Research On Privacy-preserving Blockchain Cross-Chain Transaction Method

Blockchain is widely used in online transactions due to its characteristics of immutability,traceability,and decentralization.However,different blockchains have corresponding access mechanisms,which lead to difficulties in data circulation and form "information islands".In order to realize the information exchange between blockchains,cross-chain technology is mainly used.When performing cross-chain transactions,cross-chain information needs to be recorded and verified,which is based on information sharing.Therefore,cross-chain technology also has the risk of privacy information leakage.How to ensure data security and prevent user privacy leakage is an important research direction in the current blockchain cross-chain field.This thesis deeply analyzes the privacy issues arising from cross-chain transactions,and proposes a privacy-preserving blockchain cross-chain transaction method.By refining the cross-chain transaction requirements,a cross-chain secure transaction scheme based on Pedersen commitment,a privacy protection scheme for data assets in cross-chain transactions based on secure transactions,and a cross-chain data access scheme for data security access issues in cross-chain transactions are proposed successively.The main work of this thesis can be summarized as:(1)Aiming at the problem that user privacy is easily leaked in the process of crosschain transactions,a cross-chain secure transaction scheme based on Pedersen commitment is proposed.The scheme utilizes Pedersen commitment to protect the security of transaction data,and can quickly verify user assets and transactions without revealing the plaintext data of transactions.The scheme introduces a relay-chain in cross-chain transactions,and the relay-chain is responsible for recording and confirming cross-chain transactions.Simultaneously,a privacy-preserving loan scheme is designed for the possibility of insufficient funds in the process of crosschain transactions.(2)On the basis of secure payment,a safe and efficient data asset privacy protection scheme is proposed to solve the problems of easy duplication of data assets and easy leakage of user privacy in data asset cross-chain transactions.The scheme introduces transaction agents,which are responsible for collecting users’ data asset information and coordinating transactions.The scheme designs a privacy computing protocol with multi-party participation and suitable for lightweight node execution,which collects data label information while protecting user privacy.In addition,the scheme uses Pedersen commitment to store labels of data assets,and users can analyze label types without obtaining the plaintext data of labels.(3)A cross-chain access control scheme based on smart contract is proposed to address the data security access problem during the data asset cross-chain transaction.The scheme designs an access control framework to prevent the leakage of private information in data assets and improve the security of cross-chain transactions of data assets.The scheme uses smart contract to set the access control strategy to achieve secure access to data assets in cross-chain transactions.In addition,the scheme designs a credit evaluation method,and the data owner can judge whether the user meets the access requirements and set the user’s access authority according to the credit.