TRacer: Scalable Graph-Based Transaction Tracing for Account-Based Blockchain Trading Systems

Security incidents such as scams and hacks have become a major threat to the health of the blockchain ecosystem, resulting in billions of dollars in losses to blockchain users each year. To reveal the real-world entities behind pseudonymous blockchain accounts and recover stolen funds from massive transaction data, much effort has recently been put into tracing illicit financial flows in blockchain by academia and industry. However, most of the current blockchain fund tracing methods are heuristics and taint analysis methods that are designed on the basis of expert experience and specific events, which have limitations in terms of universality, effectiveness and efficiency. This paper models blockchain transaction records as a transaction graph and tackles blockchain transaction tracing as a graph search task. To achieve efficient and effective tracing of fund transfers on the transaction graphs, we propose a scalable transaction tracing tool, TRacer, which to the best of our knowledge is the first intelligent transaction tracing tool that is generalized to multiple account-based blockchain platforms and can handle complex transaction behavior in decentralized finance (DeFi). Particularly, we tackle the transaction tracing task via a subgraph searching approach which employ a novel ranking method to infer the relevance between accounts during the graph search process in the multi-relational blockchain transaction graph. Theoretical analysis and experimental results on datasets from multiple blockchain platforms demonstrate that TRacer can efficiently perform the transaction tracing task at a lower cost and achieve better tracing results than existing methods or even expert manual audits.