The answer to most questions about passkeys is "it depends on how your OS, your browser, and your service providers implement it".

[lcamtuf@infosec.exchange]

The answer to most questions about passkeys is "it depends on how your OS, your browser, and your service providers implement it".

But if prior art teaches us anything, the answer to that answer may be "it will be done in the least convenient and least interoperable way"