Re: [Flightgear-devel] Content protection for modders?

[Curtis O. <cur...@gm...>]

On Thu, Aug 25, 2011 at 5:50 AM, Jan Mattsson <ja...@gm...> wrote:

> 2011/8/25  <li...@st...>:
> > You wouldn't even need to do that - how can you have a closed format when
> > the code for reading it would need to be open source?
>
> An encrypted file?
> The whole idea certainly seems contradictory to the spirit of the project.
>
>
Do other sims offer content encryption or content protection?  For instance,
I've been able to locate and test a blender plugin that can open up many
MSFS aircraft models.  How about xplane?  It's been a *long* *long* time
since I fiddled with their package, but at the time I was paying attention,
all their 3d formats were open and well defined.

Often the commercial sims will store things in their own binary formats, but
in most cases these aren't encrypted and the end users figure these out
pretty quickly -- so they can either edit the content or create new content
with the same format.  I wouldn't consider a binary format much of a content
protection scheme ... especially in an open source project where the source
to load and store the binary format is readily available.

I understand the desire for content creators to not get "ripped off".  But
also understand that one of the main reasons that FlightGear can be
successful is because we make all the source code and content open.  If we
didn't make everything open, then we wouldn't get nearly the same amount of
volunteer contributions and high quality volunteer contributions is the
critical reason why FlightGear has been so successful.  If we were a closed
off commercial outfit, who would want to pitch in and help someone else make
money?  But with everything open, you know that your contributions can be
enjoyed equally by everyone else, just as much as you are enjoying everyone
else's contributions.

There are some low-lifes out there that try to make a profit on other
people's work, and will gladly lie and misrepresent things to swindle as
much money as possible from unsuspecting end users.  But the truth is that
these people have always existed, and will always exist.  They are
remarkably good and persistent at copying things ... going so far as to
break copy protection schemes, reverse engineer hardware designs, copy the
exact look of products (even including the logo.)  This isn't a problem that
is unique to the FlightGear project -- and it's something we would still
face no matter how hard we worked to create copy protection schemes.

If you designed a binary content format, someone will reverse engineer it.

If you design an encryption scheme, someone will just modify the sim code to
dump out the decrypted version after it's been loaded into memory by the
proprietary decrypting plugin. (If not outright break the encryption scheme
or steal your encryption keys.)

In all these case, the content can still be easily copied, replicated, sold,
etc.

The best scheme I've seen is something that has a node-lock key that will
only run on a single PC (key'd to mac address, or processor id.)  But this
implies a more complicated 2 step install where the user must come back to
you after installing the product, report their unique id, get a key, and
then install that key before they are able to run.

And the problem with all of this is that in an open source project, someone
could simply compile a new version of the simulator that skips the key check
or accepts a trivial key, or any key.

I'm just thinking down various avenues here, but hopefully you can see that
what seems like a simple request at first is actually quite complex and
creates all kinds of down stream issues (both technically and with user
support.)  And at the end of the day, the bad guys can usually find work
arounds anyway and aren't slowed down too much.

When farmers grow crops, they have to put up with weeds.  We can try
reasonable things to minimize the weeds, but if you are too aggressive at
killing the weeds and don't tolerate a single one, then you most likely end
up killing much of your crop too.  So it's my view that this is something we
just have to put up with.  We can try to take reasonable steps to minimize
the problem, but we can't eliminate all the bad guys without harming all the
good things about our project.

Curt.
-- 
Curtis Olson:
http://www.atiak.com - http://aem.umn.edu/~uav/
http://www.flightgear.org - http://gallinazo.flightgear.org