Advanced New Technologies Co., Ltd.

Alibaba Group Holding Limited

Huanyu Ma

Wenbin Zhang

Lichun Li

Baoli Ma

Zheng Liu

Jiahui Cui

Hao Lei

Zhangjie Huang

Shuai Han

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.

System and method for information protection

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 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.

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*, a length of k is i bits, a length of N is n bits, and i&#x3c;&#x3c;n. A random number r is selected, so that hbelongs 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)&#xb7;(hmod N)mod N. 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.

Homomorphic data decryption method and apparatus for implementing privacy protection

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.

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.

Blockchain data protection based on generic account model and homomorphic encryption

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*, a length of k is i bits, a length of N is n bits, and i&#x3c;&#x3c;n. A random number r is selected, so thatbelongs 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)&#xb7;(hmod N)mod N. 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.

Homomorphic data encryption method and apparatus for implementing privacy protection

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.

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Hangzhou, China

Huanyu Ma