Joining a lot of small inputs & question about Wasabi/CoinJoins

[20kevin20]

I have a few hundreds of small inputs that I'm looking to join together. By "small", I'm talking about $10 and under. Most of them are older change addresses.

My question is.. how can I join all those small inputs together without sacrificing my privacy? I've used Coin Control on all of those specifically not to link them together, so linking them now means linking all my entire BTC history together.


Now about Wasabi and CoinJoins.. I was wondering something: doesn't the server I connect to see all the UTXOs I own? As in, say I have 5 different addresses in my offline Electrum I have never linked together before. Now I want to move these coins to 5 different addresses I generated on the same Wasabi seed.. doesn't the server see that my Tor IP owns all those 5 addresses basically, or is there 1 separate IP generated for each address balance request?

I was thinking about creating my own server with its own blockchain explorer so that I don't need to connect to external servers anymore for balance retrieval, but I can't seem to find a good tutorial for that to also work with Wasabi while still maintaining the same level of security.

[jackg]

You light have to run a pruned bitcoin core node to get anything similar to a blockchain explorer imo.

Is the input consolidation time dependent? If not you might be able to just wait for mimblewimble to come out. Otherwise you light want to create packets of transactions and send them all to one address.

If you need complete privacy, you could use a service like chipmixer and dump 5-10 inputs together into one transaction.

[mocacinno]

This is a really interesting topic... I don't have all the answers, but i'm looking foreward to seeing the discussion(s) in this thread...

There are some questions/points/concerns i do have an answer for/an opinion about tough:

The last coinjoin i performed using wasabi, i ended up with an output from an anonymity set of 70+... This means that there were 70+ outputs with the same value as mine. This also means that it would be very hard to know which of those 70+ unspent outputs belonged to me...

However, in your specific case, the current output size is slightly under 0.1 BTC: if there were 70 participants that started the coinjoin process with inputs of ~0.1, and you wanted to start the process with 10 inputs of 0.01, it would be trivial for anybody looking at the coinjoin transaction that the 10 inputs belonged to the same wallet... Coinjoin transactions are designed to create anonymous unspent outputs, not to anonymise the inputs...

There's a limit on the amount of inputs for wasabi's coinjoin btw, i think it's around 6 or 7... If you have more than x inputs, your inputs will be rejected.

I also don't think there's a new route for every input, but that shouldn't matter... AFAIK, you're not passing trough an exit node, so the hidden service setup by the company behind wasabi won't be able to log anything anything usefull. EDIT: i'm not a tor expert, but after re-reading some papers i bookmarked ages ago, i do believe that the company behind wasabi could potentially know those unspent outputs belong to the same user IF they manually patched their tor software. Both user and service do meet up at the same rendez-vous point, eventough this is usually handled by the tor daemon (and not logged), but i guess nothing would stop wasabi's owners to modify their tor daemon so it logs which packages were exchanged at which rendez-vous point, thus knowing which unspent outputs belong to the same user. But for some reason, i think we're getting into theoretical vulnerability's: at this point you have to have done something SO horrible several 3 letter agency's are trying to hunt you down AND you'd have to assume wassabi used a patched tor node for their hidden service AND the link between several of your unspent outputs would have to be enough for said 3 letter agency's to find you before i'd even consider this to be a serious problem.

I can only speak about my personal opinion here: personally, i consider all coins pre-coinjoin (or pre-mix) to be linkable to me in some way... The only thing i care about is that the post-coinjoin or post-mix unspent outputs are not linkeable to me... So i personally wouldn't care if people knew a bunch of addresses belong to my wallet just after the unspent outputs funding these addresses went trough a coinjoin transaction. As long as those people were unable to tell which of the 70+ new unspent outputs belonged to me...

And one last thing: you could probably install a full node on a server/pc and install electrs or some other electrum server on top of this full node, then connect your electrum client to your own personal electrum server. That would do the trick to anonimise your address lookups... Just make sure you connect ONLY to your own electrum node... Even if the full node isn't using tor,  people will not know which addresses you looked up: core will just download all blocks, your personal electrum node will fetch data from your own bitcoin node only, and your electrum client will fetch data from your own electrum node... So the only thing thirth party's will see is a full node downloading all blocks.

[20kevin20]

You light have to run a pruned bitcoin core node to get anything similar to a blockchain explorer imo.

Is the input consolidation time dependent? If not you might be able to just wait for mimblewimble to come out. Otherwise you light want to create packets of transactions and send them all to one address.

If you need complete privacy, you could use a service like chipmixer and dump 5-10 inputs together into one transaction.

Does the full node act as an explorer though? As far as I'm concerned, it does not act as one and to do that, I have to get my own server instead. I'm a bit concerned that as soon as I enter my wallet with all those addresses, a malicious node finds out that all of them are owned by one person. I may be very well wrong about it though, so correct me if I'm wrong.

It's not necessarily time dependent, so I could wait. I could simply transfer them one by one rather than in bulk. I have enough patience to do that, but the only difference would be that I'd have a lot of txs rather than a bulky one - they'd still basically link together upon a blockchain analysis.

I can only speak about my personal opinion here: personally, i consider all coins pre-coinjoin (or pre-mix) to be linkable to me in some way... The only thing i care about is that the post-coinjoin or post-mix unspent outputs are not linkeable to me... So i personally wouldn't care if people knew a bunch of addresses belong to my wallet just after the unspent outputs funding these addresses went trough a coinjoin transaction. As long as those people were unable to tell which of the 70+ new unspent outputs belonged to me...

Thanks for the long answer, I appreciate it. I care about the pre-coinjoined coins being linked together because that'd be crucial to linking a large part of my history together. Say I had 10 different accounts under pseudonymous names on different websites I've always used through Tor without JS. If I ever link the BTC txs I made through these accounts together, that'd make it easy for a bad actor to link all the accounts as well.

There obviously are some inputs I wouldn't care about, but they're mixed up. Hence, finding a way to privately consolidate all of them is my only hope.

[odolvlobo]

CoinJoin is probably the most effective way to consolidate your bitcoins without connecting the addresses. I would consolidate using several transactions.

[khaled0111]

^ If he mixes all the coins in one transaction, anyone who is tracking one of his addresses will assume that all inputs belong to the same wallet.
What I would do, is to find an online service (exchange, web wallet...) which generates new address for each transaction and has no minimum deposit limit. Then request a new unique address for each of my inputs.
The service has to be of the custodial type so they will be in charge of consolidating the inputs.
It's not 100% effective, but it will make linking your addresses a bit harder.

[20kevin20]

^ If he mixes all the coins in one transaction, anyone who is tracking one of his addresses will assume that all inputs belong to the same wallet.
What I would do, is to find an online service (exchange, web wallet...) which generates new address for each transaction and has no minimum deposit limit. Then request a new unique address for each of my inputs.
The service has to be of the custodial type so they will be in charge of consolidating the inputs.
It's not 100% effective, but it will make linking your addresses a bit harder.

Well, I think this is as worse as combining all of my inputs together (or maybe I didn't get it right). The exchange/wallet would literally have the information that one single customer/user has deposited all of those amounts, which is exactly what I'm trying to avoid - especially as a lot of exchanges probably hand out their customers' data to authorities every now and then.

CoinJoin is probably the most effective way to consolidate your bitcoins without connecting the addresses. I would consolidate using several transactions.

I would use CoinJoin, but I can't even use 10 addresses with it and the minimum amount is .1BTC. Hence, the best thing I can do is just keep them inside my wallet and join them with other addresses worth ~0.1BTC, but there's one issue: as long as it's not exactly the same minimum amount Wasabi requires for queue, it'd only result in yet another change.