Hi all,
I am trying to learn more about the best practices and tools to backup the Bitcoin Secure Multisig Setup (BSMS).
When you create a multisig wallet, the coordinator app usually creates a .bsms file with all the descriptors to recreate the wallet. This is described on BIP129: https://github.com/bitcoin/bips/blob/master/bip-0129.mediawiki
But having access to that file reveals the funds of the multisig wallet, so I think is not a good idea to store it in plain text. It should at least be encrypted so you can decide who can access it. Splitting the BSMS content into multiple QRs shares would be ideal, so you can distribute each share in different locations.
SeedHammer offer in my opinion one of the best approaches. They split the BSMS file content into 3 QRs and you need to scan 2 of them in order to recover your wallet. This is called "BCR-2020-010 encoding for Output Descriptors QRs". They show how to do that here:
https://twitter.com/SeedHammer/status/1666875008105295873
Nunchuk supports importing a wallet using those QRs, but not exporting a wallet in that format. So, if you don't have a SeedHammer, you can't use this approach. I created an issue so they implement that on their Nunchuk app: https://github.com/nunchuk-io/nunchuk-android/issues/21
Not sure if there is another tool/app that can export a BSMS file in "BCR-2020-010" format.
Any ideas or opinions?
Thanks