Pairing Bluetooth Keyboard on Windows and Linux using the same receiver

Found a solution on the web with authenticated connections here (the original description is far more detailed).

Short description (so that it is still available for me ;) ):

1. Pair with (each) Linux
2. Pair with Windows
3. Extract authentication key from Windows from windows registry (stored in Windows/System32/config/system) using libhivex-bin
   hivexml system | perl -ane 's/</\n</g; print' | grep -i 'key="YOUR BLUETOOTH ID WITHOUT : "' 
4. Decode the content of xml-entity with Base64
5. Replace Linux authentication key with the extracteted version Linux /var/lib/bluetooth/RECEIVERID/linkkeys
6. Restart Bluetooth service
   sudo service bluetooth restart

I can confirm that this works using Ubuntu 12.10 and Windows 8 with a Apple Wireless Keyboard.

Alternative solution without authentication (I WOULD NOT RECOMMEND THIS FOR A KEYBOARD) can be found here.

UPDATE: Still works with 13.04