[smeej]

They don't need to. Multisig is built directly into the protocol for BTC.

Search BTC multisig and you can learn all about it.

[JonathanBeuys]

I know Bitcoin multisigs.

But nobody is creating them with pencil and paper.

[smeej]

I don't know what that comment was about. That would be a weird way to do it. I don't know why anyone would want to.