0 sats \ 7 replies \ @bitgould 25 Mar 2023 \ parent \ on: Payjoin: Privacy Without Mixing bitcoin
payjoin does not change any particular exchange's view into their customer data. It's a no-brainer
Not necessarily.
Whenever you deposit coin into a CEX it undergoes automated blockchain analysis. You can get a high level view of the type of data they collect by putting a BTC address into Antinalysis. (Note: doesn't seem to support taproot addresses yet.)
If the source of the coin throws up flags such as the ones Antinalysis looks for, your account can get frozen by the algorithm.
They're all required to do this by AML laws.
So, yes, if someone pays you some BTC that was once used on the darknet, and you send it to a CEX, you could have your funds frozen while they "investigate." This is usually exactly why that type of thing happens.
And the same analysis specifically looks for signs of "coin mixers." If an exchange sees a customer sending a lot of BTC in that's flagged as being from "mixers" they can freeze the account.
And yet another reason to avoid central exchanges. Bisq ftw.
reply
good points
reply
You make a good point on why they would avoid payjoin, but if payjoin becomes a defacto for most on-chain wallets, you eventually reach a point where all coins in circulation have some history of taint bar the newly minted ones, which become less and less with time, eventually it becomes pointless for a CEX to mark joined coins as bad, because it impacts profitability and they go out of business as they can only accept a shrinking minority of coins for their platforms
reply
This is true, and I think even without payjoin or coinjoin this principle still holds up - over time, as coins circulate, and newly mined coins make up less and less of the supply, it will be virtually impossible for any coin to have not gone through something that analysis would mark as "shady" in the same way that most dollar bills have probably, at one time or another, most likely been used to buy drugs or pay hookers or whatever else.
I still prefer to avoid CEX's if possible, but it's a valid point that this method of analysis will inevitably become useless as coins circulate. The algorithms will have to be adjusted so they only flag coins that are directly correlated with blacklisted wallets or something.
reply
Unlike coinjoin, payjoin leaves no trace. The result looks exactly the same as simple spends with two inputs.
reply
The issue remains you don't know the source of the coin of the other people you're payjoining with. If it looks the same as a normal spend with two inputs, and the other input is a darknet vendor, you will also get flagged as such.
As @TheBTCManual points out, and as I agreed and elaborated on here, as coins continue to circulate, this type of analysis will effectively become useless.
However, the analysis algos heavily factor in the number of "hops" between the address they class as shady, and the address you send from.
In other words, coin that was withdrawn from a DNM ten wallets ago is less of a red flag than coin that (looks like) it was send direct from a DNM into your wallet.
Through this lens, it's possible payjoin's ability to blend with other transactions could actually make your coin more likely to get flagged by a CEX.
I say this not to FUD either coinjoin or payjoin, but rather to point out that privacy and CEX's don't really mix.
reply
все эти монеты уже были чистыми... майнеры сделали это. почему ни кто не пользуется этим?
reply