Re: [WM]: software watermarking

[mojtaba mahdavi <mahdavi110@yahoo.com>]

Hmmmm. Strange to me. 

I am searching for techniques of executable watermarking. I want to know Is there any tachnique that enables executeable to know
alteration? So they can prevent cracking ?? 

I saw
ftp://quatramaran.ens.fr/pub/madore/misc/selfmd5.c
but actually did not get the Idea. Will you please show me a paper (guide line) which I can get the Idea.

Regards. 

--- Gonzo <davec@netsoc.ucd.ie> wrote:

> > embedding the hash into the software itself can be
> a solution, while
> >keeping ping the hash unchanged after embedding.
> From reading the piece I don't believe it is possible to keep the hash 
> of a file unchanged after adding to the file the value of the hash. It 
> seems only possible to add a value to two files that hash to the same 
> value and still have them hash to the same value.
> 	It is possible for a program to contain its hash, by fixed point 
> reasoning.
> Interstingly it is also possible for a program to print its own MD5 
> hash.
> ftp://quatramaran.ens.fr/pub/madore/misc/selfmd5.c
> Such a program cannot be altered without changing its functional 
> program behaviour. This places limits on the power of software 
> watermarking, tamperproofing and obfuscation as it shows they cannot 
> be used on all programs.
> 	Regards
> 	David Curran
> 
>  On Wed, 8 Dec 2004, Ersin Esen
> wrote:
> 
> >
> > regarding hashing, the following discussion can be
> interesting:
> >
> >
>
http://developers.slashdot.org/developers/04/12/07/2019244.shtml?tid=9
> > 3&tid=172&tid=8
> >
> > embedding the hash into the software itself can be
> a solution, while keeping the hash unchanged after embedding.
> >
> > -ersin esen
> >
> >
> >
> >
> >
> > ----- Original Message -----
> > From: "mahdavi" <mahdavi@ec.iut.ac.ir>
> > To: <watermarking@watermarkingworld.org>
> > Cc: <watermarking-owner@watermarkingworld.org>
> > Sent: Monday, December 06, 2004 1:35 PM
> > Subject: Re: [WM]: software watermarking
> >
> >
> > > there must be a hash on your software on server.
> (eg an md5 hash).
> > whenever you want to verify file integrity you
> should calculate
> > > hash of your software and compare it to the hash
> on server.
> > >
> > > On Fri, 03 Dec 2004 16:51:58 +0100 (MET),
> 2630370 wrote
> > > > hello,
> > > >
> > > > i'm looking for techniques to produce software
> watermarking, i.e.,
> > > > a way any user can verify if an application or
> update downloaded
> > > > from the internet really has been released by
> the right producer
> > > > and has not been alterated.
> > > >
> > > > i would really appreciate any hint,
> > > >
> > > > thanks,
> > > > mh


______________________________________________________________________________

Watermarking Mailing List - http://www.watermarkingworld.org/ml.html
To unsubscribe send email to "majordomo@watermarkingworld.org" with
"unsubscribe watermarking YOURMAIL" in the body.
______________________________________________________________________________