How protect proprietary Python code? (bytecode obfuscation?, what better?)

[Ben Sizer]

Re: How protect proprietary Python code? (bytecode obfuscation?, what better?)

bruno at modulix wrote:[color=blue]
> Let's rephrase it:
> "do you really think that native code is harder *enough* to
> reverse-engineer ?"[/color]

I don't know. In terms of copy protection, popular off-the-shelf
software is going to get cracked whether it's written in Python or x86
ASM, that much is true. But in terms of perhaps protecting innovative
algorithms from competitors, or something similar, compilation into
native code does a great job of hiding your work. Not a perfect job,
but a good enough job.

I know some people talk a lot about using web services to keep the
proprietary data behind a secure server, but there is a large number of
applications where this is not practical - eg. image/audio processing,
computer games, artificial intelligence, or several other applications
with heavy real-time or cpu-intensive requirements, or embedded systems
that don't have web access.

Perhaps the inclusion of ctypes will make it more practical to migrate
any sensitive code into native code libraries.

--
Ben Sizer

[Alex Martelli]

Re: How protect proprietary Python code? (bytecode obfuscation?, what better?)

Ben Sizer <kylotan@gmail. com> wrote:
[color=blue]
> bruno at modulix wrote:[color=green]
> > Let's rephrase it:
> > "do you really think that native code is harder *enough* to
> > reverse-engineer ?"[/color]
>
> I don't know. In terms of copy protection, popular off-the-shelf
> software is going to get cracked whether it's written in Python or x86
> ASM, that much is true. But in terms of perhaps protecting innovative
> algorithms from competitors, or something similar, compilation into
> native code does a great job of hiding your work. Not a perfect job,
> but a good enough job.[/color]

If they're truly worth protecting, they're worth reverse engineering.

Remember, the competition includes excellent programmers working in
countries where $10 an hour's salary is luxury and IP law enforcements
non-existent, so the cost to reveng is not as high as you might think.

[color=blue]
> I know some people talk a lot about using web services to keep the
> proprietary data behind a secure server, but there is a large number of[/color]

Ah yes, that would be me;-). Except that I don't limit my advice to
proprietary DATA -- it also applies to CODE worth keeping secret.
[color=blue]
> applications where this is not practical - eg. image/audio processing,
> computer games, artificial intelligence, or several other applications
> with heavy real-time or cpu-intensive requirements, or embedded systems
> that don't have web access.[/color]

Fewer and fewer systems "intrinsica lly lack" net access. For example,
good (costly) computer games more and more need net access to be played
in the best way (multiplayer etc).

"CPU intensive" is a weird reason to want to avoid keeping in a well
protected environment any code that's really worth money -- if it IS
worth that much you're no doubt charging enough for it to afford
supplying the CPU power to your customers (whatever your business model,
say pay-per-use or subscription levels with different maxima, etc etc).
[color=blue]
>
> Perhaps the inclusion of ctypes will make it more practical to migrate
> any sensitive code into native code libraries.[/color]

Naah, ctypes shines when you access *pre-existing* dynamic libraries; if
you're building those libraries yourself, it makes more sense to make
them immediately usable from Python, e.g. via Pyrex, or SWIG, or SIP, or
the C API, etc, etc. And if your secrets are truly valuable, none of
those will really help keep them safe.

If your secrets are worth diddlysquat, and the only reason to "protect"
them is (e.g.) to keep some PHB happy (relying on the fact that he or
she has no clue as to reality anyway), then go ahead -- use a Caesar
cypher (as a just-arrested Mafia "capo di tutti i capi" appears to have
done -- Italian police easily broke it, enabling it to arrest several
other mafiosi!), or native code, or any other ineffectual approach. But
if your wallet (or jailtime;-) is really on the line, do realize that
they ARE ineffectual.


Alex

[Ben Sizer]

Re: How protect proprietary Python code? (bytecode obfuscation?, what better?)

Alex Martelli wrote:[color=blue]
> Ben Sizer <kylotan@gmail. com> wrote:
>[color=green]
> > I don't know. In terms of copy protection, popular off-the-shelf
> > software is going to get cracked whether it's written in Python or x86
> > ASM, that much is true. But in terms of perhaps protecting innovative
> > algorithms from competitors, or something similar, compilation into
> > native code does a great job of hiding your work. Not a perfect job,
> > but a good enough job.[/color]
>
> If they're truly worth protecting, they're worth reverse engineering.[/color]

It's a sliding scale though. You don't need to be able to stop
everybody to make it worthwhile.
[color=blue]
> Remember, the competition includes excellent programmers working in
> countries where $10 an hour's salary is luxury and IP law enforcements
> non-existent, so the cost to reveng is not as high as you might think.[/color]

Whether $10 is a lot or a little is not as important as whether that
$10 could be better spent. It's easy to drill down far enough to break
copy protection but nowhere near as easy to derive a high level
algorithm from the assembly language. So in the latter case, a little
protection goes a long way.
[color=blue][color=green]
> > I know some people talk a lot about using web services to keep the
> > proprietary data behind a secure server, but there is a large number of[/color]
>
> Ah yes, that would be me;-). Except that I don't limit my advice to
> proprietary DATA -- it also applies to CODE worth keeping secret.[/color]

Code is data, data is code. :) I meant it to refer to all information
stored that way.
[color=blue][color=green]
> > applications where this is not practical - eg. image/audio processing,
> > computer games, artificial intelligence, or several other applications
> > with heavy real-time or cpu-intensive requirements, or embedded systems
> > that don't have web access.[/color]
>
> Fewer and fewer systems "intrinsica lly lack" net access. For example,
> good (costly) computer games more and more need net access to be played
> in the best way (multiplayer etc).[/color]

Sure, but there's still many, many programs that don't fit that
criteria. Nor are people generally happy about being compelled to use
online services to 'activate' their games.
[color=blue]
> "CPU intensive" is a weird reason to want to avoid keeping in a well
> protected environment any code that's really worth money -- if it IS
> worth that much you're no doubt charging enough for it to afford
> supplying the CPU power to your customers (whatever your business model,
> say pay-per-use or subscription levels with different maxima, etc etc).[/color]

Maybe I wasn't making myself clear - I just meant that you can't be
doing round-trips to a web server for per-pixel calculations.

--
Ben Sizer