Public key as Identities in real world

What happens if you need to repudiate a particular public-key? If the Public Key is tied to your identity then you have a real problem.<p>Your identity is one thing, you ability to authenticate is another, your ability to encrypt is another still. Experience in other fields tells us that conflating different things and purposes into a single thing is generally a very bad move.

If you know private key that corresponds to a public key. Then you can sign messages using private key and publish it onto the network, but what you are basically doing is making statements on behalf of that public key.