Block’s new Bitkey is a 2-of-3 multi signature wallet (https://bitkey.world/en-US)
I’ve been reading their white paper, which is a good summary of their intentions, but doesn’t really go into technical details.
Basically, you need 2 of 3 (phone app “mobile key”, hard wallet “hardware key”, their web service “server key”) in order to approve a bitcoin transaction. As I understand it, n-of-m multisignature transactions is natively (and originally) supported by the BTC blockchain.
However, Bitkey also says that you cannot authorize transactions over a personal set spending limit without the hard wallet. (That is, even though “mobile key”+”server key” would be 2-of-3, the transaction still wouldn’t be authorized if it was over my set spending limit).
Is this functionality that is natively supported by the blockchain? If not (and is just a policy set of Block/Bitkey), in what ways could it fail or be exploited by a malicious actor? Could someone hack/manipulate Block/Bitkey’s servers so that you could still send BTC over the transaction limit without the hard key?
(PS Sorry for the newbie question. I’m a dev but never worked with blockchains before. I’m learning. If there is more technical tutorial/guide on how I could implement multisig wallets with transaction limits in python, I would enjoy learning about that as well).
Thank you.
