> There's a physical hardware device (the device's "body") and then there's a particular installation of an OS (the device's "soul.") This is an interesting th

> There's a physical hardware device (the device's "body") and then there's a particular installation of an OS (the device's "soul.") This is an interesting theory of device uniqueness that would be potentially cool to build a service around, but it is inaccurate to how passkeys are implemented. iCloud sync is cross-device; if you make a passkey on your iOS device, it gets synced to your Mac. You can also share them with other iOS devices that aren't even linked to your iCloud account using Airdrop. They're very separate from the OS or "instance" of your device's software. And in fact, you actually can't use platform authentication in Safari unless you sign into an iCloud account to sync your keys. Not only is it not tied to the "soul" of the device, you're not allowed to tie it to the soul of the device. Apple requires you to tie it to your account.