Do you suggest using different devices or is 3 cold cards a good option?
Discussion
I think it’s a good option, however I’m not sure I’m qualified enough to suggest a particular multi sig setup. It’s hard for me to weigh trade offs, in this case of locking into a single vendor. I have personally found more peace in using a company like Casa or Unchained, who are experts at making those types of decisions and make it super easy to setup
Separate vendors mitigate the risk of a retirement attack.
Say both secure elements of every MK4 are compromised. (very low probability, IMHO) Let's say every seed gets transmitted to Coinkite via some backdoor Wi-Fi attack. (Again, very unlikely.)
If you have a multisig wallet made of a seed signer, bitbox02, and a cold card, you have nothing to worry about.
If you have three cold cards, you have a problem.
I think it's reasonable to use a cold card plus two or more other wallets from different companies or build your own, but I encourage you to read Fkaxman's guide yourself.
Thank you for that guide!
What do you think of the guide? I browsed a lot of it and think it brings up some good points and explains certain aspects of multi sig well. However, the paper wallet/keystone choices seem non-ideal and overall like it may be out of date/not very well maintained. Also, seems like it would take a long time to set up.
At the time he wrote it, there were not many hardware wallets with secure elements. Originally, the Cobo vault was recomended. Then the Cobo vault broke. Keystone is a fork of Cobo vault.
There are better options now. I would use a seed signer instead of seedpicker. There are issues with air gapped computers, but multi-sig mitigates these risks.
You could also use a Foundation device these days too.
I think we can trust cold card and block stream jade as far as I know