Blockchain data protection based on generic account model and homomorphic encryption

Patent metadata

Field	Value
Publication number	US-11063769-B2
Application number	US-202016945533-A
Country	US
Kind code	B2
Filing date	Jul 31, 2020
Priority date	Dec 21, 2018
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

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.

First claim

What is claimed is:

1. A computer-implemented method performed by a consensus node using at least one or more hardware processors for validating a transaction between a first node and a second node within a blockchain network, the method comprising:
receiving transaction data associated with the transaction, the transaction data comprising:
data representative of a plurality of assets;
a first commitment comprising a first random number and a transaction amount of the transaction;
a second commitment comprising a second random number and a change calculated based on deducting the transaction amount from a total value of the plurality of assets, the transaction amount being encrypted by a public key of the second node;
a third random number encrypted with the transaction amount by the public key of the second node; and
the change and a fourth random number encrypted by the public key of the first node;

determining that the transaction amount and the change are each greater than, or equal to, zero;
determining that the total value of the plurality of assets equals a sum of the transaction amount and the change; and
determining that the transaction is valid by determining that the transaction amount is equal to the transaction amount encrypted by the public key of the second node, determining that the first random number is equal to the third random number, and determining that the second random number is equal to the fourth random number.

2. The computer-implemented method of claim 1 , wherein:
the third random number is encrypted with the transaction amount by the public key of the second node based upon on a linear deterministic homomorphic encryption (HE) scheme; and
the change and a fourth random number are encrypted by the public key of the first node based upon the linear deterministic HE scheme.

3. The computer-implemented method of claim 1 , wherein the transaction data includes one or more range proofs, a zero-knowledge proof (ZKP), and a digital signature generated based on a private key corresponding to the public key of the first node.

4. The computer-implemented method of claim 3 , wherein determining that the transaction amount and the change are each greater than, or equal to, zero is based upon the one or more range proofs.

5. The computer-implemented method of claim 4 , wherein determining that the transaction is valid is based upon the ZKP.

6. The computer-implemented method of claim 3 , further comprising verifying the digital signature based on the public key of the first node.

7. A non-transitory, computer-readable medium storing one or more instructions executable by a computer system to perform operations comprising:
receiving transaction data associated with a transaction between a first node and a second node within a blockchain network, the transaction data comprising:
data representative of a plurality of assets;
a first commitment comprising a first random number and a transaction amount of the transaction;
a second commitment comprising a second random number and a change calculated based on deducting the transaction amount from a total value of the plurality of assets, the transaction amount being encrypted by a public key of the second node;
a third random number encrypted with the transaction amount by the public key of the second node; and
the change and a fourth random number encrypted by the public key of the first node:

determining that the transaction amount and the change are each greater than, or equal to, zero;
determining that the total value of the plurality of assets equals a sum of the transaction amount and the change; and
determining that the transaction is valid by determining that the transaction amount is equal to the transaction amount encrypted by the public key of the second node, determining that the first random number is equal to the third random number, and determining that the second random number is equal to the fourth random number.

8. The non-transitory, computer-readable medium of claim 7 , wherein:
the third random number is encrypted with the transaction amount by the public key of the second node based upon on a linear deterministic homomorphic encryption (HE) scheme; and
the change and a fourth random number are encrypted by the public key of the first node based upon the linear deterministic HE scheme.

9. The non-transitory, computer-readable medium of claim 7 , wherein the transaction data includes one or more range proofs, a zero-knowledge proof (ZKP), and a digital signature generated based on a private key corresponding to the public key of the first node.

10. The non-transitory, computer-readable medium of claim 9 , wherein determining that the transaction amount and the change are each greater than, or equal to, zero is based upon the one or more range proofs.

11. The non-transitory, computer-readable medium of claim 10 , wherein determining that the transaction is valid is based upon the ZKP.

12. The non-transitory, computer-readable medium of claim 9 , further comprising verifying the digital signature based on the public key of the first node.

13. A computer-implemented system, comprising:
one or more computers; and
one or more computer memory devices interoperably coupled with the one or more computers and having tangible, non-transitory, machine-readable media storing one or more instructions that, when executed by the one or more computers, perform one or more operations comprising:
receiving transaction data associated a transaction between a first node and a second node within a blockchain network, the transaction data comprising:
data representative of a plurality of assets;
a first commitment comprising a first random number and a transaction amount of the transaction;
a second commitment comprising a second random number and a change calculated based on deducting the transaction amount from a total value of the plurality of assets, the transaction amount being encrypted by a public key of the second node;
a third random number encrypted with the transaction amount by the public key of the second node; and
the change and a fourth random number encrypted by the public key of the first node;

determining that the transaction amount and the change are each greater than, or equal to, zero;
determining that the total value of the plurality of assets equals a sum of the transaction amount and the change; and
determining that the transaction is valid by determining that the transaction amount is equal to the transaction amount encrypted by the public key of the second node, determining that the first random number is equal to the third random number, and determining that the second random number is equal to the fourth random number.

14. The computer-implemented system of claim 13 , wherein:
the third random number is encrypted with the transaction amount by the public key of the second node based upon on a linear deterministic homomorphic encryption (HE) scheme; and
the change and a fourth random number are encrypted by the public key of the first node based upon the linear deterministic HE scheme.

15. The computer-implemented system of claim 13 , wherein the transaction data includes one or more range proofs, a zero-knowledge proof (ZKP), and a digital signature generated based on a private key corresponding to the public key of the first node.

16. The computer-implemented system of claim 15 , wherein determining that the transaction amount and the change are each greater than, or equal to, zero is based upon the one or more range proofs.

17. The computer-im

Assignees

• Advanced New Technologies Co Ltd

Inventors

• Zhang Wenbin
• Ma Baoli
• Ma Huanyu

Classifications

• G06N7/01

  Probabilistic graphical models, e.g. probabilistic networks · CPC title

• H04L9/50

  using hash chains, e.g. blockchains or hash trees · CPC title

• H04L9/3239 Primary

  involving non-keyed hash functions, e.g. modification detection codes [MDCs], MD5, SHA or RIPEMD · CPC title

• H04L9/3218

  using proof of knowledge, e.g. Fiat-Shamir, GQ, Schnorr, ornon-interactive zero-knowledge proofs · CPC title

• H04L9/30

  Public key, i.e. encryption algorithm being computationally infeasible to invert or user's encryption keys not requiring secrecy · CPC title