An exemplary implementation of a process to update a license for a leased lighting model with one or more lighting fixtures 1000 is shown in FIG. 15B. In this exemplary process, the DSP 150 and the single board computer 300 of the processor 90 may be coupled to the license server 600 and database 602 via the Internet to facilitate operation by the manufacturer of the one or more lighting fixtures 1000 or a leasing agent. As described above, the pre-shared key 604 and license timer may be stored in the protected internal storage of the DSP 150 by the manufacturer together with the serial number of the lighting fixture 1000. The single board computer 300 may periodically check the status of the license timer. Once the license timer is near expiration, the single board computer 300 may initiate with the DSP 150 a license update request. This request may include a “challenge packet” generated by the DSP 150, which is forwarded by the single board computer 300 to the license server 600. The challenge packet may include encrypted information based, at least in part, on the serial number of the lighting fixture 1000 and a temporary random key generated using a noise accumulator. The challenge packet may then be decrypted by the license server 600. If the challenge packet is found to be valid and payment is made for additional lighting, the license server 600 may then determine a new allowed timer value. The new allowed timer value may then be encrypted and sent back to the single board computer 300, which passes the encrypted timer value to the DSP 150. The DSP 150 may then decrypt the new timer value based on the pre-shared key 604. If the new timer value is found to be valid, the DSP 150 may update the license timer stored in the protected internal storage of the DSP 150.
