The only problem is, you're going to need one HECK of an advertising
budget, Michael.  I am fairly certain it's going to take some REAL
convincing that people NEED your, far more expensive, LED flasher, as
opposed to a $1 flasher from the local thrift store.  (Unless this is a
hobby project, in which case that cost & the cost of the fissionables
are moot <G>  Or unless they WANT a nuke, in which case maybe you'd
better be careful which you sell em to <G>)

  I'm partial to the spring loaded methods, myself.

  Mark

Michael Rigby-Jones wrote:
>
> Thanks for the tips Mark!  After carefull consideration I have decided on
> the last method using the nuclear weapon.  This solution would appear to
> satisfy the anti-theft requirements with the added benefit of instantly
> notifying the owner of possible tampering with his code.  I do however seem
> to have problems tracking down the weapons grade plutonium.
>
> Nobody, but nobody is going to steal *MY* LED flasher....
>
> Regards
>
> Mike Rigby-Jones
>
> > -----Original Message-----
> > From: Mark Willis [SMTP:mwillis@NWLINK.COM]
> > Sent: Friday, April 30, 1999 9:09 PM
> > To:   PICLIST@MITVMA.MIT.EDU
> > Subject:      Re: Self destruct schemes that thwart reverse engineering -
> > Way [OT]
> >
> > Craig Lee wrote:
> > >
> > > I agree, it is in-fact the nature of Hackers to hack!
> > >
> > > Would it not be an interesting challenge to develop a self
> > > destruct mechanism, so when hacking is attempted, the chip
> > > destroys itself?
> > >
> > > As far as hardware destruction goes.  I've tried this with
> > > a 16F84, and can't manage to destroy it.....  Reversed
> > > currents, gave it high voltage spikes, etc., and all I
> > > managed to do was blow a couple of I/O pins(they still work
> > > as pull downs!)
> > > <snipped>
> > > Craig
> >
> >   Detection is one thing;  destruction is the EASY part.
> >
> >   Put a nice powerful spring in there holding a pin punch, center punch,
> > or cold chisel;  On trying to open the access door, the punch is driven
> > through the PIC die and PC board, with power still on, causing "some"
> > silicon damage.  (An old bolt would do nicely.)
> >
> >   An old truck leaf spring set to mash the PIC chip when released should
> > do, for the cheap solution.  Watch your fingers...
> >
> >   Adapt one of those .22 "blank" powered concrete nail drivers to do the
> > same damage.
> >
> >   See also short shotguns, short rifles, etc;  Be sure the person
> > opening the box is authorized to have access to firearms <G>  Or you
> > could use a crossbow, slur bow, stone bow, etc. type setup.
> >
> >   Attach a small Squib atop the PIC chip, set off upon detection of
> > unauthorized access, with a nice NiMH backup power pack.  For bonus
> > points, use a small blob of C3, a nice 4-foot coil of Det. Cord, or
> > better yet one op the above fashioned into a shaped charge.  Only 2
> > bonus points if you use a commercially made shaped charge (the people
> > who demolish buildings use these, it'll cut a steel beam, so it'll cut a
> > PIC.)  Also bonus points if you make your own Squib, etc. <G>  You lose
> > MANY points for each conviction for breaking laws here, of course...
> >
> >   Brute force method:  Fit the PIC in a module atop a small mortar
> > charge, on firing the mortar charge the entire PIC module's smashed
> > against an anvil.  NO bonus points for this, but people into this
> > approach tend to get great satisfaction without the bonus points <G>
> >
> >   Set off a pound of Thermite upon intrusion into the box.  (MESSY, yet
> > pretty darn certain!)
> >
> >   Vent a couple pounds of molten metal into the project box <G>
> > (messier than thermite, debatably.)
> >
> >   Attach the left and right sides of the PIC to opposing sides of
> > rectified 117VAC through small metal blades snapped against the PIC
> > pins, and energized upon detection of intrusion.  (Use a nice big cap, I
> > figure this should do nicely.)  Better: Alternate so even and odd pins
> > are attached to opposing sides of this voltage.  A nice DIL test clamp
> > could be used here, potentially, just don't leave it always connected as
> > it'll affect your clock oscillator.
> >
> >   Minimalist solution:  Use the above but only "Zap" the Osc1/ClkIn
> > pin;  This should probably make it QUITE hard to use the PIC chip <G>
> >
> >   Anarchists' (non-)solution:  Pot the entire PIC chip in Nitrogen
> > Tri-Iodide solution, let dry as you retreat to a safe distance, expect
> > the first vibration to come along to vaporize your PIC <G>  Powering up
> > may do it here, as well.
> >
> >   Cryogenics overkill solution:  Pour a pint of liquid N2 on the PIC
> > chip, wait 5 seconds, then drop a hammer on it <G>
> >
> >   WAY Overkill solution:  Get a small Neutron bomb, glue the PIC project
> > atop it's case, set bomb off upon intrusion <G>
> >
> >   Mark