> First dervive a number from the object code, using a suitable algorithm.
> This number is stored in eeprom during the manufacturing process. Hash it
> with
> a unique serial number. (I had a DS1994 which claims to have a
> unique serial
> number) If you don't have this then generate a unique 64 bit serial number
> for each unit manufactured. This then provides a means for your code to
> validate itself, by comparing the derived number with the number installed
> during manufacturing.
>
> Now the clever bit. If you detect a mismatch indicating that the product
> has not been "registered", generate a random time delay say 10 - 48 hours.

Maybe I'm just dense this evening.  If the PIC itself contained the unique
serial number and the hash, and I copied the PIC, wouldn't it work forever?

I spent most of today working with a product from a very nice company that I
won't name.  They sell an "appliance", which is really nothing more than a
fairly standard PC running a pretty standard UNIX.  Their *software* is what
turns a $1200 PC into a $50K appliance.

Their copy protection method is to key the software to the MAC address of
the network card(s) installed by the factory (sound familiar?).  You could
clone the software, but it won't run in a box with different network cards.
Unless, that is, you happen to have some of the older $10 ISA 10Mbit cards
that would allow you to set the MAC address with the factory setup/diag
floppy.  Only one or two (depending on the model) would be needed, and you
could use "real" NICs for the real work.

Interesting approach.  I figure if I had larceny in my heart, it would take
me a couple of hours to have a hardware workaround, and probably a week to
find & rewrite the code that checks the key to produce a cracked copy that
would run on anything.  I haven't bothered, and won't either.  There's a
built-in gotcha -- if you'd pay $50K for the first one, most likely you've
got the bucks and the business justification to pay for the rest.  And if
you're going to rip off a company to compete with their $50K appliances, you
can bet they're figuring about $10K per unit (or more) of that for lawyers
to smother you in lawsuits.

There's a message in there somewhere, I think.  Maybe a couple of them.

Dale

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