Customers Performing Own Upgrades. How Hard Can It Be?

[pedja089]

If loader is open source you can easily add encryption. Then you send encrypted file to customer, application send encrypted data to pic(prevent someone to try find encryption in exe file, or to tap communication). Also you could use every 4th byte, load dummy bytes in encrypted file, write file from bottom to top, etc. So hex should be pretty safe...
Searching forum I found this http://www.etc.ugal.ro/cchiculita/so...bootloader.htm, and it should be good starting point for pic firmware. App for PC shouldn't be problematic, read byte from file then send it to HID or serial port, easily to do in VB6...
But I'm not still sure how to use loader with PBP, how to remap interrupt vectors, etc...
Only thing is that I don't have enough time to try it. I thing it should be doable...
EDIT:
If someone really wants your hex, then he'll just send one or two mcu from your device to company like this http://itresearch.weebly.com/services.html, and copy your board.