It does, thank you! I've designed a flow that I think will work based on this and the other comments - I think the understanding that there's not an easy way wi

It does, thank you! I've designed a flow that I think will work based on this and the other comments - I think the understanding that there's not an easy way without a shared secret has been helpful. What I'm going to do is use a shared secret can be used to sign a public key for each machine, since the secret will presumably only be shared with machines I control, as long as I can prevent other security concerns from compromising them.