[Leica] Stealing Photos

[scheng at aotera.org (Spencer Cheng)]

Tina,

This is a very hard problem in practise. Digital images are just a  
bunch of bits. One nice thing about bits is that you can turn any bit  
from 1 to 0 and vice versa which makes it great for image  
manipulation. This of course means someone with the right tool can  
always change your metadata (which is also a bunch of bits) into their  
metadata.

Various solutions has been suggested but I have yet to see any that  
can be deployed on a large scale. Digital watermark can be removed if  
the attacker is willing to suffer some visual degradation. Even worse,  
the security of digital watermarks is dependent on (secret) algorithms  
which can be figured out by smart people. Once the algorithm is known,  
removing the watermark and leaving an image that is very close to the  
original is not difficult.

Digital signature(/public key crypto) is often promoted as a solution  
and it is fine until I remove your signature and apply my signature.

Regards,
Spencer

On Dec 10, 2008, at 11:09, Tina Manley wrote:

> LUG:
>
> This showed up on APA this morning:
>
> http://photobusinessforum.blogspot.com/2008/12/curious-case-of-fink-photography.html
>
> If we don't figure out some way to permanently attach metadata to  
> photos on the web, and if Orphan Works passes, I'm sure there will  
> be more and more unethical stealing of photos.
>