Jez,

I understand your enthusiasm for ecryption, but in this context there is little use for it; the DS5000 case shows that there are inherent weak links in such schemes and for real usage in fact you need to enclose the micro into a cage full of hungry lions, sorry, tamperproof sensors.

Also, the hacking dues not usually involve the acids; it's simply putting glitches and electric signals onto the part... easy, cheap, fast, effective.

That's why the users call for better inbuilt security for the content of internal code memory. A permanently fuseable programming pin is not a bad idea.

Jan Waclawek