifying the server's identity, ensuring that the services the client is accessing are legitimate. Two-way authentication builds on one-way authentication by adding server-side authentication of the client, ensuring that only legitimate users can access the service. In this invention, data transmission utilizes two-way authentication to ensure identity authenticity and data confidentiality.

[0036] Currently, the standard TLS protocol supports asymmetric algorithms such as RSA and ECC, and symmetric algorithms such as 3DES and AES. These are internationally accepted algorithms, and the lack of national standard algorithms poses security risks. GM / T does not have a separate document standardizing the SSL protocol. Instead, it defines the national SSL protocol in the SSL VPN Technical Specification. The "GM / T 0024-2014, Cryptography Industry Standard of the People's Republic of China SSL VPN Technical Specification," specifies the national SSL protocol. The present invention implements an SSL protocol that complies with national standards in accordance with this national standard.

[0037] The TLS protocol authenticates and encrypts both communicating parties. All information is transmitted encrypted, equipped with identity certificates and a verification mechanism. The essence of TLS secure communication is to securely encrypt subsequent communications based on the symmetric encryption key generated through negotiation. The TLS handshake is used to verify both parties and the encryption key used for the negotiated communication. The TLS protocol is mainly divided into the record layer protocol, the cipher specification change protocol, the alarm protocol, and the handshake protocol. This invention mainly modifies the handshake protocol, modifying the algorithm therein to the national secret standard algorithm. It adopts the national secret ECDHE negotiation algorithm, uses the national secret SM2 for signature verification, SM3 for MAC digest calculation, SM4 for symmetric encryption, and key negotiation uses SM2 asymmetric encryption.

[0038] Furthermore, key agreement is the process of establishing a shared secret key between two users. The value of the shared secret key is determined through key agreement. Assume that the two parties involved in the key agreement are A and B, the key pairs are (dA, QA) and (dB, QB), and the length of the key data obtained by both parties is klen. The key agreement protocol includes:

[0039] In the first phase, a temporary key pair is generated. User A calls the SM2 algorithm to generate a temporary key pair (PriA, PubA) and sends RubA and user A's user identity ID A to user B. User B calls the SM2 algorithm to generate a temporary key pair (PriB, PubB) and sends PubB and user B's user identity ID B to user A. The temporary private key is only valid during this handshake session and is released after the handshake ends.

[0040] The second phase calculates the shared secret key. User A inputs the following parameters to obtain key data of length klen: ① User A's public key; ② User B's public key; ③ User A's temporary public key; ④ User A's user ID; ⑤ User B's temporary public key; ⑥ User B's user ID; ⑦ User A's private key; ⑧ User A's temporary private key; ⑨ The length klen of the key data to be output. The input parameters required by User B are essentially the same as those for User A, except that the private key and temporary private key must be replaced with those of User B. The non-temporary public and private keys correspond to the national secret encryption certificate.

[0041] Another object of the present invention is to provide a safe and reliable NC-Link agent that applies the safe and reliable NC-Link agent control method. The safe and reliable NC-Link agent includes: CNC equipment, an adapter, an MES application system, a CNC system, a trusted computing 3.0 system, a trusted platform control module TPCM and a domestic high-speed cryptographic service module.

[0042] The NC-Link agent includes protocol data routing, forwarding, secure access to devices and applications, user authentication and authorization. CNC equipment must authenticate itself to the agent before transmitting data to the application layer.

[0043] CNC equipment has unique identity authentication information, including device serial number, MAC address, or other information that cannot be copied or changed;

[0044] The Trusted Computing 3.0 system includes a brand-new trusted system framework based on independent cryptography, with control chips as the backbone, dual-integration motherboards as the platform, trusted software as the core, trusted connections as the link, policy management as the system, and secure and reliable applications. It is used to solve trust issues at the network level.

[0045] The Trusted Platform Control Module (TPCM) is the core of the active immunity mechanism in the Trusted Computing 3.0 system and is used to achieve active control of the secure and trusted NC-Link agent.

[0046] The MES application system (Manufacturing Execution System) is a third-party information system used for actual production management in CNC workshops.

[0047] The adapter is responsible for converting the data collected from the CNC device into the NC-Link protocol format and sending it to the NC-Link agent, or converting the control information into information that the device can recognize and sending it from the NC-Link agent to the CNC device.

[0048] The domestically produced high-speed cryptographic service module based on FPGA includes a national secret chip, a random number generator, a key memory, an algorithm accelerator, etc. It provides a cryptographic call interface and high-speed data encryption functions.

[0049] Furthermore, the CNC equipment sends an authentication request of the NC-Link protocol to the NC-Link agent. The NC-Link agent responds to the authentication request based on the trusted identity & attribute certificate service and authenticates the CNC equipment. Only CNC equipment that passes the authentication can successfully access and exchange information.

[0050] The Trusted Computing 3.0 system uses a cryptographic system that combines symmetric and asymmetric elements as immune genes. It implants a trusted source root through the active measurement control chip TPCM, adds a trusted root control function based on TCM, and realizes the combination of cryptography and control. The trusted platform control module is designed as a trusted computing control node to realize the active control of the entire platform by the trusted platform control module TPCM.

[0051] The Trusted Platform Control Module (TPCM) is a hardware module integrated into the trusted platform. It is the trusted root of the active immune trusted system. It is used to establish and protect the source of trust and provide a series of trusted computing functions including trusted platform control, integrity measurement, secure storage, trusted reporting and cryptographic services.

[0052] Under the Trusted Computing 3.0 framework, the Trusted Identity & Attribute Certificate Service optimizes mutual access between devices, user access to devices, and user access to applications. It obtains user / device attributes through the user / device identity and implements fine-grained access control based on attribute access control policies. It provides single sign-on functionality for CNC systems with multiple applications, and authenticates access to the entire network in an open network environment with one authentication.

[0053] Another object of the present invention is to provide a computer device, which includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the secure and reliable NC-Link agent control method.

[0054] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to execute the steps of the secure and reliable NC-Link agent control method.

[0055] Another object of the present invention is to provide an information data processing terminal, which is used to implement the secure and reliable NC-Link agent.

[0056] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0057] First, identity authentication, access control and data security are the basic security requirements of open CNC systems. The present invention needs to solve the definition and management problems of the identities and attributes of the subjects and objects of the CNC system, and provide closed-loop services for the application, review, issuance, release and destruction of identity and attribute certificates; it needs to solve the security authentication and fine-grained access control problems between the subjects and objects of the CNC system, and provide a security authentication mechanism and access control strategy based on identity and attributes; it needs to provide security protection for local and remote key business data in the CNC system to ensure data integrity and confidentiality. In combination with the Trusted Computing 3.0 framework, building a CNC system cryptographic application solution based on identity and attributes and a complete key management mechanism are key technical issues that must be solved for open CNC systems to build a secure and trusted environment. It can be seen that the open CNC system currently has the following problems to be solved:

[0058] (1) Secure and fine-grained access control

[0059] In CNC systems, it is inevitable to solve the problems of security authentication and fine-grained access control between subjects and objects. In common solutions such as autonomous access control and mandatory access control, the granularity of access control is not fine enough. Using attribute-based access control (ABAC) to form access control conditions by combining a variety of richer attribute information can flexibly adapt to various resource access scenarios. ABAC is inherently more suitable for today's threat-ridden environment than traditional directory access control, and can better ensure security in an era where the zero-trust principle must be adhered to more cautiously. At the same time, the identity and attribute certificates of the subject and object also need to be protected by security policies. If the relevant certificates or keys are leaked, it will have a huge impact on the security of the CNC system.

[0060] (2) Transmission security protection (ciphertext algorithm, safe and controllable)

[0061] The mainstream communication protocols used in current domestic CNC systems generally use internationally accepted encryption algorithms (DES, SHA-1, RSA) and related standards. However, the security of these encryption algorithms cannot be guaranteed.

[0062] To solve the above problems, the present invention mainly analyzes and designs a secure and reliable NC-Link agent in response to the security requirements of information confidentiality, integrity, and controllability in open CNC systems. The agent combines trusted computing, attribute-based encryption algorithms, national secret algorithms and other technologies to establish a lightweight identity and attribute certificate service, providing credentials for trusted identity authentication and access control, and providing security management and access control functions in the context of localization. In addition, the present invention makes the NC-Link agent secure and reliable by analyzing the security enhancement issues of the domestic CNC system communication protocol NC-Link; the agent meets the network identity authentication and communication encryption functions under the Trusted Computing 3.0 framework, and can perform security filtering on commonly used CNC application protocols.

[0063] The present invention also has the following advantages and positive effects:

[0064] Innovation 1: CNC equipment interconnection protocol that supports trusted interoperability

[0065] Networking and informatization are driving CNC systems toward openness. The foundation of this openness lies in secure and trustworthy interoperability of CNC equipment. Currently, major protocols for CNC equipment interoperability include MTConnect, OPC UA, UMati, and NC-Link. This paper proposes secure and trustworthy interoperability technology based on the domestically produced NC-Link protocol and designs a proxy. Integrating this with Trusted Computing 3.0, a security enhancement mechanism is designed for the NC-Link proxy, implementing mainstream security capabilities such as identity authentication, access control, and transmission encryption, ultimately achieving secure and trustworthy interoperability across open CNC system protocols.

[0066] Innovation 2: NC-Link protocol security reinforcement based on national encryption algorithm

[0067] Based on the domestic cryptographic algorithms provided by Trusted Computing 3.0, the domestic NC-Link protocol is integrated with the national cryptographic algorithm to enhance the security of the NC-Link protocol and establish a national cryptographic secure communication channel. An NC-Link CNC communication agent based on the national cryptographic algorithm is implemented, ensuring identity trust while providing transmission encryption and integrity protection. The NC-Link protocol is also integrated with attribute-based access control, using attribute-based encryption to combine identity and attribute certificates. Both identity and attribute certificates are then embedded in NC-Link to implement permission control for both upstream and downstream CNC system operations.

[0068] Innovation 3: Organic integration of safe and reliable technology and CNC system

[0069] By integrating the trusted control module and cryptographic service module with the NC-Link agent and CNC system, the security and trustworthiness of the NC-Link agent node are guaranteed, while achieving a balance between trusted security and CNC system performance. First, the trusted control module and cryptographic service module based on Trusted 3.0 are integrated into the CNC system's host hardware to ensure trust at the hardware level. The trusted software base is then integrated into the CNC operating system to establish a trusted operating environment for the CNC operating system. Finally, the CNC software on the CNC system host is protected, providing security features such as identity authentication, access control, storage encryption, and transmission encryption.

[0070] Innovation 4: NC-Link agent server achieves distributed deployment

[0071] To address NC-Link agent message routing and bridging issues, we deploy proxy servers using a distributed approach. Data is regularly synchronized between servers, enabling load balancing across NC-Link proxy servers and improving parallel processing efficiency. A single server can handle ≥1000 concurrent clients. Furthermore, we provide disaster recovery capabilities, automatically switching nodes in the event of distributed node failures to ensure stable service.

[0072] Second, networking and informatization have made CNC systems open. The foundation of openness is the security and trustworthiness of the interconnection and interoperability of CNC equipment. Currently, the protocols for the interconnection and interoperability of CNC equipment mainly include MTConncet, OPC UA, umati, NC-Link, etc. This invention combines national secret algorithms with trusted computing, and designs a secure and trustworthy NC-LINK agent based on the national secret TLS with the domestic NC-Link protocol as the core, providing new ideas for the secure and trustworthy interconnection and interoperability technology of CNC equipment. Based on the definition and management of the main and object identities and attributes of the CNC system under the Trusted Computing 3.0 framework, the NC-Link protocol and attribute access control are integrated to develop a lightweight identity & attribute certificate service hardware and software system to realize the permission control of the upstream and downstream operations of the CNC system, and provide certificate services for the CNC system, NC-Link adapter, NC-Link agent, and application software. In terms of network agent, by integrating trusted technology, national secret algorithms and NC-Link agent, the security and trustworthiness of NC-Link agent nodes are guaranteed. At the same time, the present invention designs a security enhancement mechanism for the NC-Link agent to realize mainstream security capabilities such as identity authentication, access control, and transmission encryption, providing strong support for realizing open CNC system protocol security and trusted interconnection.

[0073] Third, the expected benefits and commercial value of the technical solution of the present invention after transformation are:

[0074] As one of the first closed-loop products of a secure and reliable CNC system in China, the agent provides comprehensive security and reliability support for the CNC system itself and open network, improving the competitiveness of domestic CNC system companies. Considering the relevant construction investment in domestic CNC systems, at least 1,000 sets are required each year, and the market size is expected to expand by about 1 billion.

[0075] Significantly reduce economic losses caused by malicious attacks and data theft. This project's results can lower production safety risks, ensure stable operations, and provide technical support for protecting sensitive processing data, reducing costs associated with security and stability issues.

[0076] Fourth, the technical solution of the present invention solves a technical problem that people have long been eager to solve but have never been able to successfully solve:

[0077] High-end CNC systems characterized by high speed, precision, and composite intelligence are strategic equipment for manufacturing various high-precision and advanced equipment in the aerospace, national defense, and military industries, and their industrial development has great strategic significance. The present invention studies the key technologies for the safe and reliable interconnection and interoperability of open CNC systems, develops safe and reliable CNC systems and supporting software and hardware, and forms a targeted, effective, and usable safe and reliable CNC system application engineering template. It has important scientific value for improving the technical level of safe and reliable CNC systems, and the project belongs to the key technology research in interdisciplinary and forward-looking fields. It provides ideas for solving the current problems of the lack of a safe and reliable architecture for CNC systems, insufficient open security technologies, and a lack of adaptive trusted modules. It has important foresight and provides technical support for ensuring strategic production safety in aerospace, military, and other industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0079] Figure 1 This is a flow chart of a control method for a secure and reliable NC-Link agent provided by an embodiment of the present invention;

[0080] Figure 2 This is a schematic diagram of the structure of a secure and reliable NC-Link agent provided by an embodiment of the present invention;

[0081] Figure 3 This is a schematic diagram of the trusted identity & attribute certificate service structure provided by an embodiment of the present invention;

[0082] Figure 4 This is a schematic diagram of the key negotiation process provided by an embodiment of the present invention.

[0083] Figure 5 This is a schematic diagram of the network environment topology provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0084] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0085] In view of the problems existing in the prior art, the present invention provides a safe and reliable NC-Link agent, control method, device and terminal. The present invention is described in detail below with reference to the accompanying drawings.

[0086] In order to enable those skilled in the art to fully understand how to implement the present invention, this section provides an explanatory embodiment that expands on the technical solutions of the claims.

[0087] like Figure 1 As shown, the secure and reliable NC-Link agent control method provided by the embodiment of the present invention includes the following steps:

[0088] S101 integrates the NC-Link protocol with the national encryption algorithm to implement the NC-Link CNC communication agent, perform identity authentication, and provide transmission encryption and integrity protection;

[0089] S102: Integrate the NC-Link protocol with attribute access control, and embed identity and attribute certificates into NC-Link to achieve permission control for uplink and downlink operations of the CNC system.

[0090] S103 provides a distributed deployment solution through message routing and bridging of NC-Link agents, and implements trusted network connection and active immunity functions of agents through customized security policies.

[0091] In view of the current situation that the communication protocols of open CNC systems are mainly based on foreign protocols, the embodiment of the present invention integrates the domestically produced NC-Link protocol with the national encryption algorithm to realize the NC-Link CNC communication agent based on the national encryption algorithm, which provides transmission encryption and transmission integrity protection while ensuring identity trust; at the same time, the NC-Link protocol is integrated with attribute access control, and the permission control of the upstream and downstream operations of the CNC system is realized by embedding identity and attribute certificates into NC-Link. The embodiment of the present invention provides a distributed deployment solution through the message routing and bridging of the NC-Link agent, thereby improving the efficiency of parallel processing; under the Trusted Computing 3.0 framework, it solves the caching, persistence and program security issues of the NC-Link protocol agent, and realizes the trusted network connection and active immunity function of the agent through customized security policies. The secure and trusted NC-Link agent model based on the national encryption algorithm provided by the embodiment of the present invention is as follows Figure 2 shown.

[0092] The NC-Link agent terminal is configured with a Trusted Platform Control Module (TPCM) and a Trusted Software Base (TSB) at the hardware and system levels, respectively. The TPCM participates in trusted status report generation, identity verification, and password negotiation during network communications. It uses a built-in Trusted Cryptography Module (TCM) to identify the terminal and ensure data confidentiality and security during interactions. The Trusted Software Base primarily performs functions such as intercepting, measuring, and managing user behavior.

[0093] In traditional industrial control system protocol communications, such as Modbus / TCP, data is transmitted unencrypted. Malicious attackers can easily access the data and perform malicious operations such as parsing and tampering, seriously compromising the security of industrial control systems. To avoid this problem, the present invention employs an encrypted transmission method that encrypts protocol communication data, ensuring that data messages are transmitted as ciphertext. This addresses the lack of confidentiality protection inherent in the protocol and ensures the security of data message transmission.

[0094] By adding domestic cryptographic algorithm modules to terminal node devices, domestic algorithms SM2 / SM3 / SM4 are used for identity authentication and data encryption protection. Since international algorithms are still mainstream under the current terminal node hardware system, it is necessary to add domestic algorithm implementations to these terminal node devices.

[0095] When terminal A launches any network application, it needs to establish a network connection with terminal B. The trusted software base detects this network activity through network hooks in Linux's LSM (Linux Security Module) and notifies the trusted authentication service program of information such as the network IP address and port number. The trusted authentication service program then determines the terminal's trust status. If terminal B's trust status meets the requirements, the connection is allowed. Upon receiving terminal A's network connection request, terminal B also uses the same mechanism to determine terminal A's trust status through the trusted authentication program. If the requirements are met, terminal A is allowed access.

[0096] Trusted Computing 3.0 proposes a new trusted system framework based on autonomous cryptography, supported by control chips, a dual-integrated motherboard as the platform, trusted software at the core, trusted connections as the link, systematic policy management, and secure and reliable applications. This framework addresses trust issues at the network level. The Trusted Platform Control Module (TPCM), the core of Trusted Computing 3.0's active immunity mechanism, enables proactive control of the entire platform.

[0097] Trusted Computing 3.0 utilizes a proprietary, innovative, and combined symmetric and asymmetric cryptographic system as its immune mechanism. By embedding a trusted source root through the Active Measurement Control Chip (TPCM), it adds trusted root control capabilities to the TCM, integrating cryptography and control. The Trusted Platform Control Module (TPCM) is designed as a trusted computing control node, enabling the TPCM to proactively control the entire platform. The TPCM, a hardware module integrated within the trusted platform, serves as the trusted root of the active immune trust system. It primarily establishes and secures the trusted source point, providing a range of trusted computing capabilities, including trusted platform control, integrity measurement, secure storage, trusted reporting, and cryptographic services.

[0098] As a preferred embodiment, the secure and reliable NC-Link agent control method provided by the embodiment of the present invention specifically includes the following steps:

[0099] 1. Identity authentication and access control

[0100] The identity authentication and access control functions are based on the trusted identity & attribute certificate service, which simplifies the identity authentication and permission verification process and improves the efficiency of secure access. Based on the X.509 standard (certificate standard specification), the dynamic policy configuration of attribute-based access control is used to break through the mismatch problem of the life cycle of identity certificates and attribute certificates, realize the merging and binding of identity certificates and attribute certificates, and simplify the storage and interaction times of certificates. Combined with the NC-Link protocol, it provides identity & attribute certificate application, review, issuance, release, cancellation and other services for users, processes, devices and other subjects. Based on the TPCM and trusted cryptographic services of Trusted Computing 3.0, it implements a multi-level key management mechanism in the certificate service, including key separation, master key derivation encryption key, encryption protection data key and session key capabilities, forming key life cycle protection at all levels and realizing lightweight identity & attribute certificate services. Figure 3 .

[0101] (1) CA certificate

[0102] A CA is a certificate issuing authority and the core of the Public Key Infrastructure (PKI). It is responsible for issuing, authenticating, and managing issued certificates.

[0103] The CA has a certificate (containing a public key and a private key). Public users trust the CA by verifying its signature. Anyone can obtain the CA's certificate (containing the public key) to verify the certificates it issues.

[0104] If a user wants to obtain a certificate of their own, they must first apply to the CA. After the CA verifies the applicant's identity, it assigns a public key to the applicant. The CA then binds the public key to the applicant's identity information, signs it, and issues the certificate to the applicant.

[0105] If a user wants to verify the authenticity of another certificate, they can use the CA's public key to verify the signature on the corresponding certificate. Once the verification is successful, the certificate is considered valid. A certificate is actually an authentication of the user's public key issued by the Certificate Authority (CA).

[0106] The contents of the certificate include: information about the electronic visa authority, public key user information, public key, signature of the authority, validity period, etc. The format and verification method of the certificate generally follow the X.509 international standard.

[0107] (2) Certificate Standard Specification X.509

[0108] The most widely used standard is the X.509 v3 specification (RFC5280) jointly developed by ITU and ISO, which defines the following certificate information fields:

[0109] Version Number: The version number of the specification, currently version 3, with a value of 0x2;

[0110] Serial Number: A unique number assigned to each certificate issued by a CA and used to track and revoke certificates. A certificate can be uniquely identified by having the issuer information and serial number. The maximum length is 20 bytes.

[0111] Signature Algorithm: The algorithm used for digital signature, such as:

[0112] ①sha256-with-RSA-Encryption

[0113] ②ccdsa-with-SHA2S6;

[0114] Issuer: Identification information of the certificate issuing organization, such as "C=CN, ST=Beijing, L=Beijing, O=org.example.com, CN=ca.org.example.com";

[0115] Validity: The validity period of the certificate, including the start and end time.

[0116] Subject: The certificate owner's identification information (Distinguished Name), such as "C=CN, ST=Beijing, L=Beijing, CN=person.org.example.com";

[0117] Subject Public Key Info: Information related to the protected public key:

[0118] ① Public Key Algorithm: the algorithm used by the public key;

[0119] ②Subject Unique Identifier: the content of the public key.

[0120] Issuer Unique Identifier: represents the unique information of the issuer, supported only by versions 2 and 3, optional;

[0121] Subject Unique Identifier: represents the unique information of the entity that owns the certificate. It is only supported by versions 2 and 3. It is optional.

[0122] Extensions (optional): Optional extensions. These may include:

[0123] ①Subject Key Identifier: The key identifier of an entity, used to distinguish multiple pairs of keys of the entity;

[0124] ②Basic Constraints: Indicates whether it belongs to CA;

[0125] ③Authority Key Identifier: Public key identifier of the certificate issuer;

[0126] ④CRL Distribution Points: the issuing address of the revocation file;

[0127] ⑤Key Usage: The purpose or function information of the certificate.

[0128] In addition, the issuer of the certificate also needs to add a signature to the certificate content using his or her own private key to prevent others from tampering with the content of the certificate.

[0129] (3) Merging and binding of identity and attribute certificates

[0130] The merging and binding of identity and attribute certificates, along with other related features, are developed using the OpenSSL and Mosquitto frameworks. OpenSSL supports adding custom fields to the extensions. These fields describe the attributes of entities, including users, processes, devices, and other entities. This enables the merging and binding of identity and attribute certificates.

[0131] Mosquitto is an open source message broker software that implements the MQTT v3.1 message push protocol. It provides a lightweight, publishable / subscribeable message push mode, making short message communication between devices simple.

[0132] MQTT (Message Queuing Telemetry Transport) is a lightweight communication protocol based on the publish / subscribe model. Built on TCP / IP, it was released in 1999. MQTT provides real-time, reliable messaging services for connected remote devices with minimal code and limited bandwidth.

[0133] During the communication process, the MQTT protocol has three roles: publisher, broker (server), and subscriber. The publisher and subscriber of a message are both clients, the message broker is the server, and the publisher can also be a subscriber.

[0134] The identity and attribute certificates are embedded in NC-Link, and the publish / subscribe model of Mosquitto is used. Subscribers subscribe to topics such as issuance, publication, and cancellation. After receiving relevant messages, they are verified in combination with attribute information. After the authentication is completed, the service is provided.

[0135] (4) Hierarchical management of keys

[0136] Key security management usually adopts a hierarchical protection method. The hierarchical key management mechanism divides keys into three layers: local master key, in-transit master key, and working key.

[0137] The first layer is the local master key, which encrypts all other keys and encrypted data stored locally. Different pairs of local master keys are used to encrypt different data or keys. All other keys and encrypted data stored locally are encrypted under the master key, making the local master key the most important key.

[0138] The second layer is the transmission key (Key-encrypting key). Its function is to encrypt the data key to be transmitted on the communication line, thereby realizing the automatic distribution of data keys. In a local or shared network, two different communication nodes use different transmission keys, thus achieving the division of key management. When stored locally, the key is encrypted under the local master key.

[0139] The third layer is the data encryption key, which encrypts various data to achieve data confidentiality, information authentication, and digital signature functions. When these data keys are stored locally, they are encrypted by the local master key.

[0140] (5) Attribute-based access control

[0141] The concept of attribute-based encryption (ABE) originates from fuzzy identity-based encryption (FIBE). The idea behind ABE is to associate ciphertext and keys with a set of attributes and an access structure. Decryption is successful only when the attribute set satisfies the access structure. Based on these pairwise correspondences, ABE can be categorized into two types: key-policy attribute-based encryption (KP-ABE) and ciphertext-policy attribute-based encryption (CP-ABE).

[0142] KP-ABE: The user's key contains an access structure (access policy), and the ciphertext corresponds to a set of attributes. Decryption is successful only if the ciphertext's attributes satisfy the user's key's access structure. The user is the principal, and only specific ciphertexts can be matched and decrypted.

[0143] CP-ABE: A user's key corresponds to a set of attributes, and the ciphertext contains an access structure (policy). Decryption is successful only if the user's attribute set satisfies the ciphertext's access structure. The ciphertext is the subject, and only a specific key can match it for decryption. This invention primarily utilizes CP-ABE, in which data owners can define appropriate access structures based on their needs.

[0144] The NC-Link proxy is designed to route and forward protocol data, securely access devices and applications, and perform user authentication and authorization. Before transmitting data to the application layer, CNC equipment must authenticate itself with the proxy. CNC equipment possesses unique authentication information, including but not limited to the device serial number, MAC address, or other non-copyable and unalterable information.

[0145] The CNC equipment sends an NC-Link protocol authentication request to the NC-Link agent. The NC-Link agent responds to the authentication request based on the trusted identity and attribute certificate service and authenticates the CNC equipment. Only CNC equipment that passes the authentication can successfully access and exchange information.

[0146] Within the Trusted Computing 3.0 framework, the Trusted Identity & Attribute Certificate Service optimizes access between devices, user access to devices, and user access to applications. By deriving user / device attributes from their identities, fine-grained access control is implemented based on attribute-based access control policies, preventing security issues such as unauthorized access and lateral control. For CNC systems with multiple applications, a single sign-on function is provided to avoid repeated authentication. In open network environments, single authentication grants full network access.

[0147] 2. Transmission encryption and integrity protection

[0148] Communication between the NC-Link agent and application systems, between the NC-Link agent and CNC equipment, and through trusted identity and attribute certificate services is based on the NC-Link protocol. This protocol, a nationally recognized cryptographic algorithm, is used to enhance the security of NC-Link, a nationally recognized CNC system communication protocol. This creates a nationally recognized secure channel for data transmission, ensuring data confidentiality, integrity, timeliness, and non-repudiation. The switch to a nationally recognized cryptographic algorithm for secure communication protocols is driven not only by policy compliance but also by the security and controllability of communications infrastructure.

[0149] The TLS protocol (Transport Layer Security) authenticates and encrypts both communicating parties. All information is transmitted encrypted, equipped with identity certificates and a verification mechanism. This invention transforms standard TLS communication into nationally encrypted secure communication that complies with national cryptographic standards. The essence of TLS secure communication is to securely encrypt subsequent communication content using a negotiated symmetric encryption key. This invention adapts the key negotiation portion of the communication message to nationally encrypted standards. It utilizes the nationally encrypted ECDHE negotiation algorithm, using SM2 for signature verification, SM3 for MAC digest calculation, and SM4 for symmetric encryption. Key negotiation utilizes SM2 asymmetric encryption.

[0150] Key agreement is the process of establishing a shared secret key between two users. This process allows the value of the shared secret key to be determined. Let's assume the parties involved are A and B, with key pairs (dA, QA) and (dB, QB) respectively. The bit length of the key data required by both parties is klen. The key agreement protocol consists of two phases.

[0151] In the first phase, a temporary key pair is generated. User A uses the SM2 algorithm to generate a temporary key pair (PriA, PubA) and sends RubA and user A's user ID, IDA, to user B. User B uses the SM2 algorithm to generate a temporary key pair (PriB, PubB) and sends PubB and user B's user ID, IDB, to user A. The temporary private key is valid only during this handshake session and is released after the handshake is complete.

[0152] The second stage calculates the shared secret key. User A inputs the following parameters to obtain key data of length klen: ① User A's public key ② User B's public key ③ User A's temporary public key ④ User A's user identity ⑤ User B's temporary public key ⑥ User B's user identity ⑦ User A's private key ⑧ User A's temporary private key ⑨ The length klen of the key data to be output. The input parameters required by user B are basically the same as those of user A. Only the private key and temporary private key need to be replaced with those of user B. The non-temporary public key and private key correspond to the national secret encryption certificate. The key negotiation process is as follows: Figure 4 shown.

[0153] In order to prove the creativity and technical value of the technical solution of the present invention, this part is a specific product or related technology of the claimed technical solution, which can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0154] The present invention implements attribute access control of the NC-Link protocol, and adds custom attributes to the identity attribute certificate, such as adding a custom field sec_level to define identity level information, adding sec_domain to define identity category information and other security attributes, which are ultimately used in the rule matching process of attribute access control.

[0155] The present invention implements identity authentication based on the NC-Link protocol. In the computer network world, all information, including user identity information, is represented by a set of specific data. Computers can only recognize users' digital identities, and all authorizations to users are also authorizations for the user's digital identity. How to ensure that the operator who operates with a digital identity is the legal owner of this digital identity, that is, to ensure that the operator's physical identity corresponds to the digital identity, the currently used "user name / password" identity authentication method will not meet the security requirements of the audit information system, and a more rigorous and complex user identity authentication system needs to be adopted. The present invention adopts certificate authentication to solve this problem, and provides two identity authentication methods: single certificate authentication and dual certificate authentication.

[0156] 1. Single certificate authentication

[0157] Users use their unique certificate and corresponding private key to perform signing and encryption operations. When signing, user A (referred to as A) encrypts a message digest using their private key, a signature operation. User B (referred to as B) decrypts the digest using A's public key and compares it to verify its accuracy. If correct, B confirms A's identity, indicating a successful signature verification. When encrypting, user A encrypts the message using B's public key and transmits it to user B, who decrypts it using their private key, obtaining the message. When a client subscribes to or publishes a message, it must first provide its own certificate.

[0158] 2. Dual certificate authentication

[0159] Dual certificates include a signing certificate and an encryption certificate. By separating the encryption and signing functions, subscribers possess both encryption and signing certificates. For signing, the signing certificate is used solely for identity verification. Both the public and private keys are generated and maintained by the user; the CA is not responsible for their safekeeping. For encryption, the encryption certificate is used to transmit encrypted data. Both the private and public keys are generated and maintained by the CA (stub). When a client subscribes to or publishes a message, it must provide both the signing and encryption certificates.

[0160] The present invention implements the transmission encryption function based on the NC-Link agent. To adapt to complex industrial interconnection and numerical control scenarios, it uses the national secret algorithm to establish a secure communication channel to ensure information integrity and identity authentication.

[0161] The present invention realizes the trusted network and active immunity function of NC-Link agent. The trusted platform control module (TPCM) and trusted software base (TSB) are configured at the hardware layer and system layer of the NC-Link agent terminal respectively. The TPCM participates in the generation of trusted status reports, identity verification, password negotiation and other tasks in network communication. The identity of the terminal is identified by the built-in trusted cryptography module (TCM) to ensure the confidentiality and security of data during the interaction process. The trusted software base mainly completes the functions of intercepting, measuring and managing user behaviors. The network environment topology example is Figure 5 shown.

[0162] The embodiments of the present invention have achieved some positive results during the development or use process, and indeed have great advantages over the existing technology. The following content describes them in conjunction with data, charts, etc. from the experimental process.

[0163] After in-depth research and multi-index experiments on the NC-Link, MT-Connect, and OPC-UA protocols, the experimental verification results are shown in the following table.

[0164] Table 1 Verification indicators of each protocol

[0165] Protocol Name Transmission method Data Flow Difficulty of data collection Remark OPC-UA binary stream Bidirectional difficulty MT-Connect XML unidirectional medium NC-Link JSON string Bidirectional Simple

[0166] The NC-Link protocol uses JSON string transmission, requiring less network bandwidth than the XML transmission of the MT-Connect protocol. NC-Link utilizes a publish-subscribe data transmission model, with bidirectional data flow, while MT-Connect's data flow is unidirectional. The NC-Link protocol offers simplified machine tool model definitions, unlike the OPC-UA protocol, which requires the manufacturer to provide a data definition manual, preventing data collection from the equipment. NC-Link can meet the requirements of high-frequency data collection, which the other two protocols cannot.

[0167] This paper implements attribute access control for the NC-Link protocol by adding custom attributes to identity attribute certificates. After technical research and experiments, detailed information on attribute access control and other mainstream access control methods is shown in Table 2.

[0168] Table 2 Comparison of NC-Link attribute access control with other access control methods

[0169] Role-based access control Attribute-based access control Role-based access control Core Idea A role set is established between the user set and the permission set. A corresponding set of access permissions is set for each role. When authorizing users, it is only necessary to establish a mapping from users to roles, so that users directly have all the permissions of the role. Whether to allow users to access resources is determined based on the attributes of the entity, where access control policies can be flexibly formulated based on attribute values ​​and the relationships between attributes. It starts from the perspective of workflow, divides the business into multiple tasks, and then dynamically manages permissions based on tasks and task status. It is suitable for solving the information management and control needs of multiple institutions in a distributed environment. advantage ①Simplified user authority management. ②Reduced system operation overhead. It overcomes the limitations of role identities, can describe access rights through attributes, and has the conditions to implement the principle of least authorization. Access rights are bound to tasks, and the rights are consumed when the task is completed. Therefore, the subject's access to the object has a time window, which improves security. shortcoming In the industrial Internet scenario, it is difficult to refine the access rights of CNC applications to each role, and the phenomenon of over-authorization and under-authorization is difficult to avoid. ① Access policies are user-defined, and their execution still relies on third-party endorsements and authoritative institutions. Users often cannot track the results of their execution, making personal data leaks difficult to detect. ② User-defined policies are stored on servers and are also susceptible to tampering by hackers, leading to data leaks. (Often combined with blockchain technology) It only focuses on workflow without designing constraints on subjects and objects, which does not conform to actual application situations. Therefore, it is often used as a supplementary mechanism in combination with other access control models. Applicable Scenarios Enterprise-level data security management Applicable to complex security scenarios, providing fine-grained access control services Solve the information management and control needs of multiple institutions in a distributed environment

[0170] It can be seen that attribute-based access control provides a more intelligent decision-making method and more proactive fine-grained security access control compared to other access control methods, and is more suitable for complex security scenarios of industrial Internet and CNC equipment.

[0171] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware portion can be implemented using dedicated logic; the software portion can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. Those skilled in the art will appreciate that the above-mentioned devices and methods can be implemented using computer-executable instructions and / or contained in processor control code, for example, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, or can be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0172] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A safe and reliable NC-Link agent control method, characterized in that: Step 1: Implement identity authentication and access control based on trusted identity and attribute certificate services; Step 2: Encrypt and protect the integrity of the NC-Link communication protocol. The transmission encryption and integrity protection in step 2 includes: Communication between the NC-Link agent and the application system, between the NC-Link agent and the CNC equipment, and between the trusted identity and attribute certificate services are all based on the NC-Link protocol. Domestic cryptographic algorithms are used to implement security reinforcement for the domestic CNC system communication protocol NC-Link, generating a national secret security channel to achieve data transmission security. The TLS protocol authenticates and encrypts both communicating parties. All information is transmitted encrypted and is equipped with identity certificates and a verification mechanism. It transforms standard TLS communication into national cryptographic secure communication that complies with national cryptographic standards. The essence of TLS secure communication is to securely encrypt subsequent communication content based on the symmetric encryption key generated through negotiation, and to adapt the key negotiation portion of the communication message to national cryptography. It adopts the national cryptographic ECDHE negotiation algorithm, uses the national cryptographic SM2 for signature verification, SM3 for MAC digest calculation, SM4 for symmetric encryption, and key negotiation uses SM2 asymmetric encryption. The value of the shared secret key is determined through key negotiation. Assume that the two parties in the key negotiation are A and B, the key pairs are (dA, QA) and (dB, QB) respectively, and the key data bit length obtained by both parties is klen. The key negotiation protocol includes: In the first phase, a temporary key pair is generated. User A calls the SM2 algorithm to generate a temporary key pair (PriA, PubA), and sends PubA and user A's user identity ID A to user B. User B calls the SM2 algorithm to generate a temporary key pair (PriB, PubB), and sends PubB and user B's user identity ID B to user A. The temporary private key is only valid during this handshake session and is released after the handshake ends. The second stage calculates the shared secret key; User A inputs the following parameters to obtain key data of length klen: ① User A's public key; ② User B's public key; ③ User A's temporary public key; ④ User A's user identity; ⑤ User B's temporary public key; ⑥ User B's user identity; ⑦ User A's private key; ⑧ User A's temporary private key; ⑨ The length klen of the key data to be output; The input parameters required by User B are basically the same as those of User A, except that the private key and temporary private key need to be replaced with those of User B; The non-temporary public key and private key correspond to the encryption certificate of the national secret; The NC-Link protocol is integrated with the national encryption algorithm to implement the NC-Link CNC communication agent, which performs identity authentication and provides transmission encryption and integrity protection. The NC-Link protocol is integrated with attribute access control to implement permission control for upstream and downstream operations of the CNC system by embedding identity and attribute certificates into NC-Link. A distributed deployment solution is provided through the message routing and bridging of the NC-Link agent.

2. The secure and reliable NC-Link agent control method according to claim 1, wherein: The implementation of identity authentication and access control in step 1 includes: Identity authentication and access control functions are based on trusted identity and attribute certificate services. Based on the X.509 standard, dynamic policy configuration of attribute-based access control is used to overcome the mismatch between the lifecycles of identity certificates and attribute certificates, and to achieve the merging and binding of identity certificates and attribute certificates. In combination with the NC-Link protocol, identity and attribute certificate application, review, issuance, release, and cancellation services are provided to users, processes, and device entities. Based on the TPCM and trusted cryptographic services of Trusted Computing 3.0, a multi-level key management mechanism is implemented in the certificate service, including key separation, master key derivation encryption key, encryption protection data key, and session key capabilities, forming lifecycle protection for keys at all levels and realizing lightweight identity and attribute certificate services. The concept of attribute-based encryption (ABE) is derived from fuzzy identity-based encryption (IBE). ABE associates ciphertext and key with attribute sets and access structures. Decryption is successful only when the attribute sets satisfy the access structure. Based on the pairwise correspondence, ABE is divided into two categories: key policy attribute-based encryption (KP-ABE) and ciphertext policy attribute-based encryption (CP-ABE). KP-ABE is an access structure and / or access policy implied in the user's key, corresponding to a set of attributes in the ciphertext. Decryption is successful if and only if the attribute set of the ciphertext satisfies the access structure of the user's key. The user is the subject, and only specific ciphertexts can be matched with them for decryption. CP-ABE is a set of attributes corresponding to the user's key. The ciphertext contains the access structure and / or access policy. The user decrypts successfully if and only if the user's attribute set satisfies the ciphertext's access structure. The ciphertext is the main body, and only a specific key can match it and thus decrypt it. With CP-ABE, the data owner in CP-ABE defines the appropriate access structure according to his or her needs.

3. A secure and reliable NC-Link agent using the secure and reliable NC-Link agent control method according to any one of claims 1 to 2, characterized in that: The secure and reliable NC-Link agent includes: CNC equipment, adapter, MES application system, CNC system, Trusted Computing 3.0 system, Trusted Platform Control Module TPCM and domestic high-speed cryptographic service module; The NC-Link agent includes protocol data routing, forwarding, secure access to devices and applications, user authentication and authorization. CNC equipment must authenticate itself to the agent before transmitting data to the application layer. CNC equipment has unique identity authentication information, including device serial number, MAC address, or other information that cannot be copied or changed; The Trusted Computing 3.0 system includes a brand-new trusted system framework based on independent cryptography, with control chips as the backbone, dual-integration motherboards as the platform, trusted software as the core, trusted connections as the link, policy management as the system, and secure and reliable applications. It is used to solve trust issues at the network level. The Trusted Platform Control Module (TPCM) is the core of the active immunity mechanism in the Trusted Computing 3.0 system and is used to achieve active control of the secure and trusted NC-Link agent.

4. The secure and reliable NC-Link agent according to claim 3, wherein: The CNC equipment sends an NC-Link protocol authentication request to the NC-Link agent. The NC-Link agent responds to the authentication request based on the trusted identity and attribute certificate service and authenticates the CNC equipment. Only CNC equipment that has passed identity authentication can successfully access and interact with information; The Trusted Computing 3.0 system uses a cryptographic system that combines symmetric and asymmetric encryption as an immune gene; By implanting the trusted source root into the active measurement control chip TPCM and adding the trusted root control function on the basis of TCM, cryptography and control are combined. The trusted platform control module is designed as a trusted computing control node to realize the active control of the entire platform by the trusted platform control module TPCM. The Trusted Platform Control Module (TPCM) is a hardware module integrated into the trusted platform. It is the root of trust for the active immune trust system and is used to establish and protect the source of trust. It provides a series of trusted computing functions including trusted platform control, integrity measurement, secure storage, trusted reporting, and cryptographic services. Under the Trusted Computing 3.0 framework, trusted identity and attribute certificate services optimize mutual access between devices, user access to devices, and user access to applications. They obtain user / device attributes through user / device identities and implement fine-grained access control based on attribute access control policies. They provide single sign-on functionality for CNC systems with multiple applications, and authenticate access to the entire network in an open network environment with one authentication.

5. A computer device, characterized in that: The computer device includes a memory and a processor. The memory stores a computer program. When the computer program is executed by the processor, the processor executes the steps of the secure and reliable NC-Link agent control method according to any one of claims 1 to 2.

6. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the secure and reliable NC-Link agent control method according to any one of claims 1 to 2.

7. An information data processing terminal, characterized in that: The information data processing terminal is used to implement the secure and reliable NC-Link agent as claimed in any one of claims 3 to 4.

Images