Digital identification using steganography, can it be broken? Digital identification using steganography, can it be broken?

I have read a few articles saying that using an I.D. embedded in video, audio, etc can help track down the origin of a copyright violation. OK, then they said it can't be broken, so I got that "I'm gonna do it, just to prove you wrong" feeling and here I am.

I know a little about video and images from working with the OpenCV library. I know OpenCV kind of simplifies things, but in essence an image is a matrix with each coordinate being a pixel, or rather a set of RGB values or a similar set of values representing the pixel's color.

So from what I have gathered, in steganography ia smaller piece of data is embedded through-out the image or video and is used for various purposes. Now, I am assuming that the data is spread out bit-wise within the RGB values of the image or even multiple images in a video, which could be used to identify the source of a copyright infringement. That's all fine and good, just don't tell me I can't break it.

So say in theory I was going to pirate a movie. If I ran the the video and each frame through an algorithm that would add or subtract a random value within a given range that would not distort the quality of the video beyond an acceptable amount, that should completely distort the hidden I.D. — correct?

Would reformatting the image to a format that used something other than the simple RGB values in each pixel also aid in distorting the I.D. beyond recognition?
tl;dr: That depends entirely on the watermarking scheme.

Longer version: That depends entirely on the watermarking scheme used, specifically on the perceptability and robustness of the watermark. If it's supposed to be visible and robust, degrading the quality as Dmitry Khovratovich suggested will retain the watermark but might achieve the effect he describes.

If the mark is too perceptable though it might be possible to remove it. According to Ross Anderson (read below for link):


  For example, where the mark was added by either increasing or decreasing the luminoscity of the image by a small fixed amount, this caused the peaks in the luminoscity graph to become twin peaks, which meant that the mark could be filtered out over much of many images.


Provided that original copies only differ in the watermarked regions, pauluss86's solution is the most sure-fire way to get rid of them. 



The following is the answer I originally set out to write but quickly got out of context. I retain it because of some interesting background information.

There's been a question on Security.SE that discusses stenography detection in images, so that's a good place to start. But more to the point, Ross Anderson's excellent book Security Engineering has an entire chapter dedicated to copyright and DRM (links to 1st edition, 2nd edition is out). So let's take a look at that (page 711 of the 2nd ed.):


  The DVD consortium became concerned that digital video or audio could be decoded to analog format and then redistributed (the so-called 'analog hole'). They set out to invent a copy generation management system that would work even with analog signals. The idea was that a video or music track might be unmarked, or marked 'never copy', or marked' copy one only'; compliant players would not record a video marked 'never copy' andwhen recording one marked 'copy once only' would change its mark to 'never copy'.


So kind of like how the "do not track" button works in browsers. One thing jumps out though: The watermark (the 'copy' flag) has to be resilient enough to be preserved through the conversion from digital to analog, which means soft degrading (like converting to another format) would also leave it untouched. The text goes on to say 


  SDMI also uses a fragile watermark that's damaged by unauthorized processing.


but it's important to note the SDMI forum no longer exists. According to the Wikipedia page linked,


  On October 15, 1999, Eric Scheirer, later a digital music analyst for Forrester Research, wrote an editorial for MP3.com titled "The End of SDMI" which declared that the group's true goal to fold the technology industry into an alliance that would guarantee the record industry's near monopoly over musical content had failed. [...] The SDMI has been inactive since May 18, 2001.