A Comprehensive Survey of Coin Mixing Protocols

Previous studies have revealed that Bitcoin’s anonymity is not absolute. Coin mixing protocols have been proposed to address these anonymity issues by breaking or obfuscating the relationship between transaction inputs and outputs, thereby ensuring privacy. Due to their ability to enhance anonymity, these protocols are often associated with illegal money laundering activities, and some mixing services have faced sanctions. This paper examines coin mixing protocols by analyzing the techniques they employ to obscure input-output relationships. Furthermore, it explorers the potential threats to which mixing protocols may be exposed and provides a comprehensive analysis of their vulnerabilities.