论文标题
要理解和神秘化比特币混合服务
Towards Understanding and Demystifying Bitcoin Mixing Services
论文作者
论文摘要
比特币受欢迎的原因之一是由于其匿名性。尽管已经使用了几种启发式方法来打破匿名性，但提出了新的方法来同时增强其匿名性。其中之一是混合服务。不幸的是，混合服务被滥用以促进犯罪活动，例如洗钱。因此，迫切需要系统地了解比特币混合服务。 在本文中，我们迈出的第一步了解最先进的比特币混合服务。具体而言，我们提出了一个通用抽象模型，用于混合服务，并观察到野外有两个混合机制，即{交换}和{obfuscating}。基于此模型，我们进行了基于交易的分析，并成功揭示了四种代表性服务的混合机制。此外，我们提出了一种确定利用混淆机制的混合交易的方法。所提出的方法能够确定$ 92 $ \％的混合交易。然后，根据已确定的交易，我们估算了混合服务的利润，并提供了一个案例研究，以追踪被盗比特币的货币流量。
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 $92$\% 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.
