CN118214761A - Attribute-based encrypted data sharing method, system and device based on blockchain - Google Patents

Abstract

The application provides a block chain-based attribute-based encrypted data sharing method, a system and a device, wherein the method comprises the following steps: and selecting one-level nodes from all nodes of the blockchain network based on a preset trust evaluation rule to form a multi-authorization center, so as to realize attribute-based encrypted data sharing transaction between different nodes which are respectively used as a data provider and a data requester in the blockchain network currently based on all the one-level nodes in the multi-authorization center, a storage system outside the blockchain network and the blockchain network, monitor the transaction state data and the number of times of disfigurement of all the one-level nodes in real time, and update the trust value of all the one-level nodes to update members of the multi-authorization center. The application can avoid the problem of easy data leakage caused by a single authorization center, can ensure the safety and privacy of the attribute-based encrypted data, and further can improve the reliability and safety of the sharing process of the attribute-based encrypted data.

Description

Attribute-based encrypted data sharing method, system and device based on blockchain

Technical Field

The present application relates to the field of blockchain technology, and in particular to a blockchain-based attribute-based encrypted data sharing method, system and device.

Background Art

Attribute-Based Encryption (ABE) is a flexible encryption technique that allows encrypted data to be access-controlled based on a set of attributes and policies, rather than based on traditional public and private key pairs. This encryption method enables data encryption and decryption operations to be performed based on the user's attributes, thereby providing a more fine-grained access control mechanism. Attribute-based encryption technology shows broad application potential in areas such as data sharing, cloud storage, and fine-grained access control. It addresses the limitations of traditional encryption methods in the face of complex access control requirements, allowing data owners to control data access rights more flexibly and accurately. In addition, ABE technology also enhances data security and privacy because even if data is shared or transmitted in an insecure environment, users without the corresponding attributes cannot decrypt the data. As digital information is increasingly shared on the Internet, the importance and application scope of attribute-based encryption technology are expected to expand further.

However, the existing attribute-based data encryption method has the problem that a single authorization center has too much power during the encryption process, which can easily lead to data leakage and loss, and thus cannot guarantee the security and privacy of user shared data. Based on this, it is urgent to design an attribute-based data encryption method that can guarantee the security and privacy of user shared data.

Summary of the invention

In view of this, the embodiments of the present application provide a blockchain-based attribute-based encrypted data sharing method, system and device to eliminate or improve one or more defects existing in the prior art.

One aspect of the present application provides an attribute-based encrypted data sharing method based on blockchain, comprising:

Based on a preset trust evaluation rule, a primary node is selected from each current node of the blockchain network to form a multi-authorization center, so as to implement an attribute-based encrypted data sharing transaction between a node currently serving as a data provider and a node serving as a data requester in the blockchain network based on each of the primary nodes in the multi-authorization center, a storage system preset outside the blockchain network, and the blockchain network;

Monitor the transaction status data and the number of malicious acts of each of the first-level nodes in real time, and update the trust value of each of the first-level nodes according to the transaction status data;

Based on the trust value of each of the first-level nodes and the number of times they have committed evil, determine whether each of the first-level nodes contains nodes to be downgraded. If so, update the same number of non-first-level nodes as the current nodes to be downgraded to new first-level nodes to join the multi-authorization centers, and delete the current nodes to be downgraded from the multi-authorization centers and update them to new non-first-level nodes.

In some embodiments of the present application, based on each of the primary nodes in the multiple authorization centers, a storage system preset outside the blockchain network, and the blockchain network, an attribute-based encrypted data sharing transaction between a node currently serving as a data provider and a node serving as a data requester in the blockchain network is implemented, including:

Each of the first-level nodes in the multiple authorization centers generates and distributes public parameters to each non-first-level node in the blockchain network;

The node currently serving as a data provider in the blockchain network selects a first random number and a second random number based on the public parameters to generate an encryption key, encrypts the target plaintext according to the encryption key, stores the encrypted target ciphertext in a storage system outside the blockchain network, and uses a pre-acquired public key to encrypt the second random number and the access path of the target ciphertext to form a policy ciphertext, publishes the policy ciphertext to the blockchain network, and sends the first random number to the node currently serving as a data requester in the blockchain network via a secure channel;

The node currently acting as a data requester in the blockchain network sends its own attribute set to the multi-authorization center;

Each of the first-level nodes of the multiple authorization centers generates a private key component for the node as the data requester using an attribute-based encryption algorithm, and sends the private key component and the policy ciphertext to the node as the data requester;

The node serving as the data requester generates a private key matching the public key based on the private key component, and decrypts the policy ciphertext based on the private key to obtain the second random number and the access path to the target ciphertext, and then retrieves the target ciphertext from the storage system based on the access path to the target ciphertext, and obtains the encryption key based on the first random number and the second random number, and uses the encryption key to decrypt the target ciphertext to obtain the target plaintext.

In some embodiments of the present application, the method of selecting a primary node from each current node of the blockchain network to form a multi-authorization center based on a preset trust evaluation rule includes:

Numbering each node in the blockchain network according to the order in which each node currently joins the blockchain network;

Selecting a preset number of nodes as current first-level nodes from the order of the numbers of the nodes from small to large;

Different initial global trust values are set for the first-level nodes and non-first-level nodes respectively, so as to serve as the current trust values of each of the first-level nodes and each of the non-first-level nodes.

In some embodiments of the present application, the real-time monitoring of the transaction status data and the number of malicious acts of each of the first-level nodes, and updating the trust value of each of the first-level nodes according to the transaction status data, includes:

Real-time monitoring of transaction status data of each of the first-level nodes, wherein the transaction status data includes: transaction success status or transaction failure status;

And, real-time monitoring of each of the first-level nodes to see whether there is any malicious behavior that meets the preset malicious judgment rules and recording the corresponding number of malicious behaviors;

Calculate the current time decay factor of the first-level node where the attribute-based encrypted data sharing transaction occurs, calculate the current standardized trust value of the first-level node based on the time decay factor of the first-level node and the transaction status data, and update the current trust value of the first-level node based on the standardized trust value.

In some embodiments of the present application, the step of determining whether each of the first-level nodes includes nodes to be downgraded according to the trust value of each of the first-level nodes and the number of times the nodes have committed evil, and if so, updating the same number of non-first-level nodes as the current nodes to be downgraded to new first-level nodes to join the multiple authorization centers, and deleting the current nodes to be downgraded from the multiple authorization centers and updating them to new non-first-level nodes includes:

Among the current first-level nodes, determine whether there is any first-level node whose current number of malicious acts is greater than a preset number threshold and/or whose trust value updated based on the standardized trust value is less than a preset trust threshold. If so, determine the first-level node as the current node to be downgraded;

According to the order of the trust values of the current non-first-level nodes from large to small, the non-first-level nodes with the same number as the current nodes to be downgraded are selected and updated to new first-level nodes to join the multi-authorization center, and the current nodes to be downgraded are deleted from the multi-authorization center and updated to new non-first-level nodes.

In some embodiments of the present application, before the order of the trust values of the current non-primary nodes from large to small, the method further includes:

If a message is received for any current primary node to exit the blockchain network, the primary node is determined as the current node to be downgraded.

Another aspect of the present application provides an attribute-based encrypted data sharing device based on blockchain, comprising:

An initial construction module, for selecting a primary node from each current node of the blockchain network to form a multi-authorization center based on a preset trust evaluation rule, so as to implement an attribute-based encrypted data sharing transaction between a node currently serving as a data provider and a node serving as a data requester in the blockchain network based on each of the primary nodes in the multi-authorization center, a storage system preset outside the blockchain network, and the blockchain network;

A status monitoring module, used to monitor the transaction status data and the number of malicious acts of each of the first-level nodes in real time, and update the trust value of each of the first-level nodes according to the transaction status data;

The member update module is used to determine whether each of the first-level nodes contains nodes to be downgraded based on the trust value of each of the first-level nodes and the number of times the nodes have committed evil deeds. If so, the non-first-level nodes with the same number as the current nodes to be downgraded will be updated to new first-level nodes to join the multiple authorization centers, and the current nodes to be downgraded will be deleted from the multiple authorization centers and updated to new non-first-level nodes.

The third aspect of the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the blockchain-based attribute-based encrypted data sharing method when executing the computer program.

The fourth aspect of the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the blockchain-based attribute-based encrypted data sharing method.

The fifth aspect of the present application provides an attribute-based encrypted data sharing system, comprising: nodes constituting a blockchain network, a multi-authorization center consisting of primary nodes selected from each of the nodes, and a storage system arranged outside the blockchain network; each of the nodes is respectively connected to the storage system for communication;

The multi-authorization center is constructed based on a blockchain-based attribute-based encrypted data sharing device and updates the primary node. The blockchain-based attribute-based encrypted data sharing device is used for the blockchain-based attribute-based encrypted data sharing method;

Among them, the transaction identities of each first-level node and non-first-level nodes in the blockchain network except the first-level node include: the node of the data provider and the data requester.

The sixth aspect of the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the blockchain-based attribute-based encrypted data sharing method.

The blockchain-based attribute-based encrypted data sharing method provided by the present application selects a first-level node from each current node of the blockchain network to form a multi-authorization center based on a preset trust evaluation rule, so as to realize the attribute-based encrypted data sharing transaction between the node currently serving as a data provider and the node serving as a data requester in the blockchain network based on each of the first-level nodes in the multi-authorization center, a storage system preset outside the blockchain network, and the blockchain network; monitors the transaction status data and the number of malicious acts of each of the first-level nodes in real time, and updates the trust value of each of the first-level nodes according to the transaction status data; determines whether each of the first-level nodes contains nodes to be downgraded according to the trust value and the number of malicious acts of each of the first-level nodes, and if so, updates the non-first-level nodes with the same number as the current nodes to be downgraded to new first-level nodes to join the multi-authorization center, and deletes the current nodes to be downgraded from the multi-authorization center and updates them to new non-first-level nodes, which can avoid the problem of easy data leakage caused by a single authorization center, can ensure the security and privacy of attribute-based encrypted data, and thus can improve the reliability and security of the attribute-based encrypted data sharing process.

Additional advantages, purposes, and features of the present application will be partially described in the following description, and will become partially apparent to those skilled in the art after studying the following, or may be learned from the practice of the present application. The purposes and other advantages of the present application can be achieved and obtained by the structures specifically pointed out in the specification and the drawings.

Those skilled in the art will understand that the purposes and advantages that can be achieved by the present application are not limited to the above specific description, and the above and other purposes that can be achieved by the present application will be more clearly understood based on the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are used to provide a further understanding of the present application, constitute a part of the present application, and do not constitute a limitation of the present application. The components in the drawings are not drawn to scale, but are only for the purpose of illustrating the principles of the present application. In order to facilitate the illustration and description of some parts of the present application, the corresponding parts in the drawings may be enlarged, that is, they may become larger relative to other components in the exemplary device actually manufactured according to the present application. In the drawings:

FIG1 is a schematic diagram of a first flow chart of a blockchain-based attribute-based encrypted data sharing method in one embodiment of the present application.

FIG. 2 is an interactive diagram of attribute-based encrypted data sharing in an example of the present application.

FIG3 is a second flow chart of the attribute-based encrypted data sharing method based on blockchain in one embodiment of the present application.

FIG4 is a schematic diagram of the structure of an attribute-based encrypted data sharing device based on blockchain in one embodiment of the present application.

FIG5 is a flow chart of a trust assessment model algorithm based on blockchain in an application example of the present application.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the implementation modes and the accompanying drawings. Here, the illustrative implementation modes and descriptions of the present application are used to explain the present application, but are not intended to limit the present application.

It should also be noted here that in order to avoid obscuring the present application due to unnecessary details, only the structures and/or processing steps closely related to the scheme according to the present application are shown in the accompanying drawings, while other details that are not very relevant to the present application are omitted.

It should be emphasized that the term “include/comprises” when used herein refers to the presence of features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components.

It should also be noted that, unless otherwise specified, the term “connection” herein may refer not only to a direct connection but also to an indirect connection with an intermediate.

Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

In order to ensure the security and privacy of attribute-based encrypted data, the embodiments of the present application respectively provide a blockchain-based attribute-based encrypted data sharing method, a blockchain-based attribute-based encrypted data sharing device for executing the blockchain-based attribute-based encrypted data sharing method, a physical device and a computer-readable storage medium, etc., which can prevent losses caused by data leakage due to excessive power of a single authorization center, thereby protecting data security.

The details are described in detail through the following examples.

Based on this, the embodiment of the present application provides a blockchain-based attribute-based encrypted data sharing method that can be implemented by a blockchain-based attribute-based encrypted data sharing device. Referring to FIG. 1 , the blockchain-based attribute-based encrypted data sharing method specifically includes the following contents:

Step 100: Based on a preset trust evaluation rule, a first-level node is selected from each current node of the blockchain network to form a multi-authorization center, so as to implement attribute-based encrypted data sharing transactions between nodes currently serving as data providers and nodes serving as data requesters in the blockchain network based on each of the first-level nodes in the multi-authorization center, a storage system preset outside the blockchain network, and the blockchain network.

In one or more embodiments of the present application, other nodes in the blockchain network that are not designated as primary nodes may be referred to as non-primary nodes or secondary nodes, etc. Specifically, all nodes may be divided into two or more levels according to node classification requirements.

Understandably, blockchain technology is an innovative distributed ledger technology known for its unique decentralized characteristics, unalterable data records, and high transparency and security. In essence, blockchain forms a series of cryptographically connected data blocks by replicating and storing data on multiple nodes of the network. Each data block contains a certain number of transaction records, and once added to the chain, these records cannot be changed or deleted. Blockchain technology has expanded to many fields such as financial services, supply chain management, healthcare, and management, bringing transparency, efficiency, and trust to these fields. By ensuring the integrity and reliability of data, blockchain technology provides a unique solution to problems such as transaction security, data tampering, and intermediary trust. With the continuous maturity of technology and the increase in application cases, blockchain is gradually being recognized as a technology that can profoundly change the ecology of multiple industries.

In an example of the present application, the trust evaluation rule can specifically adopt a trust evaluation model. The trust evaluation model is first used in a P2P network, and the calculation scope is divided into two types of calculations, namely global trust calculation (Eigen Trust) and local trust calculation (Peer Trust). The Eigen Trust algorithm calculates the global trust value of each user by aggregating the trust scores of all users in the network. Eigen Trust uses complex mathematical models, such as eigen vectors and iterative calculations, to ensure that interactions in the network are as safe and reliable as possible. It improves the trust of the entire network by reducing the impact of malicious users and increasing the visibility of well-behaved users. The Peer Trust algorithm focuses on the online trading environment, especially considering factors such as transaction feedback, transaction quantity and transaction quality to enhance the trust management of online trading platforms. Peer Trust calculates trust values by evaluating the user's historical behavior and other users' feedback on it. This method enables the algorithm to dynamically adapt to changes in user behavior and provides a reliable trust evaluation mechanism for buyers and sellers in the electronic market.

Step 200: Monitor the transaction status data and the number of malicious behaviors of each of the first-level nodes in real time, and update the trust value of each of the first-level nodes according to the transaction status data.

It should be noted that the basis for judging whether a node has committed malicious behavior can be: analyzing the transactions initiated by the node to see if there are abnormal or malicious patterns, such as the following behaviors:

(1) Frequent sending of invalid transactions: monitor the number of invalid transactions sent by a single node in a short period of time. Frequent sending of such transactions can be considered as an attempt to interfere with the network or consume other node resources.

(2) Transactions with incorrect formats or that fail to meet network rules (such as invalid signatures, incorrect nonce values, etc.) are considered invalid transactions;

(3) Nodes attempting double spending, which is an attempt to pay the same token or digital currency to two or more recipients at the same time in order to deceive the recipient of the transaction;

(4) Nodes with abnormal transaction rates, especially those that continue to initiate transactions at high speeds when the network is not busy, can be considered to be attempting to carry out DDoS attacks.

Step 300: Determine whether each of the first-level nodes contains nodes to be downgraded based on the trust value of each of the first-level nodes and the number of times the nodes have committed evil deeds. If so, update the same number of non-first-level nodes as the current number of nodes to be downgraded to new first-level nodes to join the multi-authorization center, and delete the current nodes to be downgraded from the multi-authorization center and update them to new non-first-level nodes.

From the above description, it can be seen that the blockchain-based attribute-based encrypted data sharing method provided by the embodiment of the present application can solve the problem of excessive power of a single authorization center in the attribute-based encryption process. The present application selects and constructs multiple authorization centers by adopting blockchain technology and a trust assessment model to realize the function of generating public parameters and generating corresponding private keys for users in the attribute-based encryption process. Prevent data leakage and losses due to excessive power of a single authorization center, thereby protecting data security. In order to solve the problem of data sharing from data providers to data consumers in the data sharing scenario, the present application proposes a data sharing solution based on the attribute-based encryption of the above-mentioned multiple authorization centers. The present application supports fine-grained data control and authority management. Data providers can define data usage conditions as needed, and data consumers must meet these conditions to obtain decryption and access rights, effectively protecting data security sharing.

In order to further improve the effectiveness and security of the attribute-based encrypted data sharing transaction process, in an attribute-based encrypted data sharing method based on blockchain provided in an embodiment of the present application, referring to FIG. 2, taking the storage system as an IPFS storage system as an example, the said first-level nodes in the multi-authorization center, the storage system preset outside the said blockchain network and the said blockchain network mentioned in the said step 100, realize the attribute-based encrypted data sharing transaction between the node currently serving as the data provider and the node serving as the data requester in the said blockchain network, specifically including the following contents:

(1) Each of the first-level nodes in the multiple authorization centers generates and distributes public parameters to each non-first-level node in the blockchain network.

Specifically, the initialization operation of the multi-authorization center inputs security parameters and then outputs public parameters GP and user identifier uid and aid of the multi-authorization center.

GlobalSetup(λ)→(GP,aid,uid)

Among them, GlobalSetup(λ) represents global parameter initialization.

The algorithm is executed by the first-level node (i.e., the multi-authorization center AA), inputs the public parameter GP, the authority identifier aid, and then outputs the master key MSK _aid and the public key PK _aid :

AuthSetup(GP,aid)→(MSK _aid ,PK _aid )

Among them, AuthSetup(GP,aid) indicates the initialization of the authorization center.

Generate encryption key. The data provider randomly selects K1 and K2. K1 and K2 are processed by SHA256 algorithm to obtain encryption key K.

KEncrypt(K ₁ ,K ₂ )→(K)

Here, KEncrypt (K ₁ , K ₂ ) represents key generation.

(2) The node currently serving as a data provider in the blockchain network selects a first random number K1 and a second random number K2 based on the public parameters to generate an encryption key K, encrypts the target plaintext mes according to the encryption key K, and then stores the encrypted target ciphertext CT in a storage system outside the blockchain network, and uses the pre-acquired public key PK to encrypt the second random number K2 and the access path of the target ciphertext CT to form a policy ciphertext C _w (K ₂ ,L), publishes the policy ciphertext C _w (K ₂ ,L) to the blockchain network, and sends the first random number K1 to the node currently serving as a data requester in the blockchain network via a secure channel.

Specifically, the data provider DO symmetrically encrypts the data M to be shared, uploads the obtained ciphertext CT to IPFS to obtain the corresponding path, and performs attribute-based encryption on the key K. The specific steps are as follows:

A. The data provider DO inputs the data plaintext mes and the key K2 and finally outputs the ciphertext, and uploads the ciphertext CT to IPFS, and finally obtains the path L.

MesEncrypt(M,K ₂ )→(CT)

Wherein, MesEncrypt(M,K ₂ ) represents the data encryption stage.

B. The data provider DO inputs the key K2, path L, public parameters GP, public key PK, access matrix (M, p), message m, and finally outputs the policy ciphertext Cw(K2, L). Finally, the ciphertext identifier M_ID, the data provider representation uid, and the policy ciphertext Cw(K2, L) are published to the blockchain. The blockchain network receives the request and triggers the smart contract StoreCont to respond.

OwnerEncrypt(GP,PK,w,L,K ₂ )→(C _w (K ₂ ,L))

Among them, OwnerEncrypt(GP,PK,w,L,K ₂ ) represents the attribute-based encryption stage.

In the smart contract StoreCont, as shown in Table 1, line 1 is used to configure the blockchain, line 2 records the current transaction time, line 3 is used to store transaction records, and finally line 4 returns transaction D.

Table 1

The data provider establishes a connection with the data requester through an SSL secure channel and sends K1 to the data requester through the secure channel.

SslPart(K ₁ )

(3) The node currently acting as a data requester in the blockchain network sends its own attribute set to the multi-authorization center.

(4) Each of the primary nodes of the multiple authorization centers generates a private key component SK _i for the node serving as the data requester using an attribute-based encryption algorithm, and sends the private key component SK _i and the policy ciphertext C _w (K ₂ , L) to the node serving as the data requester.

In this stage, the data requester sends an access request to the multi-authorization center, which contains the data requester's attribute set. After receiving the request, the multi-authorization center triggers the smart contract and generates the corresponding private key component for the data requester. The specific steps are as follows:

Input the public key PK, private key MK, and attribute set s of the data requester, and run the KeyGen key generation algorithm of the attribute-based encryption algorithm, in which the private key component is generated using the distributed key generation technology. t is the threshold number of DKG recovery keys, which can resist malicious attacks from t-1 nodes, protect the security of user keys, and send C _w (K ₂ ,L) to the data requester.

UserKeyGen(PL,MK,s,t)→(SK _i )

Among them, UserKeyGen(PK,MK,s,t) represents user key generation.

(5) The node as the data requester generates a private key SK matching the public key PK based on the private key component SK _i , and decrypts the policy ciphertext based on the private key SK to obtain the second random number K2 and the access path of the target ciphertext CT, and then retrieves the target ciphertext CT from the storage system based on the access path of the target ciphertext CT, and obtains the encryption key K based on the first random number K1 and the second random number K2, and uses the encryption key K to decrypt the target ciphertext CT to obtain the target plaintext mes.

Specifically, first input the private key component SKi, the ciphertext _Cw ( _K2 , L) and the public key PK. The data requester will recover the private key SK by calling the Lagrange polynomial difference formula with the obtained _SKi , and call the Decrypt decryption algorithm to decrypt _Cw ( _K2 , L), and finally output the plaintext _K2 and L.

UserDecrypt(PK,SK _i ,C _w (K ₂ ,L))→(SK,K ₂ ,L)

Among them, UserDecrypt(PK,SK _i ,C _w (K ₂ ,L)) represents the attribute-based encryption stage.

After the data requester receives _K1 and _K2 , he obtains the final encryption key K through the SHA256 algorithm, obtains the ciphertext CT on IPFS through the address L, and decrypts it with K to finally obtain the plaintext mes.

KDecrypt(K ₁ ,K ₂ ,L)→(mes)

In order to further improve the effectiveness and wide applicability of blockchain-based attribute-based encrypted data sharing, in an attribute-based encrypted data sharing method based on blockchain provided in an embodiment of the present application, referring to FIG3 , step 100 of the blockchain-based attribute-based encrypted data sharing method specifically includes the following contents:

Step 110: Number each node in the blockchain network according to the order in which each node currently joins the blockchain network.

Step 120: Select a preset number of nodes from the order of the node numbers from small to large as current first-level nodes.

Step 130: Different initial global trust values are set for the first-level nodes and non-first-level nodes respectively, to serve as the current trust values of each of the first-level nodes and each of the non-first-level nodes.

Specifically, in the initialization phase, assuming that the number of nodes in the blockchain network is N, all nodes are numbered from i to N according to the order in which they join the network, and the earliest P (P<N) nodes are used as trusted nodes. The initial global trust value of this group of nodes is 1/P, and the initial global trust value of the remaining N-P nodes is 1/N. Then the nodes are graded. The P nodes are trusted first-level nodes as the core layer, participating in the blockchain network consensus process and responsible for the work of the subsequent multi-authorization center. The other nodes are second-level nodes as the ordinary layer, which are used to receive the consensus results and daily transactions of the core layer. The nodes in the core layer can accumulate their own trust value by trading in the network. If the first-level node behaves maliciously, it will be downgraded and cannot enter the core layer for a period of time. At the same time, the node with the highest trust value is selected from the ordinary layer as the first-level node and added to the core layer.

In order to further improve the effectiveness and wide applicability of blockchain-based attribute-based encrypted data sharing, in an attribute-based encrypted data sharing method based on blockchain provided in an embodiment of the present application, referring to FIG. 3 , step 200 of the blockchain-based attribute-based encrypted data sharing method specifically includes the following contents:

Step 210: Monitor the transaction status data of each of the first-level nodes in real time, wherein the transaction status data includes: transaction success status or transaction failure status.

And, step 220: monitor in real time whether each of the first-level nodes has malicious behavior that meets the preset malicious judgment rules and record the corresponding number of malicious behaviors.

Step 230: Calculate the current time decay factor of the first-level node where the attribute-based encrypted data sharing transaction occurs, and calculate the current standardized trust value of the first-level node based on the time decay factor of the first-level node and the transaction status data, and update the current trust value of the first-level node based on the standardized trust value.

Specifically, in reality, there will be nodes that do evil. In order to ensure the normal operation of the system, it is necessary to dynamically update the nodes of the authorization center and update the private key components of each authorization center node. This application sets the number of authorization center nodes to be fixed, so nodes that do evil or exit the blockchain network need to be upgraded and downgraded.

ReSetup(σ _i )→(σ′ _i )

In order to further improve the application effectiveness and reliability of multiple authorization centers for attribute-based encrypted data sharing, in an attribute-based encrypted data sharing method based on blockchain provided in an embodiment of the present application, referring to FIG. 3 , step 300 of the attribute-based encrypted data sharing method based on blockchain specifically includes the following contents:

Step 310: Among the current first-level nodes, determine whether there is any first-level node whose current number of malicious acts is greater than a preset number threshold and/or whose trust value updated based on the standardized trust value is less than a preset trust threshold. If so, determine the first-level node as the current node to be downgraded.

If no primary node is found whose number of malicious acts is greater than the preset number threshold and/or whose trust value updated based on the standardized trust value is less than the preset trust threshold, no subsequent processing is performed and the process returns to step 200 to continue monitoring.

Step 320: According to the order of the trust values of the current non-first-level nodes from large to small, select the non-first-level nodes with the same number as the current nodes to be downgraded and update them to new first-level nodes to join the multi-authorization center, and delete the current nodes to be downgraded from the multi-authorization center and update them to new non-first-level nodes.

In order to further improve the application effectiveness and reliability of multiple authorization centers for attribute-based encrypted data sharing, in an attribute-based encrypted data sharing method based on blockchain provided in an embodiment of the present application, referring to FIG. 3 , the attribute-based encrypted data sharing method based on blockchain further specifically includes the following contents before step 320:

Step 301: If a message is received for any current first-level node to exit the blockchain network, the first-level node is determined as the current node to be downgraded.

The present application also provides a blockchain-based attribute-based encrypted data sharing device for executing all or part of the blockchain-based attribute-based encrypted data sharing method. Referring to FIG. 4 , the blockchain-based attribute-based encrypted data sharing device specifically includes the following contents:

The initial construction module 10 is used to select a first-level node from each current node of the blockchain network to form a multi-authorization center based on a preset trust evaluation rule, so as to realize attribute-based encrypted data sharing transactions between the node currently serving as a data provider and the node serving as a data requester in the blockchain network based on each of the first-level nodes in the multi-authorization center, a storage system preset outside the blockchain network, and the blockchain network.

The status monitoring module 20 is used to monitor the transaction status data and the number of malicious acts of each of the first-level nodes in real time, and update the trust value of each of the first-level nodes according to the transaction status data.

The member update module 30 is used to determine whether each of the first-level nodes contains nodes to be downgraded based on the trust value of each of the first-level nodes and the number of times the nodes have committed evil deeds. If so, the non-first-level nodes with the same number as the current nodes to be downgraded are updated to new first-level nodes to join the multi-authorization center, and the current nodes to be downgraded are deleted from the multi-authorization center and updated to new non-first-level nodes.

The embodiment of the blockchain-based attribute-based encrypted data sharing device provided in the present application can be specifically used to execute the processing flow of the embodiment of the blockchain-based attribute-based encrypted data sharing method in the above-mentioned embodiment. Its functions will not be repeated here, and reference can be made to the detailed description of the above-mentioned blockchain-based attribute-based encrypted data sharing method embodiment.

The part of the blockchain-based attribute-based encrypted data sharing device that performs blockchain-based attribute-based encrypted data sharing can be executed in the server or completed in the client device. The specific selection can be based on the processing power of the client device and the limitations of the user's usage scenario. This application is not limited to this. If all operations are completed in the client device, the client device may also include a processor for specific processing of the blockchain-based attribute-based encrypted data sharing. At the same time, the nodes in the blockchain network of this application can all be servers or client devices.

The client device may have a communication module (i.e., a communication unit) that can communicate with a remote server to achieve data transmission with the server. The server may include a server on the task scheduling center side, and other implementation scenarios may also include a server on an intermediate platform, such as a server on a third-party server platform that has a communication link with the task scheduling center server. The server may include a single computer device, or a server cluster consisting of multiple servers, or a server structure of a distributed device.

The server and the client device may communicate with each other using any suitable network protocol, including network protocols that have not yet been developed on the date of filing this application. The network protocols may include, for example, TCP/IP, UDP/IP, HTTP, HTTPS, etc. Of course, the network protocols may also include, for example, RPC (Remote Procedure Call Protocol) and REST (Representational State Transfer) protocols used on top of the above protocols.

From the above description, it can be seen that the blockchain-based attribute-based encrypted data sharing device provided in the embodiment of the present application can avoid the problem of easy data leakage caused by a single authorization center, can ensure the security and privacy of attribute-based encrypted data, and thus can improve the reliability and security of the attribute-based encrypted data sharing process.

Based on all or part of the content of the aforementioned blockchain-based attribute-based encrypted data sharing method, the present application also provides an embodiment of an attribute-based encrypted data sharing system, and the attribute-based encrypted data sharing system specifically includes the following content:

Each node constituting the blockchain network, a multi-authorization center consisting of primary nodes selected from each of the nodes, and a storage system arranged outside the blockchain network; each of the nodes is respectively connected to the storage system in communication;

The multi-authorization center is constructed based on a blockchain-based attribute-based encrypted data sharing device and updates the primary node. The blockchain-based attribute-based encrypted data sharing device is used to execute the blockchain-based attribute-based encrypted data sharing method mentioned in the above embodiment;

Among them, the transaction identities of each first-level node and non-first-level nodes in the blockchain network except the first-level node include: the node of the data provider and the data requester.

Specifically, from the perspective of system architecture, this solution includes the following five roles:

Blockchain Network (BN): BN is used to select a group of nodes as the authorization center of attribute-based encryption through a trust evaluation model.

Multiple Authorization Centers (Attribute Authority, AA): AA is mainly responsible for generating and distributing keys.

Data Owner (DO): DO mainly performs encryption operations on shared data and sends part of the key to the data requester.

Data Consumer (DC): DC provides its own attributes to AA to obtain the corresponding private key, after which the ciphertext can be decrypted to obtain the plaintext.

IPFS storage system: Introduce IPFS for off-chain storage to solve the storage problem of blockchain, and transmit the returned index value to enhance the security and efficiency of the system.

That is to say, the attribute-based encrypted data sharing system provided by the embodiment of the present application provides an effective method for sharing user data securely. By introducing the mechanism of multiple authorization centers, the situation where a single authorization center has too much power and once malicious behavior occurs, it will lead to the leakage of user privacy. The node with the highest trust value is selected as the multi-authorization center through the trust evaluation model to improve the efficiency and robustness of the system. By performing attribute-based encryption on shared data, the data provider can set a suitable access structure and perform fine-grained access control on the shared data. The fairness and traceability of the entire process are ensured by the immutable and public characteristics of the blockchain. At the same time, the shared data is stored on IPFS to achieve efficient and secure storage of large files. In order to prevent all authorization center nodes from collectively committing evil and conspiring to generate decryption keys to decrypt ciphertexts, the encryption key consists of two parts, one part is sent to the data requester by the data provider through a secure channel, and the other part is attribute-based encrypted. Finally, the decryption key can be obtained by performing SHA256 operation on part of the key to protect the security of the data to a greater extent.

To further illustrate the above scheme, this application also provides a blockchain data sharing method based on a trust evaluation model and attribute-based encryption. This method uses the trust evaluation model and blockchain technology to improve the problem of excessive power of the attribute-based encryption authorization center, and at the same time, it is safe and reliable in the data sharing process, and effectively protects the interests of data providers and data consumers. See Figures 2 and 5, where Y in Figure 5 represents "yes" and N represents "no"; the blockchain data sharing method based on a trust evaluation model and attribute-based encryption specifically includes the following contents:

(I) Step 1: Building a trust assessment model

A. Initialization phase. Assume that in the initialization phase, the number of nodes in the blockchain network is N. All nodes are numbered from i to N according to the order in which they join the network. The earliest P (P<N) nodes are taken as trusted nodes. The initial global trust value of this group of nodes is 1/P, and the initial global trust value of the remaining N-P nodes is 1/N.

B. Node grading: The P nodes are trusted first-level nodes as the core layer, participating in the blockchain network consensus process and responsible for the work of multiple authorization centers. Other nodes are second-level nodes as the ordinary layer, which are used to receive the consensus results and transactions of the core layer and update the trust value after each transaction.

To illustrate this step, the application example of this application gives a specific algorithm description.

First, the application example of this application also introduces the time attenuation factor γ through the sigmoid function, and the calculation method is as follows:

In the formula, t _trans represents the time when the transaction occurs, and t _now represents the current time. That is, the closer the transaction is to the current time, the smaller the attenuation of γ is, and vice versa.

After the time decay factor is introduced, the trust value is calculated after each transaction succeeds or fails.

Satisfactory evaluation:

Unsatisfactory evaluations:

in and are the evaluation of success and failure after the transaction between node i and node j at time t. α and β are the weights for evaluating trust value, where α+β=1.

Finally, the calculation formula of the trust value is obtained:

s _ij =sat(i,j)-unsat(i,j)-

The standardized trust value calculation formula is:

C. Nodes in the core layer can accumulate their own trust value by conducting transactions in the network. If a first-level node behaves maliciously, it will be downgraded and will not be able to enter the core layer for a period of time. At the same time, the node with the highest trust value is selected from the ordinary layer as a first-level node and added to the core layer.

To instantiate this step, the application example of this application gives a specific algorithm description:

Where x represents the number of times the node has committed evil, C _ij is the trust value before the update, and C′ _ij represents the trust value after the update.

(II) Step 2: Initialization phase

A. Initialization operation of multiple authorization centers, input security parameters, and then output public parameters GP and user identifier uid and aid of multiple authorization centers.

GlobalSetup(λ)→(GP,aid,uid)

To instantiate this step, the application example of this application gives a specific algorithm description. The algorithm inputs a security parameter λ, then selects two multiplication groups G and _GT of order p, g is the generator of G, and the bilinear map e:G×G→ _GT . The algorithm selects three hash functions, namely H:{0,1} ^* →G, When selecting an extractor h∈ and a symmetric encryption scheme SE. Finally, each AA and user is assigned a unique identity identifier uid and uid, and the public parameters GP = {ρ, G, _GT , g, e, H, _H1 , _H2 , h, SE} are output.

B. The algorithm is executed by AA, inputting the public parameter GP, the authority identifier aid, and then outputting the sub-private key MSK _aid and the sub-public key PK _aid

AuthSetup(GP,aid)→(MSK _aid ,PK _aid )

To instantiate this step, the application example of this application gives a specific algorithm description. After each authorization center executes the initialization algorithm, it generates a sub-private key and a sub-public key. Next, it needs to generate a master public key and a master private key. This is achieved through the idea of threshold sharing. Let (t, T) be the threshold, indicating that the secret requires t authorization centers to jointly recover it to be valid, and T is the set of authorization centers.

1. All authorized centers A _i participating in secret recovery randomly select d _i and k _i and establish a t-1 order polynomial _fi (x) mod q, where _fi (x) is as follows:

f _i (x)＝f _i (0)+a _1i x+a _1i x ² +…+a _i,i-1 x ^t-1 mod q

2. All authorized centers need to calculate The authorization center also needs to calculate the private key component σ _i,j = _fi (aid _j ) mod q other than its own. The calculation result is encrypted with the other party's public key and signed and sent to the other party.

3. When the authorization center receives the message from at least t-1 other authorization centers, it uses its own private key to decrypt and obtain σ _j,i , using equation Verify legality.

4. After each authorized center completes the above three steps, the following results can be obtained:

5. When the authorized centers in set T have received the data from other t-1 authorized centers, the private key component can be calculated by the Lagrange polynomial interpolation formula Where P is a constant.

Finally, we get the system public key: y = g ^F(0) Rmodq, the system private key

C. Generate encryption key. The data provider randomly selects _K1 and _K2 . _K1 and _K2 are processed by SHA256 algorithm to obtain encryption key K.

KEncrypt(K ₁ ,K ₂ )→(K)

(III) Step 3: Data encryption stage

In this stage, DO symmetrically encrypts the plaintext data mes to be shared, uploads the obtained ciphertext CT to IPFS to obtain the corresponding path, and performs attribute-based encryption on the key K _2. The specific steps are as follows:

A. The data provider DO inputs the data plaintext mes and the key K ₂ and finally outputs the ciphertext, and uploads the ciphertext CT to IPFS, and finally obtains the path L.

MesEncrypt(mes,K ₂ )→(CT)

B. The data provider DO inputs the key K ₂ , the path L, the public parameters GP, the public key PK, the access matrix (M,ρ), the shared data plaintext mes, and finally outputs the ciphertext C _w (K ₂ ,L). Finally, the ciphertext identifier M_ID, the data provider representation uid, and the ciphertext C _w (K ₂ ,L) are published on the blockchain. The blockchain network receives the request and triggers the smart contract StoreCont to respond.

OwnerEncrypt(GP,PK,(M,ρ),L,K ₂ )→(C _w (K ₂ ,L))

To instantiate this step, the application example of this application gives a specific algorithm description. This stage is performed by the data provider, who first generates a l*n access matrix M, maps the function p to each row attribute of the matrix M, namely p(i), and selects a random number s∈Z _p ,. vector and 0 as random vector set up Then calculate C ₀ = Re(g,g) ^s , The final ciphertext about K ₂ ,L is CT(K ₂ ,L)＝{(M,ρ),C ₀ ,C _1,i ,C _2,i ,C _3,i } _i∈[1,l] .

(IV) Step 4: Data Request Phase

In this stage, the data requester sends an access request to the multi-authorization center, which contains the data requester's attribute set. After receiving the request, the multi-authorization center triggers the smart contract and generates the corresponding private key component for the data requester. The specific steps are as follows:

Input the public key PK, private key MK, and attribute set s of the data requester, and run the KeyGen key generation algorithm of the attribute-based encryption algorithm, in which the private key component is generated using the distributed key generation technology. t is the threshold number of DKG recovery keys, which can resist malicious attacks from t-1 nodes and protect the security of user keys. Finally, the private key component SK _i and CT(K ₂ ,L) are sent to the data requester.

UserKeyGen(PK,MK,s,t)→(SK _i )

(V) Step 5: Data decryption stage

A. The data provider establishes a connection with the data requester through an SSL secure channel and sends _K1 to the data requester through the secure channel.

SslPart(K ₁ )

B. Input the private key component SK _i , ciphertext C _w (K ₂ ,L) and public key PK. The data requester recovers the obtained SK _i by calling the Lagrange polynomial difference formula to obtain the private key SK, and calls the Decrypt decryption algorithm to decrypt C _w (K ₂ ,L), and finally outputs the plaintext K ₂ and L.

UserDecrypt(PK,K _i ,C _w (K ₂ ,L))→(Sk,K ₂ ,L)

To instantiate this step, the application example of this application provides a specific algorithm description.

1. If the user’s access attribute s does not satisfy the access policy (M, ρ), the algorithm terminates.

2. If the user's access attribute s satisfies the access policy (M,ρ), then select a constant that satisfies ∑ _x c _i M _i ＝(1,0,…,0) For i∈{1,2,…,l} calculate:

Finally, the decrypted plaintext (K ₂ , L) is obtained.

C. After receiving _K1 and _K2 , the data requester obtains the final encryption key K through the SHA256 algorithm, obtains the ciphertext CT on IPFS through the address L, and decrypts it with K to finally obtain the plaintext M.

KDecrypt(K ₁ ,K ₂ ,L)→(M)

(VI) Step 6: Core layer node update

In reality, there will be nodes that behave maliciously. In order to ensure the normal operation of the system, it is necessary to dynamically update the nodes of the authorization center and update the private key components of each authorization center node. This application example sets the number of authorization center nodes to be fixed, so nodes that behave maliciously or exit the blockchain network need to be upgraded or downgraded.

ReSetup(σ _i )→(σ′ _i )

Node updates can be divided into the following two situations:

1. When a node exits the blockchain network, it can be considered trustworthy, and the old node can directly exchange data with the new node.

2. The node is downgraded due to malicious behavior. It is necessary to add a new node from the ordinary layer, and then delete a node from the core layer. The newly added node is AA′. AA′ needs to randomly select k' and d', and construct a t-1 order polynomial f(x)modq. Repeating step 2 can calculate σ _i+1,j = fi ₊₁ (ID _j )modq, and encrypt and sign the calculation result and send it to other authorized center nodes in the network. When AA _j receives σ _i+1,j , it calculates σ _j,i+1 = f _j (ID _i+1 )modq and returns it to AA′, while updating its own private key component σ' _j = (σ _j +σ _i+1,j )modq. Repeat this step with other authorized center nodes in the blockchain. When AA′ is synchronized with other nodes, it can obtain its own private key component. Afterwards, the malicious node AA _z is downgraded, and other authorized central nodes update their private key components to σ′ _i =(σ _i -σ _z )modq.

This application example proposes an innovative data sharing method that cleverly combines the trust evaluation model with blockchain technology, aiming to provide a multi-authorization center framework for attribute-based encryption technology. By selecting nodes with higher trust values in the blockchain as authorization centers, this application not only enhances the security and credibility of the data sharing process, but also improves the flexibility and scalability of the system. This unique combination allows data sharing and protection mechanisms to be innovatively improved in a decentralized environment, providing users with a safer and more efficient data interaction experience.

The attribute-based encrypted data sharing method based on the trust evaluation model and blockchain provides innovative and secure solutions for multiple fields. In the field of cloud computing, this method can ensure the security of sensitive data in cloud storage and cloud services, so that only users with specific attributes can access the data, greatly improving the security and privacy of data processing and storage. In the field of the Internet of Things, with the surge in the number of devices and the increasing complexity of interconnection between devices, this method can effectively manage and control data access rights between devices, ensure the secure transmission of data between devices, and prevent unauthorized access and data leakage. It also has broad application prospects in fields such as healthcare and financial services.

At the same time, to successfully implement this method, it is necessary to rely on a reliable blockchain network, establish an effective trust assessment model to evaluate and screen authorization centers, and formulate a comprehensive attribute management mechanism and security strategy. In addition, it is also crucial to ensure the authenticity of the identity of users and devices and their attributes, which requires a strict authentication process. By meeting these conditions, this method can not only enhance the security and credibility of the data exchange process, but also provide sufficient flexibility and scalability to adapt to the ever-changing business needs and technical environment, and provide new solutions for the safe and reliable sharing of data.

The embodiment of the present application also provides an electronic device, which may include a processor, a memory, a receiver and a transmitter, wherein the processor is used to execute the attribute-based encrypted data sharing method based on blockchain mentioned in the above embodiment, wherein the processor and the memory may be connected via a bus or other means, such as by bus connection. The receiver may be connected to the processor and the memory via wired or wireless means.

The processor may be a central processing unit (CPU). The processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or a combination of the above chips.

As a non-transient computer-readable storage medium, the memory can be used to store non-transient software programs, non-transient computer executable programs and modules, such as program instructions/modules corresponding to the attribute-based encrypted data sharing method based on blockchain in the embodiment of the present application. The processor executes various functional applications and data processing of the processor by running the non-transient software programs, instructions and modules stored in the memory, that is, realizing the attribute-based encrypted data sharing method based on blockchain in the above method embodiment.

The memory may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created by the processor, etc. In addition, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

The one or more modules are stored in the memory, and when executed by the processor, the blockchain-based attribute-based encrypted data sharing method in the embodiment is executed.

In some embodiments of the present application, the user equipment may include a processor, a memory, and a transceiver unit, which may include a receiver and a transmitter. The processor, memory, receiver, and transmitter may be connected through a bus system. The memory is used to store computer instructions, and the processor is used to execute the computer instructions stored in the memory to control the transceiver unit to send and receive signals.

As an implementation method, the functions of the receiver and the transmitter in the present application can be considered to be implemented through a transceiver circuit or a dedicated chip for transceiver, and the processor can be considered to be implemented through a dedicated processing chip, a processing circuit or a general chip.

As another implementation method, it is possible to use a general-purpose computer to implement the server provided in the embodiment of the present application, that is, to store the program code for implementing the functions of the processor, receiver, and transmitter in a memory, and the general-purpose processor implements the functions of the processor, receiver, and transmitter by executing the code in the memory.

The embodiment of the present application also provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the steps of the aforementioned attribute-based encrypted data sharing method based on blockchain are implemented. The computer-readable storage medium can be a tangible storage medium, such as a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a floppy disk, a hard disk, a removable storage disk, a CD-ROM, or any other form of storage medium known in the technical field.

It should be understood by those skilled in the art that the exemplary components, systems and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software or a combination of the two. Whether it is specifically performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier.

It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

In the present application, features described and/or illustrated for one embodiment may be used in the same manner or in a similar manner in one or more other embodiments, and/or combined with features of other embodiments or replace features of other embodiments.

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

Claims (10)

1. A method for sharing attribute-based encrypted data based on blockchain, comprising: Based on a preset trust evaluation rule, a primary node is selected from each current node of the blockchain network to form a multi-authorization center, so as to implement an attribute-based encrypted data sharing transaction between a node currently serving as a data provider and a node serving as a data requester in the blockchain network based on each of the primary nodes in the multi-authorization center, a storage system preset outside the blockchain network, and the blockchain network; Monitor the transaction status data and the number of malicious acts of each of the first-level nodes in real time, and update the trust value of each of the first-level nodes according to the transaction status data; Based on the trust value of each of the first-level nodes and the number of times they have committed evil, determine whether each of the first-level nodes contains nodes to be downgraded. If so, update the same number of non-first-level nodes as the current nodes to be downgraded to new first-level nodes to join the multi-authorization centers, and delete the current nodes to be downgraded from the multi-authorization centers and update them to new non-first-level nodes. 2. The method for sharing attribute-based encrypted data based on blockchain according to claim 1 is characterized in that the method based on each of the primary nodes in the multi-authorization center, the storage system preset outside the blockchain network and the blockchain network, realizes the attribute-based encrypted data sharing transaction between the node currently serving as the data provider and the node serving as the data requester in the blockchain network, including: Each of the first-level nodes in the multiple authorization centers generates and distributes public parameters to each non-first-level node in the blockchain network; The node currently serving as a data provider in the blockchain network selects a first random number and a second random number based on the public parameters to generate an encryption key, encrypts the target plaintext according to the encryption key, stores the encrypted target ciphertext in a storage system outside the blockchain network, and uses a pre-acquired public key to encrypt the second random number and the access path of the target ciphertext to form a policy ciphertext, publishes the policy ciphertext to the blockchain network, and sends the first random number to the node currently serving as a data requester in the blockchain network via a secure channel; The node currently serving as a data requester in the blockchain network sends its own attribute set to the multi-authorization center; Each of the first-level nodes of the multiple authorization centers generates a private key component for the node as the data requester using an attribute-based encryption algorithm, and sends the private key component and the policy ciphertext to the node as the data requester; The node serving as the data requester generates a private key matching the public key based on the private key component, and decrypts the policy ciphertext based on the private key to obtain the second random number and the access path to the target ciphertext, and then retrieves the target ciphertext from the storage system based on the access path to the target ciphertext, and obtains the encryption key based on the first random number and the second random number, and uses the encryption key to decrypt the target ciphertext to obtain the target plaintext. 3. The attribute-based encrypted data sharing method based on blockchain according to claim 1 is characterized in that, based on the preset trust evaluation rules, the first-level nodes are selected from the current nodes of the blockchain network to form a multi-authorization center, including: Numbering each node in the blockchain network according to the order in which each node currently joins the blockchain network; Selecting a preset number of nodes as current first-level nodes from the order of the numbers of the nodes from small to large; Different initial global trust values are set for the first-level nodes and non-first-level nodes respectively, so as to serve as the current trust values of each of the first-level nodes and each of the non-first-level nodes. 4. The attribute-based encrypted data sharing method based on blockchain according to claim 1 is characterized in that the real-time monitoring of the transaction status data and the number of malicious acts of each of the first-level nodes and updating the trust value of each of the first-level nodes according to the transaction status data includes: Real-time monitoring of transaction status data of each of the first-level nodes, wherein the transaction status data includes: transaction success status or transaction failure status; And, monitor in real time whether each of the first-level nodes has malicious behavior that meets the preset malicious judgment rules and record the corresponding number of malicious behaviors; Calculate the current time decay factor of the first-level node where the attribute-based encrypted data sharing transaction occurs, calculate the current standardized trust value of the first-level node based on the time decay factor of the first-level node and the transaction status data, and update the current trust value of the first-level node based on the standardized trust value. 5. The attribute-based encrypted data sharing method based on blockchain according to claim 4 is characterized in that, according to the trust value of each of the first-level nodes and the number of times of committing evil, it is determined whether each of the first-level nodes contains nodes to be downgraded, and if so, the non-first-level nodes with the same number as the current nodes to be downgraded are updated to new first-level nodes to join the multiple authorization centers, and the current nodes to be downgraded are deleted from the multiple authorization centers and updated to new non-first-level nodes, including: Among the current first-level nodes, determine whether there is any first-level node whose current number of malicious acts is greater than a preset number threshold and/or whose trust value updated based on the standardized trust value is less than a preset trust threshold. If so, determine the first-level node as the current node to be downgraded; According to the order of the trust values of the current non-first-level nodes from large to small, the non-first-level nodes with the same number as the current nodes to be downgraded are selected and updated to new first-level nodes to join the multi-authorization center, and the current nodes to be downgraded are deleted from the multi-authorization center and updated to new non-first-level nodes. 6. The method for sharing attribute-based encrypted data based on blockchain according to claim 5, characterized in that before the order of the trust values of the current non-primary nodes from large to small, it also includes: If a message is received for any current primary node to exit the blockchain network, the primary node is determined as the current node to be downgraded. 7. A blockchain-based attribute-based encrypted data sharing device, comprising: An initial construction module, for selecting a primary node from each current node of the blockchain network to form a multi-authorization center based on a preset trust evaluation rule, so as to implement an attribute-based encrypted data sharing transaction between a node currently serving as a data provider and a node serving as a data requester in the blockchain network based on each of the primary nodes in the multi-authorization center, a storage system preset outside the blockchain network, and the blockchain network; A status monitoring module, used to monitor the transaction status data and the number of malicious acts of each of the first-level nodes in real time, and update the trust value of each of the first-level nodes according to the transaction status data; The member update module is used to determine whether each of the first-level nodes contains nodes to be downgraded based on the trust value of each of the first-level nodes and the number of times the nodes have committed evil deeds. If so, the non-first-level nodes with the same number as the current nodes to be downgraded will be updated to new first-level nodes to join the multi-authorization center, and the current nodes to be downgraded will be deleted from the multi-authorization center and updated to new non-first-level nodes. 8. An electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the attribute-based encrypted data sharing method based on blockchain as described in any one of claims 1 to 6 is implemented. 9. A computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the attribute-based encrypted data sharing method based on blockchain as described in any one of claims 1 to 6 is implemented. 10. An attribute-based encrypted data sharing system, characterized in that it comprises: each node constituting a blockchain network, a multi-authorization center consisting of primary nodes selected from each of the nodes, and a storage system arranged outside the blockchain network; each of the nodes is respectively connected to the storage system for communication; The multi-authorization center is constructed based on a blockchain-based attribute-based encrypted data sharing device and updates the first-level node, and the blockchain-based attribute-based encrypted data sharing device is used to execute the blockchain-based attribute-based encrypted data sharing method according to any one of claims 1 to 6; Among them, the transaction identities of each first-level node and non-first-level nodes in the blockchain network except the first-level node include: the node of the data provider and the data requester.