English

Towards Understanding and Demystifying Bitcoin Mixing Services

Cryptography and Security 2021-03-03 v2

Abstract

One reason for the popularity of Bitcoin is due to its anonymity. Although several heuristics have been used to break the anonymity, new approaches are proposed to enhance its anonymity at the same time. One of them is the mixing service. Unfortunately, mixing services have been abused to facilitate criminal activities, e.g., money laundering. As such, there is an urgent need to systematically understand Bitcoin mixing services. In this paper, we take the first step to understand state-of-the-art Bitcoin mixing services. Specifically, we propose a generic abstraction model for mixing services and observe that there are two mixing mechanisms in the wild, i.e. {swapping} and {obfuscating}. Based on this model, we conduct a transaction-based analysis and successfully reveal the mixing mechanisms of four representative services. Besides, we propose a method to identify mixing transactions that leverage the obfuscating mechanism. The proposed approach is able to identify over 9292\% of the mixing transactions. Based on identified transactions, we then estimate the profit of mixing services and provide a case study of tracing the money flow of stolen Bitcoins.

Keywords

Cite

@article{arxiv.2010.16274,
  title  = {Towards Understanding and Demystifying Bitcoin Mixing Services},
  author = {Lei Wu and Yufeng Hu and Yajin Zhou and Haoyu Wang and Xiaopu Luo and Zhi Wang and Fan Zhang and Kui Ren},
  journal= {arXiv preprint arXiv:2010.16274},
  year   = {2021}
}
R2 v1 2026-06-23T19:46:45.675Z