From the FAQ [1]: > Q: Are stored passkeys included in Bitwarden imports and exports? > A: Passkeys are not included in imports and exports. I think it's the same for iCloud [2]. That is why I don't love it. I prefer a very long password, and Bitwarden "Device login" that will prompt in my iPhone that will require FaceID (So essentially I have bio login). And 2FA to lower hacking chances. I'm aware I'm still vulnerab…
It's a private key, not a certificate (at least not without using attestation).
But there is currently no portable specification of WebAuthN credentials; each authenticator is free to implement its own storage backend, and in fact some hardware authenticators deterministically re-derive the private key from an internal secret and the key handle before each signature.
Others store a randomly generated key in local storage, indexed by the key handle; yet others encrypt a randomly generated key and make that encrypted key part of the key handle.
The point being: Not all implementations can even support key imports, and there's no standardized serialization format for key exports yet.