If I use Microsoft Authenticator, they do control the passkeys. It doesn't matter who "owns" them if they control them.

They can "control" them in any meaningful way if they use them for access of things that you do not allow or denies access for things that you do allow. If neither are happening, then you're effectively the one controlling, not them.

The specific issue at hand is sharing. With passwords, I can easily share my passwords. Is it easy to share passkeys? And could doing so be prevented by Microsoft?

The point of passkeys is that you can have many of them unlike a single password. Each device should have its own passkey that I can revoke if my device is lost.

Give an actual working example on how you would share with a friend access to an arbitrary Passkey-enabled account of yours.

Do all using services allow this? Is it at least ad easy and straightforward as telling your trustworthy auntie your password?

Does the Passkey-enabled account support multiple passkeys?

I'm pretty sure I have my Android phone setup with a passkey for my Google account and also my Windows laptop.

Presuambly the same logic applies for a service that permits multiple passkeys. Each person would register a passkey on their device using the shared credential.

> Does the Passkey-enabled account support multiple passkeys?

There in lies the issue. With passwords, it doesn't matter if the account supports multiple passwords. I can share the one I have

> Presuambly the same logic applies for a service that permits multiple passkeys. Each person would register a passkey on their device using the shared credential.

but can I simply share the passkeys without someone's permission (other than my own)?