Advanced New Technologies Co., Ltd.

Alibaba Group Holding Limited

Baoli Ma

Wenbin Zhang

Zheng Liu

Lichun Li

Shan Yin

Huanyu Ma

Jiahui Cui

Implementations of the present specification provide a blockchain-based transaction method and apparatus, and a remitter device. The method includes: calculating a transaction amount commitment, a first commitment random number ciphertext, a first transaction amount ciphertext, a second commitment random number ciphertext, and a second transaction amount ciphertext; and submitting transaction data to the blockchain, the transaction data including the transaction amount commitment, the first commitment random number ciphertext, the first transaction amount ciphertext, the second commitment random number ciphertext, and the second transaction amount ciphertext, for the transaction amount commitment, the first commitment random number ciphertext, and the first transaction amount ciphertext to be recorded into a remitter account, and the transaction amount commitment, the second commitment random number ciphertext, and the second transaction amount ciphertext to be recorded into a remittee account.

Blockchain-based transaction method and apparatus, and remitter device

A method for implementing blockchain-based transactions comprises: determining a transaction amount to be remitted from a remitter's blockchain account into a receiver's blockchain account, wherein a balance of the remitter's blockchain account comprises multiple reserve balances, and commitments of the reserve balances are recorded in a blockchain; selecting one or more of the reserve balances from the remitter's blockchain account, wherein the sum of the selected one or more reserve balances is not smaller than the transaction amount; and submitting to the blockchain a transaction comprising an identification of each of the selected one or more reserve balances and a commitment of the transaction amount, for the selected one or more reserve balances to be removed from the remitter's blockchain account and the transaction amount to be added to the receiver's blockchain account.

Method, apparatus and electronic device for blockchain transactions

A computer-implemented information protection method comprises: obtaining a plurality of encrypted transaction amounts associated with transactions among a plurality of accounts, wherein each of the encrypted transaction amounts is associated with one of the accounts that sends or receives one of the transaction amounts, and the encryption of each of the transaction amounts at least conceals whether the one account sends or receives the one of the transaction amounts; generating a sum proof based on the obtained encrypted transaction amounts, the sum proof at least indicating that the transaction amounts are balanced; and transmitting the encrypted transaction amounts and the sum proof to one or more nodes on a blockchain network for the nodes to verify the transactions.

System and method for information protection

A method for implementing blockchain-based transactions comprises: determining a transaction amount to be remitted from a blockchain account of a remitter into a blockchain account of a receiver, wherein the blockchain account of the remitter records a homomorphic encryption ciphertext of the remitter's balance, the blockchain account of the receiver records a homomorphic encryption ciphertext of the receiver's balance; generating a homomorphic encryption ciphertext of the transaction amount with respect to the remitter and a homomorphic encryption ciphertext of the transaction amount with respect to the receiver; and submitting to the blockchain a transaction for the homomorphic encryption ciphertext of the transaction amount with respect to the remitter to be subtracted from the homomorphic encryption ciphertext of the remitter's balance and for the homomorphic encryption ciphertext of the transaction amount with respect to the receiver to be added to the homomorphic encryption ciphertext of the receiver's balance.

Embodiments of the application provide a method, apparatus, and electronic device for implementing blockchain-based transactions. The method comprises: determining a transaction amount to be remitted from a remitter's blockchain account into a receiver's blockchain account, wherein a commitment of the remitter's balance is recorded with the remitter's blockchain account in a blockchain, a commitment of the receiver's balance is recorded with the receiver's blockchain account in the blockchain; obtaining a commitment of the transaction amount by using the homomorphic encryption algorithm according to the transaction amount; and submitting to the blockchain a transaction comprising information of the remitter's and the receiver's blockchain accounts, and the commitment of the transaction amount, for the commitment of the transaction amount to be deducted from the commitment of the remitter's balance and the commitment of the transaction amount to be added to the commitment of the receiver's balance.

A method comprises: selecting one or more blockchain assets from a remitter's blockchain account according to a transaction amount of a transaction to be remitted from the remitter's blockchain account into a receiver's blockchain account, wherein a total asset amount represented by the selected one or more blockchain assets is not less than the transaction amount, and a commitment of an individual asset amount represented by each of the selected one or more blockchain assets is recorded in a blockchain; generating a commitment of the transaction amount; and submitting to the blockchain the transaction comprising information of the selected one or more blockchain assets and the commitment of the transaction amount, for the selected one or more blockchain assets to be removed from the remitter's blockchain account and one or more blockchain assets corresponding to the commitment of the transaction amount to be added to the receiver's blockchain account.

A computer-implemented method comprises: committing a transaction amount t of a transaction with a commitment scheme to obtain a transaction commitment value T, the commitment scheme comprising at least a transaction blinding factor r_t; encrypting a combination of the transaction blinding factor r_t and the transaction amount t with a public key PK_B of a recipient of the transaction; and transmitting the transaction commitment value T and the encrypted combination to a recipient node associated with the recipient for the recipient node to verify the transaction.

A computer-implemented method comprises: committing a transaction amount of a transaction with a commitment scheme to obtain a transaction commitment value, the commitment scheme comprising at least a transaction blinding factor; generating a first key of a symmetric key pair; encrypting a combination of the transaction blinding factor and the transaction amount t with the first key; and transmitting the transaction commitment value T and the encrypted combination to a recipient node associated with a recipient of the transaction for the recipient node to verify the transaction. The first key is a symmetrical key generated with Diffie-Hellman (DH) key exchange protocol that can be used to encrypt/decrypt the random numbers and the plaintext balances, thus providing convenient management. The method provides a robust privacy protection for transaction amounts, asset values, and blinding factors in commitment schemes.

A method for implementing blockchain-based transactions includes: determining a to-be-remitted amount for each of a plurality of remitters participating in a transaction and a to-be-received amount for each of a plurality of receivers participating in the transaction, wherein the plurality of remitters include one or more real remitters, the plurality of receivers include one or more real receivers, and the plurality of remitters include one or more cover-up remitters and/or the plurality of receivers include one or more cover-up receivers; generating a commitment of the to-be-remitted amount corresponding to the each remitter and a commitment of the to-be-received amount corresponding to the each receiver; and submitting the transaction to a blockchain for execution, wherein the transaction comprises blockchain account addresses of the remitters and receivers, and the commitments of the to-be-remitted amounts and the to-be-received amounts.

A node device in a blockchain receives an asset issuance transaction from an asset issuer, where the asset issuance transaction comprises a commitment value and a proof for performing a zero-knowledge proof with respect to the commitment value, and where the commitment value is calculated by inputting at least an asset type of a target asset object issued by the asset issuer to a commitment function. The zero-knowledge proof with respect to the commitment value based on the proof is initiated. It is determined that the asset type of the target asset object is in a set of legal asset types allowed to be issued by the asset issuer. In response to determining that the asset type of the target asset object is in the set of legal asset types allowed to be issued by the asset issuer, the commitment value to the blockchain is issued for storage.

Method, apparatus and electronic device for blockchain-based asset issuance

A computer-implemented method for information protection comprises: committing a transaction amount of a transaction with a first commitment scheme to obtain a transaction commitment value, committing a change of the transaction with a second commitment scheme to obtain a change commitment value, the first commitment scheme comprising a transaction blinding factor, and the second commitment scheme comprising a change blinding factor; encrypting a first combination of the change blinding factor and the change with a first key; transmitting the transaction blinding factor, the transaction amount, and the transaction commitment value to a recipient node associated with a recipient for the recipient node to verify the transaction; in response to that the recipient successfully verifies the transaction, obtaining an encrypted second combination of the transaction blinding factor and the transaction amount encrypted with a second key.

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Hangzhou, China

Baoli Ma