Originally published at: https://boingboing.net/2019/05/18/watermarks-r-us.html
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Interesting paper. The one thing I conclude from it is that to be successful at preventing counter-forensics, the imperceptible watermark schemes need to remain absolutely secret (true security through obscurity) or they’ll be removable. That means they risk exposure with every court case and every patent filed.
If they’re willing to go with slightly perceptible, though, the opportunities are endless. They could shift movement pseudo-randomly in every single frame. (Think of the uncertainty of the original image beneath MPEG haloes.) These shifts could be mapped using a cryptographic secret sharing scheme such that individual acts of collusion could be identified (only X and Y would have these specific differences in common, therefore if mark #1 is missing, it must be because X and Y were compromised, and colluded to remove it.) Repeat for X and Z, Y and Z, and X and Y and Z. Sure, it exponentially scales horribly, but there are only a finite number of screeners released. Creating a unique set for each screener is then simply a math and cataloging problem.
A pirate couldn’t successfully undo that across an entire film, not even with a dozen correlated copies. And it only takes one small set of unambiguous watermarks to identify each participating traitor.
Once the watermarking people achieve true cryptographic security, they should be able to publish their algorithms publicly and their watermarks would still be unremovable.
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I was honoured to visit Deluxe and talk to it’s manager, and he told us that most movie piracy doesn’t come from encryption breaking, but by pure brute force crime: stealing spare dvd copies in the factory or the truck transporting the first copies, extortion to movie theatres, and even kidnapping, mostly done by Russian or East-european mafias working in the EU.
It is “fun” how we try to solve some problems with more technology when the good old dirty tricks just work the same.
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Watermarking of the type described in the article is strictly about identifying the leakers before a movie is released to the theaters. There are only a few dozen copies made of the pre-release screeners; these are reviewers, voting members of the Academy, VIPs, and manufacturing distributors. If they find the leak at that point, they can prosecute and prevent future leaks.
Once a movie is on the shelves at Target, yeah, it’s going to be copied by the millions.
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You should know that DVD/Blu-Ray copies are done before the movies are released. That is precisely one of the things they do at Deluxe, months before release they already had assembled the disks images with dubs, subs and extras in a dozen languages. I saw them finish Logan’s dvd/blu-ray five weeks before it’s premiere in cinemas, really cool, nice, people.
Obviously the security in the building was over the top to the point of having armed security and bulletproof glasses… IN SPAIN*!
PD: The are not who print the disks, they do the post production and disk image.
*Crimes involving guns are rare in Spain.
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They also watermark the copies distributed to theaters, though - I recall that you could sometimes notice the ‘visual artifacts’ mentioned in the patents for early versions of the watermarking tech. They’d show up as curious patterns of dots just for one frame, usually not noticeable, but occasionally you could see them if they happened to be on a bright shot. This was on 35mm film prints. Digital distribution may have allowed them to get a bit more subtle.
And of course there’s the ridiculously blatant watermarks applied to the versions they send to airlines… huge block letters spelling out the name of the airline that appear on screen for a few seconds every so often, extremely distracting (and what are those watermarks hoping to prove…? Are the airlines required by contract to keep an eye on their passengers to make sure nobody’s filming the crappy seat-back displays?)
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So, this:
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I am not sure I follow that. If you have more than 1 version of the watermarked work (i.e. one with watermark A, another with watermark B, and a third with watermark C) you should be able to diff them to locate the watermark scheme, and take countermeasures, right? Or am I misunderstanding? Are you assuming a single version of the watermarked work?
Version A: 1234AA567890
Version B: 1234BB567890
Version C: 1234567CC890
If versions like A & B wouldn’t you simply zero or average the bits* at the common address?
If versions like A & C wouldn’t you simply look for discontinuities in otherwise identical strings, and once again zero or average the bits?
* Or something similar depending on encoding scheme of media and details about the pattern of watermarking.
But each copy could have masses of noise in one channel, only a small part of which is the marker.
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What if every copy was just edited slightly. Like a couple frames here and there or a color or unimportant visual element changed . How could that be perceptible to anyone, and if you know the code (which person received which copy with which edit) you could trace it. Right?
(I’m talking about a screener with limited copies. Not once the film is teased publicly)
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I think you underestimate the high demand for the shitty bowdlerised airplane edits of last year’s blockbusters.
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Sure you are not talking about cue marks?
Conventional release prints, which are made from timed internegatives, usually contain black motor and changeover cue marks as the printing internegatives are “punched” and “inked” for this specific purpose. Showprints, being made from the composite
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We argue that this conjuncture allows for an understanding of the posthumanities as
inviting a deepened relation between the enquiries into meaning and of
power characteristic of the humanities, and the imaginary and compos-
ition of the technical, a form of culture often reduced to being the imple-
mentation of scientific knowledge.
Well of course they would argue that! Who wouldn’t?
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It can’t be to discourage whoever is uploading the movies to the planes from pirating them and/or to encourage the airlines to put some effort into preventing that. I mean, why would disgruntled, underpaid airline employees pirate movies?
It’s a myth that only disgruntled employees will steal. In actuality the majority of theft is perpetrated by gruntled employees.
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This is even funnier read with a Viennese accent.
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Good point, but they work for an airline. What are the odds that they’re not disgruntled?
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I lived in Madrid, and armed security near most of the major government/tourist buildings was very common. While gun crime may be rare, armed police is very common.
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“Cigarette burns” in projectionist lingo
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Yes. I noticed the watermark dots because I was staring hard at the screen watching for the cue mark. (I was a projectionist for campus movie nights in college.)
[edit: I was thinking of CAP, there’s an image there showing the dots.]
Only in the world of Fight Club.
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