Thread Subject:

How save is pcode?

I just wonder how save pcode is against re-engineering by
back translating to m-code. Are there any nasty cracks
somewhere out in the www.

"Stefan " <stefan.vonbergen.nospam@aerodynamics.ch> wrote
in message <frtv5d$60d$1@fred.mathworks.com>...
> I just wonder how save pcode is against re-engineering by
> back translating to m-code. Are there any nasty cracks
> somewhere out in the www.
>
>
Do you mean to say "How SAFE is P-Code?" or "How to save a
P-Code?"
If I am not mistaken, probably you are interested in the
former question.
I am not sure, if there exists any code out there to
convert P code to M code. Pcode is encrypted using AES
encryption, using a key only known to Mathworks, so only
Mathworks could convert it back to M-code.
But my friend, there are hackers and crackers out there
who have hacked and cracked the most intelligent of
systems. So, it could be quite possible for some
intelligent life form to crack the AES encryption.
Vihang

"Vihang Patil" <vihang_patil@yahoo.com> wrote in message
news:frvm47$b8b$1@fred.mathworks.com...
> "Stefan " <stefan.vonbergen.nospam@aerodynamics.ch> wrote
> in message <frtv5d$60d$1@fred.mathworks.com>...
>> I just wonder how save pcode is against re-engineering by
>> back translating to m-code. Are there any nasty cracks
>> somewhere out in the www.
>>
>>
> Do you mean to say "How SAFE is P-Code?" or "How to save a
> P-Code?"
> If I am not mistaken, probably you are interested in the
> former question.
> I am not sure, if there exists any code out there to
> convert P code to M code. Pcode is encrypted using AES
> encryption,

You're thinking of the CTF file generated by MATLAB Compiler, not PCODE.

http://www.mathworks.com/access/helpdesk/help/toolbox/compiler/f10-998688.html

*snip*

--
Steve Lord
slord@mathworks.com

In article <frvm47$b8b$1@fred.mathworks.com>,
 "Vihang Patil" <vihang_patil@yahoo.com> wrote:

> "Stefan " <stefan.vonbergen.nospam@aerodynamics.ch> wrote
> in message <frtv5d$60d$1@fred.mathworks.com>...
> > I just wonder how save pcode is against re-engineering by
> > back translating to m-code. Are there any nasty cracks
> > somewhere out in the www.
> >
> >
> Do you mean to say "How SAFE is P-Code?" or "How to save a
> P-Code?"
> If I am not mistaken, probably you are interested in the
> former question.
> I am not sure, if there exists any code out there to
> convert P code to M code. Pcode is encrypted using AES
> encryption, using a key only known to Mathworks, so only
> Mathworks could convert it back to M-code.
> But my friend, there are hackers and crackers out there
> who have hacked and cracked the most intelligent of
> systems. So, it could be quite possible for some
> intelligent life form to crack the AES encryption.
> Vihang

In addition to what Steve said I would like to point out that The
MathWorks has never said what form of encryption they use for p-code. I
have gotten the impression over the years that it isn't very strong (or
at least wasn't at first), perhaps it is stronger today. However, as
far as I know, what is being encrypted is not the m-file, but the
intermediate byte code which has never been specified. So I think it
would be rather difficult to break the p-code encryption given that we
don't even know what language is being encrypted. I wouldn't worry
about it.

--
Doug Schwarz
dmschwarz&ieee,org
Make obvious changes to get real email address.

In article <see-67C48F.09351921032008@71-129-133-66.dollamir.com>,
Doug Schwarz <see@sig.for.address.edu> wrote:

>In addition to what Steve said I would like to point out that The
>MathWorks has never said what form of encryption they use for p-code.

Mathworks documents that AES is used to encrypt Component Technology
Files (CTF). Which, as Steve Lord points out, is not the same
as p-code (created by the 'pcode' command) which is merely pre-parsed
code.
--
  "Let me live in my house by the side of the road --
   It's here the race of men go by.
   They are good, they are bad, they are weak, they are strong
   Wise, foolish -- so am I;" -- Sam Walter Foss

Thanks to all for the feedback. Yes, I was interessted in
safety (not how to save...).

As far as I understand the feedbacks, there is no really
obvious way to translate p back to m. I guess for my
application this is safe enough.

Thanks!