Providing data authorization based on blockchain

A computer-implemented system, comprising:

• one or more computers, and
• one or more computer memory devices interoperably coupled with the one or more computers and having tangible, non-transitory, machine-readable media storing one or more instructions that, when executed by the one or more computers, perform operations comprising:
• receiving, by a blockchain node, a data acquisition transaction submitted by a data user for obtaining target data possessed by a data owner;
• transmitting, by the blockchain node, the data acquisition transaction to a second blockchain node based on a blockchain consensus process;
• determining, by the blockchain node, that the data user has obtained authorization of the target data;
• executing, by the blockchain node, a smart contract invoked by the data acquisition transaction to provide one or more of the target data and a computational result of one or more predetermined computational operations performed based on the target data to the data user;
• providing, by the blockchain node and based at least on the blockchain node and the second blockchain node executing the smart contract, the target data and the computational result to the data user, wherein a transaction execution result event based on the target data and the computational result are written in a transaction log by the smart contract, and wherein the transaction log is monitored and available to be acquired by the data user;
• encrypting, by the blockchain node, the target data in a trusted execution environment (TEE) to obtain encrypted target data;
• and
• storing, by the blockchain node, the encrypted target data to a database associated with the blockchain node;
• wherein the executing the smart contract is performed in the TEE after reading the encrypted target data into the TEE and decrypting the encrypted target data,
• wherein the smart contract is executed to provide the target data to the data user if the target data has low data privacy level, and the smart contract is executed to provide the computational result of the one or more predetermined computational operations if the target data has high data privacy level.

A non-transitory, computer-readable medium storing one or more instructions executable by a computer system to perform operations comprising:

• receiving, by a blockchain node, a data acquisition transaction submitted by a data user for obtaining target data possessed by a data owner;
• transmitting, by the blockchain node, the data acquisition transaction to a second blockchain node based on a blockchain consensus process;
• determining, by the blockchain node, that the data user has obtained authorization of the target data;
• executing, by the blockchain node, a smart contract invoked by the data acquisition transaction to provide one or more of the target data and a computational result of one or more predetermined computational operations performed based on the target data to the data user;
• providing, by the blockchain node and based at least on the blockchain node and the second blockchain node executing the smart contract, the target data and the computational result to the data user, wherein a transaction execution result event based on the target data and the computational result are written in a transaction log by the smart contract, and wherein the transaction log is monitored and available to be acquired by the data user;
• encrypting, by the blockchain node, the target data in a trusted execution environment (TEE) to obtain encrypted target data;
• and
• storing, by the blockchain node, the encrypted target data to a database associated with the blockchain node;
• wherein the executing the smart contract is performed in the TEE after reading the encrypted target data into the TEE and decrypting the encrypted target data,
• wherein the smart contract is executed to provide the target data to the data user if the target data has low data privacy level, and the smart contract is executed to provide the computational result of the one or more predetermined computational operations if the target data has high data privacy level.