Which type of repudiation states that the creator of the message denies ever creating the message even after creating it?

Repudiation of submission refers to a sender denying that a message was ever submitted to a network or delivery system, not denying that they originally created it.

Repudiation of creation is not a recognized standard classification in repudiation taxonomy - the correct term for denying authorship of a message is repudiation of origin.

Repudiation of receipt refers to the recipient denying they ever received a message, which is the opposite end of the communication chain from creation.

Repudiation of origin specifically describes the scenario where the originator of a message denies having created or sent it, even though they did. This is the standard term used in information security taxonomy to distinguish sender-side denial from other repudiation types. Non-repudiation mechanisms such as digital signatures and audit logs are implemented precisely to counter repudiation of origin.