Ask SN: How to sign multisig tx virtually \ stacker news ~bitcoin

Ask SN: How to sign multisig tx virtually

227 sats \ 15 comments \ @021da48107 14 Jun 2023 bitcoin

I'm looking to setup a multisig wallet and wanted to have someone I trust be one of the signers, that way if I die or I loose a key they can help recovery funds.

Is there a way to have them sign the PSBT virtually? So far I think the best way would be to start a video call with them and have them scan the QR code / show their QR code to sign the tx but I'm not 100% sure how that would even work.

Currently I'm using Sparrow wallet and I think they would use Ledger live (which I don't think has support for this). Even if they were using Sparrow I'm not sure how they would actually just sign the tx since they didn't initiate the tx; would I have to send them the sparrow wallet file?

Any suggestions/thoughts. Thanks!

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474 sats \ 1 reply \ @ek 14 Jun 2023

I'm looking to setup a multisig wallet and wanted to have someone I trust be one of the signers, that way if I die or I loose a key they can help recovery funds.

So you are going for a 2of3 multisig where they can recover one key after you die or help you recover your funds if you lose one key?

Is there a way to have them sign the PSBT virtually? So far I think the best way would be to start a video call with them and have them scan the QR code / show their QR code to sign the tx but I'm not 100% sure how that would even work.

I think it's not clear to me what you are trying to do. Which transaction do you want them to sign? If you have a 2of3 multisig, you don't need them to sign any tx since you have two keys. If you lose one key, you can just tell them to give you their key so you can setup a new multisig.

And if you are dead, you can't do a video call anymore.

So I assume you are talking about the case where you lost one key and then want to do a video call with them, right?

Showing them a QR code of the PSBT over a video call should work.

Even if they were using Sparrow I'm not sure how they would actually just sign the tx since they didn't initiate the tx; would I have to send them the sparrow wallet file?

No, you need to export the partially signed bitcoin transaction (PSBT) from Sparrow and send this file to them. They can then import it into whatever software they are using and sign it.

This works since every signer needs to know the pubkey of every other cosigner.

10 sats \ 0 replies \ @021da48107 OP 14 Jun 2023

So you are going for a 2of3 multisig where they can recover one key after you die or help you recover your funds if you lose one key?

Correct

No, you need to export the partially signed bitcoin transaction (PSBT) from Sparrow and send this file to them. They can then import it into whatever software they are using and sign it.

Ah okay I think this answers my question. In the event that I lost a key I could create a tx with my remaining key, sign it and then send the PSBT to my remote cosigner. They would just import the PSBT and sign it.

I set this up as a test and for some reason my ledger hardware wallet doesn't seem to be able to sign the PSBT, not sure why, might have something to do with the deviation path being incorrect. Initially I setup the deviation path and tpub in sparrow from what I found in ledger live. However I noticed that the deviation path in ledger live and sparrow are different.

474 sats \ 11 replies \ @fanis 14 Jun 2023

Nunchuk seems a great fit to your needs: it has a collaborative multisig functionality with an integrated chat to exchange signatures and more easily collaboratively sign transactions while not in the same place.

0 sats \ 10 replies \ @021da48107 OP 14 Jun 2023

I experimented with nunchuk before but had an issue with it. I just gave it another try and it looks like it doesn't support any ledger hardware wallets, which currently makes it not work for me.

10 sats \ 9 replies \ @021da48107 OP 14 Jun 2023

Looks like nunchuck does support ledger hardware wallets but you have to use the desktop app, which fails to launch for me and says it is in beta on their website.

0 sats \ 5 replies \ @hugohanoi 15 Jun 2023

Which OS are you using? And which Nunchuk desktop version?

We have a pre-release here for 1.9.20 which has a couple of fixes for hardware related issues. Could you give it a try? https://github.com/nunchuk-io/nunchuk-desktop/releases

As for SeedSigner, here’s a useful thread: https://twitter.com/seedsigner/status/1585732014224932871?s=46&t=6W91tgLsshrWoRVvOZskMg

0 sats \ 4 replies \ @021da48107 OP 15 Jun 2023

I'm on Linux (Debian testing), Looks like the bug I'm having with the app on Linux is here: https://github.com/nunchuk-io/nunchuk-desktop/issues/28

We have a pre-release here for 1.9.20

I tried 1.9.20, and 1.9.19, both have the same error that seems to be related to requiring an old version of libssl.

I tried the app on MacOS and it launches however it never wants to actually add my seedsigner airgapped wallet. It scans the QR code but never actually fills in the xpub, or related info.

100 sats \ 3 replies \ @hugohanoi 15 Jun 2023

I see. Looks like on certain Linux distros there is an issue with the OpenSSL library (libssl) dependency. Have you tried the fixes suggested in that GH thread?

I've filed a ticket for the SeedSigner issue on desktop. Have you tried using SeedSigner with the Nunchuk mobile app?

10 sats \ 2 replies \ @021da48107 OP 15 Jun 2023

Have you tried the fixes suggested in that GH thread?

libssl1.1 isn't available in the debian repos for bookworm or testing so It won't be easy to install, if I have some free time I can look into it. libssl1.1 is pretty old though, Nunchuk should update to use a newer version IMO.

I've filed a ticket for the SeedSigner issue on desktop.

Thank you, please provide a link and I can help in the issue if needed.

Have you tried using SeedSigner with the Nunchuk mobile app?

Yes, Seedsigner works with the Nunchuk mobile app.

0 sats \ 0 replies \ @hugohanoi 27 Jun 2023

We have a fix here in the pre-release (1.9.20). Could you try it out? Tested with my SeedSigner and was able to scan the XPUB.

https://github.com/nunchuk-io/nunchuk-desktop/releases/tag/1.9.20

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0 sats \ 0 replies \ @hugohanoi 16 Jun 2023

Here it is: https://github.com/nunchuk-io/nunchuk-desktop/issues/42

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0 sats \ 2 replies \ @021da48107 OP 14 Jun 2023

I tried the Nunchuk app on another device and it launched, I was able to add my ledger hardware wallet fine, however adding my seedsigner wallet did not work. The app also crashed once on me. All in all the software needs some improvement.

10 sats \ 1 reply \ @hugohanoi 15 Jun 2023

Thanks for sharing. If it helps, do know that we are actively working on improving/stabilizing the desktop app!

10 sats \ 0 replies \ @021da48107 OP 15 Jun 2023

No problem. Thanks for being active on sites like this, that matters a lot in my book.

30 sats \ 0 replies \ @03365d6a53 15 Jun 2023

Thanks for posting, this thread is gold, hope to see more conversations like this.

FWIW, for testing your setup with an additional software provider (good to do), you could try Specter. It's available on server edition (with Start 9) but for hardware signing you would need a desktop version

Nunchuk are legends for making their co-ordinator software available for free, and 100x more so for this letter right here: https://twitter.com/nunchuk_io/status/1494885897577271299

This tells you everything you need to know about the company culture :-)