grinding down chips was Re: QX10 graphics board

[Richard]

On 1/24/06, Chris M <chrism3667 at yahoo.com> wrote:
>  I've been dying to ask this question. Can you
> actually learn something (hopefully a whole lot!)
> about a chip if you actually did this??? What if there
> was some old chip for which there is no documentation.
> If, given the availability of the proper equipment
> (surface grinder?), you were able to take off say
> .0001" of material at a time, or thereabouts ;), would
> you have the ability to photograph it, and have
> something in the way of a working schematic?

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
:).
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