Recovery of Multisig Problems for Regular People

[ChristopherA]

One thing I believe that we are under-thinking for multisig for regular people is that backup is significantly harder than it is for single signature. To backup a single key, you can't put just 12 or 24 words on titanium in a vault (as I recommend in the free #SmartCustody book, you also have to store all the other pubkeys.

Best I've been able to puzzle through something that offers similar fire-proofness and resilience but it that means another BIP39-like system that would put 36 words on titanium for 2of3 to 56 words (3 of 5). This is doable on 2 to 4 typical plates. But OUCH.

The 2nd alternative suggested by Peter Denton @fonta1n3 was that one QR code (with a privatekeyless wallet descriptor) be printed on paper for every key. Some people don't like printing any kind of key, but there is less risk as these are only public keys. The idea being that you are unlikely to have every paper burn if you keep keys in multiple locations.

Currently Blockchain Commons has a 2nd iOS app called QR Vault, that captures a QR code which locks it to the iOS keychain securing it both the biometric and 2FA (Sign in Apple). Right now the FullyNoded2 app would save as QR one private key in the descriptor with all the other public keys. So for a 2 of 3 you'd need 3 iOS devices. You'd could have an iPod Touch or another iPhone on each, and ideally each are on a different Apple account, so this is less than ideal (though very easy for users.) Also, there is the inevitable bitrot that happens to computer equipment

Any ideas I'm missing?

-- Christopher Allen