Research On Privacy Protection Of Transaction Audit In Consortium Blockchain

Consortium blockchain is a kind of blockchain.Unlike traditional public blockchain,which is completely open,consortium blockchain is only targeted at limited groups and specific third parties.It is very similar to business model,and has been widely used in organizational collaboration due to its advantages of strong controllability,semi-decentralization,fast transaction speed and good data privacy.Audit is a kind of economic supervision activity,which can find out the compliance and effectiveness of relevant economic activities of the audited organization.Auditability is also essential for consortium blockchain application.The traditional consortium blockchain transaction audit scheme has some limitations.The auditor must be absolutely trusted in order to have the right to decrypt the private information of the transaction,which affects the scalability of the audit scheme and is not suitable for the rapidly changing audit scene in real life.Two different audit protocols for different application scenarios of consortium blockchain transaction is proposed.The main contributions are as follows:(1)In the application scenario of emphasizing audit security and audit integrity,a transaction privacy protection protocol based on threshold audit is proposed.Combined with the improved Shamir threshold secret sharing scheme,the individual auditor is changed into mutil auditor.Each audit is jointly completed by the randomly designated main auditor and several cooperative auditors,which solves the problem of excessive concentration of power in the audit process.This protocol has good flexibility,security and computing efficiency.(2)In the application scenario of emphasizing privacy protection,a security audit protocol based on CL encryption is proposed.Through additive homomorphic encryption and zero knowledge proof,the semi trusted auditor can complete the audit of the transaction without disclosing the details of the transaction,so as to ensure the user’s transaction privacy.(3)Build the consortium blockchain platform Hyperledger Fabric,deploy the above two protocols to the consortium blockchain in the form of smart contract,and simulate and analyze the efficiency of the protocols.