Reiterating centralized coinjoin (Wasabi & Samourai) deanonymization attacks

The email highlights a significant dispute regarding the misrepresentation of a service's cost and functionality, emphasizing the critical distinction between presumed and informed consent. The sender accuses the recipient of uncritically propagating unverified claims made by a sponsor, particularly about the nature of the service being free and trustless, which contradicts the reality that the service generates substantial revenue. Specifically, it generates approximately 0.2 bitcoin per month, challenging the claim of it being a free service. This discrepancy raises concerns about users being misled regarding what they are consenting to when using the service.

Moreover, the email delves into technical critiques concerning the implementation of Wasabi coinjoins, indicating that the policy allowing excess fees to be claimed by the coordinator exploits a leniency bug. This practice diverged from the previous understanding that surplus would go towards mining fees, a change implemented without adequate justification or timely public documentation. The sender references changes in the coordinator software and suggests that these alterations were inadequately justified, citing a pull request and subsequent documentation as evidence. They recommend examining the WabiSabi paper, specifically section 7.2.2, to understand the distinction between costs associated with mining fees and coordinator revenues, arguing that the latter could potentially lower the cost of sybil attacks, thereby harming users.

The sender further criticizes the recipient for minimizing the significance of generating revenue from what is purported to be a free service, suggesting this stance aligns with the sponsor's financial interests rather than user transparency or consent. They outline a history of misleading practices, including instances where clients were deceived into paying money without receiving value, attributing this issue to a lack of verifiably fair computation of coordinator fees. The email argues for the importance of clearly informing users about the nature of excess fees and the trust required in the coordinator's honesty, implying that failing to do so previously led to deceptively obtained consent.

This contention underscores broader issues of transparency, informed consent, and ethical conduct within the development and promotion of services, suggesting a need for clearer communication and integrity in representing service costs and operations to users. The sender provides various links throughout the email to support their claims, including to GitHub repositories and documentation, advocating for a more honest and evidence-supported discussion around the protocol and its implementation.