Most info I've seen published on multisig requires a hardware wallet and a convoluted arrangement that would scare most newbs to even try. I don't think multisig requires that level of sophistication and contrary to what I've seen many times written, most people with cold storage should use it.
I've recently made a 2/4 multisig using Electrum with signers being: one ledger, one air gapped laptop and two cell phones. I feel pretty comfortable with it, and much more at ease comparing with the previous cold storage I had where it was a single sig built on the air gapped laptop.
This solution has several pros that I wanted to share:
- Teaching normies about BTC wallets, signing transactions etc. is not simple so using HWW for them was out of question. Explaining to them how to do it on phone was quite simple and straightforward.
- Phone security for storing private keys is ok (for a multisig). Even if one phone is lost or stolen, nothing goes wrong. Same goes for the seed words.
- No single point of failure! This I like a lot, any 2 signers can be compromised/disappear and no coins are lost.
- Even though I trust my friend to the point of giving him one of the signing keys, it's not possible for him to transfer coins on his own. He's there only to help me or family members in case I die. Inheritance problem is solved.
- All 4 signing devices are in different locations, so no problem of losing something and getting screwed.
Cons:
- Physical backups for the 4 wallets are needed, not just one. You need both the seed and the zpubs.
- My experience showed you need to do this simultaneously with all signers in order to share the zbpubs while building the wallet.
- It's a little more complicate than using a single seed, but really not that much.
I think this could be done only with phones, but I like that 2 of the signing devices are more secure. Would like to hear your thoughts on this. Are there any problems with this arrangement?