Protection of memory on PIC18F4550
I am designing a device that uses a PIC18F4550. Among other things, I need to protect a portion of the memory from being erased or rewritten by another unauthorized person, even if it uses any programmer. I need to protect only a few bytes, like a serial number. Is it possible ? If it is not possible, What level of similar protection can I achieve using PIC18F4550?
I know there are other cheap solution ways, like EEPROM chips with pre-programmed Serial Numbers. However, I have some doubts:
From what I understand, they would come from the factory with the serial already programmed, so my application on the PIC should read this external EEPROM chip to get the serial number, correct? would be possible to change these values? Could a person easily read this chip externally, swap this number or even swap the chip by another one?
I've heard about crypto memorys, but I was warned that they are a difficult solution to implement. What's the difficulty of using them?
post edited by danbakana - 2019/05/24 04:55:36