We have customers using PICs who sometimes need to re-program them with updated firmware. It's inconvenient to have to ship the equipment back to a service centre, and most customers are quite capable of doing it themselves.
The problem is that the PIC hex or bin file is easily disassembled, and this may give away some proprietary secrets. If we could supply our customers with a USB programmer and PC software which would allow them to program a PIC from encrypted files we'd be a lot happier. Obviously, a determined person could capture the ICSP data as it's loaded to the PIC, but we think the risk is small and is one we'd be prepared to take.
Does anyone make a USB PIC ICSP programmer capable of using encrypted files?