Research On Traceable Privacy Preserving And Fair Transaction On Blockchain

Blockchain is a digital transaction ledger that is decentralized,fully trusted,and unalterable through consensus mechanism,hash algorithm,public key cryptography,and other technologies.It can build a trust relationship at a low cost between parties that do not trust each other to ensure secure transactions of all parties.The concept of blockchain first appeared in the Bitcoin proposed by Satoshi Nakamoto in 2008,which has aroused wide attention and discussion from all walks of life.Blockchain has developed from the first generation represented by Bitcoin and the second generation represented by Ethereum,smart contract,and alliance chain to now,and has officially entered the third generation of promoting social security and healthy development and promoting the deep integration of various industries.Blockchain has become an indispensable basic part of people’s lives.However,sensitive content such as user information and transaction information on blockchain is stored in clear text,which greatly endangers the security of users’ personal information.Although pseudonyms can be used to hide real identities on blockchain,studies have shown that information can be efficiently decrypted through means such as big data.On the other hand,due to its unregulated nature,there are some malicious users using blockchain to carry out illegal activities,the most common problems are fraud,illegal transactions and unfair transactions.Therefore,based on the problems existing in the above blockchain,privacy protection,regulation and fair trading on the blockchain have become the current pain points in the field of blockchain security.How to provide the regulatable property under the premise of privacy protection is a hot topic in the current research direction of blockchain privacy protection.How to provide the property of fair transaction while providing the nature of privacy protection is a hot topic in the field of fair transaction of blockchain,both of which are urgent problems to be solved at present.The purpose of this thesis is to explore how to ensure effective and practical privacy protection on the blockchain while providing regulation,so as to protect the privacy of users while preventing the use of blockchain for evil.And how to ensure that their privacy is not infringed in the process of fair trade,the specific research content is as follows:· This thesis proposes an efficient traceable privacy-preserving blockchain transaction protocol FTPP.It is based on the newly designed zero-knowledge proof protocol and the blockchain of account model,which realizes the characteristicsof traceability,privacy protection,efficient execution and so on.Simulation experiments were then carried out to prove that the efficiency of the system was significantly improved compared to existing blockchain systems.In addition,we give the security proof for the newly designed zero-knowledge proof protocol,the security definition and security proof for the transaction protocol proposed in this thesis,and prove that they can meet the security requirements.· This thesis proposed a universal traceable privacy-preserving fair transaction scheme(ETPP)based on blockchain.It is based on the improved zero-knowledge proof protocol and the blockchain with account models,achieving universality,privacy protection,traceability,fair transaction,etc.We define its threat model and security definition,and prove that it can meet the defined security requirements under the given threat model based on the general composable model.We also conducted simulation experiments on the Ethereum test network,and the experimental results proved that it is effective and practical,and can be deployed in real world environments.