Walletwasabi: Coordination fee tracked

[john951]

Hello Team,

As you probably noticed at least one user reported issue with withdrawing BTC from Binance to Wasabi wallet as their account was subsequently frozen: Binance CoinJoin Strangeness
Originally posted on Twitter @bittlecat

While PlusToken scammers using Wasabi is really unfortunate their actions affect everyone who wants to have at least a little bit of privacy with Wasabi.

Is there any plan/way how to mitigate this?

What Might Work:

To me adding extra hops seems like an obvious method to plausible deniability ie. wasn't me who did the mixing as it was the 3 wallets (users) after the withdrawal.

[RiccardoMasutti]

The idea of multiple hops is interesting but does not solve the problem. As Binance, as we have seen, follows the transaction even after the withdraw (and we do not know for how many hops it does)

BTW, remember that it is a Binance problem, and not a Wasabi problem, you can safely mitigate the problem manually by doing multiple hops before CoinJoining, by open a Lightning Network channel, or by withdrawing Monero from Binance, send them to XMR.to, and then receive BTC in Wasabi.

There are a lot of methods to bypass this (ridicolous) censhorship.

[john951]

Binance, as we have seen, follows the transaction even after the withdraw (and we do not know for how many hops it does)

I believe 3-10 hops should be sufficient as they cannot go back 20 hops - they would eventually get to the miner for really large portion of customers.

it is a Binance problem, and not a Wasabi problem, you can safely mitigate the problem manually by doing multiple hops before CoinJoining, by open a Lightning Network channel, or by withdrawing Monero from Binance, send them to XMR.to, and then receive BTC in Wasabi.

You are right but having one integrated solution would be nice. Charging for each hop with some random wait built-in feature does make sense. I can see it as additional revenue stream for the Wasabi team.

Also during the hops, assuming the BTC value will be standardized at blocks of 0.1 BTC as it is now, you can do swaps of funds with other users. This would also deter scammers who need to move large amount of coins at once as they would end up swapping coins with themselves.

As Andreas Antonopoulos said privacy is moving target. Also if I remember correctly he did mention that something like 10 hops is more than enough (not sure if it was in that particular video).

[MaxHillebrand]

A possible solution for this is partially blind atomic utxo swaps that will be possible when wasabi implements taproot.

Another solution are schemes that do not fingerprint as a coinjoin, like pay to endpoint.

Doing multiple self spends will likely not solve the issue, as it is trivial to trace back the hops, and a self spending chain is probably also fingerprinted.

Please note that this is not an issue with "Coorination fee address tracked", coinjoins are by design inherently trivial to fingerprint onchain.

[molnard]

Wasabi should not start to make solutions that will hide the CoinJoin transaction - as it is an endless war. With the current CoinJoin technique, it is impossible. Whatever we would do are only patches that can easily be walked around by a regular chain analysis company.
IMO the solution is not in Wasabi's hand but in the users - as if they prefer to not use a service where their wallet can be frozen. And it doesn't matter because of CoinJoin or any other reason.