Author: ZmnSCPxj 2019-12-29 10:23:39
Published on: 2019-12-29T10:23:39+00:00
The email conversation between Yuval and ZmnSCPxj focuses on the privacy issues related to CoinJoin transactions. The email mentions a broader criticism of CoinJoin based privacy and not specific to unequal amounts, which refers to the assertion of 0 linkability. ZmnSCPxj expresses concern about perspectives that focus on linkability information revealed by a single CoinJoin transaction in isolation. The post/pre mix transaction graph could present a computationally much harder problem when looking at the combinatorics through the same lens, but reality it can also be used to place many constraints on valid partitions/sub-transaction assignments for a single transaction with equal amounts. ZeroLink protocol fixes this by strongly constraining user behavior. However, ZeroLink is not "purely" implemented in Wasabi as Wasabi still allows spending pre- and post-mix coins in the same tx, and any mix change should be considered as still linked to the inputs. The email points out that the proof, as well as its applicability, seems suspect since it involves trusting the server. Equal-valued CoinJoins fix this by using a Chaumian bank, which constrains value transfers to specific fixed amounts. Since an equal-valued CoinJoin uses a single fixed amount anyway, it is not an additional restriction. CashFusion cannot use the same technique without dropping into something very much like an equal-valued CoinJoin. The email concludes that there are still some privacy concerns related to CoinJoin transactions that need to be addressed.
Updated on: 2023-06-13T22:57:57.567930+00:00