27 Jan
2006
27 Jan
'06
12:10 a.m.
Aren't there chips (i.e. crypto) that are designed
to be destroyed
if they are disassembled? I don't know what they do to the package,
but if I had an IC with an EPROM containing my crypto keys, I'd want
the chip to self-destruct during an attempt to pry open the package
:).
I read a brilliant article on the encryption boards used in banking. The
actual clever bits are encased in epoxy, and powered by batteries on the
board. If you remove the batteries, it loses the contents of memory (and
all keys). If you attempt to cut the package open, you cut through a
layer consisting of many turns of resistance wire. If yout cut it, or
bypass bits, the resistance changes and it clobbers the memory. If it
gets too cold, or too hot, again it clobbers the memory. X-raying it is
right out, too.
Gordon.