Transaction Data Set And Anonymity Optimization Of Bitcoin-Like Blockchain System

As a new type of decentralized distributed data system,blockchain can securely store digital cryptocurrency transactions and other data.Blockchain has greatly reduced the cost of building trust on the Internet with its information immutability,openness,and anonymity,allowing people to cross over from the Internet of information to the Internet of value.Blockchain technology is an important core force of the future digital economy.Bitcoin is the most typical blockchain system whose underlying storage method has been used until now,and most blockchain applications are developed based on Bitcoin-like systems.At present,the rapid development of blockchain technology has made the transaction data in the blockchain soar,and what directly results in the transaction data expansion is the Unspent Transaction Output(UTXO)model in the Bitcoin-like blockchain systems.The small periodical increase of UTXOs will directly cause the expansion of the transaction database.In addition,transactions are implemented through transaction scripts in a Bitcoin-like blockchain system.The user’s public key hash and address information are recorded in the transaction script and published on the blockchain for verification.By analyzing all the transaction records of an address,anyone can obtain the transaction behavior of that address,making user privacy at risk to some extent.To slow down the expansion of blockchain transaction datasets,this thesis studies the development status of existing UTXO datasets and proposes an optimization scheme for the transaction datasets of Bitcoin-like blockchain systems.To solve the problem of existing blockchain scripts leaking user privacy,this thesis analyses the existing blockchain transaction scripts and proposes an Anonymous Hidden Transaction System(AHTS)based on blockchain.Specifically,the main work of this thesis is as follows.1.By studying and analyzing the distribution of UTXO sets on existing blockchain systems,this thesis proposes a Jump Selection Sort(JSS)mechanism for digital currencies to achieve the optimization of transaction datasets.For the proposed Bitcoin-like blockchain system transaction dataset optimization scheme,this thesis designs corresponding experiments for validation.The results show that the transaction dataset optimization scheme can effectively slow down the database expansion rate.2.By studying the script transaction model of the blockchain system,this thesis designs the P2SAPKH(Pay-to-Shell-Address-Public-Key-Hash)transaction script for the blockchain privacy leakage problem.Based on the P2SAPKH scripting scheme,this thesis proposes AHTS.In addition,this thesis proposes a mathematical analysis model for the AHTS and evaluates the anonymity of the user address tracking rate of the original blockchain system and AHTS.The evaluation results show that AHTS has better anonymity than the original system.This thesis conducts in-depth research and analysis on the current UTXO transaction model and transaction system of the blockchain system,designs a new UTXO transaction algorithm to solve the storage problem of the transaction dataset,and further proposes AHTS to improve the privacy and security of blockchain system.This thesis has corresponding theoretical and application values for the optimization of blockchain systems and provides new ideas for the future development of blockchain technology.