Re: Snoop-proof DSP: possible?

On Oct 5, 12:10 pm, "steveu" <ste...@xxxxxxxxxxx> wrote:
On Sep 28, 12:06=A0pm, Jerry Avins <j...@xxxxxxxx> wrote:
axlq wrote:
In article <E_adneyngKqVlCLXnZ2dnUVZ_qydn...@xxxxxxxxxxxx>,
Tim Wescott =A0<t...@xxxxxxxxxxxxxxxx> wrote:
On Sat, 26 Sep 2009 16:59:44 +0000, axlq wrote:
A business partner has an algorithm applicable to schocastic data,
fo=
r
which it isn't possible to reverse engineer by studying the outputs
a=
nd
inputs. =A0Is it possible to fabricate a custom DSP chip in such a
wa=
y to
prevent the underlying algorithm from being extracted, so it can
rema=
in
a trade secret?

Nothing will keep a well-funded potential competitor from grinding
the
top off the chip and reverse-engineering (or just outright copying)
th=
e
code and/or design.

But as others have said, there are chips with security features
that'l=
l
make it harder.

All you can ever do is make it hard enough to be unprofitable;
you'll
never make it impossible.

That's what I figured. =A0I appreciate all the responses.

I would have thought these days the chip circuitry might be
sufficiently 3-dimensional to make grinding off the top impractical
for copying purposes.

You can probe the various parts. After all, with a lot of probing and
analysis, you can work out the circuit defined by a multi-layer
circuit
board. Some masked ROMs can be read by looking at them under a
microscope=
.

Jerry
--
Engineering is the art of making what you want from things you can
get.

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=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=A­F=
=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF- Hide
qu=
oted text -

- Show quoted text -

I've seen where the circuit is potted in an explosive compound with an
internal photo sensor and battery. Try to disolve away the potting
compound and the circuit explodes - true you may try this in the dark,
but you can put some other gottchas in the circuits that will likely
get disturbed by working in the dark. And if the battery goes flat,
the circuit forgets important data. True not 100% foolproof, but it
does get pretty difficult to beat.

Those things have an unpleasant safety record.


True, but the items being protected are highly desirable and thus
extreme protection methods being acceptable.

Clay



.

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