My goal here is almost exactly like your all talking about. I'm thinking of having an 8 pin dip socket on my new version of an on going production board. the goal would be to send a client a 15 cent serial eeprom that has updated encrypted firmware code in it. Once power is supplied, the bootloader would decrypt the code in the serial eeprom and program itself. Without the decrypted code from ever seeing daylight and having at least 64bit encryption method It should be next to impossible from using it to make clones. Once programed a green light would come on and the client could power down and take out the ereased serial eeprom and through it away.

Any suggestions would be greatly aprpeciated. Here in this topic you guys have givin me several helpful tips, Thank you.