By the same line of reasoning, JoinMarket and WabiSabi are permissioned, because you need to trust that the coordinator or the offer makers will allow you to join their coins with them.
It's not the same, remixers are
*required* to wait in Whirlpool since their fees are paid by new entrants, a remixed output can't afford to pay another mining fee because then the output would drop below the fixed 0.5/0.05/0.01/0.001 pool size. WabiSabi and JoinMarket allow you to remix at any time (JoinMarket takers can remix immediately, WabiSabi at the end of the coordinator's round timer).
Yes, however, if my understanding is correct, in every coinjoin implementation you'll have to trust the coordinator slightly at least. With maybe Joinmarket being the most resistant among all, due to fidelity bonds.
You don't have to trust the coordinator in WabiSabi. You gain no privacy against the coordinator (taker) as a JoinMarket maker. JoinMarket takers, who are their own coordinator, don't have to trust makers thanks to fidelity bonds.
In Samourai, for example, there is structurally enforced liquidity going into a mix, which means one coin in per mix, without mixing with yourself. That is verifiable by the client though (i.e., Sparrow), so you don't need to trust the coordinator.
This doesn't have anything to do with the coordinator.
However, explain why wouldn't Alice double register ("Mix with herself") in this scenario?
- Alice creates premix inputs A, B, C.
- The first round creates postmix outputs D, E, F,
- After waiting, D, E, F, all remix creating G, H, I,
- When waiting for further remixing, let's say the coordinator selects both G and H, (both owned by Alice) for the same coinjoin round. Alice has an incentive to register both.
If I'm not mistaken, in Wasabi you can choose which round to join. Isn't that much more prone to sybil attack?
All participants join the same round, there's no choosing (under normal conditions).
