A computer-implemented method for processing data with different levels of data privacy based on blockchain technologies, wherein: an internal computer system of a service platform performs: receiving, from a computing device associated with a user, an encryption key and data for storage on a blockchain connected to the internal computer system of the service platform, wherein the data includes public data and private data, and the encryption key encrypts the private data; storing the encryption key and an identifier of the data in a cache storage dedicated to storing smart contract data for executing a smart contract; generating zero-knowledge proofs related to values associated with the private data, wherein the zero-knowledge proofs comprise a proof under a homomorphic encryption scheme, a range proof, and a zero test, wherein i) the homomorphic encryption scheme separately encrypts the values associated with the private data such that after the homomorphic encryption scheme is performed, the encrypted values cannot be revealed without decryption, ii) the range proof proves whether an amount is within a range without revealing the actual amount, and iii) the zero test proves whether that an amount is zero; providing the zero-knowledge proofs and encrypted private data to blockchain nodes of the blockchain; and wherein the blockchain nodes of the blockchain perform the verification of the legitimacy of the private data based on verifying the zero-knowledge proofs and perform a consensus algorithm to record the encrypted private data on the blockchain in response to verifying that the private data is legitimate. receiving, from a computing device associated with a user, an encryption key and data for storage on a blockchain connected to the internal computer system of the service platform, wherein the data includes public data and private data, and the encryption key encrypts the private data; storing the encryption key and an identifier of the data in a cache storage dedicated to storing smart contract data for executing a smart contract; generating zero-knowledge proofs related to values associated with the private data, wherein the zero-knowledge proofs comprise a proof under a homomorphic encryption scheme, a range proof, and a zero test, wherein i) the homomorphic encryption scheme separately encrypts the values associated with the private data such that after the homomorphic encryption scheme is performed, the encrypted values cannot be revealed without decryption, ii) the range proof proves whether an amount is within a range without revealing the actual amount, and iii) the zero test proves whether that an amount is zero; providing the zero-knowledge proofs and encrypted private data to blockchain nodes of the blockchain; and i) the homomorphic encryption scheme separately encrypts the values associated with the private data such that after the homomorphic encryption scheme is performed, the encrypted values cannot be revealed without decryption, ii) the range proof proves whether an amount is within a range without revealing the actual amount, and iii) the zero test proves whether that an amount is zero; providing the zero-knowledge proofs and encrypted private data to blockchain nodes of the blockchain; and wherein the blockchain nodes of the blockchain perform the verification of the legitimacy of the private data based on verifying the zero-knowledge proofs and perform a consensus algorithm to record the encrypted private data on the blockchain in response to verifying that the private data is legitimate.