webauthn-recovery-extension

r support both discoverability and user verification, or neither discoverability nor user verification, I suspect there won't be business drivers to support such user agent storage/functionality. Note that the CredProtect extension protects discoverability of a resident credential without user verification, and Chrome requests this extension on sites' behalf by default. This protects against scenarios where a third party who gets physical access to your authenticator (thief, partner, law enforcement, border control) can introspect the websites you have accounts at without your participation. > Also, how is enrollment of an attested-but-not-present token or a multisig group of tokens or anything that enables off site storage of a token not part of the spec? It even seems like a company like Yubico could hack up a pair of tokens that separate enrollment and authentication without a spec change. Of course, discoverable credentials are a bit of a step backwards in this regard. There was a serious proposal: https://github.com/Yubico/webauthn-recovery-extension The challenge is that support for such things (new multisig algorithms, this recovery extension) require active relying party participation, and many would just choose not to take on the extra effort. So instead we have multi-device credentials, where there is a sync fabric behind the scenes. Nothing would preclude hardware credentials from participating in such a thing, although they would obviously need either radios or software assistance to do so. To capture the change in physical hardware, a new extension (devicePubKey) is being proposed under Web Authentication. This would have the benefit over the previous recoverability proposal in that sites opt-in to extra responsibility as needed for their business logic, compared to usability being restricted unless sites do extra work.

dor lock-in 2. Can rapidly respond in case a security vulnerability is discovered in one of your authenticators, as has occurred for both Yubico [2] and Google [3]. One could use Apple's Passkeys as one's day-to-day "personal" authenticator, and use an authenticator from a different vendor (e.g. Yubico Yubikey or Google Titan Security Key) as their backup key. I don't see how Apple's implementation increases the risk of lock-in beyond that of any of the other major Webauthn authenticator providers. [0]: https://github.com/w3c/webauthn/issues/865#issuecomment-3804... [1]: https://github.com/Yubico/webauthn-recovery-extension [2]: https://www.yubico.com/support/issue-rating-system/security-... [3]: https://security.googleblog.com/2019/05/titan-keys-update.ht...