an even more clever variant just occurred to me.  use conductive epoxy
to make some of the connections!  these will be dissolved along with the
encapsulating epoxy.  the conductive epoxy could form some of the
traces, be used to attach some of the chips (meaning they'd be loose
when the epoxy dissolved/softened) and to connect the previously
suggested wire wrap (or small magnet wire) connections.  using some
conductive epoxy with epoxy potting would make it very, very hard to
brute force reverse engineer.  though as noted, most applications are
fairly simple to design from scratch to a good engineer, it's only worth
so much effort to block the casual and clumsy cloner.

as far as reverse engineering, there are several variations.  outright
copying of a product is (rightfully i believe) wrong to many engineers.  

however, some reverse engineering is often required to add functionality
or interface to other products, this is completely ok.  i had to add
controls and some computer monitorable outputs to a stabilized laser,
fortunately the schematic was available as was the theory of operation
(it was clever, but i could do it from scratch from memory, nothing
"fancy").  the main job was figuring out how to modify the stock circuit
board.  some traces were cut, some holes were drilled to connect extra
wires, no big deal.  a year later i wound up completely redesigning the
electronics and the case for the original manufacturer, largely because
they new of our prior additions and enhancements to their unit.  of
course the redesigned unit had the computer monitoring and control
additions built in.  the original seller wound up with a much better
design (the original was very poorly executed, a variable inductor to
tune out a noise signal from the hv power supply didn't have enough
range, we replaced it with one which did.  there were also things like
using a green wire for the hot lead to a power transformer, mounted
sideways so that the bare hot leads were 1/4" from the bottom of the
case, creating a nice shock hazard and other just careless things).

this is the difference between hacking (in general) and cracking
(hacking specifically aimed at circumventing access and control
restrictions placed by the owner to protect property) as well.  i've no
problem with hacking, cracking however is violating someone's trust and
ethics at the least and possibly the law.  what bothers me is the move
to make hacking in general illegal in many areas where frankly i believe
people should be allowed to enhance performance when they aren't
stealing anything.  for instance, our satellite receiver has terrible,
terrible software, i'd love to be able to change just the menus, but the
satellite provider would not like me to even open the case due to their
paranoia and absurd desire for "absolute" security, which they can't
have which makes them paranoid about things that pose no real threat to
their profits and might even increase them.  the same goes for the dvd
clowns in holey wood.  i've learned a great deal by "tinkering" with
commercial systems and equipment like video games etc., it is a very
good way to learn a lot of very practical things quickly and harms no
one, yet many think that as soon as you remove the screws from some
boxes you are doing something wrong, balloony.

Joe McCauley wrote:
-----
ads in this way as well.
> 
> One of the best lines of defense is to encapsulate using a delicate circiut
> construction. That way the reverse engineer will most likely wreck the
> circuit taking it apart. At least if they finally succeed, they will have to
> have bought a few.... A useful variation of this (though labour intensive)
> is to leave out a few PCB traces and make the connections using the type of
> wire used for wire wrapping. (remember that anyone?) These connections
> should form loops which end up embedded in the encapsulant. Taking apart the
> package usually destroys these connections. If you use the same colour of
> wire for all connections it will add to the confusion.
-------
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