1. At setup, Find My generates private key shared to all your Apple devices.
2. The private key generates a perpetual sequence of public keys. These change (iterates to the next) "frequently".
3. The rotating public key is shared accross all (including other people's) Apple devices via Bluetooth and can even do this when it's off.
4. The shared scheme pings to Apple's central system and uploads A. hashes of the public keys in the area and B. the location.
5. When you try to find a device you send your hashed public key to Apples server and they return the last picked up location (encrypted). (You thus need at least 2 Apple devices, one to find the other. Also, they don't say how the previously iterated public keys are remembered.)
- Loss of a companion device that was never found and it took the private keys with it
- Got a new companion device
How do I reset the keys and how do I make sure a theif can't reset these?
1. Resell - you turn off 'Find My' on your phone and sign out of iCloud then wipe the device
2. Loss - Go into iCloud and mark the device as lost. Not sure what this means for finding other devices
3. New companion device - sign it into iCloud.