Yup, you can't. Keys are perfectly trackable by Cloudflare, but they promise they won't do this. Edit: I was wrong. Cloudflare claims they could track people,

Yup, you can't. Keys are perfectly trackable by Cloudflare, but they promise they won't do this. Edit: I was wrong. Cloudflare claims they could track people, but it would require tracking via cookies. [1] The hardware security keys have an "attestation key pair" that is shared among all units in one production batch (which contains at least 100K units). [2] 1: https://blog.cloudflare.com/introducing-cryptographic-attestation-of-personhood/ https://blog.cloudflare.com/introducing-cryptographic-attest... 2: https://www.w3.org/TR/webauthn-2/#sctn-attestation-privacy https://www.w3.org/TR/webauthn-2/#sctn-attestation-privacy