CN118133325B - Data management method based on on-chain and off-chain - Google Patents

Abstract

The present invention relates to the field of blockchain storage technology, and in particular to a data management method based on an on-chain and off-chain, including: the data owner encrypts the original data and the original data hash value based on a key and a preset access control method, obtains the ciphertext and the encrypted hash value of the original data, and then sends the data information, the original data hash value, the encrypted hash value and the ciphertext to the off-chain node for asynchronous BFT consensus, stores the ciphertext in the off-chain node, and uploads the data information and the encrypted hash value to the on-chain node to generate an on-chain index; the data user accesses the on-chain node based on the on-chain index, the data user decrypts the encrypted hash value based on the key, and sends the decrypted hash value to the off-chain node for asynchronous BFT consensus, obtains the ciphertext, and then decrypts the ciphertext to obtain the original data. The present invention balances performance and privacy by introducing new security and privacy mechanisms to meet the needs of different fields.

Description

Data management method based on on-chain and off-chain

Technical Field

The present invention relates to the field of blockchain storage technology, and in particular to a data management method based on on-chain and off-chain.

Background technique

The financial, government, and healthcare sectors generate a large amount of data every day, including financial transactions, government records, and medical data. This data is very sensitive and needs to be securely stored, efficiently transmitted, and easily accessible. However, traditional data management methods based on on-chain and off-chain face challenges in meeting these needs. For example, the financial sector involves a large amount of transaction data, and each payment generates a new data record. This data needs to be stored with high security to protect the privacy of customers and the integrity of transaction data. At the same time, financial institutions need to ensure accurate management of access rights to comply with regulations and regulations. Government departments continuously generate a large amount of records in their daily operations, including administrative processes, policy decisions, and regulations. These government records need to be stored securely to protect the privacy of citizens and ensure the integrity of records. Government agencies also need to be able to easily share data with trusted peers (such as other government agencies and officials) while ensuring the security, integrity, and consistency of the data. The medical field generates a large amount of data through procedures such as CT scans, X-rays, and prescriptions. This medical data is crucial for the diagnosis and treatment of patients. Therefore, this data needs to be highly secure and ensure that only authorized users can access it.

Blockchain technology has been introduced as an ideal solution to these data management problems. In a blockchain network, sensitive data such as government records, financial transactions, and medical data can be easily shared between trusted peers while maintaining the security, integrity, and consistency of the data. This technology is based on the sequential connection of blocks, which are protected by hash encryption to ensure the immutability of transactions. This enables complex record details, including historical and current information, to be easily accessed by authorized parties. Therefore, blockchain technology has great potential in the field of data management.

However, there are inherent problems in applying traditional public blockchain designs to data storage and transmission: Blockchain technology is a distributed data management method that has developed in recent years. It links data in the form of blocks to form an immutable ledger for storing transaction information. The distributed nature and encryption protection of blockchain make it highly secure and can be used to ensure the consistency and integrity of data. Disadvantages of the technical solution: Traditional public blockchains may be inefficient in data storage and transmission, and may encounter bottlenecks when processing large-scale data; public blockchains are usually designed for transparency, but this conflicts with the privacy requirements of certain data. Reasons for the disadvantages: The performance problems of blockchain technology are partly due to the consensus mechanism and on-chain storage characteristics of public blockchains, which lead to efficiency problems when processing large-scale data.

Summary of the invention

The purpose of the present invention is to provide a data management method based on on-chain and off-chain, aiming to introduce various customer access control methods, emphasize the efficiency of fine-grained access control, ensure security and accountability, and improve the efficiency, security and user experience of data management by using asynchronous Byzantine consensus and fault-tolerant off-chain storage.

To achieve the above object, the present invention provides the following solutions:

A data management method based on both on-chain and off-chain, comprising:

The data owner encrypts the original data and the hash value of the original data based on the key and the preset access control method, obtains the ciphertext and the encrypted hash value of the original data, and then sends the data information, the hash value of the original data, the encrypted hash value and the ciphertext to the off-chain node for asynchronous BFT consensus, stores the ciphertext in the off-chain node, and uploads the data information and the encrypted hash value to the on-chain node to generate an on-chain index;

The data user accesses the on-chain node based on the on-chain index, decrypts the encrypted hash value based on the key, and sends the decrypted hash value to the off-chain node for the asynchronous BFT consensus, obtains the ciphertext, and then decrypts the ciphertext to obtain the original data.

Optionally, the access control method is broadcast encryption, attribute encryption, or threshold encryption.

Optionally, after sending the data information, the original data hash value, the encrypted hash value, and the ciphertext to the off-chain node for asynchronous BFT consensus, storing the ciphertext in the off-chain node includes:

Packing the data information, the original data hash value, the encrypted hash value and the ciphertext to obtain packaged data, wherein the data information includes the preset access control mode, the encrypted access control list, the file size and the file type;

The packaged data is sent to the off-chain node, and the off-chain node puts the packaged data into a message queue and then performs the asynchronous BFT consensus;

After the asynchronous BFT consensus is performed, the leveldb database of the off-chain node stores the original data hash value and the ciphertext in a key-value format.

Optionally, uploading the data information and the encrypted hash value to an on-chain node to generate an on-chain index includes:

The off-chain node will send the marking instructions, the data information and the encrypted hash value generated after the asynchronous BFT consensus to the on-chain node. When the on-chain node receives a preset number of the marking instructions, it will upload the data information and the encrypted hash value to the on-chain node, generate the on-chain index, and send the on-chain index to the data owner, wherein the data owner will share the on-chain index with the data user.

Optionally, the data user decrypting the hash value based on the key includes:

Sending the access type corresponding to the on-chain index and the encrypted access control list to a trusted execution environment, wherein the trusted execution environment decrypts the encrypted access control list to obtain the decrypted access control list;

The trusted execution environment compares and authenticates the identity information of the data user, the access type, and the decrypted access control list, wherein the trusted execution environment is a trusted TEE verifier implemented based on SGX;

After successful authentication, the data information and the encrypted hash value are sent to the data user;

The data user uses the private key in the key to decrypt the encrypted hash value and obtain a read command.

Optionally, sending the decrypted hash value to the off-chain node for the asynchronous BFT consensus, and obtaining the ciphertext includes:

After sending the read command and the decrypted hash value to the off-chain node for the asynchronous BFT consensus, the leveldb database is accessed using the decrypted hash value to obtain the ciphertext.

Optionally, decrypting the ciphertext to obtain the original data includes:

The ciphertext is decrypted based on the private key and the preset access control method to obtain the original data.

The beneficial effects of the present invention are:

Compared with the prior art, the present invention provides more powerful fine-grained access control, and users can define data access rights in an extremely detailed manner, thereby better protecting privacy and data security.

The present invention implements a trusted TEE verifier based on SGX to verify user access rights. SGX provides hardware-level isolation to ensure the security of programs and data;

The present invention introduces off-chain storage based on asynchronous Byzantine consensus as a solution to improve the efficiency of data transmission. This method reduces redundant data on the blockchain, makes data transmission more efficient, reduces the risk of single point failure, and improves the robustness of the entire system. The present invention overcomes network uncertainty and attacks. The asynchronous Byzantine consensus technology improves the fault tolerance of the system. Even if there are malicious nodes or poor network conditions in the network, the system can still reach a consensus to ensure the security and consistency of the data, providing greater flexibility for distributed systems, enabling them to adapt to various complex situations, including network attacks, node failures, and network delays. This adaptability makes the system more robust and reliable.

The present invention successfully achieves a balance between performance and privacy. It not only provides efficient data management but also protects the privacy of data, which is a balance that is crucial for various application scenarios.

The present invention enhances the security of data and the robustness of the system, using blockchain technology to protect the integrity of data while reducing the risk of single point failures.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

FIG1 is a schematic diagram of a flow chart of a data management method based on on-chain and off-chain according to an embodiment of the present invention;

FIG2 is a flow chart of a data management method based on on-chain and off-chain according to an embodiment of the present invention;

FIG3 is a schematic diagram of the structure of selecting data and encrypting according to an embodiment of the present invention;

FIG4 is a schematic structural diagram of the RBC stage of an embodiment of the present invention;

FIG5 is a schematic diagram of the structure of the MVBA stage of an embodiment of the present invention.

Detailed ways

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

This embodiment provides a data management method based on on-chain and off-chain, as shown in FIG1 , including:

The data owner encrypts the original data and the hash value of the original data based on the key and the preset access control method to obtain the ciphertext of the original data and the encrypted hash value;

Specifically, the data owner generates the key, and the key generation center distributes the key. The data owner uses the key and the selected access control scheme to encrypt the original data and the original data hash value.

Then, the data information, the original data hash value, the encrypted hash value and the ciphertext are sent to the off-chain node for asynchronous BFT consensus, the ciphertext is stored in the off-chain node, and the data information and the encrypted hash value are uploaded to the on-chain node to generate an on-chain index;

Specifically, the data information (access control method, encrypted access control list, file size, file type, etc.), encrypted data (ciphertext), original data hash value and encrypted hash value are packaged and sent to one of the nodes off the chain. After receiving the data, the off-chain node puts it into the message queue, runs the off-chain BFT storage protocol (off-chain node asynchronous BFT consensus) off-chain, and reaches a consensus on the packaged data information, encrypted data, original data hash value and encrypted hash value. After the off-chain node protocol is completed, the databases of N nodes off the chain are all stored with the same ciphertext. Use the leveldb database for storage, the key is the original data hash value, and the value is the encrypted data. Each node sends the completed instructions (the completed instructions are a marking instruction generated after the off-chain consensus storage is completed), data information and encrypted hash value to the on-chain node. After receiving f+1 instructions, the on-chain node will upload the data information and encrypted hash value to the chain. When the chain is successfully uploaded, a unique on-chain index will be generated and returned to the data owner. The data owner can share the on-chain index with the data user.

The data user accesses the on-chain node based on the on-chain index, decrypts the encrypted hash value based on the key, and sends the decrypted hash value to the off-chain node for the asynchronous BFT consensus, obtains the ciphertext, and then decrypts the ciphertext to obtain the original data.

Specifically, the data user has a private key, identity information, and an on-chain index, where the private key is generated by the data owner when the key is generated at the key generation center and is assigned by the data owner. The data user uses the on-chain index to access the on-chain node. The on-chain node sends the access type and encrypted access control list corresponding to the on-chain index to the trusted execution environment (trusted TEE verifier based on SGX implementation). TEE will decrypt the encrypted access control list. TEE has a unique decryptable private key. The trusted execution environment compares and authenticates the identity information, access type, and access control list of the data user. After successful authentication, the chain returns the data information and the encrypted hash value to the data user. The data user uses the private key to decrypt the encrypted hash value, and sends the read command and the decrypted hash value to the next node on the chain. The read command makes the off-chain node think that this is reading the database instead of storing it. The off-chain node performs asynchronous BFT consensus on the decrypted hash value. After asynchronous BFT consensus, the decrypted hash value (key) is used to access the database to obtain the encrypted data (value), and the encrypted data is returned to the data user.

The ciphertext is decrypted to obtain the original data.

Specifically, the data user obtains the original data after successfully decrypting the data using the private key and the preset access control method.

As shown in Figure 2, there are 6 entities including blockchain network, data owner, off-chain BFT storage, trusted verifier, key generation center, and data user. The method of this embodiment has two steps: upload phase and download phase.

Upload phase:

1. The data owner inputs message m.

2. The data owner selects an access control method (broadcast encryption, attribute encryption, threshold encryption) to encrypt m.

3. The data owner packages the data information (access control method, encrypted access control list, file size, file type, etc.), encrypted data (ciphertext), original data hash value and encrypted hash value and uploads them to the off-chain BFT storage.

Implementation process of off-chain BFT storage protocol (asynchronous BFT consensus):

Preparation: Create N buf[i] (FIFO queues), buf[i] is the message queue of the i -th node; create a PK (public key) and N SKi (private keys), SKi is the private key of the i -th node.

User deposits data: puts the data into an empty message queue or randomly puts it into the i-th message queue.

consensus:

A. Data selection and encryption: N nodes randomly select B/N data from the message queue and encrypt them as input of txi (data randomly selected by the i-th node), as shown in Figure 3.

B. RBC (Reliable Broadcast Protocol) phase: Input vi to RBCi . Use erasure code to divide txi into N blocks of sj data blocks. Set it to N-2f blocks of data blocks to restore txi . Use the Merkle tree to calculate VAL ( h , bj , sj ) and send it to N nodes respectively. After each node receives it, send VALi to N nodes. After each node receives it, verify whether it is a Merkle tree branch, otherwise discard it. After each node receives N-2f messages, it restores the data to vi . The node sends the shared signature id to all nodes. The node receives f + 1 valid id shared signatures, and can combine these shared signatures into the signature σ of the id, and then output σ. Among them, vi (data output by message queue i) , RBCi (the i-th node of PRBC), sj (the leaf node sequence number of the Merkle tree is j), h (the hash value of the node), bj (the path from the j node to the root node of the Merkle tree) , VALi = (h, bi, si) . As shown in Figure 4.

C. MVBA phase (multi-value Byzantine consensus): After Nf PRBCs are completed, Nf data are input, the MVBA protocol is called and the output Wi is obtained from MVBA. MVBA votes on Wi as a whole. If Wi satisfies Nf correctness, input 1 to Wi. Finally, ABA is performed to obtain 2f +1 data outputs, and the corresponding threshold encryption of 2f+1 data is decrypted. The remaining f data are stored in the message queue after the second step. As shown in Figure 5. Among them, Wi (the i-th node votes 1｜0 for Wi ), ABA (ABA protocol).

D. Store data: Store the data in MVBA into N databases.

4. Off-chain nodes reach a consensus on data information (access control method, encrypted access control list, file size, file type, etc.), encrypted data (ciphertext), original data hash value and encrypted hash value.

5. The off-chain node stores the original data hash value h and the encrypted data c in key-value format.

6. When the off-chain phase is completed, the off-chain node returns “ done ” to the data owner.

7. When the data owner receives a sufficient number of “ done ” responses from off-chain nodes, the data owner uploads the data information and encrypted data hash value to the blockchain network.

8. After the on-chain phase is completed, the blockchain returns the ID to the data owner. The data owner can share the ID with some data users according to his or her wishes.

Download phase:

1. The data user sends the ID shared by the data owner to the blockchain.

2. The blockchain network (on-chain) sends the access type and encrypted access control list to the trusted verifier (trusted execution environment). The data user also sends his or her identity information to the trusted verifier.

3. After the trusted verifier compares the data user's identity information, access type and access control list and the authentication is successful, the data user can obtain the key from the key generation center in step 4.

4. The data user has a private key, identity information, and on-chain index. The private key is generated by the data owner when the key is generated at the key generation center. When the data user decrypts the encrypted hash value with the key received from the key generation center, the decrypted hash value is sent to the off-chain BFT storage.

5. Data users can download the ciphertext c from the off-chain node and use the key and corresponding access control method to finally obtain the ciphertext m .

The solution of the present invention adopts advanced encryption and security control mechanisms, and the trusted execution environment can grant users access to protected data. It provides strong hardware and software isolation, which can resist multiple attacks to ensure strong data security. By using cryptographic hashing based on blockchain technology, data can be protected in an unalterable manner, which helps reduce the risk of data leakage and unauthorized access, thereby providing more reliable protection for the security of sensitive data such as finance, government, and healthcare. The technical solution of the present invention provides fine-grained privacy protection (attribute encryption, broadcast encryption, and threshold encryption to achieve fine-grained privacy protection), allowing data owners to precisely control who can access their data and which attributes and tags can be accessed, which helps to meet personal privacy protection regulations and ensure that only authorized users can obtain data. The sovereignty of the data is clearer and users can better control their personal information.

The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the claims of the present invention.

Claims (4)

1. A data management method based on both on-chain and off-chain, characterized by including: The data owner encrypts the original data and the hash value of the original data based on the key and the preset access control method, obtains the ciphertext and the encrypted hash value of the original data, and then sends the data information, the hash value of the original data, the encrypted hash value and the ciphertext to the off-chain node for asynchronous BFT consensus, stores the ciphertext in the off-chain node, and uploads the data information and the encrypted hash value to the on-chain node to generate an on-chain index; After sending the data information, the original data hash value, the encrypted hash value and the ciphertext to the off-chain node for asynchronous BFT consensus, storing the ciphertext in the off-chain node includes: Packing the data information, the original data hash value, the encrypted hash value and the ciphertext to obtain packaged data, wherein the data information includes the preset access control mode, the encrypted access control list, the file size and the file type; The packaged data is sent to the off-chain node, and the off-chain node puts the packaged data into a message queue and then performs the asynchronous BFT consensus; After the asynchronous BFT consensus is performed, the leveldb database of the off-chain node stores the original data hash value and the ciphertext in a key-value format; The data user accesses the on-chain node based on the on-chain index, decrypts the encrypted hash value based on the key, and sends the decrypted hash value to the off-chain node for the asynchronous BFT consensus, obtains the ciphertext, and then decrypts the ciphertext to obtain the original data; The data user decrypting the hash value based on the key includes: Sending the access type corresponding to the on-chain index and the encrypted access control list to a trusted execution environment, wherein the trusted execution environment decrypts the encrypted access control list to obtain the decrypted access control list; The trusted execution environment compares and authenticates the identity information of the data user, the access type, and the decrypted access control list, wherein the trusted execution environment is a trusted TEE verifier implemented based on SGX; After successful authentication, the data information and the encrypted hash value are sent to the data user; The data user decrypts the encrypted hash value using the private key in the key and obtains a read command; The decrypted hash value is sent to the off-chain node for the asynchronous BFT consensus, and obtaining the ciphertext includes: After sending the read command and the decrypted hash value to the off-chain node for the asynchronous BFT consensus, the leveldb database is accessed using the decrypted hash value to obtain the ciphertext. 2. According to the on-chain and off-chain data management method according to claim 1, it is characterized in that the access control method is broadcast encryption, attribute encryption or threshold encryption. 3. The data management method based on on-chain and off-chain according to claim 1 is characterized in that uploading the data information and the encrypted hash value to the on-chain node and generating the on-chain index comprises: The off-chain node will send the marking instructions, the data information and the encrypted hash value generated after the asynchronous BFT consensus to the on-chain node. When the on-chain node receives a preset number of the marking instructions, it will upload the data information and the encrypted hash value to the on-chain node, generate the on-chain index, and send the on-chain index to the data owner, wherein the data owner will share the on-chain index with the data user. 4. The data management method based on on-chain and off-chain according to claim 1 is characterized in that decrypting the ciphertext to obtain the original data comprises: The ciphertext is decrypted based on the private key and the preset access control method to obtain the original data.