Reverse Engineering Techniques

Is there any anti-reverse engineering techniques out there? I was thinking of making some not-so-obvious shorts between tracks though would easily be fixable if you knew they weren't suppose to be there. Other ideas would be to split the board up and have them fab'ed by different places but easily hooked back up. These don't work too well for boards that are obvious and simple. While impossible to completely prevent reverse engineering it would be nice to be able to prevent the chinese farmers from making a profit off of someone elses hard work.

ld

Having worked at the Martin Marietta missle plant near Ocala, FL, I can tell you that the parts needed to assemble the Hellfire missle (AGM-114) are never all in one place until final assembly. Each plants makes certain pieces. Nobody has the complete build schematics.

....little round circuit boards every where you look.!!

That's almost the only method. If large qties then have the uC programmed at whoever pruduces it, and locked. Then you know exactly how many were shipped to your assembler and how much attrition there is.

Xray will unearth all that in a jiffy.

A monkey such as one of these:

Is that a deliberate strategy or just a result of splitting work between congressional districts or some such thing?

Best regards, Spehro Pefhany

Cool. But Jon can't possibly justify the cost to go quite that far :-)

This is a simple board and because of mechanical reasons is obvious what it does and potting is impossible. My main thing is not so much the finished product but the fab. The idea is "What keeps a pcb fab company from stealing the gerbers"? Chinese farmers can easily take the gerbers and send them to their friends and not even RE the stuff(since there is no real method to prosecute them in china?). Or the can simply RE the stuff and mod the layout to make it look more original.

This is a very simple design. I thought about trying to break the board in half which would definitely obscure it's application but makes it very difficult to put back together again... mainly because of mechanical reasons(cannot have connectors on the board) with quite a few traces that would be broken and need to be connected.

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The defense contractors do the same thing with custom chips.

ld

I've noticed some boards have the markings erased off the chips. Is that of any value regarding security?

That's why you put stuff in firmware and you supply the chips pre-programmed. Gerbers won't do you any good unless you have the schematic and firmware. Some people go to the trouble of adding various superfluous micros who's sole purpose is to confuse the reverse engineerers and make it difficult for them. Functions that don't really need a micro get one anyway :-)

Dave.

Rigol tried it on their oscilloscopes, and well, didn't put enough effort into it:

Dave.

I've noticed some boards have the markings erased off the chips. Is that of any value regarding security?

Just takes a little longer to crack...

Jon Slaughter a écrit :

Yeah, break you design in tiny boards and connect them together. Say, one resistor per board, one capacitor per board, one transistor per board, one diode per board,... The nice thing is that this also allow to highly standardize your PCBs, hence reduce your costs...

Think there's some difference between reverse engineering and stealing design documents. If a design is really simple, one can build another from scratch more easily then reverse engineering it. Fiddling with a simple designs PCB will do more harm then good. The only way to hide something is using a programmable device like a micro or a PLD that can be read protected after programming. If you program that devices yourself you will have no code files or master devices laying around. Think you cannot do better unless you want to do all the assembling yourself.

petrus bitbyter

I worked on the equivalent in the early '90s for the 3090 and ES9000 series processors. It was a bit more cluncky though and there was no pretense of protecting code (I'm sure there isn't here either), only the cryptographic keys and other "secret" information.

It can't be done; the best you can do is slow them down a bit. The way to do it is to have millions of your device built quickly, and sell them fast, before the copyists get into the act.

Good Luck! Rich

Probably some of that, plus for military stuff there's the threat of imprisonment or execution for revealing classified information to "the enemy."

Cheers! Rich

...unless you're the NYT.