  This manuscript presents an exhaustive review of blockchain-based mixing
services, aiming to fill the existing gap between academic innovations and
real-world implementations. Starting with an identification of the core
functionalities and techniques employed by mixing services, the paper delves
into detailed explanations of these operational mechanisms. It further outlines
an evaluation framework tailored for a rigorous assessment, highlighting the
key vulnerabilities and strengths of various solutions. In addition, the study
identifies potential attack vectors that compromise these services. The paper
explores the dual nature of mixing services, while they contribute to the
preservation of privacy, a cornerstone of blockchain technologies, they can
also facilitate illicit activities. By addressing key research questions, this
study not only offers a comprehensive overview of the current state of mixing
services but also sets the stage for future academic discourse in this evolving
field.
