Topic: Consolidation of mixed outputs - page 4. (Read 1041 times)

I tried to keep it vague; for instance some people inadvertently leak multiple addresses of a wallet online, give the xpub to a non-trustworthy party or - the easiest - address reuse. But sure, if you 'follow protocol', addresses in a wallet shouldn't be linked, so total wallet amount is unknown to the outside.

I hope they will; as far as I know it has never happened yet. A few months back, when 1x 0.001BTC chip was over 50 bucks (or now at roughly 30), they didn't make them smaller either; and as o_e_l_e_o said it was the same size when Bitcoin was $1,500 a pop.

Creative way of (ab)using an exchange for gaining instead of losing privacy! Since we're speaking about small amounts, actually an 'instant exchanger' might be perfect for this.
These platforms like https://fixedfloat.com/; they require no registration at all. I don't know if you can deposit multiple times there, though.

A wallet could have multiple addresses and blockchain data alone sometimes not enough to determine whether set of address belong to same address/person. But if you meant an address rather than a wallet, you could set higher fee or use option to use multiple address as destination.


If Bitcoin price keep increasing, IMO it's likely ChipMixer will introduce smaller chip amount.

To me at least it also depends on the amount of the dust and how much time and effort and money you want to put into it.

There are a few exchanges that don't need anything more then an email address to sign up and will give you a new address with each deposit. They do have miinnium deposit amounts but will credit you once you hit it in total usually 0.001

So in theory it would be known that all these outputs went to one exchange and the exchange would know what email address they were linked to but that is about it.

You could then exchange the coins to a privacy based coin like XMR to another exchange that just requires an email to sign up and exchange them back to BTC

Downsides:
2 x exchange fees
2 x withdraw fees
A lot of time for what may not be a lot of money in the end
If you don't use public Wi-Fi or the like there is still the risk of being found out
You have to trust the exchanges with the funds

-Dave

The idea is: if you had a total of 0.7 BTC in a wallet previously and after the consolidation, it adds up to slightly less than 0.7; a correlation could be made.

Reused change addresses not only allow tracing what you're doing with the change but also tracing what you're doing with the rest of your BTC. Let's say I'm a merchant and you pay me some BTC; I can look at the change address and see other deposits. I can follow the transactions of these deposits and see that you also sent BTC to other (known or unknown) addresses; which could be exchanges (authorities can call them and ask 'who is the human behind address X'), stores or friends of yours that I now know you have some sort of connection to.

Therefore I think you need to send the inputs to the mixer individually and only combine the mixed outputs, right?
It might also depend on the mixer in question; honestly I'm most familiar with ChipMixer and I don't know whether you can even send multiple UTXOs to e.g. CoinJoin and get out one consolidated output (like in CM with user-choosable chip sizes).

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So you just got tons of 0.001BTC chips from ChipMixer and used them in full when paying something? Wouldn't that make for pretty large (and expensive) transactions? Or would you create and withdraw appropriately sized chips / UTXOs on the spot?

All sound like pretty cool options; the last one surely the most convenient one and with 0 'loss'!

I tried to bring this idea up but wasn't sure how to correctly phrase it. Sending multiple outputs to a single CM mix, individually, will keep them completely unlinked, right? If they're below the minimum of 0.001, I guess you could 'LN mix them' and then send to CM afterwards. It may be less secure and whatnot, but if you can't afford to just throw away 30 bucks it may be an option.

That's pretty cool; but I wonder how long it will be sustainable; 0.001BTC might be well over 100$ in the future; in some countries like Colombia, BTC0.001 is already over 100k of their home currency COP. I'm not sure as to how much purchasing power it sums up there, though.

There we go.

Monero is particularly private, so sending your money through a mostly-private exchange such as LocalMonero, using it all to buy XMR for BTC and then back again, and withdrawing in chunks instead of the whole thing (the chunks must be large enough to negate the repeated withdrawal fee) would be a good starting point for untainting mixer outputs - it will be flagged by an exchange as from some other exchange should the transaction chain between the internal addresses in the exchange be long enough.

You won't have to worry about being tracked on the Monero chain because of its use of bulletproofs which makes it harder to unmask the identity of the transaction inputs (by putting in a bunch of spent inputs as fakes). This assumes the exchange won't sell you over though.

An option here might be to try to find a service which will accept such small inputs in exchange for either a Lightning payment or a Monero payment without too much in the way of fees, and consolidate them that way before converting them back to a Bitcoin UTXO (although you would obviously have minimal privacy when considering the service you were using).

You might be lowering the amount of privacy you gain. If I consolidate a bunch of different sized outputs in a single transaction which then sends (for example) 1 BTC to a mixer, and then immediately withdraw a 1 BTC output, then there is a potential link there. If I separately send 0.164 BTC, 0.051 BTC, 0.391 BTC, and so on, particularly spread out over a period of days rather than within a few minutes of each other, and then later withdraw 1 BTC, then I obfuscate that link as my deposits are obscured by everyone else's deposits during the same time.

But if inputs came from a mixing service and therefore have no connection to each other, why not just consolidate them in one transaction before sending them to a mixer again? What traces are you leaving in this case? That some anonymous person used a particular mixing service several times and later decided to mix their funds again but in a single transaction, in my view, doesn't tell much because it is still unknown to an observer where funds have landed up after a final mixing round. The thing is UTXO consolidation always involves certain trade-offs, but sending everything (mixed outputs) in a single transaction is at least less time-consuming and, more importantly, a lot less block space-consuming. Please note that I was talking about a specific case in which you are using the same mixing service both for the obfuscation of your inputs and their subsequent consolidation. If your inputs are from completely different sources (Wasabi, JoinMarket, Whirlpool, Chipmixer, Mercury, etc), then it definitely makes more sense to send them one by one to a mixing service before consolidating them.

What if instead of mixing your entire input amount at once, you break the amount into successive mixing sessions, so long as the broken inputs are still fairly large (anything less than $500 is strictly a no-no)?

Then you could combine up to 1 output from each session, and the trackers would not know any better, because the splitted outputs themselves from each broken-up session are not linked together.

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Of course, if you could hypothetically have your own private coinjoin network of senders, you'd be able to create long chains of transactions fairly easily without being detected as such. Because most commercial trackers have a limit on the chain length to track - maybe 50 for example - so they won't rewind the chain any further to check.

I don't know if he's referring to this but it's one of the types of backtracking chainalysis tries to do when it comes to those, it goes back in time looking for any possible transactions that would match the input that is missing from their history, for example when an address that is tracked deposits coins on a known exchange address it will try to match an outgoing sum from the same exchange or consolidations further down in time that match the value deposited.


I made the mistake of sending freshly coins mixed to exchanges, but I've never and I don't plan on ever linking mixed coins, as o_e_l_e_o said, it's better to have them split in reasonable amounts based on your needs and spending habits that will not create change which is of a too-large value to ignore. Rather than trying to consolidate 5 addresses with 10$ worth to pay for a subscription, I would rather break in 5 a 500$ one and use one of the fractions.

That being said I do have a ton of "dust" in my wallets but I've always postponed any consolidation simply because at this point one screwup and years of mixing have been for nothing, so I'll just let it sit there till I can buy a house with the change from a protonvpn payment 

The best thing you can do is not create change at all. This was very easy to do when ChipMixer was launched and Bitcoin was ~$1,500, since the smallest chip - 0.001 BTC - was only worth around $1.50. So any payment you wanted to make you could round up to the nearest $1.50, have no change output, and not really mind paying an extra buck (or just add the extra on to the fee). Now that 0.001 BTC is worth $30 or more, then it isn't so economical.

You can still avoid creating change outputs with careful UTXO selection. Or instead of rounding up your payment as described above, round up your basket - throw in a couple more cans of beer or an extra month subscription or whatever else you were buying to bring the total up to whatever UTXO you have available so you can avoid creating change. Or just let the merchant keep the rest as a tip. Other options are merchants which will let you open an account or tab with them, top up that account with any amount, and then spend from your available balance.

The way that I deal with the change I do create is usually via ChipMixer, because I find it more economical than trying to coinjoin lots of small change outputs. If I already have some bitcoin stored on ChipMixer under a voucher, then I can just add any change in to that same stack to better hide it. So if, for example, I have 0.012 BTC in a voucher on ChipMixer, than after a couple of small change deposits I can withdraw a 0.016 chip, which prevents them being linked from people looking at individual sizes as you suggest.

If I ever have to deal with any really small change outputs, I usually just fire them off to the donation address of something like Tor, Tails, EFF, etc.

Tracing wallet sizes? Like?

It's a big privacy risk if you can trace what I'm doing with it. But, if I just mix all of my change in one transaction, I don't think it's so bad. Making it official that I'm the owner of those UTXO's doesn't harm much, and you've pretty much already known it.

Of course, if they appear to be a lot, then you might not want to reveal you own that much money. In any case, it's better to split your inputs in several transactions.

After talking about Anonymous UTXO consolidation through LN a few months ago, I'd like to hear a few opinions about consolidation of (traditionally) mixed outputs.
With this I mean mixing through ChipMixer, CoinJoin, JoinMarket and the like.

I pondered on this a bit and I see a few reasons for and against it. Some questions seem trivial or silly, but I'm just trying to give food for thought and discussion.

[1] Firstly, if you're looking to consolidate many small inputs, you could send everything to the mixer 1 input at a time. This way you won't link them when sending.
Next, send all the mixed, anonymous outputs to one address in one transaction.

It should be reasonably secure except from one aspect which is tracing wallet sizes. However if the inputs weren't linked to each other before mixing, it should be fine, right?

[2] If you perform a UTXO mix on ChipMixer and don't want to end up with many little UTXOs, you may consider doing one transaction that bundles all those output chips into one fresh UTXO.
Since chips can be chosen in relatively large sizes, I don't think that having too many little output chips is really a realistic risk, so best would be to just make them large enough and withdraw each one to a fresh new address?

[3] Consolidating change. As we all know, using a common change address is one big privacy risk in Bitcoin. However if you deal with mixed coins and separate change addresses, you're generally speaking fine; but you quickly rack up a lot of 'change UTXOs' that you will sooner or later need to join together. Is it a good idea to individually mix change UTXOs and then join them, what do you think?

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By the way, if you want to get notified about low mempool fees to consolidate small inputs, this is the thread to watch: [May 2022] Mempool empty! Use this opportunity to Consolidate your small inputs!