Matching Accounts on Blockchain via Pseudo Fine-tuning of Language Models

Web 3.0, built on blockchain technology, prioritizes user privacy and autonomy, presenting new opportunities for financial systems while also complicating the regulation of illicit activities. In this study, we present a novel infrastructure named Pseudo Fine-tuning (PFT) that provides account matching services to combat financial crimes on account-based blockchains such as money laundering through coin-mixing services. The significance of PFT lies in overcoming the need for real labels to fine-tune language models for account matching, given the limited availability of labeled account pairs for the task. Specifically, our design involves (1) crafting pseudo-labeled pairs from transactions of an account across different periods, and (2) fine-tuning language models to distill knowledge from pseudo pairs, which is transferable to the target task. We provide an in-depth analysis to investigate the inherent knowledge acquired during the PFT process and the conditions conducive to its effectiveness. Comprehensive experiments on real-world datasets collected from coin-mixing services and ENS name services, corroborate that the framework delivers pronounced enhancements over state-of-the-art approaches. Our implementation is released at https://github.com/git-disl/PFT .