Questions about Multi-sig with Hardware wallets

[richuurd]

Hi, so I've been playing around with Electrum 3.3.8 w/ Electrum Personal Server 0.1.7, with the intent to use 2/2 multisig with a Trezor and Coldcard for personal security.

Successfully received and sent some sats on a test 2/2 multisig wallet using Trezor One and a Model T.

Questions:

1.) How do I recover the multisig wallet in the event that I lose access to the computer where the wallet is stored? I.e. if the computer was wiped and I didn't backup the wallet, would the wallet, tx history, utxo set be derived deterministically from my 2 hardware devices if I were to setup a new multisig wallet on a fresh install of Electrum?

2.) If I lost my hardware devices but know the seeds and restore them on different devices, would they be valid as signers?

3.) Is the workflow for multisig using .PSBT the same? Ie. would I be exporting the .PSBT file to sign on the hardware device, then popping it back in to broadcast for 1/2?

Thanks and kind regards.

[Rath_]

1.) How do I recover the multisig wallet in the event that I lose access to the computer where the wallet is stored? I.e. if the computer was wiped and I didn't backup the wallet, would the wallet, tx history, utxo set be derived deterministically from my 2 hardware devices if I were to setup a new multisig wallet on a fresh install of Electrum?

As long as nothing happens to your hardware wallets (or both mnemonic phrases to be more precise), you will be able to recreate the wallet in Electrum. Transaction history and UXTO will be fetched from the node. Why don't you give it a try? Create a new wallet file under a different name to see how it works.

2.) If I lost my hardware devices but know the seeds and restore them on different devices, would they be valid as signers?

Yes, but you might need to recreate the wallet if you use, for example, Ledger instead of ColdCard.

[richuurd]

Awesome, thanks for the reply. Yes, I should try that.

Follow up question: is re-creating multisig wallets from hardware wallets standardized across different software? Is this only being done on Electrum at the moment?

Appreciate it again.

[pooya87]

Follow up question: is re-creating multisig wallets from hardware wallets standardized across different software? Is this only being done on Electrum at the moment?

unfortunately not.
there are two things that could be different among wallets. the derivation paths that they use and the order at which they sort the public keys to create the redeem script (and your address from), Electrum sorts keys in lexicographical order but others may use them in the exact order they receive them which can result in a different address.
on top of that when one signer is your Electrum, its seed can not be used in other wallets because Electrum seeds are not BIP39

[richuurd]

Thanks for the response! I'll keep that in mind.

I'm a non-technical user pushing my limits of technical comfort. Bitcoin has come pretty far in 10 years for someone like me to be using these tools. Long ways to go until my mom/dad can, but the future looks bright.

[pooya87]

Thanks for the response! I'll keep that in mind.

I'm a non-technical user pushing my limits of technical comfort. Bitcoin has come pretty far in 10 years for someone like me to be using these tools. Long ways to go until my mom/dad can, but the future looks bright.

it is good to learn more about advanced concepts, i started the same as you and little by little i learned more. feel free to ask any questions you have in here or beginners and help board.
but i have to say for regular users (mom/dad) using bitcoin, it is still pretty easy. for most of them a simple desktop wallet is more than enough. and for more secure setups a simple usage of a hardware wallet satisfies their needs. anything else is more advanced and is only useful for more advanced users with more advanced needs.