user112354: Does signing a message as specified in Address Ownership Proof Protocol (AOPP) incur a fee? I think not - there is nothing written in the specification about broadcasting
anything to the Bitcoin blockchain. Am I correct assuming that such proof of ownership does not incur a fee?

user5406: The transaction fee is a bid for the transaction to get included in a block. Since signed messages are only transferred out of band directly to the recipient of the message, they do not incur a fee.

112354: <p>Does signing a message as specified in <a href="https://gitlab.com/aopp/address-ownership-proof-protocol/-/blob/master/README.md" rel="nofollow noreferrer">Address Ownership Proof Protocol</a> (AOPP) incur a fee? I think not - there is nothing written in the specification about broadcasting
anything to the Bitcoin blockchain. Am I correct assuming that such proof of ownership does not incur a fee?</p>
 5406: <p>The transaction fee is a bid for the transaction to get included in a block. Since signed messages are only transferred out of band directly to the recipient of the message, they do not incur a fee.</p>
