The biggest issue with passkeys is that since most USB tokens that support them don't allow syncing the private key to a backup device you have to enroll ALL of them to every site that supports passkeys. This is annoying but it makes storing backups in secure offsite locations impractical.
This is a fair criticism and needs work, I have some short thoughts on it here: https://news.ycombinator.com/item?id=49755217
The entire problem with passkeys is that zero of the issues should have been a surprise, because it should have been part of the design discussion from the start, so the fact that it's not properly implemented before being forced on users says that either it's been done horrifically incompetently and nobody should trust it, or they internally found these concerns and ignored them which means this system is not at all meant to help us, so why is it being forced on us?
It's beyond annoying. It's creating needless toil that no "normies" will ever actually do.
I'd love a hardware sold in multi-packs and "born" at the factory with identical internal device key encryption keys (DKEK). I'd love, even more, if a token just allowed you to "commission" new ones w/ a user-specified DKEK on first use.
I'd use one token as a daily driver and store the other(s) in safe location(s), empty of my personal key material. (Or, if I can just commission a new token w/ my DKEK, store a printed copy of my DKEK in a safe location.)
Give the token a mechanism to "type" a backup of its internal state, encrypted with the DKEK, as a USB HID keyboard. That gives me an easy way to backup the token each time I enroll a new website.
If I lose my daily-driver token I just pull a spare from storage, import my last backup, and I'm up and running.
That would kick ass. No "You just need to buy two tokens and enroll them in every website" bullshit.
Maybe each token also needs a second key, with the DKEK used for authentication and the second used only for revocation. The main reason not to reuse the DKEK is so a lost key can be easily decommissioned.
You would need some out of band way to collect and save your key IDs and publish revocations.
I’m not sure if this would work from a security theoretic perspective, need to think about how the request is signed and transmitted so someone can’t fake a key being “alive” when it’s really “dead”.
I do agree this would be incredibly useful if it can be made to work.
I haven't used a FIDO2 token other than playing around with it on a Yubikey. There, at least, I have to have the PIN to unlock the Yubikey before I can use the FIDO2 credentials (if I'm remembering correctly).
Are there hardware token implementations where mere possession of the token is all that's necessary to use the passkeys stored on it? That's incredibly stupid, and should have been disallowed by the standard, if that's the case.
Yes, the PIN is optional even on Yubikeys, although I think individual providers can require it. Ideally a strong PIN should be used but people may just reuse their ATM PIN, birthday, etc.
I didn't realize PIN was optional.
See my other comment re: the IT industry being fools.
That is how almost all standard FIDO2 tokens work. You just have to press the capacitive sensor when prompted. You can get fancier biometric tokens that require a fingerprint.
That's the stupidest thing ever.
All this hullabaloo taking away user freedom to export keys and backup tokens but physical possession is all that's necessary to use it by default.
We are a ship of fools, the IT industry.