Topic: Few questions (First time Lighting,Wasabi & CoinJoin,using Bitcoin Core offline) (Read 549 times)

To demonstrate that Wasabi CoinJoin have fixed output of mixed coins and usually there's "left over" coin which isn't mixed since it's amount is too low.


There's no single/best how it's done probably, but don't spend all mixed coin and following guide by wasabi which i mentioned on previous posts should be good enough.

You forget 0.05001234BTC which isn't mixed


As @fillippone mentioned, that would reduce your and other's privacy, so the answer is no.

Wasabi Wallet have good documentation about it at https://docs.wasabiwallet.io/using-wasabi/ChangeCoins.html and https://docs.wasabiwallet.io/using-wasabi/Deanonimization.html

But aside from docs, i only know few possible faults :
1. Disable Tor connection on Wasabi Wallet
2. Use all mixed coins in a transaction. For example, you mixed 1.05001234BTC continuously and got 10 mixed UTXO with amount 0.1BTC, then you use all those 10 mixed UTXO in a transaction.

I've no idea how serious the privacy implication of faults i mentioned though.

a) why did you include 0.05001234BTC in the first please i am confused

b) if mixing is not about using all of mixed coins in a single transaction then how is it done probably a.k.a. post-mix i mean

@BitCryptex : I want to thank you so so so much for answering all of my questions in this thread I am sorry if I caused any issues for you and I would like you to keep watching the thread to learn more about coinjoins 

@ETFbitcoin :

a) I can not figure from where the number 1.05001234BTC came you said we have 10 mixed UTXO with each UTXO with 0.1BTC so total is 1BTC or I am missing something

b) you said we shall not use all the mixed coins in a single transaction I can not get that point isn't mixing about using all of the mixed coins in a single transaction or more than a transaction ?

@fillippone : may you ELI5 your last post please as you know I am still new to coinjoining

From a theoretical point of view, mixing and then consolidating your outputs not only reduce your own anonymity set, but also the other coinjoin participants. So it's an harmful practice.
Think of a coinjoin with three people, if Alice and Bob consolidate their coins after the mix, also Charlie, who is diligently spending his coin consciously without consolidating, has his anonymity set almost destroyed.
You have to take into account this "negative externality" when consolidating.

I don't think if there is any way to mitigate that without using an additional device. Did you consider buying a hardware wallet? You wouldn't have to bother with a separate computer or VMs if you bought one.


Besides that threat, it is a little difficult to maintain because you are using Bitcoin Core. You wouldn't have to worry about keeping your client up-to-date if you used Electrum, for example.

Soon, but don't hold your breath.
I am going to publish it on the italian board first (it was requested there). The translation is quite trivial.
But RL/quarantine are taking a toll on my activities on the forum, so I had to delay it a little bit.

@fillippone : when can we expect to see the coinjoin guide please ?

@BitCryptex : as you know there is nothing fail-proof a.k.a. 100% secure but your threat model is totally legit. I had a question in mind how could we mitigate this if I have only access to a single physical pc ?

edit: if you could as well please tell I what is wrong in my setup beside the threat model you shared.

@ETFbitcoin : could you please list for I/us what faults we could accidently/non-accidently cause that would degenerate the anonymity of the mixed coins ?

Yes, it was a little bit of overstatement. Better not to derail the thread too much discussing pro and cons of the different solutions. I just wanted to make things clear (maybe only to me).

Using some kind of malware. You seem to be cautious enough not to be fooled by malware replacing addresses. Keep in mind that if your wallet file is stolen while you go online, the attacker could broadcast a transaction with a higher fee so that there would be a chance that it would be accepted by the miners earlier. Those are really extreme cases. I have never been affected by those.


'overcomplicated' is an exaggeration. It is a good setup if one does not trust hardware wallets. OP didn't mention them so I assumed that he doesn't want to use them.

This setup you are suggesting is actually and over-complicated Hardware wallet, after all. Where you store your private keys offline and use them to sign a transaction prepared on an online PC.

Regarding Wasabi, I am preparing a very Basic guide to run Coinjoins.
@scott.carter.2020 I will try to answer some of your answer on that one, and maybe post an international version. (even if I have the suspect the average reader I am referring to has way less technical competence than you.

A very good read on privacy, overall is this A Treatise On Bitcoin And Privacy Part 1: A Match Made In The Whitepaper. I do recommend the read.


Bear in mind that coinjoins aren't compatible with Hardware Wallet YET. You must store your coins on Wasabi hot wallet.

I am not against reconsidering my setup and I thank you so much for that

but what I am thinking of is the following

if I am already hacked for example and that is the worst case scenario, once I am offline all the work will be done.

once I am online, the transactions will be broadcasted to the blockchain and everything is over.

how would the hacker steal the funds ?

what he could only steal are the funds which are I want to spend.

am I right or is there anything wrong please ?

The problem is that by the time you realise that you have been hacked, your funds will have been already stolen. You won't have any time to react. That's why I recommend you to reconsider your setup.

correct me if I am wrong please

lets suppose my (host) pc is (currently) hacked

if I went (totally offline) and did the following

- created few wallets in my vm
- backed them up using different mediums
- copied my old wallet into my up-to-date bitcoin core and sent the coins to that few wallets i created
- done

what the risks i am facing me and/or what could go wrong ?

the only thing I will risk in the few satoshis I would have on my machine which I will be spending as I mentioned earlier I will leave some satoshis on my machine as I need to sell them

What machine are you referring to? The host? As I wrote earlier, if your host gets hacked then your VMs should be also considered as compromised. Ideally, it would be great if you used a completely separate machine to sign your transactions. Creating raw transactions using Bitcoin Core is a bit complicated so I would recommend you either using Armory + Bitcoin Core or Electrum (wallet backup would be in a form of 12 words which you wouldn't need to update after each transaction unlike your current setup).

I like bisq network and hodl hodl plus p2p transactions like here in the forum or other forums, so I was asking if wasabi is more than enough to vanish the origin of my coins or you prefer something better or maybe a combo of other solutions/technologies for example ?

here is what i have in mind

i already have the old wallet.dat on several mediums as a backup

i want to divide the amount on that old wallet.dat into several smaller ones, to be less paranoid about working with a single wallet in case if something went wrong then i am rekt plus i want to spend some of the coins.

i will make the whole process being totally offline as you have read what i am trying to do, after i finish, i will backup those wallets as i used to do.

what will remain on the pc is the amount i want to spend

i stressed on everything must be able to work offline that in case even if i am already hacked, i am not in danger of losing anything except the coins i want to spend which will always be on the machine whatever it's online or offline.

am i missing anything here in the above sentence ?

I got that part. What I meant was asking if you are going to spend those coins often. Once you move your wallet from the offline machine to your main one, your wallet will be completely exposed. You can mitigate that by preparing transactions on the online machine, signing them on the offline one and moving the signed transaction to any online PC. This won't expose your private keys. Also, I don't think that using virtual machines is a good idea. If your host is compromised, so are your VMs. Using a separate computer would be safer.

here what I am thinking about

I have a virtual machine with bitcoin core installed on plus I have bitcoin core installed on the main machine

being totally offline

I will create several offline wallets from the virtual machine and send the bitcoins to them from the old wallet using my main machine as being some how paranoid here

regarding mixing, I am first timer into coinjoining, so I will read more about post-mix on how to keep the anonymity the same or with at least, least degradation possible.

Most probably i will go with wasabi due to high anon. set

It should be as easy as that. If it doesn't happen to work, open Console in Bitcoin Core (Window -> Console) and type in rescanblockchain after you load your backup and confirm that its balance is wrong.


Yes, you can. Your transaction will be broadcast once you connect your main PC to the Internet and let Bitcoin Core catch up with the blockchain.


Unfortunately, no. Wait for ETFbitcoin's reply.

By the way, how do you intend to spend your coins from the guest machine?

thanks for your reply

- if I have a an old wallet.dat which had transactions lets say from 2017 and I have my bitcoin core fully synced and up-to-date, so simply replacing the default generated wallet.dat with that old one will be enough (while it's offline) ?

- i am afraid you have missed this, I have underlined the question for you

lets first assume we have a host machine (main pc) and a guest machine (machine with bitcoin core installed in it) and an old wallet.dat file with 1 btc in it on a usb flash

guest machine :

- have the already generated wallet.dat file deleted to let the bitcoin core create a new one offline (will the bitcoin core be able to create a wallet.dat file offline)
- open bitcoin core
- create a new address

main pc :

- open bitcoin core
- the bitcoin core will detect the old wallet.dat file which is in the usb flash, the 1 btc old wallet.dat (will it be able to detect the wallet with the balance on it even if it is offline, the bitcoin core here is fully synced to take notice)
- send the 1 btc to the new address offline created on the guest machine

- can I do all the following (totally offline) ?

- hopefully you have any answer for my Wasabi question, if no, no problem ?

Sure, any software wallet should be able to generate a new wallet without the Internet connection. In fact, some storage setups are meant to be offline all the time.


Wallet.dat contains information about transactions so your balance will be visible while being offline. As for importing your backup, if there are any confirmed transactions associated with that wallet after you made that backup, the balance won't be up-to-date if your online node has already downloaded the blocks in which they were included. You will have to run Bitcoin Core with -rescan parameter. If you copied you wallet file after all transactions have been confirmed then simply importing it should be enough.

oh sorry, it was a typo

can i infer from your helpful post that wasabi is great in p2p transactions, like for example, sending you bitcoins in exchange for fiat or alt. coin like xrp for example ?

- hopefully you have any answer for my Wasabi question, if no, no problem

- correct me please if I am wrong here

lets first assume we have a host machine (main pc) and a guest machine (machine with bitcoin core installed in it) and an old wallet.dat file with 1 btc in it on a usb flash

can I do all the following (totally offline)

guest machine :

- have the already generated wallet.dat file deleted to let the bitcoin core create a new one offline (will the bitcoin core be able to create a wallet.dat file offline)
- open bitcoin core
- create a new address

main pc :

- open bitcoin core
- the bitcoin core will detect the old wallet.dat file which is in the usb flash, the 1 btc old wallet.dat (will it be able to detect the wallet with the balance on it even if it is offline, the bitcoin core here is fully synced to take notice)
- send the 1 btc to the new address offline created on the guest machine

once online, the transaction will be broadcasted

i have underlined the questions for you please to not get distracted


can i infer from your helpful post that wasabi is got in p2p transaction, like for example, sending you bitcoins in exchange for fiat or alt. coin ?

I haven't done throughtful research about privacy of both of them, but here's few pros. and cons. that i know

Wasabi :
+ Easy to use
+ Hardware wallet support
+ Many participant, so you don't need wait too long to before
- Minimum about 0.1BTC required to mix your coin
- It's very obvious your coin going through CoinJoin process due to fixed output size

JoinMarket :
+ Very low minimum bitcoin required to mix your coin (depending on maker though)
- There are less participant (market), so you might need to wait longer.
- Difficult to use (compared with Wasabi)


There's no good/best practice since it's unknown how exchange trace your coin, how far they're willing spend resource to trace your coin and how "sensitive" their system to flag your coin or not.

When you try to send a payment to a node which is not directly connected to you, your payment is routed through other nodes. Those nodes must be connected to each other. Payments usually fail if there is no route available or if the amount of coins you are trying to send exceeds the amount available in the channels which route the payment.

Let's say you are Alice and you want to pay Dave 0.1 BTC via the Lightning Network. You didn't open a channel to Dave but you did to Bob. However, Bob has an open channel with Charlie who has a direct channel with Dave. The path looks like this: Alice -> Bob -> Charlie -> Dave. Your payment will be routed through Bob and Charlie. Depending on their fee policy, they might charge you a small fee (usually under 1 satoshi) for routing. For example, if Charlie had only 0.05 BTC on his side of the channel, he wouldn't be able to route your 0.1 BTC payment so it would fail.

If your payment fails then there is nothing you can do except funding another channel or trying sending less coins.


While the development has slowed down significantly, it doesn't lack any crucial features. The app works fairly well and is user-friendly.


Sorry, but I haven't used Wasabi much. I might try answering it in the morning.

thank you so so much

- Why payments does fail in general ? and if failed, what shall be done, just re-initiate it ?

- is zap still active and fully functional till nowadays as i saw the latest release was in 2019

- is there any chance you could help me with my question about wasabi and coinjoin please

1. Download Zap and set it up (create a new wallet, write down the seed which can be used for wallet recovery). Wait for Zap to synchronise.
2. Send some coins from your Bitcoin Core wallet to Zap.
3. Click on 'Channels' in the top-right corner and select 'Create'. Now you can either use a specific node or use a suggested one. I would recommend you the latter option since it will be your first time using the Lightning Network. Whether or not your payments are going to fail often depend on the node you choose. Enter the amount of coins you want to lock up in a channel and select the fee of the funding transaction.
4. Once the funding transaction gets 3 or 6 confirmations, the channel should appear as active. Now, you should be able to send payments over the Lightning Network by paying the invoices generated by merchants or other users.

Feel free to ask questions if you get stuck at one of these steps. You can also try looking for videos on YouTube. The UI has changed slightly with updates but everything should look similar.

could you please break it down for I as this post (https://bitcointalksearch.org/topic/m.54291539)

lets assume I have some bitcoins in a wallet on bitcoin core and I am going to use zap to send you some bitcoins over lighting, a simple walkthrough from the very beginning till the moment you receive the bitcoins

No, you don't have to swap your bitcoins. The Lightning Network doesn't use any form of tokens; it uses real bitcoins. In order to be able to transact using the Lightning Network, you have to open a channel using a wallet which supports the Lightning Network (i.e. Zap, Eclair Mobile). When you open a channel, you lock up your coins in a multi-signature address which is controlled by you and the other node. Once you have opened your channel, you can send payments over the LN (with some limitations). Every time you send a payment over the LN, the balance of the channel updates but it's not broadcast to the Bitcoin network in order to save money on the fees. If you want to retrieve your coins on-chain then you have to close the channel. The amount of coins + routing fees you spent on the LN will go to the other node's address while the rest minus the closing fee will be returned to you.

It's a little bit more complicated than that; consider reading basics of the Lightning Network and The Lightning Network FAQ if you want to learn more. It's not a perfect solution. Keep in mind that some of your payments might fail and not many merchants accept LN payments.

for lighting, do not I need to swap btc to l-btc first in order to be able to transact via lighting ?

Yes, your transaction will be broadcast once Bitcoin Core has been fully synchronised with the network after you go online. You can always sign a transaction in Bitcoin Core and broadcast it using third-party software without having to wait for the sync to finish if you need to spend your funds urgently (assuming you synchronised your wallet at some point).

Lets say you gave me your bitcoin address to send you 0.1 btc,

could I do the following offline

1- open bitcoin core
2- input your address and value of the bitcoin I want to send, in this example, it's 0.1 btc
3- click send and input the wallet password if there is one

and when bitcoin core is online,

- the transaction gets broadcasted to the network/blockchain and eventually you will get the 0.1 btc I have sent you

Lightning:
you'll need a lightning wallet for this task.
You send your funds, on-chain to the lightning wallet, then your lightning wallet uses this unspent output to create an on-chain transaction opening a lightning channel with an other node. From this point on, you can pay lightning invoices offchain using this channel. Once no more funds are left on your side of the channel, you can either leave it open or close it using an on-chain transaction. This closing transaction will distribute the funds between you and the node you had an open channel with, how much each partner gets depends on the state the offchain transactions left the channel in.

I've used zap wallet in the past, and on my mobile i use eclair. To be 100% honest, i found eclair more user-friendly than zap.

I'd urge you to use zap or eclair on the TESTnet before trying it out on the mainnet... Eclair defenately has a testnet version, there are testnet lightning nodes, and even a testnet lightning store.

Wasabi & CoinJoin
Wasabi is a wallet that has built-in support for coinjoining. Coinjoining is usually fine privacy and security-wise. Other options are mixing or exchanging your BTC for a privacy-centered coin, and after moving those funds around for a bit back to BTC.
Each of these methods has pro's and con's, but they depend on your point of view... If you really want the highest level of anonimity, you'll probably need more than one method.

To be honest, i've never had my deposit flagged (so far), but i've heared horror stories aswell. Apparently, some companies actually do some data mining and follow the unspent-outputs-trace several transactions deep. So, if you want to be certain your deposit won't get flagged, you might even move it around several times before spending it... I'm not an expert about this tough, somebody else might have something more usefull to say.

Using Bitcoin Core offline:
yes, you can create an address while being offline. An address is a hash of a public key belonging to the private key stored in your wallet. Your address is not "registered" with a central authority. If you create a private key, you can derive a public key, and you can hash this public key to generate an address. This address exists because you created a private key, not because it was broadcasted or registered.
It is possible to create 2 exactly thesame private keys, this is called key collision... The odds of creating a key collising when using a proper RNG are incredibly, incredibly small (allmost nonexistant).
When i say: "allmost nonexistant", i actually mean "allmost nonexistant"... Not like: you have 1% chance of having a key collision in your lifetime... No, those odds are waaaaaay smaller.

I actually did the math a while back: https://bitcointalksearch.org/topic/m.54220088
The actual discussion was about generating a private key whose public key hash was a predetermined address that was funded by somebody else, and this was the end conclusion:

I've never used Wasabi or CoinJoined before so I can't answer for that. For lightning, I've only used Eclair to send coins before (on my phone so I can't really give sound advice on that either.

No. Firstly, its a misconception that addresses must be made known to the network so that the rest can't generate it. It's completely untrue and it doesn't make sense (given Bitcoin's model). The generation of the address relies on the probability of someone else generating the same address as you. The probability is so small, that it would take you quite a few lifetimes even if everyone were to bruteforce it with the strongest computer today.
Bitcoin Core would send transactions only when it detects an internet connection and is connected to its peers.

Lighting :

- I have never used lighting before and I want to use it to send someone some sats, i have funds in my bitcoin core wallet and i prefer desktop wallet as my mobile is android 4.3 and most probably wont support lighting wallets, i do not know from where to start and how to make a swap from on chain funds to lighting funds and so on, maybe explanation or youtube video or something will help a lot

Wasabi & CoinJoin :

- what are the pros. and cons. of wasabi and join market, which route shall i go for the best privacy.

- to avoid having my coins flagged/rejected due to being coinjoined if sent to a exchange, is it a good practice to send the coins after mixing to a new bitcoin core wallet/address and from there send it to the exchange, if no, how would you advise me to send the coinjoined coins without being flagged

Using Bitcoin Core offline :

- i have my bitcoin core wallet fully synced (bitcoin core 0.19.1), can i create an address while i am offline and after i have fully synced the wallet, if yes, then how there will be ever an coincidence that the offline generated wallet is already generated or will be future generated ? (I'm referring to the (How to Deposit Funds) in this article https://en.bitcoin.it/wiki/How_to_set_up_a_secure_offline_savings_wallet)

- lets assume i have a wallet with 1 btc, would bitcoin core after being fully synced and then go offline allow me to send 0.5 btc to address x and 0.5 btc to address y
and after the internet connection is back and i am online, the transaction would take place immediately as if it is just waiting to sense internet connection in order to log the transaction on the blockchain or not possible and i must send the funds while i am online