I do kinda understand steganography....

but i don't actually get how a serialized video can be used to track generations of usage and content migration, the diaspora, as it were....

I give my clip to A, and it's passed down to W,X,Y, and now Z, and if i look at Z's clip, it'd have the same serialization as A's.

what has this told me? there's no counter, after all.....

I guess it is only good at tracking the origin of
a given copy if multiple "originals" exist online.
Kind of like that MPAA proposal a few years ago to include a digital encoded signal (inaudible/embedded) in the sound track of each release print of major films so that if any pirate dubs were found the origin could be pinpointed.
As far as I know it was never implemented.

Yes, that'd work, and it'd be another instance of pattern recognition too, haha.

quote:

Originally posted by nobody:
I do kinda understand steganography....

but i don't actually get how a serialized video can be used to track generations of usage and content migration, the diaspora, as it were...

I'm with you there. I don't see how a watermark can, in itself, be used to trace an image. I understand that some things such as html graphics can create a request to an originating server that lets the sender know when it's been opened...but my understanding of such things is a bit fuzzy and I'm forced to accept that the technology is sufficiently advanced that I can't always distinguish it from magic.

Part of the confusion is that a "watermark" is different from steganography in general.

In GENERAL, steganography can be any coded message superimposed on the least significant bits of an image. Such a communication is likely to be exceedingly sensitive to even a slight alteration of the image, since that makes random changes in the coded numbers.

The really sneaky thing about the "Watermarking" stuff is that it allows coding of a message that is HIGHLY REDUNDANT and remains decipherable as the image is processed. The original paper in Nature cited a case in which the image was resized, brightness and contrast adjusted, cropped, printed out on an INKJET PRINTER, scanned in, and the watermark was still detectable in the data. It's a trick so sinister that if you didn't know about it you'd never imagine it possible, which is the source of what appeal it may have.

Now this still doesn't translate directly into tracking, but there are many ways in which it is possible to imagine the tracking done. For example, the film viewing program might have some hidden spyware function (or they might not even bother to hide it) that sends reports of any watermarks that it can decode back to its home company. Or maybe there's some Russian version of ECHELON with searchable records of all Net communications. Or any other scheme...

It's the study of stegosauruses. Common in the mid-Jurassic.