Anyways yes, I agree otherwise. That said for all intents and purposes, the private key is a password. It’s the thing you store that gives you access to the service. That it’s not transmitted, but instead the whole public key / challenge response dance is done, is IMO sufficiently well summarized as “well, it’s a special kind of autogenerated password, which can’t be insecurely transmitted or badly stored by the service”.
If we really want people to adopt passkeys we gotta begin talking about them in terms people understand. I consider myself pretty tech savvy and it took me like 6 articles until I finally grokked that a passkey is just an autogenerated password (plus some free automatic bonus security that doesn’t affect my UX)
Signing is different from encrypting.
https://en.wikipedia.org/wiki/Digital_Signature_Algorithm
And yes, 100% agree we can do better in terms of explaining passkeys. The hardest part is that different audiences require such different approaches.
When you log in later, the server uses an API to give your client a random unique challenge (just some bytes), you unlock and approve and the pwm signs some stuff including the challenge and sends the signature back. The server verifies with the public key, and is satisfied because only your private key could’ve generated that signature.
But you are exactly right - this is detail and the UX is essentially the same as having the pwm generate random passwords that you never get to see or copy.