609: You're the Oreo Cookie

2289.129 - 2306.762 Marco Arment

It's integrated into iCloud Keychain. Once you get a passkey, if you have iCloud Keychain enabled, it's everywhere on all your Apple stuff. So if you create a passkey and then drop your phone on the ocean a day later, you did not lose your ability to log into your stuff. That thing is synced through iCloud Keychain. It's available as long as you still have access to your Apple ID.