Blockchain system supporting public and private transactions under account models

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

• receiving, by a consensus node of a blockchain network, transaction data and a digital signature of the transaction data, wherein the transaction data includes a commitment value, a random number, and a transaction amount to be transferred from one of a public account or a private account of a first user node to one of a public account or a private account of a second user node, and wherein the digital signature is generated by digitally signing the transaction data using a private key of the first user node and the commitment value is generated based on the random number and the transaction amount using a commitment scheme;
• verifying the digital signature of the transaction data using a public key of the first user node;
• and
• determining that the transaction amount is valid, if the commitment value is correct based on the random number and the commitment scheme, and the transaction amount is less than or equal to a balance of the one of the public account or the private account of the first user node before transfer of the transaction amount.

A system, comprising:

• one or more computers;
• and
• one or more computer-readable memories coupled to the one or more computers and having instructions stored thereon which are executable by the one or more computers to perform operations comprising:
• receiving, by a consensus node of a blockchain network, transaction data and a digital signature of the transaction data, wherein the transaction data includes a commitment value, a random number, and a transaction amount to be transferred from one of a public account or a private account of a first user node to one of a public account or a private account of a second user node, and wherein the digital signature is generated by digitally signing the transaction data using a private key of the first user node and the commitment value is generated based on the random number and the transaction amount using a commitment scheme;
• verifying the digital signature of the transaction data using a public key of the first user node;
• and
• determining that the transaction amount is valid, if the commitment value is correct based on the random number and the commitment scheme, and the transaction amount is less than or equal to a balance of the one of the public account or the private account of the first user node before transfer of the transaction amount.