Method, apparatus and electronic device for blockchain transactions

A non-transitory computer-readable media storing instructions executable by a plurality of processors, wherein execution of the instructions cause the plurality of processors to perform operations comprising:

• determining, by a first computing device corresponding to a remitter, a transaction amount to be remitted from a blockchain account of the remitter to a blockchain account of a receiver, wherein the blockchain account of the remitter records a commitment of the remitter's balance in a blockchain of a blockchain computer network, and the blockchain account of the receiver records a commitment of the receiver's balance in the blockchain;
• generating, by the first computing device corresponding to the remitter, a commitment of the transaction amount by applying a homomorphic encryption algorithm to the transaction amount according to a transaction random number;
• sending, by the first computing device corresponding to the remitter via a non-blockchain computer network, the transaction random number, the transaction amount, and the commitment of the transaction amount to a computing device corresponding to the receiver;
• receiving, by the first computing device corresponding to the remitter, a receiver signature generated with a private key of the receiver, the receiver signature indicating that the receiver agrees to the commitment of the transaction amount from the blockchain account of the remitter to the blockchain account of the receiver;
• generating, by the first computing device corresponding to the remitter, a range proof according to a remitter random number, the remitter's balance, the commitment of the remitter's balance, the transaction random number, the transaction amount, and the commitment of the transaction amount;
• generating, by the first computing device corresponding to the remitter with a private key of the remitter, a remitter signature of the commitment of the transaction amount;
• generating, by the first computing device corresponding to the remitter, a blockchain transaction comprising:
• information of the remitter's blockchain account, information of the receiver's blockchain account, the commitment of the transaction amount, the range proof, the receiver signature, and the remitter signature, wherein the blockchain transaction does not include the transaction random number and the transaction amount;
• submitting, by the first computing device corresponding to the remitter, the blockchain transaction to one or more nodes of the blockchain computer network;
• generating, by the second computing device corresponding to the receiver, the commitment of the receiver's balance in the blockchain by applying the homomorphic encryption algorithm to the receiver's balance based on a receiver random number;
• verifying, by each of the one or more nodes of the blockchain computer network, the blockchain transaction by at least verifying, based on a blockchain-based double-spending prevention mechanism or replay attack prevention mechanism, that the blockchain transaction has not been executed, validating the receiver signature and the remitter signature, and verifying, based on the range proof, that the transaction amount is not less than zero and not more than the remitter's balance;
• deducting, by the each of the one or more nodes of the blockchain computer network, the commitment of the transaction amount from the commitment of the remitter's balance;
• and
• adding, by the each of the one or more nodes of the blockchain computer network, the commitment of the transaction amount to the commitment of the receiver's balance.

A method, comprising:

• determining, at a first computing device of a remitter, a transaction amount to be remitted from a blockchain account of the remitter to a blockchain account of a receiver, wherein the blockchain account of the remitter records a commitment of the remitter's balance in a blockchain of a blockchain computer network, and the blockchain account of the receiver records a commitment of the receiver's balance in the blockchain;
• generating, at the first computing device, a commitment of the transaction amount by applying a homomorphic encryption algorithm to the transaction amount according to a transaction random number;
• sending, at the first computing device, via a non-blockchain computer network, the transaction random number, the transaction amount, and the commitment of the transaction amount to a second computing device corresponding to the receiver;
• receiving, at the first computing device, from the second computing device, a receiver signature generated with a private key of the receiver, the receiver signature indicating that the receiver agrees to the commitment of the transaction amount from the blockchain account of the remitter to the blockchain account of the receiver;
• generating, at the first computing device, a range proof according to a remitter random number, the remitter's balance, the commitment of the remitter's balance, the transaction random number, the transaction amount, and the commitment of the transaction amount;
• generating, at the first computing device, with a private key of the remitter, a remitter signature of the commitment of the transaction amount;
• generating, at the first computing device, a blockchain transaction comprising:
• information of the remitter's blockchain account, information of the receiver's blockchain account, the commitment of the transaction amount, the range proof, the receiver signature, and the remitter signature, wherein the blockchain transaction does not include the transaction random number and the transaction amount;
• submitting, at the first computing device, the blockchain transaction to one or more nodes of the blockchain computer network;
• generating, at the second computing device, the commitment of the receiver's balance in the blockchain by applying the homomorphic encryption algorithm to the receiver's balance based on a receiver random number;
• verifying, at the one or more nodes, the blockchain transaction by at least verifying, based on a blockchain-based double-spending prevention mechanism or replay attack prevention mechanism, that the blockchain transaction has not been executed, validating the receiver signature and the remitter signature, and verifying, based on the range proof, that the transaction amount is not less than zero and not more than the remitter's balance;
• deducting, at the one or more nodes, the commitment of the transaction amount from the commitment of the remitter's balance;
• and
• adding, at the one or more nodes, the commitment of the transaction amount to the commitment of the receiver's balance.