I have grave concerns regarding the authenticated key replacement mechanism as proposed by HIP-1 and implemented in current hockeypuck versions. I believe it to be not complete, not functional, and dangerous.

First, because it uses OpenPGP's detached signature mechanism, it requires a signing-capable (sub)key. Therefore, the mechanism fails to protect OpenPGP certificates without signing-capable (sub)key. The solution is not complete.

Second, after a key has been replaced with a clean version, presumably to get rid of a flood of certifications, an attacker can simply re-add the certifications. The replacement mechanism does not assure sovereignty, only a momentarily relief. Therefore, the solution is not functional.

I haven't looked into how gossiping plays into that, but if gossiping uses the same policy as updates using hkp, then gossiping will also re-add any third party certifications.

Third, the pair of keytext and keysig are a capability to reset the copy of the certificate on the server to keytext. If a malicious party ever gets hold of such a pair, then they have the ability to remove updates from the certificate stored on the server. Undoing an update that extends the validity period of a certificate leads to an DoS because the certificate can no longer be used (e.g. for encryption). Undoing an update that revokes a key leads to a certificate being used even though it shouldn't, compromising authenticity and confidentiality. Therefore, I conclude that the mechanism is dangerous.