Research On Auditable Blockchain Privacy Protection Technologies

In the traditional blockchain,all user transaction information is public,and there is a potential risk of privacy leakage.With the development of blockchain technology,the anonymity of the blockchain has been gradually enhanced,but the increase in anonymity has brought about the problems of difficulty in auditing and accountability for regulation.At the same time,as the blockchain becomes more and more widely used,it has real editing needs in terms of information regulation,privacy protection,data update,etc.,such as modifying incorrect data,updating out-of-date information,and so on.Therefore,this thesis focuses on auditable blockchain privacy protection technologies and editable blockchain technology.The main research work includes the following two points:(1)In order to protect the privacy of blockchain transactions,the illegal transactions in the blockchain can be audited,and the identities of both parties to the illegal transactions can be traced,this thesis proposes an auditable and traceable blockchain anonymous transaction scheme.In this scheme,the Elgamal encryption algorithm is used,so that users other than the regulator cannot confirm the identity of the sender,and other parties other than the auditor cannot know the content of the transaction data;an improved hidden address method is adopted to generate a one-time address to protect the privacy of the identity of the recipient of the transaction;the source of the trace request is authenticated by using the signature to ensure that only the auditor has the authority to request trace.By introducing the two roles of the auditor and the regulator,the distribution of privileges is realized and the abuse of privileges is further prevented.Through the security proof,the solution satisfies anonymity,auditability and traceability.The simulation experiment results show that the execution efficiency of each algorithm is higher.(2)In view of the accountability problem faced when edited blocks in editable blockchains fail to pass verification,this thesis proposes an editable and accountable blockchain scheme,using publicly verifiable secret sharing,zero-knowledge proof,chameleon hash,which realizes the legal editing of block data,all members can verify the edited content,and the regulator can realize the accountability of the responsible party.Through the security proof,the solution satisfies the trapdoor security,editability and accountability.The simulation experiment results show that the time of each algorithm is in the order of milliseconds except for the parameter generation algorithm,and the parameter generation algorithm is executed only once,and can be processed in advance,so the efficiency of the scheme is higher.