Intelligent construction site management system based on BIM

Abstract

The invention belongs to the technical field of BIM intelligent building management, and particularly relates to a BIM-based intelligent construction site management system, which comprises a cloud storage platform, a cloud service platform, a plurality of data owners, an acquisition port and a plurality of data demanders, a data owner constructs intelligent construction site building data based on BIM and directly sends the data to a cloud storage platform, and the cloud storage platform intelligently classifies and grades the building data and stores the building data; a building data retrieval table, an identity recognition unit and a processing unit are arranged in the cloud service platform; the data demand side inputs the storage unit ciphertext code into a downloading port of the cloud storage platform, the cloud storage platform obtains the storage unit code through decryption and matches the building data of the corresponding storage unit, and the cloud storage platform encrypts the building data through an SSL / TLS encryption protocol and sends the encrypted building data to the downloading port of the cloud storage platform. And the data demand side obtains the building data ciphertext and decrypts the building data ciphertext to obtain the original building data. According to the method, the safety of the BIM data can be ensured, and the BIM privacy and the commercial secret are ensured not to be leaked.

Description

Technical Field

[0001] The present invention belongs to the technical field of BIM smart building management, and in particular relates to a BIM-based smart construction site management system. Background Art

[0002] BIM is a building information model, which is an engineering data model based on three-dimensional digital technology and integrates various relevant information of construction projects. BIM technology is a multi-dimensional model information integration technology, which is a digital carrier and visual expression of the physical characteristics and functional characteristics of construction projects. It is shared and transmitted throughout the entire life cycle of project planning, operation and maintenance, so that engineering and technical personnel can correctly understand and efficiently respond to various building information, provide a basis for collaborative work for all construction entities, and play an important role in improving production efficiency, saving costs and shortening construction periods.

[0003] However, with the popularity of BIM systems, project data is usually stored in the cloud or on digital platforms, which brings potential problems of data security and privacy. For example, unauthorized access, data loss, hacker attacks, etc. may affect the progress of the project and the security of the enterprise. Therefore, how to ensure the security of BIM data and ensure that BIM privacy and business secrets are not leaked is an urgent problem to be solved. To this end, the present invention proposes a BIM-based smart construction site management system. Summary of the invention

[0004] The purpose of the present invention is to provide a BIM-based smart construction site management system that can protect the security of BIM data and ensure that BIM privacy and commercial secrets are not leaked.

[0005] The technical solution adopted by the present invention is as follows:

[0006] The BIM-based smart construction site management system includes a cloud storage platform, a cloud service platform, several data owners, access ports, and several data demanders;

[0007] The data owner constructs smart construction site data based on BIM and directly sends the data to the cloud storage platform, which intelligently classifies and grades the construction data, then stores and encodes the storage units. The storage unit code of each storage unit is statically encrypted using the AES-256 strong encryption algorithm to obtain the storage unit ciphertext code;

[0008] The cloud service platform is bidirectionally connected to the cloud storage platform by dual branches, and the cloud service platform is bidirectionally connected to the acquisition port by single branch. The cloud service platform is provided with a building data retrieval table, an identity recognition unit, and a processing unit;

[0009] The building data retrieval table is used to store the building data summary and the corresponding storage unit ciphertext code;

[0010] The identity recognition unit automatically recognizes whether the data demander logged in at the acquisition port is legitimate based on a neural network recognition model, and if the current data demander is judged to be legitimate, the authority of the current data demander is judged;

[0011] The processing unit verifies whether the level of the building data that the data demander wants to obtain matches its own authority. If it matches, the processing unit traverses the building data search table, outputs the corresponding storage unit ciphertext code according to the building data summary that the data demander wants to obtain, and automatically pushes the cloud storage platform download port;

[0012] The data demander inputs the storage unit ciphertext code into the download port of the cloud storage platform. The cloud storage platform obtains the storage unit code through decryption and matches the building data of the corresponding storage unit. The cloud storage platform encrypts the building data through the SSL / TLS encryption protocol. The data demander obtains the ciphertext of the building data and decrypts it to obtain the original building data.

[0013] Preferably, the cloud service platform and all data owners simultaneously record each download process of the building data and generate respective building data download record tables.

[0014] Preferably, the cloud storage platform first performs intelligent classification of the building data, and divides the building data into: geometric data, non-geometric data, time data, cost data, environmental data, operation and maintenance data, and standard data based on big data processing and feature extraction.

[0015] Preferably, in the process of grading the intelligently classified building data, the cloud storage platform divides the building data into special-grade building data, first-grade building data, second-grade building data and third-grade building data based on the impact of the building data on project goals, decision support, compliance, progress control, safety, and the real-time nature, integrity, frequency of use, scope of influence, and role in subsequent operations and maintenance of the data itself.

[0016] Preferably, the cloud storage platform stores the intelligently classified and graded building data in a storage unit. If a group of building data is less than or equal to the storage capacity of a storage unit, the group of building data is stored in a single storage unit. If a group of building data is larger than the storage capacity of a storage unit, multiple storage units are used simultaneously to store the group of building data, and the cloud storage platform encodes each storage unit.

[0017] Preferably, the cloud storage platform uses the AES-256 strong encryption algorithm to statically encrypt the storage unit code of each storage unit, and in the process of obtaining the storage unit ciphertext code:

[0018] Key expansion: Generate a series of round keys based on the input key;

[0019] Initial round: XOR the storage unit code with the first round key;

[0020] Main round: obfuscates and diffuses the data using multiple rounds of substitution, row shift, column obfuscation, and round key addition operations;

[0021] Final round: In the final round, no column confusion operation is performed, only substitution, row shift and round key addition operations are performed to obtain the storage unit ciphertext encoding.

[0022] Preferably, the building data summary in the building data retrieval table is a brief summary of the building data stored in the current storage unit and does not contain specific content. One data summary corresponds to one or more storage unit ciphertext codes. When the data owner constructs smart construction site building data based on BIM and directly sends the data to the cloud storage platform, the building data retrieval table is updated accordingly.

[0023] Preferably, in the process of the neural network recognition model used by the identity recognition unit, the model is first trained, and the neural network recognition model is trained using data demanders with legal identities and data demanders with illegal identities. The neural network recognition model retains data demanders with legal identities and data demanders with illegal identities at the same time; when the data demander logs in to the acquisition port, he inputs multiple identity feature information, and the neural network recognition model identifies the input multiple identity feature information and completes autonomous judgment whether there are abnormalities in the multiple identity feature information. If there are abnormalities, the data demander is directly judged to be an illegal identity.

[0024] Preferably, the processing unit verifies whether the building data level that the data demander wants to obtain matches its own authority. If not, the acquisition port prompts that the current data demander's authority level does not match.

[0025] Preferably, the specific process of the download port of the cloud storage platform encrypting the building data through the SSL / TLS encryption protocol and the data demander obtaining the ciphertext of the building data and then decrypting it to obtain the original building data is:

[0026] First, the handshake phase: the data demander and the cloud storage platform establish a secure connection by negotiating encryption algorithms, exchanging public keys and digital certificates, and generating shared keys;

[0027] Then in the data transmission phase: data encryption and authentication are performed using a shared symmetric key;

[0028] Final connection closing stage: After completing data transmission, the data demander and the cloud storage platform terminate the connection by sending a closing notification message;

[0029] The data demander obtains the ciphertext of the building data and decrypts it to obtain the original building data. The shared symmetric key is used to decrypt the data.

[0030] The technical effects achieved by the present invention are:

[0031] In the present invention, by constructing a cloud service platform and a cloud storage platform, and the cloud service platform and the cloud storage platform are bidirectionally connected in two branches, the cloud service platform, as an agent of the cloud storage platform, can achieve a rapid rate of finding the building data belonging to the data demander by constructing a building data retrieval table, and at the same time complete the identity authentication and authority verification of the data demander through the identity recognition unit and the processing unit, so that only the legitimate data demander and the data with the corresponding level of their own authority can obtain the building data through the subsequent steps, thereby ensuring the security of building data transmission in the BIM model.

[0032] In the present invention, the storage unit code is statically encrypted using the AES-256 strong encryption algorithm instead of encrypting all the building data. This first reduces the encryption and decryption computational efficiency. At the same time, encrypting the storage unit code is equivalent to encrypting the location where the data is stored, so that in the event of an illegal attack, it is impossible to correctly find the specific storage location where the required data exists in countless storage units, thereby making it impossible to illegally obtain building data, thereby ensuring the security of data in a static state, thereby ensuring the security of BIM data and ensuring that BIM privacy and commercial secrets are not leaked.

[0033] In the present invention, by building a neural network recognition model, it is possible to automatically identify whether the data demander is legitimate, and by verifying through a processing unit whether the building data level that the data demander wants to obtain matches its own authority, further protecting the security of BIM data and ensuring that BIM privacy and commercial secrets are not leaked. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a system block diagram of the BIM-based smart construction site management system of the present invention;

[0035] Figure 2 It is an operation flow chart of the BIM-based smart construction site management system of the present invention;

[0036] Figure 3 It is a correspondence diagram between building data levels and data demander permissions in the BIM-based smart construction site management system of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific embodiments of the present invention, and does not strictly limit the scope of protection of the specific claims of the present invention.

[0038] like Figure 1 - Figure 3 As shown, the BIM-based smart construction site management system includes a cloud storage platform, a cloud service platform, several data owners, acquisition ports, and several data demanders;

[0039] The data owner builds smart construction site data based on BIM and directly sends the data to the cloud storage platform. The cloud storage platform intelligently classifies and grades the construction data, then stores and encodes the storage units. The storage unit code of each storage unit is statically encrypted using the AES-256 strong encryption algorithm to obtain the storage unit ciphertext code.

[0040] The cloud service platform and the cloud storage platform are bidirectionally connected by two branches, and the cloud service platform and the acquisition port are bidirectionally connected by one branch. The cloud service platform is provided with a building data retrieval table, an identity recognition unit, and a processing unit;

[0041] The building data retrieval table is used to store the building data summary and the corresponding storage unit ciphertext code;

[0042] The identity recognition unit automatically recognizes whether the data demander who obtains the port login is legal based on the neural network recognition model. If the current data demander is judged to be legal, the authority of the current data demander is judged;

[0043] The processing unit verifies whether the building data level that the data demander wants to obtain matches its own authority. If it matches, the processing unit traverses the building data retrieval table, outputs the corresponding storage unit ciphertext code according to the building data summary that the data demander wants to obtain, and automatically pushes it to the cloud storage platform download port; if it does not match, the acquisition port prompts that the current data demander's authority level does not match;

[0044] The data demander inputs the storage unit ciphertext code into the download port of the cloud storage platform. The cloud storage platform obtains the storage unit code through decryption and matches the building data of the corresponding storage unit. The cloud storage platform encrypts the building data through the SSL / TLS encryption protocol. After the data demander obtains the ciphertext of the building data, it decrypts it to obtain the original building data.

[0045] like Figure 1 - Figure 3As shown, in the present invention, by constructing a cloud service platform and a cloud storage platform, and the cloud service platform and the cloud storage platform are bidirectionally connected in two branches, the cloud service platform, as an agent of the cloud storage platform, can achieve a rapid rate of finding the building data belonging to the data demander by constructing a building data retrieval table, and at the same time, the identity authentication and authority verification of the data demander are completed through the identity recognition unit and the processing unit, so that only the legitimate data demander and the data with the corresponding level of authority can obtain the building data through the subsequent steps, thereby ensuring the security of building data transmission in the BIM model.

[0046] like Figure 1 - Figure 3 As shown, in the present invention, the storage unit code is statically encrypted using the AES-256 strong encryption algorithm instead of encrypting all the building data, which firstly reduces the encryption and decryption operation efficiency. At the same time, by encrypting the storage unit code, it is equivalent to encrypting the location where the data is stored, so that in the event of an illegal attack, it is impossible to correctly find the specific storage location where the required data exists in countless storage units, and thus it is impossible to illegally obtain the building data, thereby ensuring the security of the data in a static state, thereby ensuring the security of the BIM data and ensuring that the BIM privacy and commercial secrets are not leaked.

[0047] Preferably, the cloud service platform and all data owners simultaneously record each download process of building data and generate respective building data download record sheets.

[0048] In the present invention, in the BIM smart construction site management system, each download process of construction data is recorded simultaneously by the cloud service platform and all data owners. By decentralizing the data acquisition process, data traceability can be better performed, and blockchain can provide secure storage and sharing of these data. Combining the BIM building system with blockchain can achieve smarter and safer construction management.

[0049] The cloud storage platform first intelligently classifies the building data, and divides the building data into the following based on big data processing and feature extraction: geometric data: the space, structure, shape and size of the building; non-geometric data: including information such as materials, specifications, brands, costs, suppliers, etc. of building components; time data: construction schedule, project time nodes, construction period, etc.; cost data: budget, cost estimation, cost control, etc.; environmental data: energy efficiency, temperature and humidity control, energy consumption, etc. of the building; operation and maintenance data: equipment maintenance, building health monitoring, maintenance history, etc.; standard data: building regulations, construction specifications, design standards, etc.

[0050] In actual use, the intelligent classification of building data in this embodiment is a task that uses artificial intelligence and machine learning technology to automatically extract and classify information from a large amount of building data. It can help the BIM smart construction site management system to manage, organize and analyze data more efficiently, thereby improving the efficiency of building design, construction management and operation and maintenance.

[0051] Preferably, in the process of grading the intelligently classified building data, the cloud storage platform divides the building data into special-grade building data, first-grade building data, second-grade building data and third-grade building data based on the impact of the building data on project goals, decision support, compliance, progress control, safety, and the real-time nature, integrity, frequency of use, scope of influence, and role in subsequent operations and maintenance of the data itself.

[0052] In actual use of this embodiment, project goal relevance: If a piece of data directly affects the core goals of a construction project, such as design, budget, schedule, quality, etc., then such data is generally considered important. For example, data such as building design plans, construction progress, budget control, material selection, etc. are usually crucial to the success of a project.

[0053] Decision support: If a certain type of data can help project managers make key decisions, such as design adjustments and resource allocation; The value of real-time data: Some data is critical to the project at a specific time point; For example, real-time data on the construction site, weather data, material transportation status, etc., can directly affect the construction progress and cost; Long-term impact data: For example, the energy efficiency data and maintenance records of the building, etc., they may not show their importance immediately, but in the long run, they are crucial to the sustainability and use value of the building; Frequently used data: Some data will be frequently used at all stages of the construction project, and they directly affect all aspects of the project. Such data is usually important. For example, construction progress data and cost control data will run through almost the entire project cycle; Widely affected data: If a certain data has a wide range of impacts, even involving multiple links or stakeholders, then such data usually has a higher priority; For example, working environment data involving construction safety and worker health is very important to all parties involved on the construction site; Asset management: Including the tracking of building assets, maintenance history records, etc., these data are directly related to the long-term value and operational efficiency of the building.

[0054] In the present invention, by intelligently classifying and grading the building data in the BIM model, the huge amount of building data in the BIM model can be accurately managed.

[0055] Preferably, the cloud storage platform stores the intelligently classified and graded building data in a storage unit. If a group of building data is less than or equal to the storage capacity of a storage unit, the group of building data is stored in a single storage unit. If a group of building data is larger than the storage capacity of a storage unit, multiple storage units are used simultaneously to store the group of building data. The cloud storage platform encodes each storage unit. Specifically, the cloud storage platform also encodes vacant storage units that do not store building data.

[0056] In actual use, this embodiment encrypts the storage unit code, which is equivalent to encrypting the data storage location. This makes it impossible to correctly find the specific storage location of the required data in countless storage units during an illegal attack, thereby making it impossible to illegally obtain building data. The security of data in a static state is guaranteed, thereby ensuring the security of BIM data and ensuring that BIM privacy and commercial secrets are not leaked.

[0057] Preferably, the cloud storage platform uses the AES-256 strong encryption algorithm to statically encrypt the storage unit code of each storage unit, and in the process of obtaining the storage unit ciphertext code:

[0058] Key expansion: Generate a series of round keys RoundKeys based on the input key;

[0059] First, the 256-bit key is expanded into multiple round keys; AES-256 needs to generate 60 32-bit words, or 192 bytes of round keys, to accommodate 14 rounds of encryption. The purpose of key expansion is to convert the initial key into the subkey required for each round;

[0060] InitialRound: XOR the storage unit code with the first round key. After this step is completed, the storage unit code will be merged with the round key.

[0061] MainRounds: Use multiple rounds of SubBytes substitution, ShiftRows row shift, MixColumns column mix and AddRoundKey operations to confuse and diffuse the data.

[0062] AES-256 goes through 13 rounds of main encryption, each of which consists of the following four steps:

[0063] Multiple rounds of SubBytes substitution: Use S-Box substitution box to replace each byte in the data; S-Box is a lookup table that enhances the obfuscation of encryption through byte substitution.

[0064] ShiftRows: Circularly shift each row in the data block so that the byte position of each row changes. This can enhance the diffusion of data.

[0065] MixColumns: Performs mathematical mixing operations on each column of the data; it mixes data between different columns by linearly transforming the bytes in the column, further increasing the complexity of the data.

[0066] Round key plus AddRoundKey: XOR the data with the round key of the current round to update the data block;

[0067] Final Round: In the last round, the MixColumns operation is not performed, and only the SubBytes substitution, row shift ShiftRows and round key addition AddRoundKey operations are performed to obtain the storage unit ciphertext encoding;

[0068] After the encryption process is completed, the result is the ciphertext, which is completely different from the original plaintext data and the original text cannot be directly inferred.

[0069] In the decryption process of the AES-256 strong encryption algorithm: the decryption process is similar to the encryption process, but the order of using the round keys is opposite to the encryption process, and the original plaintext data can be obtained in the end.

[0070] In the present invention, the storage unit code is statically encrypted using the AES-256 strong encryption algorithm instead of encrypting all the building data. This first reduces the encryption and decryption computational efficiency. At the same time, encrypting the storage unit code is equivalent to encrypting the location where the data is stored, so that in the event of an illegal attack, it is impossible to correctly find the specific storage location where the required data exists in countless storage units, thereby making it impossible to illegally obtain building data, thereby ensuring the security of data in a static state, thereby ensuring the security of BIM data and ensuring that BIM privacy and commercial secrets are not leaked.

[0071] Preferably, the building data summary in the building data retrieval table is a brief summary of the building data stored in the current storage unit and does not include specific content. One data summary corresponds to one or more storage unit ciphertext codes. When the data owner builds smart construction site building data based on BIM and directly sends the data to the cloud storage platform, the building data retrieval table is updated accordingly.

[0072] In generating the building data retrieval table, de-identification is used: for data containing sensitive information, such as personal identity information and commercial secrets, the sensitive parts can be removed or replaced through de-identification technology, so that the data can still be used for project management without exposing sensitive content, and finally complete the data summarization.

[0073] Preferably, in the process of the neural network recognition model used by the identity recognition unit, the model is first trained, and the neural network recognition model is trained using data demanders with legal identities and data demanders with illegal identities. The neural network recognition model retains data demanders with legal identities and data demanders with illegal identities at the same time; when the data demander logs in to the acquisition port, he inputs multiple identity feature information, and the neural network recognition model identifies the input multiple identity feature information and completes autonomous judgment whether there are abnormalities in the multiple identity feature information. If there are abnormalities, the data demander is directly judged to be an illegal identity.

[0074] In actual use of this embodiment, when building a neural network recognition model, different data demanders are divided into super administrators, first-level administrators, second-level administrators and third-level administrators according to their positions in the retained legal identities. The multiple identity feature information input by the data demander includes: name, company, position title, real-time face video and work badge certification document. The neural network recognition model identifies whether the multiple identity feature information inputted corresponds correctly. If one identity feature is wrong, the neural network model determines that the current data demander is an illegal user.

[0075] In actual use of this embodiment, during the process of the processing unit verifying whether the building data level that the data demander wants to obtain matches its own authority, the super administrator can view special-grade building data, first-grade building data, second-grade building data and third-grade building data. For example, the chief engineer as a super administrator can view all data, such as non-geometric data cost data; the first-grade administrator can view first-grade building data, second-grade building data and third-grade building data, for example, the BIM modeling engineer can view time data and geometric data; the second-grade administrator can view second-grade building data and third-grade building data, for example, the project administrator can view environmental data and dimensional data, and the third-grade administrator can only view third-grade building data, for example, the construction worker can only view dimensional data.

[0076] In the present invention, by building a neural network recognition model, it is possible to automatically identify whether the data demander is legitimate, and by verifying through a processing unit whether the building data level that the data demander wants to obtain matches its own authority, further protecting the security of BIM data and ensuring that BIM privacy and commercial secrets are not leaked.

[0077] Preferably, the specific process of the download port of the cloud storage platform encrypting the building data through the SSL / TLS encryption protocol and the data demander obtaining the ciphertext of the building data and then decrypting it to obtain the original building data is:

[0078] First, the handshake phase: the data demander and the cloud storage platform establish a secure connection by negotiating encryption algorithms, exchanging public keys and digital certificates, and generating shared keys.

[0079] Then in the data transmission phase: data encryption and authentication are performed using a shared symmetric key to ensure data confidentiality and integrity;

[0080] Final connection closing phase: After data transmission is completed, the data demander and the cloud storage platform end the connection by sending a closing notification message;

[0081] When the data demander obtains the ciphertext of the building data and decrypts it to obtain the original building data, the shared symmetric key is directly used to decrypt the data.

[0082] In the present invention, by using the SSL / TLS encryption protocol to encrypt the building data during the building data transmission process, the security of building data transmission is guaranteed, the confidentiality and integrity of the building data are further guaranteed, and the BIM privacy and commercial secrets are ensured not to be leaked.

[0083] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.

Claims

1. BIM-based smart construction site management system, characterized by: Including cloud storage platform, cloud service platform, several data owners, access ports and several data demanders; The data owner constructs smart construction site data based on BIM and directly sends the data to the cloud storage platform, which intelligently classifies and grades the construction data, then stores and encodes the storage units. The storage unit code of each storage unit is statically encrypted using the AES-256 strong encryption algorithm to obtain the storage unit ciphertext code; The cloud service platform is bidirectionally connected to the cloud storage platform by dual branches, and the cloud service platform is bidirectionally connected to the acquisition port by single branch. The cloud service platform is provided with a building data retrieval table, an identity recognition unit, and a processing unit; The building data retrieval table is used to store the building data summary and the corresponding storage unit ciphertext code; The identity recognition unit automatically recognizes whether the data demander logged in at the acquisition port is legitimate based on a neural network recognition model, and if the current data demander is judged to be legitimate, the authority of the current data demander is judged; The processing unit verifies whether the level of the building data that the data demander wants to obtain matches its own authority. If it matches, the processing unit traverses the building data search table, outputs the corresponding storage unit ciphertext code according to the building data summary that the data demander wants to obtain, and automatically pushes the cloud storage platform download port; The data demander inputs the storage unit ciphertext code into the download port of the cloud storage platform. The cloud storage platform obtains the storage unit code through decryption and matches the building data of the corresponding storage unit. The cloud storage platform encrypts the building data through the SSL / TLS encryption protocol. The data demander obtains the ciphertext of the building data and decrypts it to obtain the original building data.

2. The BIM-based smart construction site management system according to claim 1, characterized in that: The cloud service platform and all data owners simultaneously record each download process of the building data and generate respective building data download record sheets.

3. The BIM-based smart construction site management system according to claim 1 is characterized in that: The cloud storage platform first intelligently classifies the building data, and divides the building data into: geometric data, non-geometric data, time data, cost data, environmental data, operation and maintenance data, and standard data based on big data processing and feature extraction.

4. The BIM-based smart construction site management system according to claim 3 is characterized by: In the process of grading the intelligently classified building data, the cloud storage platform divides the building data into special-grade building data, first-grade building data, second-grade building data and third-grade building data based on the impact of the building data on project goals, decision support, compliance, progress control, and security, as well as the real-time nature, integrity, frequency of use, scope of impact, and role in subsequent operations and maintenance of the data itself.

5. The BIM-based smart construction site management system according to claim 4 is characterized in that: The cloud storage platform stores the intelligently classified and graded building data in a storage unit. If a group of building data is less than or equal to the storage capacity of a storage unit, the group of building data is stored in a single storage unit. If a group of building data is larger than the storage capacity of a storage unit, multiple storage units are used simultaneously to store the reorganized building data. The cloud storage platform encodes each storage unit.

6. The BIM-based smart construction site management system according to claim 1, characterized in that: The cloud storage platform uses the AES-256 strong encryption algorithm to statically encrypt the storage unit code of each storage unit, and in the process of obtaining the storage unit ciphertext code: Key expansion: Generate a series of round keys based on the input key; Initial round: XOR the storage unit code with the first round key; Main round: obfuscates and diffuses the data using multiple rounds of substitution, row shift, column obfuscation, and round key addition operations; Final round: In the final round, no column confusion operation is performed, only substitution, row shift and round key addition operations are performed to obtain the storage unit ciphertext encoding.

7. The BIM-based smart construction site management system according to claim 1, characterized in that: The building data summary in the building data retrieval table is a brief summary of the building data stored in the current storage unit and does not include specific content. One data summary corresponds to one or more storage unit ciphertext codes. When the data owner constructs smart construction site building data based on BIM and directly sends the data to the cloud storage platform, the building data retrieval table is updated accordingly.

8. The BIM-based smart construction site management system according to claim 1, characterized in that: In the process of the neural network recognition model used by the identity recognition unit, the model is first trained, and the neural network recognition model is trained using data demanders with legal identities and data demanders with illegal identities. The neural network recognition model retains data demanders with legal identities and data demanders with illegal identities at the same time; when the data demander logs in to the acquisition port, he inputs multiple identity feature information, and the neural network recognition model identifies the input multiple identity feature information and completes autonomous judgment whether there are abnormalities in the multiple identity feature information. If there are abnormalities, the data demander is directly judged to be an illegal identity.

9. The BIM-based smart construction site management system according to claim 1, characterized in that: The processing unit verifies whether the building data level that the data demander wants to obtain matches its own authority. If not, the acquisition port prompts the current data demander that the authority level does not match.

10. The BIM-based smart construction site management system according to claim 1, characterized in that: The specific process of the download port of the cloud storage platform encrypting the building data through the SSL / TLS encryption protocol and the data demander obtaining the ciphertext of the building data and decrypting it to obtain the original building data is: First, the handshake phase: the data demander and the cloud storage platform establish a secure connection by negotiating encryption algorithms, exchanging public keys and digital certificates, and generating shared keys; Then in the data transmission phase: data encryption and authentication are performed using a shared symmetric key; Final connection closing stage: After completing data transmission, the data demander and the cloud storage platform terminate the connection by sending a closing notification message; The data demander obtains the ciphertext of the building data and decrypts it to obtain the original building data, and directly uses the shared symmetric key to decrypt the data.

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