Passkeys are built on the FIDO2 standard (CTAP2 + WebAuthn standards). They remove the shared secret, stop phishing at the source, and make credential-stuffing useless.
But adoption is still low, and interoperability between Apple, Google, and Microsoft isn’t seamless.
I broke down how passkeys work, their strengths, and what’s still missing
Currently I use a FOSS (I think?) password manager, BitWarden, that supports passkeys. I use it across Mac, Windows and Android so I’m while my passkeys are locked yo the password manager, I am not locked to any of the aforementioned megacorps.
KeePassXC has begun rollout of their own implementation, and I’m pretty sure they’re considered FOSS.
From a quick scan of the white paper, it appears they’re currently using on-device passkey discovery and otherwise “intercepting” passkey registration workflows, which I take to mean they aren’t originating the request as a passkey registrar. This may be the easiest method to satisfy FIDO’s dID requirements.
While I use and love bitwarden, it’s not exactly foss. Although there is a foss implementation of their server backend
Vaultwarden (the free server implementation) also supports passkeys.
I use BitWarden too. OS , device and browser agnostic is a win
But I imagine the vast amount of people will use whatever their platform is pushing, so Apple Google or Microsoft. And in 5 years time “3rd party passkeys” are not “secure enough” and blocked by the OS. (Ok that’s a bit tinfoil hat, but Google’s recent Android app developer verification scheme is fresh in mind)