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Digital Watermarks to Replace DRM
palegray.net noted a wired story about an
industry trend towards watermarking and away from DRM. It says "With all of the Big Four record labels now jettisoning digital rights management, music fans have every reason to rejoice. But consumer advocates are singing a note of caution, as the music industry experiments with digital-watermarking technology as a DRM substitute.
Watermarking offers copyright protection by letting a company track music that finds its way to illegal peer-to-peer networks. At its most precise, a watermark could encode a unique serial number that a music company could match to the original purchaser. So far, though, labels say they won't do that: Warner and EMI have not embraced watermarking at all, while Sony's and Universal's DRM-free lineups contain "anonymous" watermarks that won't trace to an individual."
Here is a
Technical discussion on AudioBox and PSU.edu's Abstract Index
In the real watermarking scheme, every single byte is changed. Basically the entire thing is covered with a huge watermark that is noise, with randomly and sparsely distributed blocks of the actual watermark. So finding identical bytes does not work.
Averaging would seem to work but supposedly the algorithims can survive quite a lot of coverage with random noise. If the watermarks are sparse enough, all that averaging will do is make a result that has *all* the watermarks of the originals. What they do need to do is avoid having huge numbers of different watermarks, as I doubt it will survive tens of thousands of different samples being averaged. This is probably a reason there will not be per-user watermarks.
The technique is based upon steganography, and it also works better in higher quality files than in the 126 bitrate junk. Nobody hears everything in a sound file once there is enough complexity, and the watermark parts go into the areas that people aren't able to really hear.
There's no reason why an end user, or anybody other than the person doing the watermarking needs to be able to find it. If you randomly intersperse the watermark through a large enough portion of the file, it becomes quite difficult to find and effectively remove without causing damage to the file.
The trick to it is to touch every single frame, but in random spots, and to do so with enough variety that you would need to compare a huge number of copies to have a shot at unwatermarking the file. Doing so will change the results of the checksums making it a pain to figure out where the signature actually belongs. Most of the changes don't even have to have anything to do with the watermark. The weakness then is comparing against a clean copy, and to be honest, anybody that has a clean copy and cares about the watermarking is just going to use the clean copy. And if there's enough variability, it's going to be a tough thing to strip out without causing other problems.
It's one of those things where unless you've allowed your copy to make it onto the net, nobody is going to be able to examin the file anyways. It is several steps above the current system in terms of convenience. One could probably screw it up by transcoding it, but that is similar to what ITMS allows presently, and it does lose quality as well.
You might want to argue against watermarking technology if you'd had RTFA.
(emphasis mine)TFA goes on to describe how this is a bit difficult in practice with current technology, but "they're working on it". Given the hit that classic DRM is taking in the PR space now, and given that the media company execs haven't all dropped acid and wandered back into the sixties, I think it's a safe bet that they're going to work on DRM II (New and improved, patent pending). You may return to wearing your tin foil hats now.
Faster! Faster! Faster would be better!
I think a better example might be like...
(view source if you don't see it)
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