best breakproof potting compound

[Simon]

 it hardly bears trying to copy and trying to complicate it with decoys will double it's size and cost

Well, then you can sell it with twice as big price tag 

If the price is right it won't be worth them going through the hassle of reverse engineering it and setting up their own manufacturing of it, far easier to contact us and let us handle it. If we increase the price then it may be worth their while. Selling price should be 30ish

[wiss]

What about fibres that jams a drill bit?  Thick layer of fibreglass around the board and then epoxy?

[SeanB]

Granite or ceramic sand does a number on drill bits quite quickly. No need to use fibres, unless you add short strand chopped aramid fibre ( kevlar cloth) for added rigidity between a inner flexible potting compound and a rigid exterior potting. If you really want to fool them blow a few diodes open circuit and add across power rails.

If you are really anal a fine grid of insulated copper wire scramble wound around it consisting of 6 strands to assorted pads where they supply power, ground, sinals and no connects will defeat most depotting methods. Used in the bank crypto modules for that purpose, though there it also has the keep alive circuitry power through it.

[Alex Eisenhut]

Ask IBM how they do it.

http://www-03.ibm.com/security/cryptocards/pcixcc/overhardware.shtml

[wagon]

Scrap the numbers off the chips, too.

[wagon]

'Back in the day' I reverse-engineered the serial number & copy count 'chip' on various colour photocopiers.  I eventually made & sold a product that  read them & enabled them to be 'reset'.  I used a normal serial eeprom programmer with a 'do nothing' box in the wiring harness.  The do nothing box did do something, but it was enough to confuse any potential copiers. 

[electronic_eel]

Make sure your device still works after potting it and going through a few thermal cycles.

If your potting compound is too hard and has a slightly different coefficient of thermal expansion than your board, the potting compound will rip you the components right off the board.

I learned that the hard way when I was trying to protect some electronics for outdoor use. In winter the parts broke, one by one.

[SL4P]

Pretentiously Posting Polysyllabic Prose
He said it not me.

[timb]

Pretentiously Posting Polysyllabic Prose
He said it not me.

Hahahaha, what?


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