[ NNSquad ] Re: Speculation, how AT&T can implement "copyright filtering" without wiretapping/dpi...

[Edward Almasy <ealmasy@scout.wisc.edu>]

On Jan 28, 2008, at 11:54 AM, Nick Weaver wrote:
> Thus all the schemes for "video DNA" and "audio DNA" tracking are
> robust in the arms race, at least with a bit of effort.

I believe you're grossly underestimating the power of even the  
existing tools for obfuscation, as well as the ingenuity of the  
programmers involved.

Encryption is not my field, however I have implemented a few  
encryption and/or obfuscation routines in my time, as well as a few  
media identification algorithms, and I'm fairly confident that it  
will always be easier to come up with new ways to hide digital media  
DNA than it is to come up with ways to accurately identify that  
hidden DNA amongst the oceans of data streaming across the 'net.   
It's difficult enough to accurately automatically identify a media  
stream when it's *not* obfuscated, given the number of encoding  
permutations in use.  When someone is actively working to prevent  
that identification *and* you need to have an identification method  
that's efficient enough to be run in real time on the quantities of  
traffic in question, well...

Keep in mind that:  A) at least in the case of video or audio, we're  
not talking about identifying bit-for-bit copies, but rather digital  
streams encoded using any one of hundreds of scheme and parameter  
permutations, each of which results in a distinctly different binary  
stream, and  B) because the obfuscater can count on a human being  
available to play a part in the de-obfuscation of any content before  
use, they can take advantage of obfuscation techniques that are  
impossible (or at least impractical) to wholly implement in content  
identification software.

ANYWAY, to get back to the original point, the spidered blocking idea  
certainly has merit, if applied judiciously with due process.   
Fortunately that due process will likely involve some degree of human  
judgement, which will mean that possible problem content  
identification can be far less accurate (and thus far more viable to  
implement) without inflicting collateral damage on the innocent.

Ed