techniques to obfuscate circuit designs

Discussion in 'General Electronics Chat' started by DaveH, May 6, 2009.

  1. DaveH

    Thread Starter Active Member

    Jan 1, 2009
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    Not a very technical question I guess, but I think it's worth discussing.

    Many of the people on this forum have spent years or decades getting to the skill levels they have. In s/w engineering (open source aside) companies go to great lengths to protect their work. It may take a guy only a few days, weeks or months to produce something, but that doesn't take into account how they got to the level of being able to do that.

    If you design a circuit that you believe is exceptional and you want to market it, it would not be nice if someone copied it and started selling cut price copies on ebay. Worse, they would copy it and put up the schematic somewhere for everyone else to copy. Generally I think for someone to do that they'd need a fair bit of knowledge and skill - which is usually not compatible with such unethical deeds - in most people. But you never know.

    I have some designs I want to protect. I reckon if I made the first batch myself, I would use single sided coper clad, lots of obscure and not so obscure opamps, other ICs and many passive components.

    I'm thinking about erasing the markings on the ICs with a Dremel power tool, by lightly scrapping it. Usually with single DIP8 opamps a skilled guy would know they are opamps, by looking at the tracks he'd figure out the differential inputs and the output, but when you're using high pin count packages I think they'd have to be very switched on to figure it out.

    Has anyone else addressed this issue and tried to protect their work without damaging it?

    I'm all for spreading knowledge and understanding, like AAC does, but I think that should be used by people creatively and ethically.
     
  2. DonQ

    Active Member

    May 6, 2009
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    Two words...

    Potting compound!
     
  3. Wendy

    Moderator

    Mar 24, 2008
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    Potting compound and removing the numbers seems like it would do it.

    I've always heard that every extra component is money, so if you are going to commercialize your product that would probably be a nonstarter.

    I hate to say this, but complexity is the only real protection, and not so much there. That and if it were truely inovative patent it. Form follows fuction, and duplicating, even with the steps we mentioned, is simplier than an original thought.

    It's a lot like programming, the idea is the thing, not how it is made.
     
  4. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
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    Try the exclusive KL7AJ Circuit Obfuscator. Available now for the introductory price of $29.95, the price of an Earl Scheib paint job!

    Call today! You'll sleep better tonight!


    Eric
     
  5. studiot

    AAC Fanatic!

    Nov 9, 2007
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    If you are in the UK

    Patent protection is expensive.

    You may be able to use the registered design route initially, which is much cheaper.

    http://www.ipo.gov.uk/whyuse.htm

    You might also try deliberately mislabelling your boards and components. Also the inclusion of a redundant component will help show if the design has been copied.
     
  6. Papabravo

    Expert

    Feb 24, 2006
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    I keep having to remind you all, that in the imortal words of Don Lancaster, a very smart cookie:

    "...any involvement whatsoever with the patent system in any
    way, shape, or form, is virtually guaranteed to cause you a
    monumental long term loss of time, money, and sanity."

    http://www.tinaja.com/glib/casagpat.pdf

    Read the article and then tell me what level of entusiasm you have for getting a patent. Your best defense is to be the low cost producer or get out of the business when the copycats show up.
     
  7. SgtWookie

    Expert

    Jul 17, 2007
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    Nothing's sacred.

    If you produce something great, with great profit potential, it won't be long before someone either flat-out copies your design, or comes up with something even better that your product can't compete with.

    Low parts count, protected microcontroller code, and house-marked components are merely delaying tactics. Good way to start, though. If you can "get the jump" on the competition, introducing a complex product in a simplistic, easy-to-use and reliable form, you'll build confidence with your customers.

    However, it won't be long before someone will reverse-engineer it, re-design it, and build a clone with equal or better functionality; maybe a few months at best - and they may have a much better marketing team available than you do.

    Early market penetration is your key. Someone will sooner or later (probably sooner) figure out your circuits, and your market will rapidly shrink.

    If you try to get attorneys involved, you will go in the hole very quickly.

    I genuinely wish you good luck.
     
  8. Papabravo

    Expert

    Feb 24, 2006
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    Yeah, good luck DaveH. I've been there and done that several times. Nothing I said should be construed as an attempt to denigrate what you are doing. I hold you in the highest regard. I'm just trying to warn you if you'll listen. Even if you won't I still feel obligated to try.

    This is sorta like tellin' an engaged fella that his betrothed is a troll!
     
  9. Darren Holdstock

    Active Member

    Feb 10, 2009
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    I seem to remember an extra-secure potting compound being available that claimed to render IC markings permanently obscured, even if attempts at removal are made. Stuffing with diamond or carborundum also makes the epoxy much less machinable.

    It's a difficult situation. Patents aren't much use unless one can match the big corporation's legal resources.
     
  10. Slider2732

    Member

    May 6, 2009
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    It used to be the scene in the early 80's, with arcade games. Being as electronics and arcade games are two hobbies of mine, I find all sorts of circuit boards and all sorts of protections. Some are quite horrid, like epoxy clad battery backed ram stages :eek:
    The guys were basically building a machine, boards at least, that would only last the time of the machines popularity in the arcades, 1 or 2 years.
    Nowadays, people have worked to find out what was in those stages and back engineered, to produce rom chips with that missing info within them. Same as others are saying though, eventually any protection will be just a delay...even if of 25 years.

    I went down the patent route in the 90's, for The Electronic Book. Nightmare. The firm who advertised on UK TV (when I lived there) were scam merchants. Took a lot of money from me and I got a generic book back with my design sort of cut&pasted into their 'research report'. High fees for the first year of patent and that was that.

    Success can sometimes be in the form of having a design that someone does indeed copy. Means you had the jump on them and had a new fresh idea worthy of other peoples notice.
    When a person has one good idea, they're likely to have another.
    My fave thought there is that a photocopier will never create a photo.
     
  11. thingmaker3

    Retired Moderator

    May 16, 2005
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    Put the sucker out as open source from the get-go. Write a "how-to" book and sell the book for your profit. Sponsor contests to innovate from your design seed. This all worked out well for Massimo Banzi and his cohorts.
     
  12. DaveH

    Thread Starter Active Member

    Jan 1, 2009
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    Thanks, this is all very interesting. I must admit I was only thinking about small simple things I can do for not much money. My circuits aren't going to revolutionize the world so there's no way I would look at patents or anything extreme like that.

    I'd just wanted a little bit of 'insurance' so that I have a shot at avoiding starvation - because that's what I'm facing in the near future. One thing I like about circuit design, is I find it so absorbing and it takes my mind away from the real world. It's a bit like the old days in s/w when it was fun.

    I like that idea about dummy components and KL when you release the Professional Edition of your obfuscator, please let me know, thanks for the tips.
     
  13. Papabravo

    Expert

    Feb 24, 2006
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    Yeah...I got some of those dummy components from a gray market distributor. They claimed they were an SPI parallel port MC68HC68. Turns out they were plastic encapsulated leadframes with no silicon inside. We had to lay out a new board with an FPGA to replace the obsolete part.
     
  14. beenthere

    Retired Moderator

    Apr 20, 2004
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    IBM used to make up proprietary IC's in unique cans (still TTL, but with with different pin-outs) and do fun things like completely encapsulate control boards in a rubbery compound. You may also notice how much unique IBM hardware is still with us.
     
  15. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    I once worked at a place where a desperate and creative engineer had a small potted circuit Xrayed to reveal the IC footprints and PC board layout. It gave him enough info to reverse engineer it.
     
  16. atferrari

    AAC Fanatic!

    Jan 6, 2004
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    THe use of X rays to peek inside of potted ICs was frequently alluded to by Don Lancaster in his column "Hardware Hacker" (Radio Electronics). Can't recall if a dentist (?) was who helped him on that. I can not imagine actually what equipment he actually used.
     
  17. Darren Holdstock

    Active Member

    Feb 10, 2009
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    Like the x-ray technique, that's really fiendish. It would also give a map of where to excavate if one wished to access the components or tracks with the minimum of damage.

    I recall reading of an ancient Egyptian mummy that was partly bandaged up in old scrolls. Scholars were aching to read the hidden writings, but couldn't without destroying the mummy. Happily new techniques in MRI (or was it CAT?) scanning enabled the hidden layers to be deciphered in situ. Maybe such techniques could read the idents on potted components? A bit extreme, but where there's a will...
     
  18. beenthere

    Retired Moderator

    Apr 20, 2004
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    Probably why FPGA's and microprocessors are so popular. You can't retrieve the programming in either case.
     
  19. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
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    When I was in the throes of having Plasma Dreams published, my first agent was a dry-humored English gentleman by the name of Pip Theodore. When I expressed my worries about having my masterpiece stolen before it was even finished, Pip didn't miss a beat.

    "Don't flatter yourself."

    I think that was the best advice I ever got. When you have a marvelous product, then you can worry about patenting it.....or not.

    Eric
     
  20. thingmaker3

    Retired Moderator

    May 16, 2005
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    I wonder what a few bits of aluminum foil in the potting compound might look like.:cool:
     
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