WabiSabi proposes variable-amount coordinated CoinJoin
WabiSabi proposed a coordinated CoinJoin protocol that could mix unequal output amounts without revealing the link between a participant's inputs and outputs to the coordinator.
WabiSabi introduced a credential-based approach to coordinated CoinJoin intended to remove one of the major constraints of earlier schemes: participants no longer needed to create identical-denomination outputs to obtain privacy.
Using blinded credentials, the coordinator could verify that participants were not creating value while learning less about which outputs belonged to which inputs. The proposal was particularly relevant to wallet privacy because equal-output structures can be cumbersome and can themselves create recognizable transaction patterns.
In June 2020 WabiSabi was a protocol proposal, not a deployed privacy standard. It nevertheless became an important step in the evolution of practical CoinJoin design.