Does silent payments work with musig/frost?
Discussion
Interesting question, intuitively it should work.
For musig, you should be able to just add the tweak to the group private/public key and that should be it (didn't check the math).
For FROST, I'd have to refresh my math, I guess yes but I don't know.
The implications could be cool 😎
You can make it work. It requires some UX finesse. You have to sort of “prepare” the silent payment address by getting a threshold of frost signers to do partial Diffie-Hellman and give the result to the coordinator. From there the coordinator can instantiate the silent payment outputs without the signers but it needs to be done once for each SP address.
I think we’re gonna try and hide this behind a kind of “save address” feature which (for security as well) requires you to sign the address with a threshold of devices to associate it with human readable identifier e.g. “Max”. You can slip this crypto in there.