Abstract: Implementations of the specification include receiving transaction data associated with a transaction, the transaction data comprising: data representative of a plurality of assets, a first commitment that hides a first random number and a transaction amount, a second commitment that hides a second random number and a change, the transaction amount and a third random number both encrypted by a public key of the second node, the change and a fourth random number both encrypted by a public key of the first node, and a zero-knowledge proof (ZKP); determining, based on the ZKP, whether the transaction is valid based on determining if the first random number is equal to the third random number, the second random number is equal to the fourth random number, and the transaction amount hidden in the first commitment is equal to the transaction amount encrypted by the public key of the second node.

Abstract: A computer-implemented method, non-transitory, computer-readable medium, and computer-implemented system are provided for implementing privacy protection. In an implementation, a public key pk={N, h} corresponding to a target user is obtained, where h is a generator of a predetermined cyclic group with a size of k in a random number space Z*N, a length of k is i bits, a length of N is n bits, and i<<n. A random number r is selected, so that hr belongs to the predetermined cyclic group. To-be-encrypted data m, corresponding to the target user using the public key pk and the random number r, is processed to generate a homomorphic ciphertext c=(1+N)m·(hN mod N2)r mod N2. The homomorphic ciphertext c is provided to the target user, where the homomorphic ciphertext c can be decrypted using a private key sk to obtain the data m.

Abstract: One or more implementations of the present specification provide a method and an apparatus for implementing a confidential transaction in a blockchain network.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Embodiments of the present application discloses an information authentication method, which includes: generating first transaction information based on content information of first information to be published by an original information publishing end and a HASH value of the first information, wherein the first information is original information or a copy of the original information; writing the first transaction information into a central database and Blockchain, or into the Blockchain; obtaining reprinted information published by an information reprinting end, and generating a HASH value of the reprinted information; comparing the HASH value of the first information with the HASH value of the reprinted information; and returning a first credential, which indicates the reprinted information is true or has not been tampered with, to the information reprinting end, if the HASH value of the first information is equal to the HASH value of the reprinted information.

Abstract: Implementations of the specification include receiving transaction data associated with a transaction, the transaction data comprising: data representative of a plurality of assets, a first commitment that hides a first random number and a transaction amount, a second commitment that hides a second random number and a change, the transaction amount and a third random number both encrypted by a public key of the second node, the change and a fourth random number both encrypted by a public key of the first node, and a zero-knowledge proof (ZKP); determining, based on the ZKP, whether the transaction is valid based on determining if the first random number is equal to the third random number, the second random number is equal to the fourth random number, and the transaction amount hidden in the first commitment is equal to the transaction amount encrypted by the public key of the second node.

Abstract: The present invention provides a method, an apparatus and a system for realizing communication between blockchains, and the method comprises: receiving a first communication packet sent by a first blockchain, the first communication packet comprising a first transaction, and the first transaction corresponding to a change of a database state on the first blockchain; generating a second communication packet according to the first communication packet; and sending the second communication packet to a second blockchain. In the present invention, the communication between a first blockchain and a second blockchain is realized by receiving a first communication packet including a transaction sent by the first blockchain, generating a second communication packet according to the first communication packet and sending the second communication packet to the second blockchain, and thus the transaction processing capability of a blockchain is improved.

Abstract: Implementations of the specification include receiving transaction data associated with the transaction, the transaction data comprising: data representative of a plurality of assets, a first commitment hiding a first random number and a transaction amount of the transaction, a second commitment that hides a second random number and a change, the transaction amount and a third random number both encrypted by a public key of the second node, the change and a fourth random number both encrypted by a public key of the first node, and a zero-knowledge proof (ZKP); determining, based on the ZKP, whether the transaction is valid based on determining if the first random number is equal to the third random number, the second random number is equal to the fourth random number, and the transaction amount hidden in the first commitment is equal to the transaction amount encrypted by the public key of the second node.

Abstract: 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.

Abstract: Implementations of the present disclosure include receiving, from a first account, a digitally signed copy of a plurality of notes, a commitment of a transaction amount of a transaction between the first account and a second account paid by at least a portion of the plurality of notes, a commitment of a change from deducting the transaction amount from a total value of the plurality of notes, and a zero-knowledge proof generated based on one or more selected random numbers. The first account determines that the total value of the plurality of notes equals the sum of the transaction amount and the change, validates the transaction, and updates the first account and the second account based on the plurality of notes, the transaction amount, and the change.