@cft I must disagree. Well, you could include feed,seq as a hint, but you should always include the message hash. The message hash is much more immutable than a signed message. it's possible the private key you are responding to is stolen or leaked, so it's possible that in the future a new message with that sequence exists. Or even, it seems more likely that the asymmetric signature algorithm gets compromised (quantum computers) but hashes should still work.