Migrate UTXOs from one wallet to another

[gusto2458]

Question is what's the best strategy to now go to the desired end state:

Singlesig (offline-wallet) --> Multisig (offline-wallet)

In that case, you don't really have any option other than sending the UTXOs from one wallet to the other and paying the transaction fee each time.

Why do you want to move the coins to a multi-sig wallet? Is your offline wallet no longer secure? Is leaving the coins where they are not an option?

If you do still want to send them across, then you can either wait until fees are lower or just bite the bullet and pay the fees. You will have to spread the transactions out over a period of time so they are not obviously linked together. You could potentially consolidate two or three of the UTXOs together each time to save on fees if you are happy with the privacy implications of doing so.

albert0bsd had the same question. I believe OP wants to ameliorate his setup and I don't believe it is a bad idea. But since two members of this forum found this curious, I can't help but ask, why? I mean don't you think it is a good idea to move the coins to a better setup? Of course provided that the multisig vault will be properly set up. Fully airgapped, different devices, proper backups etc.

Yes! a properly set up singlesig wallet, where the seed phrase is produced from a permanently airgapped device, where the backups are stored offline in separate locations, where you add a strong passphrase that provides >128 bits of entropy is safe.

But, a multisig vault can have some advantages compared to the singlesig wallet:
1. In terms of safety, I reckon that both wallets are impossible to get compromised with brute-force.
2. In terms of theft, then the multisig vault is safer because the attacker will find one backup and they have no clue that you have set a multisig vault with another wallet. They will probably think of bruteforcing the passphrase though.
3. In terms of physical disaster, multisig and singlesig are equal if you have backed up the signers properly.
4. In terms of usage, signing a transaction with a multisig is much easier, because you can create a PSBT with the 1st cosigner and then sign with the rest of them, bringing the PSBT to the rest of the signers. However, with singlesig you need to get the passphrase where the device is, unless you remember it, but this is highly unlikely with a proper random passphrase.
5. In terms of fees, provided that we talk about the same amount of inputs and outputs, singlesig is cheaper.

Having said all that, I want to make clear that multisig creates a false sense of security. Multisig is in general safer, indeed, but you must know what you do and avoid obvious mistakes. Multisig is not a panacea.

Supposing that OP knows all the dangers and follows all the necessary measures, then, according to the list above, I think moving to a multisig is not a bad idea.

But if the only motivation is security, OP must know that a proper singlesig wallet with a strong random passphrase is safe enough.

Thanks for all the feedback. I think sending UTXOs one by one is the best option and swallow the fees.

[o_e_l_e_o]

I mean don't you think it is a good idea to move the coins to a better setup?

Yes, of course, but that assumes that his current set up is inadequate. If he is using a truly cold wallet, set up on a permanently airgapped machine, with a strong passphrase backed up separately, then that is already very secure and moving to a multi-sig provides only very marginal gains.

2. In terms of theft, then the multisig vault is safer because the attacker will find one backup and they have no clue that you have set a multisig vault with another wallet. They will probably think of bruteforcing the passphrase though.

Well, with multi-sig back ups you should be backing up a subset of your other xpubs alongside each seed phrase, which makes it obvious it's a multi-sig back up.

[Kruw]

Thanks for all the feedback. I think sending UTXOs one by one is the best option and swallow the fees.

Why don't you save fees by privately consolidating your UTXOs in a WabiSabi coinjoin instead?

[apogio]

Thanks for all the feedback. I think sending UTXOs one by one is the best option and swallow the fees.

Why don't you save fees by privately consolidating your UTXOs in a WabiSabi coinjoin instead?

Why do you always suggest WabiSabi? OP clearly doesn't want to consolidate the inputs. I don't know how this wabisabi works but I think it is not what op wants

[Kruw]

Why do you always suggest WabiSabi? OP clearly doesn't want to consolidate the inputs. I don't know how this wabisabi works but I think it is not what op wants

WabiSabi coinjoins allow you to consolidate inputs without revealing they are owned by the same person.  It's exactly what OP needs.

[apogio]

Why do you always suggest WabiSabi? OP clearly doesn't want to consolidate the inputs. I don't know how this wabisabi works but I think it is not what op wants

WabiSabi coinjoins allow you to consolidate inputs without revealing they are owned by the same person.  It's exactly what OP needs.

Consolidation is a process where you get multiple inputs and produce one output. Are you sure this is what OP needs? Because I think he wants to maintain multiple UTXOs. Which is btw the best thing to do.

[Kruw]

Consolidation is a process where you get multiple inputs and produce one output. Are you sure this is what OP needs? Because I think he wants to maintain multiple UTXOs. Which is btw the best thing to do.

OP's concern is about his privacy from his Whirlpool coinjoin being ruined from consolidation:

If they're all consolidated, you've just undone all the mixing previously.

With a WabiSabi coinjoin, he can privately consolidate his 20 UTXOs into one UTXO if he wants to (depending on their value), or he can split it into multiple coinjoin outputs in case he wants UTXOs of specific sizes.

[apogio]

OP's concern is about his privacy from his Whirlpool coinjoin being ruined from consolidation:

If they're all consolidated, you've just undone all the mixing previously.

With a WabiSabi coinjoin, he can privately consolidate his 20 UTXOs into one UTXO if he wants to (depending on their value), or he can split it into multiple coinjoin outputs in case he wants UTXOs of specific sizes.

I highly recommend NOT to consolidate the inputs. Use whatever tool you wish, but I would also recommend what o_e_l_e_o said. Just send every UTXO in various time intervals and you will be more than ok. Keep it simple. That's my opinion, but I must say I am biased because I don't trust Wasabi at all.

[Kruw]

I highly recommend NOT to consolidate the inputs. Use whatever tool you wish, but I would also recommend what o_e_l_e_o said. Just send every UTXO in various time intervals and you will be more than ok. Keep it simple. That's my opinion, but I must say I am biased because I don't trust Wasabi at all.

Why would you highly recommend not to consolidate the inputs?...

That's my opinion, but I must say I am biased because I don't trust Wasabi at all.

You don't have to trust Wasabi, it's completely open source.

[apogio]

Why would you highly recommend not to consolidate the inputs?...

Because multiple UTXOs can be beneficial in the future where OP may need to spend an entire UTXO without creating change.

Also for privacy reasons, because consolidating them is not a good choice. Don't give me the Wasabi consolidation argument once more. I understand you like it but I don't like it so it's not worth trying to convince me. There is also no need to suggest Wasabi every single time. There are multiple tools for multiple use cases. Using only wasabi products for everything is not a good choice any way you decide to see it.

[Kruw]

Because multiple UTXOs can be beneficial in the future where OP may need to spend an entire UTXO without creating change.

Creating multiple UTXOs in the present doesn't provide a benefit compared to creating multiple UTXOs in the future, you're still creating them no matter what.  Besides, what are the chances the UTXO sizes he picks today will match the exact value he needs for a purchase made in the future?

Also for privacy reasons, because consolidating them is not a good choice. Don't give me the Wasabi consolidation argument once more. I understand you like it but I don't like it so it's not worth trying to convince me. There is also no need to suggest Wasabi every single time. There are multiple tools for multiple use cases. Using only wasabi products for everything is not a good choice any way you decide to see it.

Why don't you like coinjoins?

[apogio]

Why don't you like coinjoins?

I love coinjoins! Not WabiSabi conjoins though.

In general I love pluralism, so I am not using only one product or tool. That's why I sincerely doubt your motives. You always suggest wabisabi like it is the only tool that exists.

 I tried not to criticise the tool because I respect everyone's opinion, but using ONLY one tool, for me is bad, no matter what the tool is. So I will put a full stop here, because I think OP has taken all the opinions he wanted. Lets allow him to decide anything he wants, there is no reason to argue once again. Have a nice day

[Kruw]

I love coinjoins! Not WabiSabi coinjoins though.

In general I love pluralism, so I am not using only one product or tool. That's why I sincerely doubt your motives. You always suggest wabisabi like it is the only tool that exists.

I tried not to criticise the tool because I respect everyone's opinion, but using ONLY one tool, for me is bad, no matter what the tool is. So I will put a full stop here, because I think OP has taken all the opinions he wanted. Lets allow him to decide anything he wants, there is no reason to argue once again. Have a nice day

WabiSabi coinjoins are the most private coinjoins, and it is the perfect solution for OP's privacy concerns.  Take this WabiSabi coinjoin that confirmed in the last block for example:

https://mempool.space/tx/921ad5bfd23403e04682222387608b6231ef715cc4ce079ffd1644f2480dab37

There's 237 inputs and 225 outputs in this coinjoin (net consolidation of 12 UTXOs). If OP consolidates his 20 inputs within this transaction, how would anyone be able to determine that those 20 inputs belong to him?  You can't tell how many users are involved in the coinjoin, or which inputs are commonly owned by each user.

[Medusah]

If OP consolidates his 20 inputs within this transaction, how would anyone be able to determine that those 20 inputs belong to him?  You can't tell how many users are involved in the coinjoin, or which inputs are commonly owned by each user.

No, but if OP consolidates 20 inputs then it is clear these were owned by the same person.

OP's concern is about his privacy from his Whirlpool coinjoin being ruined from consolidation

Consolidating all your whirlpooled outputs alone is impossible without noticing the warnings.  In sparrow when spending a mixed output you are told to use Stonewall by default.

[Kruw]

No, but if OP consolidates 20 inputs then it is clear these were owned by the same person.

Not if he consolidates them in a WabiSabi coinjoin, observers would have no idea if those inputs are owned by 1 person or 20 people.

[Medusah]

Not if he consolidates them in a WabiSabi coinjoin, observers would have no idea if those inputs are owned by 1 person or 20 people.

If you consolidate 20 inputs into 1 output then, unless taproot or multi-sig as destination is used, all inputs are probably owned by one person.

Can you give me an example of private consolidation with wasabi?  I do not understand.  You mean after the coinjoin or during coinjoin?

[Kruw]

Can you give me an example of private consolidation with wasabi?  I do not understand.  You mean after the coinjoin or during coinjoin?

During coinjoin.  You can see how 12 UTXOs were consolidated in this coinjoin transaction:

Take this WabiSabi coinjoin that confirmed in the last block for example:

https://mempool.space/tx/921ad5bfd23403e04682222387608b6231ef715cc4ce079ffd1644f2480dab37

There's 237 inputs and 225 outputs in this coinjoin (net consolidation of 12 UTXOs). If OP consolidates his 20 inputs within this transaction, how would anyone be able to determine that those 20 inputs belong to him?  You can't tell how many users are involved in the coinjoin, or which inputs are commonly owned by each user.

If this were a normal transaction, you would assume all 237 inputs were owned by the same user.  But, since it's a WabiSabi coinjoin, you can't determine how many users are participating, or which inputs belong to each user.

[Medusah]

If this were a normal transaction, you would assume all 237 inputs were owned by the same user.  But, since it's a WabiSabi coinjoin, you can't determine how many users are participating, or which inputs belong to each user.

So when a user wants to consolidate his many mixed inputs into an output, does he spend them in a WabiSabi coinjoin where other users can consolidate and coinjoin simultaneously?

[Kruw]

So when a user wants to consolidate his many mixed inputs into an output, does he spend them in a WabiSabi coinjoin where other users can consolidate and coinjoin simultaneously?

If a user is going to consolidate anyway (regardless of whether their inputs are already mixed or not), then doing so in a WabiSabi coinjoin is strictly a privacy benefit.  I'm not sure what nuance you are trying to discover here, so I'll provide more context:

- Consolidation within a WabiSabi coinjoin by whales is inherently limited by the number of UTXOs or size of their UTXOs. Different clients that implement the WabiSabi protocol have different limits on the number of UTXOs you can consolidate in a single round.  With Wasabi, it's 10, with Trezor, it's 20, and with BTCPay Server, you can register up to 30 inputs using "Coinsolidation mode".
- Consolidating mixed WabiSabi outputs is generally not harmful to your privacy even outside of a coinjoin transaction, a whale consolidated 207 inputs in this extreme case (about 205 of these inputs are WabiSabi coinjoin outputs, I saw 2 inputs that weren't coinjoined just by glancing), but there's no link established as to which inputs originally created these mixed outputs that were consolidated.
- Consolidating mixed Whirlpool inputs without sufficient remixing is different and does hurt your privacy because the tx0 premix transaction shows all of the coinjoin rounds you entered initially.  When a user consolidates many outputs from all these linked coinjoin rounds, it provides little obfuscation as to which premix transaction led to that postmix payment:

The first is the fee to Whirlpool itself, which is a flat fee depending on the pool you are joining.

The flat pool entry fee structure is designed to incentivize worst privacy practices.  Since fees are not collected directly based on volume, it is cheaper to participate in a smaller pool and create more outputs than participate in a larger pool and create less outputs. Additionally, it incentivizes revealing common inputs ownership of premix UTXOs since it is cheaper to consolidate them to enter the pool once than to enter the pool with each UTXO individually.  Samourai has never explained why they purposely chose a fee structure that heavily penalizes the most private usage of their protocol.

Because of this backwards design, you can easily link premix inputs to postmix outputs in many cases.  Notice how this Whirlpool tx0 premix creates 70 outputs for 0.05 BTC - https://mempool.space/tx/63679c9ec82f246811acbab0c04cc0fc77ba050e1b6c23661d78afcfc13cf8aa

Notice how every single input of this Whirlpool exit transaction is a direct descendant of rounds created by the aforementioned premix transaction: https://mempool.space/tx/ce2f84f7c5ff74fb1da103acb7b279bd34f02f5e9e3a2e1b6417ce8b9b7392db

When many inputs used in the postmix exit transaction are created directly from a round that the premix transaction entered, it makes it trivial to trace the user through Whirlpool.  Fortunately, the user abandoned Whirlpool and upgraded to using the WabiSabi coinjoin protocol instead, which made him completely untraceable: https://mempool.space/address/bc1qjjw5gaglkycu2lm5fskl7qhktk0hec4a5me3da

^The difference with WabiSabi is there is no tx0 premix transaction, so an observer tracking your input can only watch it go directly into a single WabiSabi coinjoin, whereas an observer tracking a Whirlpool input can watch it enter up to 70 Whirlpool coinjoins from the tx0 premix (or even more than 70 if the user links toxic change from multiple tx0s together).

[satscraper]

I highly recommend NOT to consolidate the inputs. Use whatever tool you wish, but I would also recommend what o_e_l_e_o said. Just send every UTXO in various time intervals and you will be more than ok. Keep it simple. That's my opinion, but I must say I am biased because I don't trust Wasabi at all.

It all depends on your habits on how to spend UTXO.

If you tend to spend the large amounts  that require a large number of small UTXOs consolidating them during an empty mempool can lead to cost savings.

On the contrary, if you only require a single UTXO for a payment, there might be a different outcome.