alt Hacker News>Hardware Attestation solves this problem
Only in theory. Suppose you are a bank, which enclaves/sources/devices do you support vs. not support? What do you do for users on a desktop PC that don't have an enclave? Phishing sites will leverage your weakest enrollment option.
Strictly speaking it's mainly hardware attestation but it's technically "hardware based passkeys" and "remote attestation". So if you rely on attestation in general and don't restrict the attestation source it works just as well.
Software passkeys can be stolen if the client is compromised but they aren't vulnerable to MITM or phishing as long as attestation is used.
> which enclaves/sources/devices do you support vs. not support?
You support all of them and prefer the strongest configuration for the source available.
If you've registered a hardware based key with attestation and then an attack tries to intercept that via phishing or MITM, the key already has its capabilities established and if you try to use the key without attest it should fail.
If you register a key without attestation support then you may be vulnerable to MITM or phishing but you can't intercept a user/their passkey with a stronger set of capabilities and downgrade them.