Bitcoin Mixing Service Detection Based on Spatio-Temporal Information Representation of Transaction Graph

Hanzhi Yang, Zhenzhen Li, Gaopeng Gou, Junzheng Shi, Gang Xiong, Zhen Li

Abstract: Coin mixing is a technique used to enhance Bitcoin’s anonymity and can be used to obfuscate the relationship among transaction input addresses. Due to this property, much of the criminal activity on Bitcoin uses coin-mixing techniques to launder money, making these illicit funds difficult to trace. Therefore, it is important to implement the detection of Bitcoin mixing services. Several methods for identifying bitcoin mixing services have been proposed, but balancing their efficiency and generality at the same time is a challenging task. In this paper, We propose STMD (Spatio-Temporal Mixing Detector), which combines local features and global features of Bitcoin transactions to identify coin-mixing transactions. On one hand, we extract and process the statistical features of neighboring nodes of the transaction as local features. On the other hand, we construct a global position encoding (GPE) containing spatio-temporal information of the transaction as global features. Additionally, we employ the attention mechanism to handle these two types of features, effectively combining them. Finally, we utilize linear layers to achieve the detection of coin-mixing transactions. The experimental results show that STMD performs better than existing methods on the same dataset; it also has a higher recall on the test set of other types of coin-mixing transactions, which reflects the generality of the model. In particular, We apply local features and global features for experiments separately and verify the necessity of the two features. The results of the model trained using only global features also outperform the existing methods, which shows that the global position encoding (GPE) we constructed is effective for mixed currency transaction identification.

External IDs:dblp:conf/ipccc/YangLGS0023