| Blockchain is an open source,transparent,immutable and decentralized distributed database that has attracted much attention since its inception in 2008.The application of blockchain technology by platforms such as Bitcoin and Ethereum has made it widely disseminated.There have been many studies combining blockchain technology with finance,logistics,government,electricity and other fields.Ethereum is the representative of the blockchain 2.0 era.It allows users to publish customized applications to achieve specific functions,bringing more scenarios and possibilities to the blockchain ecosystem.But at the same time,malicious incidents on the Ethereum platform have occurred frequently in recent years,such as currency theft,fraud,gambling,etc.,which have caused huge losses to users and exchanges,and also brought threats to the blockchain ecosystem.Therefore,the regulation and restriction of malicious events is of great significance.First,based on the transaction history replay mechanism,this thesis proposes an ETH tracking algorithm to track the transaction amount of Ethereum to obtain the ETH tracking tree.This algorithm can be used to obtain the flow and distribution of dirty money behind malicious events,and to help locate suspects.In addition,hackers often complete malicious events through Ethereum accounts.For this reason,this thesis designs malicious account identification models for external accounts and contract accounts,respectively,to detect suspicious accounts and prevent malicious events.This thesis also conducts several control experiments for the model,and the experimental results prove the validity and stability of the model.Based on the above-mentioned ETH tracking algorithm and malicious account identification model,this thesis establishes a system based on B/S architecture with front-end and back-end separation.The system mainly provides users with the services of the above algorithms and models.The back-end of the system is based on the Django framework,the front-end uses the IceJS framework based on ReactJS,and Geth is used to synchronize Ethereum node information,and the relational database Mysql is used to store records.This article introduces the system from the requirements analysis,summary design,and detailed design of the system.Finally,the thesis also tests the system,both functional and non-functional.In the functional test,all test cases passed smoothly,which proves that the system has completed the basic functions agreed in the requirement analysis and can work normally.In the non-functional test,the accuracy of the services provided by the system is guaranteed through experiments. |
