Blockchain's Mixing Transaction And Verifiable Query

The blockchain is essentially a decentralized distributed database.Unlike traditional distributed databases,blockchain does not require a safe and reliable third party to act as a central control role.The nodes in the system have equal status.By maintaining the chain structure of data blocks,it stores continuously growing and non-tamperable data records.,Use cryptography and consensus mechanisms to ensure data integrity and consistency.The advantages of blockchain anti-counterfeiting,anti-tampering,transparency,credibility,and traceability have enabled blockchain technology to gradually be applied to areas such as financial services,medical care,resource sharing,and the Internet of Things.In the blockchain system,for an ordinary transaction,the number of input addresses and output addresses is small and stored publicly,which easily exposes the connectivity between addresses.In order to enhance the privacy of nodes and destroy the connectivity between addresses,mixed currency transactions have appeared.This article summarizes the definition and process of mixed currency transactions,analyzes a variety of currency mixing methods and query layers of several blockchain databases,and summarizes three problems in currency mixing and query.CoinJoin:(1)Participating in currency mixing The amount cannot be customized;(2)The efficiency of mixed currency transactions is not high;(3)Node privacy is not strong.Querying:(1)Centralized management of data on the chain,and light node queries rely on third-party trusted institutions;(2)The data structure of the original blockchain needs to be modified;(3)The cost of query and integrity verification is unstable.In order to solve the problems of the above-mentioned currency mixing method and query,the work of this article is as follows:1.Aiming at the problem that it takes more time to complete the coin mixing transaction in CoinShuffle,a hybrid scheme based on ring signatures,RSCoinJoin is proposed.First,the user announces the input and output addresses by means of ring signatures;then the user confirms whether his output address is in the collection,and if it exists,attaches his own signature,otherwise enters the marking stage to confirm the information again.The ring signature hides the participant's information,and the mark improves the speed of completing the coin mixing.The experimental results show that when the number of users participating in the mixing of RSCoinJoin is 50,the average time to complete a transaction is 2s,which improves the efficiency of the mixing transaction.2.Aiming at the problem of relying on a trusted third party to provide data for light node query,an index structure based on Merkle-B+tree is proposed.This structure is a variant of Merkle tree and B+tree.All nodes store the data on the chain locally for transaction legality verification.In order to ensure that each full node stores the same Merkle-B+tree,all nodes publish according to the block.The insert order specified by the author updates the data of the Merkle-B+tree index and processes verifiable query requests from light nodes.Through the comparison of construction time,update time and query verification experiment,it is proved that Merkle-B+tree realizes efficient and stable verifiable query.