Railway knowledge intelligent hierarchical access control method and device and electronic equipment

Abstract

The invention relates to an intelligent hierarchical access control method and device for railway knowledge and electronic equipment, and the method comprises the steps: registering key certificates for national railway group nodes, railway bureau group nodes and basic-level station nodes, and generating global trusted identity chain certificates; dividing the to-be-accessed railway knowledge assets into four levels, and establishing a relationship between the security level and the user role; loading a railway exclusive strategy expression, and supporting hierarchical inheritance and timeliness logic combination; in response to a user data access request, based on an identity certificate and role attributes, matching a security level of request data with a user role permission threshold, analyzing a railway service dynamic combination condition, judging a current service scene access permission, generating a decryption key or calling an edge gateway to execute outsourcing decryption; and storing the encrypted data to a distributed file system, and recording data hash, a security level and an access operation log. According to the method, the problems of weak identity credibility mechanism, low efficiency of authority management coarse granularity and insufficient industrial characteristic adaptation are solved.

Description

Technical Field

[0001] The present invention relates to the field of railway knowledge intelligent hierarchical access control method, device and electronic equipment, and in particular to a railway knowledge intelligent hierarchical access control method, device and electronic equipment. Background Art

[0002] As the railway's digital transformation deepens, multiple levels of organizations, including the National Railway Group, Railway Bureau Group, and grassroots stations, need to efficiently share sensitive intellectual assets such as official documents, operational data, and strategic documents. However, existing access control technologies have the following key flaws: Weak identity trust mechanism: Traditional centralized or decentralized permission models lack global identity authentication capabilities.

[0003] Coarse-grained and inefficient permission management: Static role-based authorization (RBAC) relies on manual configuration and cannot support dynamic combinations of conditions unique to railways, such as "administrative jurisdiction + job type + business time window." This makes it poorly suited for cross-regional scheduling and time-sensitive data flow scenarios.

[0004] Insufficient adaptation to industry characteristics: Existing blockchain access solutions (such as Fabric-iot) focus on IoT stream data management. Their resource models, policy expressions, and architectural designs do not integrate the core needs of railways: they do not cover the four-level security classification system of railway knowledge (L1~L4), and cannot achieve accurate mapping of sensitive data and roles; they lack support for railway-specific attributes such as hierarchical permission inheritance and operation diagram sensitivity, and the success rate of cross-domain authorization is low; the lack of light node computing power optimization makes it difficult for grassroots stations to bear high-overhead encryption and decryption operations.

[0005] The above-mentioned defects have resulted in the railway knowledge flow facing triple bottlenecks in terms of security, efficiency, and compliance, and there is an urgent need to build a hierarchical access control solution that deeply integrates industry characteristics. Summary of the Invention

[0006] Based on this, it is necessary to provide a railway knowledge intelligent hierarchical access control method, device and electronic equipment to address the technical problems of weak identity trust mechanism, coarse-grained and inefficient authority management and insufficient adaptation to industry characteristics.

[0007] The present invention provides a method for intelligent hierarchical access control of railway knowledge, the method comprising: Through the blockchain network, key certificates are registered for the National Railway Group nodes, Railway Bureau Group nodes, and grassroots station nodes to generate global trusted identity chain credentials and build a three-level trusted identity mapping; The railway knowledge assets to be accessed are divided into four security levels according to their sensitivity, and a binding relationship between security levels and user roles is established; Railway-specific policy expressions containing administrative areas, job types, and business time windows are loaded through smart contracts, supporting hierarchical inheritance and time-efficiency logic combinations; In response to user data access requests, the identity certificate and role attributes of the requesting node are verified based on the blockchain, and the security level of the requested data is matched with the user role permission threshold. The railway business dynamic combination conditions in the policy expression are parsed to determine the access rights for the current business scenario. When the permission verification passes, a decryption key is generated according to the attribute encryption mechanism or an edge gateway is called to perform outsourced decryption. The encrypted data is stored in a distributed file system, and the data hash, security level, and access operation log are recorded on the blockchain.

[0008] In one embodiment, generating a decryption key according to an attribute encryption mechanism includes: For each attribute Generate private key components and , to generate the user attribute key; Through bilinear mapping Recover the symmetric key z and finally decrypt the ciphertext .

[0009] In one embodiment, performing outsourced decryption includes: User generates a temporary authorization key ; The edge gateway calculates the intermediate value based on the authorization key ; Users calculate Get the plaintext.

[0010] In one embodiment, the blockchain-based verification of the identity certificate and role attributes of the requesting node includes: Verify the legitimacy of the user node certificate through the CA certificate chain deployed by the China Railway Group node; Extract the railway bureau group code, station number and job role label to which the user belongs from the blockchain attribute ledger.

[0011] In one embodiment, the matching of the security level of the request data with the user role authority threshold includes: Establish a dynamic permission threshold matrix to map L1~L4 security levels to role permission values; If the security level of the requested data exceeds the user role permission threshold, a blockchain alarm event will be triggered immediately.

[0012] In one embodiment, the railway business dynamic combination condition in the parsing strategy expression includes: Compile the policy expression into a syntax tree structure, where the root node is a logical operator and the leaf node is an atomic condition; Inject real-time railway scheduling data stream and dynamically update the decision threshold of grammatical leaf nodes.

[0013] In one embodiment, the step of calling the edge gateway to perform outsourced decryption also includes: Verify the availability of edge gateways through a lightweight consensus protocol and filter edge nodes with load rates lower than a preset value; Generate partial decryption key fragments based on the attribute encryption mechanism and distribute them to the selected edge gateways.

[0014] In one embodiment, the step of calling an edge gateway to perform outsourced decryption may include: The gateway encrypts the decryption result with the public key of the requesting node, generating a double-layer ciphertext and sending it back; If the decryption times out or the result verification fails, the key fragment rotation mechanism is triggered.

[0015] The present invention also provides a railway knowledge intelligent hierarchical access control device, the device comprising: The identity mapping construction module is used to register key certificates for the National Railway Group nodes, Railway Bureau Group nodes, and grassroots station nodes through the blockchain network, generate domain-wide trusted identity chain credentials, and build a three-level trusted identity mapping; The railway knowledge classification module is used to classify railway knowledge assets to be accessed into four security levels according to their sensitivity, and to establish a binding relationship between security levels and user roles; Access policy parsing module, used to load railway-specific policy expressions containing administrative jurisdictions, job types, and business time windows through smart contracts, supporting hierarchical inheritance and time-sensitive logic combinations; The control decision execution module is used to respond to user data access requests, verify the identity certificate and role attributes of the requesting node based on the blockchain, match the security level of the requested data with the user role permission threshold, and parse the railway business dynamic combination conditions in the policy expression to determine the access rights of the current business scenario. When the permission verification passes, the module generates a decryption key based on the attribute encryption mechanism or calls the edge gateway to perform outsourced decryption. The distributed traceability operation module is used to store encrypted data in a distributed file system and record data hashes, security levels, and access operation logs on the blockchain.

[0016] The present invention also provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it implements any of the above-described intelligent hierarchical access control methods for railway knowledge.

[0017] The above-mentioned intelligent hierarchical access control method, device and electronic equipment for railway knowledge eliminate the risk of cross-level identity forgery by building a three-level trusted identity mapping, and realize traceability of full-domain operations; implement railway knowledge grading to accurately match L1~L4 sensitive data and role permissions, eliminating the risk of unauthorized access; analyze dynamic access strategies to replace static RBAC authorization with dynamic combination conditions of "jurisdiction + position + time window", breaking through the adaptation bottleneck of traditional RBAC in cross-regional scheduling and time-sensitive data flow, and improving the success rate of cross-regional scheduling authorization; execute access control decisions through attribute encryption and edge computing collaboration, while ensuring L3 / L4 level data security, significantly reducing the computing power load of grassroots nodes, breaking through the computing power bottleneck of light nodes; realize distributed traceability to make full-link operations traceable and data tampering detectable, ensuring full-link compliance audit. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A flow chart of a method for intelligent hierarchical access control of railway knowledge according to an embodiment; Figure 2 A flow chart of a method for intelligent hierarchical access control of railway knowledge according to another embodiment; Figure 3 A schematic diagram of a railway knowledge intelligent hierarchical access control device according to one embodiment; Figure 4 FIG. 1 is a diagram showing the internal structure of a computer device according to an embodiment. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0021] As the digital transformation of the railway system deepens, the demand for cross-level and cross-regional knowledge sharing is increasing in businesses such as transportation scheduling, equipment operation and maintenance, and emergency command. The railway industry involves multiple levels of units, including the National Railway Group, Railway Bureau Group, and grassroots stations. Compliance access to sensitive information such as announcements, regulations, and operational data must be achieved while ensuring security. Traditional access control methods have significant drawbacks: Insufficient reliability: Existing railway knowledge access relies heavily on centralized permission models or decentralized local authorization, lacking a network-wide trusted identity authentication mechanism, making it difficult to meet the high security requirements of the railway system.

[0022] Low level of automation: Mainstream coarse-grained role-based access control (RBAC) permission management requires manual configuration of policies and cannot adapt to the complex organizational structure and dynamic access requirements of railways (such as cross-regional scheduling and time-sensitive data flow), resulting in low efficiency and prone to errors.

[0023] To address the above issues, a universal access control solution based on blockchain is proposed. It uses Hyperledger Fabric and attribute-based access control (ABAC) to manage IoT device resources. Its core solution includes: Resource and contract model: Maps the streaming data generated by the device (such as video URLs and sensor topics) to on-chain resources, and defines access policies for user attributes (ID, role, group), resource attributes (device ID), permission attributes (allow / deny), and environmental attributes (time, IP) through smart contracts.

[0024] System architecture: Consists of users, blockchain, smart gateway, and devices. Devices upload resource URLs to the blockchain through the smart gateway. After users initiate attribute requests, the blockchain verifies permissions through the access contract (AC) and returns the resource URL.

[0025] Smart contract design: Three types of contracts are used - contract contract (PC) management strategy, device contract (DC) storage URL, and access contract (AC) execution permission verification, to achieve dynamic authorization through automated processes.

[0026] However, this solution is not suitable for railway scenarios: Lack of industry characteristics: Its resource model focuses on IoT streaming data (such as video URLs and sensor topics), and is not adapted to the multi-level classification of railway knowledge (L1~L4), administrative hierarchy inheritance (such as the bureau group inheriting the national railway authority) and business sensitivity (such as the timeliness of the operation diagram).

[0027] Insufficient permission granularity: Policy expressions lack railway-specific dimensions (such as jurisdiction, position, and business time window), and cannot support complex conditions such as "access is limited to the dispatching director of the Zhengzhou Bureau during the timetable adjustment period."

[0028] Performance and architecture mismatch: The encryption and decryption overhead of railway light nodes (limited station computing power) was not optimized, and policy management did not consider railway collaboration requirements such as version inheritance, resulting in inefficient cross-domain authorization (the measured success rate was only 76%).

[0029] Therefore, there is an urgent need for a knowledge-based hierarchical access control solution that deeply integrates railway business characteristics and supports fine-grained dynamic authorization. This solution deeply integrates blockchain smart contracts, distributed attribute encryption, and multi-level node collaborative authentication technology. It targets the railway industry's unique multi-level organizational structure (National Railway Group-Railway Bureau Group-grassroots stations / work sections), complex knowledge types (official documents, operational data, etc.), and dynamic business scenarios, and builds a fine-grained, traceable knowledge-based hierarchical access control system to achieve the compliant flow and secure sharing of sensitive railway information.

[0030] The following combination Figures 1 to 4 The present invention describes the railway knowledge intelligent hierarchical access control method, device and electronic equipment.

[0031] like Figure 1 As shown, in one embodiment, a method for intelligent hierarchical access control of railway knowledge includes the following steps: Step S110: register key certificates for the National Railway Group nodes, Railway Bureau Group nodes and grassroots station nodes through the blockchain network, generate domain-wide trusted identity chain credentials, and build a three-level trusted identity mapping.

[0032] Construct a multi-level node authentication network based on blockchain, in which China Railway Group nodes, Railway Bureau Group nodes and grassroots station nodes are registered on the chain through keys, forming a three-level trusted identity mapping system of "China Railway Group-Railway Bureau Group-Grassroots Station", including: Attribute management layer: led by the National Railway Administration node, generating public parameters , where G is a bilinear group, g is a generator, e:G×G→G is a bilinear mapping, and H / F is a hash function. A global policy template is deployed, defining user roles, regional attributes, and time windows. The access control layer is managed by the railway bureau group node and deploys a policy execution contract (PEP) and a cross-domain access contract (DAA) to perform permission verification, cross-domain coordination, and encryption and decryption proxying. The data management layer is executed by grassroots station nodes, storing encrypted data in a distributed file system and recording data hash values, security levels, and access policies on the blockchain. A three-level node authentication network is used to build a trusted foundation for railway-wide identity authentication, eliminating the risk of identity forgery at the source.

[0033] In step S120 , the railway knowledge assets to be accessed are divided into four security levels according to their sensitivity, and a binding relationship between the security level and the user role is established.

[0034] Railway knowledge assets are divided into four security levels according to their sensitivity: L1 fully public level, L2 restricted public level, L3 audited public level and L4 sensitive core level, and a binding relationship is established between security levels and user roles. Level L1 corresponds to fully public data, allowing ordinary terminal users to have unrestricted access to train timetables and station announcements; Level L2 corresponds to restricted public data of station / section nodes, allowing only station administrators and grassroots employees to access the station's equipment inspection logs and employee attendance data; Level L3 corresponds to the audited public data of the railway bureau group node, allowing only bureau group engineers and middle-level managers to access cross-bureau scheduling plans and financial budget reports; Level L4 corresponds to the sensitive core data of the National Railway Administration node, allowing only National Railway Administration analysts and leaders to access the high-speed rail core technical solutions. Among them, L1~L2 data are symmetric encrypted. , L3~L4 level data uses attribute encryption , where M is the plaintext data, SK is the symmetric key used for AES-256 encryption, and ⊕ is the XOR operation, which mixes the plaintext M with the encryption result to generate the ciphertext. is a bilinear map, is the generator of the cyclic group G. z (master key), a randomly generated key, is used to protect sensitive data. Level 1 public data supports passenger services, while level 4 core data ensures the highest level of security, forming a hierarchical protection system unique to the railway industry. The railway knowledge grading engine accurately matches L1-L4 sensitive data with roles, eliminating the risk of unauthorized access and resolving the "coarse-grained permission division" issue in traditional solutions. This prevents low-privilege roles from accessing highly sensitive data (e.g., grassroots employees accidentally accessing high-speed rail technical solutions).

[0035] Step S130, loading railway-specific policy expressions including administrative areas, job types, and business time windows through smart contracts, supporting hierarchical inheritance and timeliness logic combinations.

[0036] Railway-specific access policies are defined through smart contracts, supporting dynamic logical combinations of administrative jurisdictions, job types, and business time windows, with syntax supporting hierarchical inheritance and time constraints. Railway-specific policy expressions support the following logical combinations: AND / OR relationships: Administrative jurisdictions and job type attributes are linked using AND / OR operators; hierarchical inheritance: Automatic inheritance of parent organization permissions, implemented using the syntax (Org@subordinate bureau group) OR (ParentOrg@superior bureau group); and dynamic time windows: Access validity periods are limited using the syntax Time@[start time, end time]. The logical combination of policy expressions supports cross-regional railway collaboration (such as bureau groups inheriting national railway authority) and accommodates time-sensitive scenarios such as dispatch instructions. Policy expressions also incorporate attributes specific to railway transportation scenarios, such as binding the train timetable to the timetable sensitivity attribute, generating the expression: (Sensitivity ≥ 3 AND Job = Dispatcher) AND (Time period ∈ Timetable Adjustment Period). Railway-specific attributes (such as "diagram sensitivity ≥ 3" AND "dispatcher position" AND "adjustment period") are introduced to implement dynamic business policies and provide refined control for train dispatching scenarios, preventing non-dispatchers from erroneously manipulating the diagram during highly sensitive periods. Railway-specific policy expressions support dynamic authorization based on "jurisdiction + position + time window," addressing the adaptability shortcomings of traditional RBAC models in scenarios such as cross-regional dispatching and time-sensitive data transfer.

[0037] Step S140, in response to the user data access request, verifies the identity certificate and role attributes of the requesting node based on the blockchain, matches the security level of the requested data with the user role authority threshold, and parses the railway business dynamic combination conditions in the policy expression to determine the access rights of the current business scenario, and, when the authority verification is passed, generates a decryption key according to the attribute encryption mechanism or calls the edge gateway to perform outsourced decryption.

[0038] When a user initiates a data access request, the access control layer smart contract performs the following operations: Verify the identity certificate and role attributes of the user node. Optionally, verify the legitimacy of the user node certificate through the CA certificate chain deployed by the National Railway Group node; extract the railway bureau group code, station number and job role label to which the user belongs from the blockchain attribute ledger.

[0039] The security level of the requested data is matched to the user role permission level. The matching rules for user role permission thresholds are as follows: users requesting L3 data must be engineers or mid-level managers of railway bureau groups; users requesting L4 data must be analysts or leaders of the National Railway Administration; and the user's node level must be at least the node level corresponding to the data security level. Optionally, a dynamic permission threshold matrix is ​​established, mapping security levels L1-4 to role permission values ​​(L1: 0-25, L2: 26-50, L3: 51-75, L4: 76-100). If the security level of the requested data exceeds the user role permission threshold, an immediate blockchain alert is triggered. The CA certificate chain verifies global identity trust, and the attribute ledger extracts railway coded tags (such as bureau group / station ID). The dynamic permission matrix maps L1-L4 to numerical thresholds (0-100), enabling quantitative permission determination. This provides a computable mathematical foundation for permission matching and supports the automated execution of smart contracts.

[0040] The policy expression parses the combination of railway business attributes and, optionally, compiles the policy expression into a syntax tree structure, where the root node is a logical operator (AND / OR) and the leaf nodes are atomic conditions (administrative area, position type, business time window). Real-time railway scheduling data streams are then injected to dynamically update the thresholds for the syntax leaf nodes. By compiling the policy into a syntax tree structure (root node = logical operator, leaf node = atomic condition) and injecting real-time railway data streams (such as Spring Festival travel schedule instructions), the leaf node thresholds are dynamically updated to adapt to railway business fluctuations. When the dynamic permission threshold matrix works in conjunction with the policy syntax tree, if the business time window in the atomic condition falls within the Spring Festival travel period, the permission threshold is automatically increased by 20%. If permission verification fails, the core atomic condition in the syntax tree that caused the rejection is recorded in the blockchain alert log. This allows for rapid identification of the root cause of permission failures and improves operational efficiency.

[0041] Dynamically generate decryption keys based on attribute encryption mechanisms or call edge gateways to perform outsourced decryption.

[0042] The decryption process of the attribute encryption mechanism includes: User attribute key generation: For each attribute Generate private key components ,as well as, , where A unique identifier for the user. is the user attribute, is a generator, is the component of the institution's master key ( Indicates the organizational level, such as National Railway Administration, Railway Administration Group), As a hash function, mapped to group elements (for identity binding), Attribute hash function, which converts the attribute Mapped to group elements, is a random number to ensure key security. , Target attributes for users The private key component of the

[0043] Decryption calculation: through bilinear mapping Recovering the symmetric key , and finally decrypt the ciphertext , Encrypted ciphertext for railway knowledge. Key sharding design ( ) Combined with bilinear mapping , achieving fine-grained attribute decryption.

[0044] Outsourced decryption process: User generates temporary authorization key , where A random number generated for the user to protect the original private key. The ID of the user group to which the user belongs. is the user attribute, K ' is the identifier of the temporary authorization key, which is different from the original private key. It is the original key component generated based on the user group identifier and user attributes. It is one of the basic keys for users to decrypt data. The proxy server can only calculate the intermediate result. ; The edge gateway calculates the intermediate value based on the authorization key ; User calculates Obtain plaintext and restore it in a lightweight manner. This solves the problem of insufficient computing power at grassroots stations and improves L3 / L4 data decryption efficiency (measured latency reduction of 74%).

[0045] Before calling an edge gateway to perform outsourced decryption, a lightweight consensus protocol verifies the edge gateway's availability, screens edge nodes with load rates below 40%, generates partial decryption key fragments based on an attribute encryption mechanism, and distributes them to the selected edge gateway. After the edge gateway performs outsourced decryption, it encrypts the decryption result with the requesting node's public key, generating a double-layer ciphertext for return. If the decryption timeout or verification fails, a key fragment rotation mechanism is triggered. This ensures the reliability of outsourced decryption and meets the security requirements of the weak computing environment of station nodes.

[0046] Step S150: Store the encrypted data in the distributed file system and record the data hash, security level and access operation log in the blockchain.

[0047] Encrypted data is stored in a distributed file system, and the data hash, security level, and access policy are recorded on the blockchain, enabling distributed traceability of the entire operation process. The distributed file system uses IPFS to store encrypted data, and the blockchain records metadata such as the IPFS access address, data hash value (Hash (C0), data security level identifier, and associated access policy expression. Distributed traceability operations include generating a unique RailChain_ID for the encrypted data (format: jurisdiction code_station ID_timestamp_first 8 digits of the hash), and associating the smart contract address and execution status code storing the access policy in the blockchain traceability log. This enables full-chain traceability of the operation and complies with the Level 3 compliance requirements of railway security protection. When the edge gateway interacts with the RailChain_ID, the gateway verifies the consistency of the jurisdiction code in the RailChain_ID with its own deployment region before decryption. After the decryption operation is complete, the gateway device fingerprint is appended to the blockchain log associated with the RailChain_ID, thereby strengthening regional cooperation.

[0048] This embodiment of the intelligent hierarchical access control method for railway knowledge eliminates the risk of cross-level identity forgery by establishing a three-level trusted identity mapping, achieving full-domain operation traceability. Railway knowledge hierarchies accurately match L1-L4 sensitive data with role permissions, eliminating the risk of unauthorized access. Dynamic access policy parsing replaces static RBAC authorization with a dynamic combination of "jurisdiction + position + time window" conditions, breaking through the adaptation bottleneck of traditional RBAC in cross-regional scheduling and time-sensitive data flow, and increasing the success rate of cross-regional scheduling authorization to 98% (compared to 76% with traditional solutions). Access control decision execution utilizes attribute encryption and edge computing to significantly reduce the computing load on grassroots nodes while ensuring L3 / L4 data security. Encryption and decryption resource consumption at grassroots station nodes is reduced by 67%, breaking through the computing bottleneck of light nodes. Distributed traceability ensures full-link operation traceability and data tampering detection, ensuring full-link compliance auditing. The overall solution reduces policy response latency to 210ms (compared to 820ms with traditional solutions), meeting the Level 3 requirements of railway security protection.

[0049] like Figure 2 As shown, in one embodiment, the present invention is implemented by the following technical solutions: In the digital transformation of the railway system, secure knowledge sharing faces complex challenges posed by multi-level collaboration and the intersection of multiple business scenarios. To address this, a three-level node mapping ("National Railway Group-Railway Bureau Group Company-Station") and blockchain registration and authentication mechanisms can be used to build a trusted identity infrastructure. To address the security tiering requirements for diverse knowledge types, such as railway announcements and operational data, this solution, combined with the aforementioned knowledge access control technology, further refines the security tiers and designs a four-level access control system covering "fully public" to "sensitive core." This system, combined with automated smart contract verification and blockchain distributed storage, enables precise matching of user roles and knowledge levels, providing technical support for the compliant transfer and efficient utilization of railway knowledge across different security dimensions.

[0050] First, a multi-level blockchain-based document sharing platform was constructed, followed by a railway-specific attribute access control system. When issuing official documents, grassroots railway units (such as stations and sections) can define policy expressions (e.g., Region@Zhengzhou Bureau Group AND Role@Station Administrator). This ensures that only users with both region management permissions and the station administrator role granted by the Zhengzhou Bureau Group can decrypt and access the document. The platform is collaboratively maintained by multiple management organizations, including the National Railway Administration and the Railway Bureau Group Corporation. Each organization acts as a blockchain node to jointly verify data access rights. Given the limited computing power of grassroots units like stations and sections, encryption and decryption operations can be securely outsourced to the edge computing nodes of the affiliated Railway Bureau Group. These nodes perform the complex cryptographic operations, leaving grassroots units only requiring lightweight identity verification. This ensures security while improving document circulation efficiency.

[0051] (1) Knowledge security level and user role mapping Railway knowledge is divided into four levels based on sensitivity and access control requirements, forming a precise mapping system of "user role-node type-security level": 1) L1 is fully public For ordinary terminal users (such as external personnel and passengers), they can have unrestricted access to basic railway information (such as train timetables and station announcements), with only read-only permissions. The corresponding node is an ordinary terminal that does not require special authentication.

[0052] 2) L2 Limited Public It covers data stored in station / section nodes and is aimed at station managers and grassroots employees. It allows them to read and download restricted data (such as equipment inspection logs and employee attendance data at the station) within the jurisdiction. They must pass the basic permission verification of the railway bureau group to which they belong. The node type is a lightweight terminal with limited computing resources.

[0053] 3) L3 audit disclosure It matches the node-level data of the railway bureau group company / branch, and is aimed at bureau group engineers and middle-level managers. They can read, modify and forward data within their respective areas (such as cross-branch scheduling plans and financial budget reports). They need to pass cross-domain authority review and time window control. The node has medium to high computing power and is responsible for regional authority coordination tasks.

[0054] 4) L4 sensitive core Exclusive data at the National Railway Administration / Regulatory Bureau node level is available to analysts and leaders of the National Railway Administration. They have full permissions (read, write, modify, and manage) and can access the most advanced data (such as high-speed rail core technical solutions). This data must pass strict global authentication and encryption processing. The node is the core node in the blockchain network and is responsible for global strategy formulation and cross-domain collaboration.

[0055] (2) Cross-system attribute strategy expression Extended policy syntax to support complex logical combinations: 1) And / or relationship: (Region@National Railway Administration) AND (Time@Working Day) AND (Role@Analyst) 2) Hierarchical inheritance: automatically includes the permissions of the parent organization (Org@Zhengzhou Railway Bureau Group) OR (ParentOrg@National Railway Administration) 3) Dynamic time window: valid within a specified year Time@[2025-05-01,2025-12-31] (3) Access control architecture design The railway knowledge hierarchical access control architecture adopts a three-layer system of "attribute management layer, access control layer, and data management layer" to achieve hierarchical collaboration among policy definition, permission verification, and data storage. 1) Attribute management layer (led by the National Railway Administration) As the global policy hub, it is responsible for defining basic permission parameters such as user roles, regional attributes, time windows, and generating and distributing public and private key pairs and root certificates.

[0056] By initializing public parameters such as bilinear groups and hash functions through smart contracts, the mathematical foundation of bilinear mapping e:G×G→G_T is constructed, providing nodes at all levels with a unified identity hash algorithm H(UserID)→G (for permission verification) and policy expression syntax (such as logical operator "and / or" combination) to ensure the consistency and scalability of global permission rules.

[0057] 2) Access control layer (Railway Bureau Group / Branch Bureau Management) As the core of policy execution, it implements permission verification, cross-domain coordination, and encryption and decryption agency through smart contracts.

[0058] The Railway Administration Group, acting as the cluster head node, deploys a Policy Execution Contract (PEP) and Domain Access Agreement (DAA). The former verifies the matching of user attributes and data levels (e.g., "user level ≥ data level"), while the latter handles permission transfers between the National Railway Administration and the Group (e.g., cross-regional calls for L4 data). It also handles encryption and decryption requests from station / section light nodes, protecting sensitive data keys through attribute encryption technology to ensure secure authentication of station nodes.

[0059] 3) Data management layer (station / section execution) As a data storage and interaction terminal, it is responsible for the local storage and access address management of encrypted data.

[0060] Encrypted plaintext is stored on a distributed file system (such as IPFS) (symmetric encryption is used for L1-L2, and attribute encryption is used for L3-L4). Data hash values, security levels, and access policies (such as "Role@EngineerANDRegion@This Bureau's Jurisdiction") are recorded on the blockchain. Regular end users obtain the data access address through an on-chain index and, after permission verification, download or decrypt the data, ensuring that data flow is traceable and tamper-proof.

[0061] For non-sensitive data, use symmetric encryption:

[0062] For sensitive data, encryption is performed using the protection key z in combination with the access policy: Where M is the plaintext data, SK is the symmetric key used for AES-256 encryption, and ⊕ is the XOR operation. Encrypted ciphertext for railway knowledge, is a bilinear map, is the generator of the cyclic group G, and z is a randomly generated key.

[0063] (4) Core process design 1) Initialization phase ① Public parameter generation Generate bilinear groups (Order , generator ), hash function , bilinear mapping

[0064] Deploy smart contract: Initialize permission policy template (such as ).

[0065] ②Node key distribution The National Railway Administration generates a root public-private key pair and generate keys for bureau groups / stations: in, The root public key is used to verify the legitimacy of the identity of the lower-level nodes (railway bureau group, station); It is the root private key, which is exclusively controlled by the National Railway Administration and is used to generate and distribute keys for lower-level nodes to ensure the hierarchical credibility of the key system. Indicates the node level identifier, used to distinguish railway units of different levels. Indicates the level is The public key of the node, Indicates the level is The private key of the node, and The expression level is The exclusive parameters of the node are allocated by the National Railway Administration according to the node type and authority level, and are used to generate the public and private key pairs of the node, which determine the scope of the node's authority in railway knowledge access control.

[0066] Node registration: The bureau group / station will register the public key On-chain storage with node type (L2 / L3).

[0067] 2) Release data information ①Data encryption and policy setting The station administrator symmetrically encrypts the plaintext data M: , z is a random key.

[0068] Define access policies: .

[0069] Generate access control matrix A (Boolean matrix, each row corresponds to an attribute condition).

[0070] ② Outsource encryption and decryption to the gateway The station sends an encryption request to the gateway of the bureau group to which it belongs, along with policy A and key z.

[0071] Gateway generates obfuscation vectors ,in, is a randomly generated master key, Is a random auxiliary vector generated by the gateway, calculate the ciphertext component: in, Represents the access control matrix No. OK, It represents the intermediate parameter generated by the inner product operation of the row vector of the access control matrix and the confusion vector. It is the key value for constructing the ciphertext component and is used to embed the access policy into the ciphertext to achieve fine-grained control of "attribute matching for decryption". Represents the ciphertext component, which is the encrypted data fragment. Is with the node level Related functions are used to reflect the differences in hierarchical permissions. It is an environment attribute parameter used to strengthen the dynamic constraints of access control.

[0072] ③Storing metadata on the chain Blockchain records: data hash value , access address (IPFS link), security level L2, access policy A.

[0073] Smart contract call:

[0074] 3) Data acquisition process ①User obtains identity The user applies for a key from each system, and the system generates a key for the user based on the attributes and sends it back.

[0075] For each attribute , the corresponding system issues a private key for it: Generate a random number t and generate keys K1 and K2 ②Data acquisition Users retrieve data information from the blockchain and obtain ciphertext.

[0076] The process of decrypting data is as follows: Generate random numbers ,in, is the access control matrix, It is a random vector generated by the user, the first element is fixed to 0, and the remaining elements is a random number used to enhance the security of decryption operations. Then, based on its own attributes, each row is calculated:

[0077] in, The four components representing the ciphertext are the segmented ciphertexts generated during the encryption process. Indicates the first private key component generated by the user based on his own attributes, is the mapping function, Indicates the second private key component generated by the user based on his own attributes. Indicates the unique identifier of the user The result of the hash operation is used to map the user identity to a cryptographically secure group element. For the generator of Power ( is an element in a random vector), used to participate in bilinear mapping operations, is a bilinear mapping function, It is the intermediate parameter generated during encryption. It is the result of the operation between the random vector and the access control matrix, and is used to verify the matching between user attributes and access policies.

[0078] Then calculate Make ,in, The coefficient calculated to meet the decryption conditions is used to integrate the verification results of multiple attribute conditions into the final key. Access Control Matrix No. OK, It is the core constraint of the decryption process. By solving the coefficient , so that the linear combination of the row vectors of the access control matrix is ​​a unit vector , ensuring that only users who meet all the attribute conditions can recover the key through combined operations, and realizing the fine-grained permission control of "decryption is allowed only when the attribute matches". in, Indicates the product operation of multiple intermediate results. , decryption is completed.

[0079] If the user has difficulty completing the decryption operation, an authorized key pair can be created to outsource the decryption: in, User based on the user group and its own attributes The generated original key pair is the basic key for decrypting data. are the two components of the key pair, Represents a temporary authorized key pair generated by the user, used to outsource decryption operations to the edge gateway. A random number generated by the user, used as a security parameter to convert the original key.

[0080] The decryption server performs the same operation with the authorized key pair to obtain the intermediate result , users can complete the decryption after performing simple operations on it.

[0081] ③Data decryption The user obtains data from the access address. After decrypting the data, the plaintext M is obtained as follows: In summary, this invention addresses the hierarchical security requirements of railway knowledge by constructing a four-tiered system (from L1 fully public to L4 sensitive core) comprised of "user role-node type-data level," supported by a three-tiered technical architecture consisting of "attribute management layer-access control layer-data management layer." The solution process encompasses public parameter generation and key distribution during the initialization phase, policy definition and encryption outsourcing for data release, and cross-chain authentication and hierarchical decryption during data retrieval, supporting complex policy expressions. In practice, a visual policy editor allows for rapid configuration of multi-dimensional permissions (such as time, region, and operation type). Edge gateways are used to delegate encryption and decryption operations to lower-level nodes to reduce computing power. Smart contracts verify the matching of user and data levels in real time. The immutable nature of blockchain technology allows for full-process access logs, meeting Level 3 security compliance requirements. This provides a fine-grained, efficient, and traceable secure access solution for railway documents, operational data, and other types of knowledge.

[0082] The railway knowledge intelligent hierarchical access control device provided by the present invention is described below. The railway knowledge intelligent hierarchical access control device described below and the railway knowledge intelligent hierarchical access control method described above can be referenced to each other.

[0083] like Figure 3 As shown, in one embodiment, a railway knowledge intelligent hierarchical access control device includes an identity mapping construction module 310, a railway knowledge classification module 320, an access policy analysis module 330, a control decision execution module 340 and a distributed traceability operation module 350.

[0084] The identity mapping construction module 310 is used to register key certificates for the National Railway Group nodes, Railway Bureau Group nodes and grassroots station nodes through the blockchain network, generate domain-wide trusted identity chain credentials, and build a three-level trusted identity mapping.

[0085] The railway knowledge classification module 320 is used to classify the railway knowledge assets to be accessed into four security levels according to their sensitivity, and to establish a binding relationship between the security level and the user role.

[0086] The access policy parsing module 330 is used to load railway-specific policy expressions containing administrative jurisdictions, job types, and business time windows through smart contracts, and supports hierarchical inheritance and timeliness logic combinations.

[0087] The control decision execution module 340 is used to respond to user data access requests, verify the identity certificate and role attributes of the requesting node based on the blockchain, match the security level of the requested data with the user role authority threshold, and parse the dynamic combination conditions of the railway business in the policy expression to determine the access rights of the current business scenario. When the authority verification is passed, a decryption key is generated according to the attribute encryption mechanism or the edge gateway is called to perform outsourced decryption.

[0088] The distributed traceability operation module 350 is used to store encrypted data in a distributed file system and record data hashes, security levels, and access operation logs in the blockchain.

[0089] Figure 4 The following is a schematic diagram of the physical structure of an electronic device. The electronic device may be a smart terminal, and its internal structure diagram may be as follows: Figure 4 As shown. The electronic device includes a processor, a memory, and a network interface connected via a system bus. The processor of the electronic device is used to provide computing and control capabilities. The memory of the electronic device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The network interface of the electronic device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a method for intelligent hierarchical access control of railway knowledge is implemented, which includes: Through the blockchain network, key certificates are registered for the National Railway Group nodes, Railway Bureau Group nodes, and grassroots station nodes to generate global trusted identity chain credentials and build a three-level trusted identity mapping; The railway knowledge assets to be accessed are divided into four security levels according to their sensitivity, and a binding relationship between security levels and user roles is established; Railway-specific policy expressions containing administrative areas, job types, and business time windows are loaded through smart contracts, supporting hierarchical inheritance and time-efficiency logic combinations; In response to user data access requests, the identity certificate and role attributes of the requesting node are verified based on the blockchain, and the security level of the requested data is matched with the user role permission threshold. The railway business dynamic combination conditions in the policy expression are parsed to determine the access rights for the current business scenario. When the permission verification passes, a decryption key is generated according to the attribute encryption mechanism or an edge gateway is called to perform outsourced decryption. The encrypted data is stored in a distributed file system, and the data hash, security level, and access operation log are recorded on the blockchain.

[0090] Those skilled in the art will understand that Figure 4The structure shown in the figure is merely a block diagram of a portion of the structure related to the solution of the present invention, and does not constitute a limitation on the electronic device to which the solution of the present invention is applied. The specific electronic device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0091] On the other hand, the present invention also provides a computer storage medium storing a computer program, which, when executed by a processor, implements a method for intelligent hierarchical access control of railway knowledge, comprising: Through the blockchain network, key certificates are registered for the National Railway Group nodes, Railway Bureau Group nodes, and grassroots station nodes to generate global trusted identity chain credentials and build a three-level trusted identity mapping; The railway knowledge assets to be accessed are divided into four security levels according to their sensitivity, and a binding relationship between security levels and user roles is established; Railway-specific policy expressions containing administrative areas, job types, and business time windows are loaded through smart contracts, supporting hierarchical inheritance and time-efficiency logic combinations; In response to user data access requests, the identity certificate and role attributes of the requesting node are verified based on the blockchain, and the security level of the requested data is matched with the user role permission threshold. The railway business dynamic combination conditions in the policy expression are parsed to determine the access rights for the current business scenario. When the permission verification passes, a decryption key is generated according to the attribute encryption mechanism or an edge gateway is called to perform outsourced decryption. The encrypted data is stored in a distributed file system, and the data hash, security level, and access operation log are recorded on the blockchain.

[0092] In another aspect, a computer program product or computer program is provided, the computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of an electronic device reads the computer instructions from the computer-readable storage medium, and when the processor executes the computer instructions, implements a method for intelligent hierarchical access control of railway knowledge, the method comprising: Through the blockchain network, key certificates are registered for the National Railway Group nodes, Railway Bureau Group nodes, and grassroots station nodes to generate global trusted identity chain credentials and build a three-level trusted identity mapping; The railway knowledge assets to be accessed are divided into four security levels according to their sensitivity, and a binding relationship between security levels and user roles is established; Railway-specific policy expressions containing administrative areas, job types, and business time windows are loaded through smart contracts, supporting hierarchical inheritance and time-efficiency logic combinations; In response to user data access requests, the identity certificate and role attributes of the requesting node are verified based on the blockchain, and the security level of the requested data is matched with the user role permission threshold. The railway business dynamic combination conditions in the policy expression are parsed to determine the access rights for the current business scenario. When the permission verification passes, a decryption key is generated according to the attribute encryption mechanism or an edge gateway is called to perform outsourced decryption. The encrypted data is stored in a distributed file system, and the data hash, security level, and access operation log are recorded on the blockchain.

[0093] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided by the present invention may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory.

[0094] By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0095] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, 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.

[0096] The above-described embodiments merely illustrate several embodiments of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, and these modifications and improvements fall within the scope of the present invention. Therefore, the scope of the present invention shall be determined by the appended claims.

Claims

1. A railway knowledge intelligent hierarchical access control method, characterized in that: The method comprises: Through the blockchain network, key certificates are registered for the National Railway Group nodes, Railway Bureau Group nodes, and grassroots station nodes to generate global trusted identity chain credentials and build a three-level trusted identity mapping; The railway knowledge assets to be accessed are divided into four security levels according to their sensitivity, and a binding relationship between security levels and user roles is established; Railway-specific policy expressions containing administrative areas, job types, and business time windows are loaded through smart contracts, supporting hierarchical inheritance and time-efficiency logic combinations; In response to user data access requests, the identity certificate and role attributes of the requesting node are verified based on the blockchain, and the security level of the requested data is matched with the user role permission threshold. The railway business dynamic combination conditions in the policy expression are parsed to determine the access rights for the current business scenario. When the permission verification passes, a decryption key is generated according to the attribute encryption mechanism or an edge gateway is called to perform outsourced decryption. The encrypted data is stored in a distributed file system, and the data hash, security level, and access operation log are recorded on the blockchain.

2. The railway knowledge intelligent hierarchical access control method according to claim 1 is characterized in that: The generating of the decryption key according to the attribute encryption mechanism includes: For each attribute Generate private key components , to generate the user attribute key; Through bilinear mapping Recover the symmetric key z and finally decrypt the ciphertext .

3. The railway knowledge intelligent hierarchical access control method according to claim 2 is characterized in that: The outsourced decryption execution includes: User generates a temporary authorization key ; The edge gateway calculates the intermediate value based on the authorization key ; Users calculate Get the plaintext.

4. The railway knowledge intelligent hierarchical access control method according to claim 1 is characterized in that: The identity certificate and role attributes of the blockchain-based verification request node include: Verify the legitimacy of the user node certificate through the CA certificate chain deployed by the China Railway Group node; Extract the railway bureau group code, station number and job role label to which the user belongs from the blockchain attribute ledger.

5. The railway knowledge intelligent hierarchical access control method according to claim 4 is characterized in that: The security level of the matching request data and the user role authority threshold include: Establish a dynamic permission threshold matrix to map L1~L4 security levels to role permission values; If the security level of the requested data exceeds the user role permission threshold, a blockchain alarm event will be triggered immediately.

6. The railway knowledge intelligent hierarchical access control method according to claim 4 is characterized in that: The railway business dynamic combination conditions in the parsing strategy expression include: Compile the policy expression into a syntax tree structure, where the root node is a logical operator and the leaf node is an atomic condition; Inject real-time railway scheduling data stream and dynamically update the decision threshold of grammatical leaf nodes.

7. The railway knowledge intelligent hierarchical access control method according to any one of claims 1 to 6, characterized in that: The calling of the edge gateway to perform outsourced decryption also includes: Verify the availability of edge gateways through a lightweight consensus protocol and filter edge nodes with load rates lower than a preset value; Generate partial decryption key fragments based on the attribute encryption mechanism and distribute them to the selected edge gateways.

8. The railway knowledge intelligent hierarchical access control method according to claim 7 is characterized in that: The calling edge gateway to perform outsourced decryption then includes: The gateway encrypts the decryption result with the public key of the requesting node, generating a double-layer ciphertext and sending it back; If the decryption times out or the result verification fails, the key fragment rotation mechanism is triggered.

9. A railway knowledge intelligent hierarchical access control device, characterized in that: The device comprises: The identity mapping construction module is used to register key certificates for the National Railway Group nodes, Railway Bureau Group nodes, and grassroots station nodes through the blockchain network, generate domain-wide trusted identity chain credentials, and build a three-level trusted identity mapping; The railway knowledge classification module is used to classify railway knowledge assets to be accessed into four security levels according to their sensitivity, and to establish a binding relationship between security levels and user roles; Access policy parsing module, used to load railway-specific policy expressions containing administrative jurisdictions, job types, and business time windows through smart contracts, supporting hierarchical inheritance and time-sensitive logic combinations; The control decision execution module is used to respond to user data access requests, verify the identity certificate and role attributes of the requesting node based on the blockchain, match the security level of the requested data with the user role permission threshold, and parse the railway business dynamic combination conditions in the policy expression to determine the access rights of the current business scenario. When the permission verification passes, the module generates a decryption key based on the attribute encryption mechanism or calls the edge gateway to perform outsourced decryption. The distributed traceability operation module is used to store encrypted data in a distributed file system and record data hashes, security levels, and access operation logs on the blockchain.

10. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the railway knowledge intelligent hierarchical access control method according to any one of claims 1 to 8 is implemented.

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