Jiaxin Wang, Qian’ang Mao, Jiaqi Yan, Jie Yin, Yuan He, Yi Zhang
Accepted: 2025-01-20
The rapid development of blockchain technology and the rise of cryptocurrency not only challenge traditional financial and asset management concepts but also bring about a series of privacy and security issues. Coin mixing technology is the primary means of privacy protection in blockchain. It is designed to improve the anonymity of transactions and protect the privacy of user identities. However, this enhanced anonymity also makes cryptocurrencies a tool for criminal activities such as money laundering, theft, and fraud. Therefore, there is an urgent need for a comprehensive review of technology for the identification, detection, and regulation of coin mixing services to support law enforcement agencies and promote cryptocurrency security compliance. This paper first systematically sorts out the technical principles and mechanism classification of coin mixing services, designs a general classification system of coin mixing tools, and discusses in detail the criminal activities that may be caused by coin mixing services. Then this paper focuses on the latest academic research progress of five coin-mixing regulatory technologies based on manual rules, address clustering, entity classification, abnormal transaction detection, and mixing service traceability, and summarizes the existing coin-mixing supervision-related tools in the industry. Finally, the challenges faced by coin mixing regulation are put forward, and future research directions are prospected.