Relationship Between MAC address & Device Key

[adiwajshing]

So, I've been playing around with these devices for some time.

As far as I understand,

1. the device never sends out the "deviceKey" to the phone that is pairing it
2. the MAC of the device is never sent to the server
3. So, when you register the device with the server from the client, the phone doesn't know the "deviceKey" & server does not know the "MAC" -- so how does the server know it's whose device it is from the pings?

Do let me know if I've skipped as step or missed something.

Thanks

[hllhll]

(Forgot about this)
I was wondering the same things; I've used a friend to see what value changes with respect to his device. and found the "deviceKey"
I Assume there is some identifier, maybe that's it... One can tear the apk and see what is the identifier used.