Depends. But the simple fact is if it’s REALLY important; you had better be doing it online and passing the result to the device.
I could tell you about hardware security modules (HSM) or the new ARM trustzone for small micros, but I’m designing new products so that if I handed you the source - you still can’t clone a board. That requires a connection to a better trusted device.
I could tell you about hardware security modules (HSM) or the new ARM trustzone for small micros, but I’m designing new products so that if I handed you the source - you still can’t clone a board. That requires a connection to a better trusted device.