> If you have a unique key embedded in each keyboard/dongle pair, you would lose the ability to do this. In addition, if you lost the dongle, you would be SOL.
What about initializing the key during pairing? See parent's edit
Yes, initializing the key during pairing would work great.
I posted my reply before the parent's edit. I don't think this is an intractable problem; my suggestion of a physical connection for pairing or even a remote pairing with a button press would work fine. My ONLY point was that hard coding a symmetric key into the keyboard/dongle pair and then using that key for all communication wouldn't be practical.
What about initializing the key during pairing? See parent's edit