Managing user authorizations for blockchain-based custom clearance services

1. A computer-implemented method for processing data with different levels of data privacy based on blockchain technologies, the method comprising:

at a service platform, receiving, from a computing device associated with a first user, a symmetric key and a data package for storage on a blockchain, wherein the data package includes public data and private data, wherein the symmetric key encrypts the private data, and wherein the symmetric key is encrypted by a public key of a second user to generate an encrypted key;

dividing the data package into the private data and the public data;

storing the encrypted key, the private data, and an identifier (ID) of the data package in a cache storage dedicated to storing smart contract data for executing a smart contract;

invoking a first application programming interface (API) to cause a blockchain node to initiate a consensus algorithm and record the public data and the ID of the data package on the blockchain;

providing a second API configured to:

retrieve the encrypted key and the public data from the blockchain;

retrieve the private data from the cache storage; and

provide the retrieved encrypted key, public data, and private data to a device associated with the second user;

decrypting, by the device associated with the second user, the encrypted key by using a private key corresponding to the public key of the second user to obtain the symmetric key;

decrypting, by the device associated with the second user, the private data by using the obtained symmetric key; and

recovering, by the device associated with the second user, the data package based on the retrieved public data and the decrypted private data.

2. The computer-implemented method of claim 1 , wherein the private data is in cyphertext encrypted using the symmetric key.

3. The computer-implemented method of claim 1 , the method further comprising:

receiving, from the computing device associated with the first user, a list of one or more other users permitted to access plaintext of the private data;

encrypting the symmetric key by using each of public keys of the one or more other users to generate encrypted symmetric keys; and

storing the encrypted symmetric keys in the cache storage.

4. The computer-implemented method of claim 1 , the method further comprising providing the second API to enable the first user or the second user to retrieve the public data from the blockchain and the private data from the cache storage based on the ID of the data package.

5. The computer-implemented method of claim 4 , wherein the ID of the data package is a hash value of the data package or an ID of a document associated with the data package.

6. The computer-implemented method of claim 4 , wherein the second API further enables the first user to record an updated version of the public data associated with the ID of the data package on the blockchain, and disables the second user to record the updated version of the public data associated with the ID of the data package on the blockchain.

7. The computer-implemented method of claim 1 , wherein an address of the smart contract is stored on the blockchain in a database storage.

8. The computer-implemented method of claim 1 , wherein the method further comprises:

generating one or more zero-knowledge proofs (ZKPs) related to one or more values associated with the private data; and

wherein the data package includes at least one of order data or payment data, and the ZKPs are related to one or more values associated with at least one of the order data or the payment data.

9. A system for managing user authorizations, comprising:

one or more processors; and

one or more computer-readable memories coupled to the one or more processors and having instructions stored thereon that are executable by the one or more processors that cause the processors to realize a service platform and perform operations comprising:

at the service platform, receiving, from a computing device associated with a first user, a symmetric key and a data package for storage on a blockchain, wherein the data package includes public data and private data, wherein the symmetric key encrypts the private data, and wherein the symmetric key is encrypted by a public key of a second user to generate an encrypted key;

dividing the data package into the private data and the public data;

storing the encrypted key, the private data, and an identifier (ID) of the data package in a cache storage dedicated to storing smart contract data for executing a smart contract;

invoking a first application programming interface (API) to cause a blockchain node to initiate a consensus algorithm and record the public data and the ID of the data package on the blockchain; and

providing a second API configured to:

retrieve the encrypted key and the public data from the blockchain;

retrieve the private data from the cache storage; and

provide the retrieved encrypted key, public data, and private data to a device associated with the second user;

decrypt the encrypted key by using a private key corresponding to the public key of the second user to obtain the symmetric key;

decrypt the private data by using the symmetric key; and

recover the data package based on the public data and the private data.

10. The system of claim 9 , wherein the private data is in cyphertext encrypted using the symmetric key.

11. The system of claim 9 , wherein the operations further comprise:

receiving, from the computing device associated with the first user, a list of one or more other users permitted to access plaintext of the private data;

encrypting the symmetric key by using each of public keys of the one or more other users to generate encrypted symmetric keys; and

storing the encrypted symmetric keys in the cache storage.

12. The system of claim 9 , wherein the operations further comprise providing the second API to enable the first user or the second user to retrieve the public data from the blockchain and the private data from the cache storage based on the ID of the data package.

13. The system of claim 9 , wherein the operations further comprises:

generating one or more zero-knowledge proofs (ZKPs) related to one or more values associated with the private data; and

wherein the data package includes at least one of order data or payment data, and the ZKPs are related to one or more values associated with at least one of the order data or the payment data.

14. A non-transitory computer readable storage medium storing instructions executable by one or more computers and that upon such execution cause the one or more computers to perform operations comprising:

at a service platform, receiving, from a computing device associated with a first user a symmetric key and a data package for storage on a blockchain, wherein the data package includes public data and private data, wherein the symmetric key encrypts the private data, and wherein the symmetric key is encrypted by a public key of a second user to generate an encrypted key;

dividing the data package into the private data and the public data;

storing the encrypted key, the private data, and an identifier (ID) of the data package in a cache storage dedicated to storing smart contract data for executing a smart contract; and

invoking a first application programming interface (API) to cause a blockchain node to initiate a consensus algorithm and record the public data and the ID of the data package on the blockchain;

providing a second API configured to:

retrieve the encrypted key and the public data from the blockchain;

retrieve the private data from the cache storage; and

provide the retrieved encrypted key, public data, and private data to a device associated with the second user;

decrypt the encrypted key by using a private key corresponding to the public key of the second user to obtain the symmetric key;

decrypt the private data by using the symmetric key; and

recover the data package based on the public data and the private data.