I want to use message signing to prove control of a multi signature Bitcoin address. Is it possible? In theory it must be. In practice, are there any Bitcoin wallets that allow this? Specifically, how can I do this with Armory Lockboxes?
Add a comment
|
1 Answer
Signing message is proof of ownership of private key
Multisignature/P2SH address is hash of several (including zero) public keys
So, signing message with M private keys and disclosing the "contents" of msig address M-of-N is proof of control on address.
I do not know are there existing services to sign/verify p2sh addresses, but it is possible. Do not know about Armory/others.
-
Yes. You would need to disclose public keys and provide signed messages with them. There must be a way in theory to do that without disclosing the public keys. It's actually no different than creating a signed transaction. Is it not?– Emre K.Dec 1, 2014 at 9:49
-
It is not possible (by default) to get public keys from p2sh-address, so all public keys and their order must be known for verification.– amaclinDec 1, 2014 at 9:57
-
But can we still verify the signature without knowing the public keys and their order? Is it not the same with verification of transaction signatures?– Emre K.Dec 1, 2014 at 10:03
-
ECDSA verification requires public keys. It is not possible to verify signature without knowledge of public key. It is nonsense to verify message by signature only - no proof of anything.– amaclinDec 1, 2014 at 10:08
-
Ok Thanks. Bear with me for a little while longer :) Does this mean that everytime you broadcast a multi sig transaction you are disclosing the public keys and their order?– Emre K.Dec 1, 2014 at 10:20