Thank you all for your replies. I guess the most fail-safe way of creating an inviolable multisig wallet would be to do it through Bitcoin Core? Given that that is likely above my technical capabilities at present, I could just keep a copy of Electrum backed up.
The sovereign recovery info for my current multisig setup directs me to use p2sh-segwit on Electrum with derivation path m/49, not m/1. All keys on my current setup use BIP-39 passphrases, which I successfully tested when one of my keys became corrupted. Can I establish a multisig quorum by just inputting the BIP-39 seeds of my wallets?
Topic: Electrum multisig for long-term cold storage - page 3. (Read 540 times)
There is a 2FA (multi-sig) seed phrase, but the multi-sig wallet uses normal "single-sig" seed phrases.
My bad. I had in my head that version 0x101 was for multi-sig wallets, but you are right - it is specifically for 2FA wallets. Multi-sig wallets just use the usual 0x100 version of Segwit seed phrases.You can use the same nmemonic for both wallets too but you might lose some privacy doing that as you'll have the same public keys used again.
By default, Electrum uses path m/0' for single sig segwit wallets but path m/1' for multi-sig segwit wallets, so the public keys would be different. 
It'd be very hard to make electrum.unavailqble. Most open source projects often maintain an end of life version or get someone (in this case another wallet) to accept their seed phrases before they become obselete. You'd be able to recover everything if you backup the electrum binaries somewhere though (there are likely enough backups made already). Just don't use old software on an online machine to load up your wallet because that can lead to vulnerabilities that are already fixed that previously existed (in the past ~5 years we've seen two fairly substantial vulnerabilities - one with a phishing attack and one with a json rpc vulnerability that meant unsigned transaction data could be changed for an open wallet (and nmemonics could be extracted in unencrypted wallets but I didn't see an instance of this being reported at the time that wasn't a proof of concept)).
You can use the same nmemonic for both wallets too but you might lose some privacy doing that as you'll have the same public keys used again.
You can use the same nmemonic for both wallets too but you might lose some privacy doing that as you'll have the same public keys used again.
Also, I assume I can use one of the seeds for my multisig wallet for a single sig wallet?
Not with Electrum seed phrases. It has built in version which tells Electrum it is a multi-sig seed phraseMy question is, should Electrum be unavailable, will I be able to reestablish access to the multisig wallet if in 10 years I want to spend funds and have all seeds and xpubs available to me?
Yes, although if Electrum is no longer available then it could be tricky.Even if Electrum is no longer maintained, chances are you will still be able to find a version of the software which is usable. If you can't find the software at all, then you might need to tinker with another piece of software in order to recover this wallet since Electrum seed phrases are not the same as BIP39 seed phrases. You should also note that Electrum Segwit multi-sig derives at m/1'.
Also, I assume I can use one of the seeds for my multisig wallet for a single sig wallet?
Correction below.
If you were to use BIP39 seed phrases, then you could use one of your multi-sig seed phrases for a single sig wallet.
I am thinking of establishing a 2 of 3 multisig with Electrum, creating a watch only wallet from the xpubs, and leaving it there for a long while, backing up all seeds in separate locations.
I'll probably use native segwit as a derivation path.
My question is, should Electrum be unavailable, will I be able to reestablish access to the multisig wallet if in 10 years I want to spend funds and have all seeds and xpubs available to me?
Also, I assume I can use one of the seeds for my multisig wallet for a single sig wallet?
I'll probably use native segwit as a derivation path.
My question is, should Electrum be unavailable, will I be able to reestablish access to the multisig wallet if in 10 years I want to spend funds and have all seeds and xpubs available to me?
I am thinking of establishing a 2 of 3 multisig with Electrum, creating a watch only wallet from the xpubs, and leaving it there for a long while, backing up all seeds in separate locations.
I'll probably use native segwit as a derivation path.
My question is, should Electrum be unavailable, will I be able to reestablish access to the multisig wallet if in 10 years I want to spend funds and have all seeds and xpubs available to me?
I'll probably use native segwit as a derivation path.
My question is, should Electrum be unavailable, will I be able to reestablish access to the multisig wallet if in 10 years I want to spend funds and have all seeds and xpubs available to me?
Also, I assume I can use one of the seeds for my multisig wallet for a single sig wallet?
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