Passkey is some sort of specific unique key to a device allowing to use a pin on a device instead of the password. But which won’t work on another device.
Now I don’t know if that key can be stolen or not, or if it’s really more secure or not, as people have really unsecure pins.
I have a long list of questions about PassKeys and none of this articles explains them well enough.
Nothing of that?
You don’t need to export or know what is the key.
The key is different for each device.
https://youtu.be/6lBixL_qpro?si=wFFQwrfjQBKDHs5B
But is it possible in the implementation of Android/iOS?
Backups are a thing. With SSH keys I have different key for every device too, but as they are stored in an accessable file (as all computer data should be) they are backed up with the rest of the system.