On Thu, Sep 15, 2011 at 11:14 AM, G. Allegri <gioha...@gmail.com> wrote: > I've been asked to create a custom qgis, to be distributed via CD/DVD along > with some data (vector and raster) that should be only visible and usable > thorugh the customized qgis and not by any other tool. > Has somebody in this list ever had to manage this kind of obfuscation? > giovanni
The keyphrase you are missing here is "DRM" - Digital Rights Management - although I agree it essentially obfuscation. Its security depends upon two things: the code having the cryptographic key to decrypt the data, and the key not being accessible outside the code. The first part is easy - the second is impossible. I think every DRM scheme has been cracked. The effort required varies. If you wrote a Python plugin to do this, the user could look at your Python code and see the decryption key (difficulty level: easy). If you wrote it in C++, the user could disassemble the executable code and get the encryption key (difficulty level: medium). If you put the code on a circuit board, stuck it on a USB dongle, and made QGIS do calls to the USB device to do the decryption, the user could take the USB device apart, scrape off any epoxy covering your chips, stick digital logic probes onto the chips, and get the keys out that way (difficulty level: God-mode). The latter procedure, of digging into the hardware, has been done by dedicated people working on cracking the DRM on games consoles, primarily so they can run their own programs and operating systems on them. You have to realise that an effective DRM scheme has to be harder to crack than the gain obtained from cracking it. The guys who crack games console DRM get the gains of massive respect from the games community :) +1 for calling it obfuscation and not encryption though. The British Library didn't get that right. http://geospaced.blogspot.com/2010/02/great-british-library-drm-flip-flop.html Barry _______________________________________________ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer