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Game of Thrones leak and watermark: a stupid tracking system

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Re: Game of Thrones leak and watermark: a stupid tracking system

#191

Post by anigbrowl »

jjoonathan wrote: post #67
URSpider94 wrote: post #43

Earlier quoted context omitted.

This. The minimum difference in scene length allowable would be a single frame.

Do you actually know that or are you speculating? I wouldn't be surprised if MP4 (or other video formats) provided a mechanism for tweaking the timing of a given frame. Of course, if you're using such a primitive watermark you might as well just add a note in the metadata...

Yes, I know that - I work in film and post-production for a living and I can explain the origin and workflow aspects of video frame rates to you in excruciating detail.

You know how annoying it is when you watch a movie and there's some sort of 2-dimensional 'hacker' character and s/he just says some gobbledegook about 'hacking the password' or whatever, you see something a progress bar briefly on screen, and then the actor says 'we're in!' In short, how stupid movies can be about computer topics? Well that's how it feels when someone who knows nothing about video formats or editing comes up with suggestions about adjusting the length between scenes by a few milliseconds and having it slightly different for every viewer.

Re: Game of Thrones leak and watermark: a stupid tracking system

#193

Post by OSButler »

This is just a wild guess, but the visible watermark could be the result of a legal issue. Having hidden tracking elements in such videos could require disclosing them, whereas a visible watermark could be used to argue that the viewer is aware of the video being marked and therefore other included tracking elements do not need to be specifically named.

It has the potential side-effect of the watermark getting blurred out by the leaker, but leaving other tracking pieces intact.

Re: Game of Thrones leak and watermark: a stupid tracking system

#195

Post by anigbrowl »

avn2109 wrote: post #69
fredley wrote: post #16

Earlier quoted context omitted.

To be honest, when I heard that the files were protected with a watermark, I assumed that they actually meant a steganographic watermark. I thought that this tech had been adopted into the industry ages ago, I'm rather surprised if it isn't the case, given the arms-race between the media and illegal distribution.

Arms race? The entertainment industry has cantered out onto the jousting pitch with their horse and lance. Meanwhile illegal distribution is calibrating the laser cannons in their orbital battle station and dispatching their aircraft carrier battle groups.

The entertainment industry operates some 40 actual satellites that were put up into space using actual rockets, engages in petabyte-scale asset management as a matter of course, and constantly reworks its content acquisition pipelines as new digital and analog technologies come to market. We're a little bit more technologically sophisticated than you seem to imagine.

Re: Game of Thrones leak and watermark: a stupid tracking system

#196

Post by iron_ball »

anigbrowl wrote: post #188

Next iteration would be changing the length of each scene by a few milliseconds. One can count that the first episode holds s=18 scenes. Each scene lasts several minutes. Once again each copy can be made shorter or longer by a couple milliseconds, providing a unique fingerprint for each version sent. This sort of thing makes it hard for me to take any of the article seriously. The author doesn't seem to know the firs…

Anyone who was going to get hooked on Game of Thrones is hooked, and anyone who is still on the fence isn't likely to torrent the leaked episodes. Incompetence is a better explanation, I think.

Re: Game of Thrones leak and watermark: a stupid tracking system

#197

Post by TazeTSchnitzel »

CHY872 wrote: post #149
TazeTSchnitzel wrote: post #115

Earlier quoted context omitted.

It's not a very compression-resistant approach and more sophisticated methods are usually used, but a simple one is using the low bits of colour channels. In a red pixel you have bits like so: RED GREEN BLUE 11111111 00000000 00000000 A change in the most significant bit of any of these colours would be massive. 01111111 is half as bright as 11111111. But a change in the least significant bit(s) is barely noticeable.…

You don't get plausible deniability in any way. Turns out that the least significant bits of a pixel are not uniformly distributed. The obvious example of failure is that you expect more pixels with value 255 than 254, since any overexposure will be stuck at 255. The rest is obvious when you look at a histogram of pixel values; as the number of LSBs used increases you see the curve become stepped. LSB replacement ste…

Ah, I see. I hadn't thought of the 255 issue, in hindsight that seems obvious.

Still, I think LSB replacement steganography is useful if only to provide an example of how it steganography can be done, even if it's not particularly sophisticated.

Re: Game of Thrones leak and watermark: a stupid tracking system

#198

Post by allemagne »

waspleg wrote: post #148

The website says his method of randomly changing the length of the credits is a step in the right direction. I think that's completely wrong. https://www.techdirt.com/articles/20130808/02084524106/time-... "Our experience is that it leads to more paying subs. I think you're right that Game of Thrones is the most pirated show in the world," he said. "That's better than an Emmy." - Time Warner CEO Jeff Bewkes THAT is a…

I think he meant it's a step in the right direction towards solving the technical problem of identifying who leaked the material.

More generally he could have meant that tracking the leak is a step in the right direction towards HBO having control over when their material is released. Even in a fantasy world where all entertainment is free I think artists should have control over releasing their own work.

In any case, I'm curious as to what the endgame is in the right direction you mentioned.

Re: Game of Thrones leak and watermark: a stupid tracking system

#199

Post by anigbrowl »

jjoonathan wrote: post #62
rlx0x wrote: post #54

Earlier quoted context omitted.

Your initial assumption was correct, it is widely deployed in the industry, there are multiple vendors that provide fingerprinting technology that is orders of magnitude more advanced then what the article suggests. The visible fingerprint might just have been there to deter the clueless. In any case even with a fingerprint its hard to proof without a doubt, the individual who actually stole it.

The visible fingerprint might also be there to prove intent or add circumvention charges in court. I don't think they need to prove that a certain individual stole it. The party which received the advanced copies likely had to take on liability, so HBO can go after them. Of course, that doesn't mean they won't turn around and lean on the actual culprit, but whether or not they catch someone HBO will have their due.

It's there to advertise HBO. It's that simple.

Re: Game of Thrones leak and watermark: a stupid tracking system

#200

Post by TazeTSchnitzel »

CHY872 wrote: post #142
TazeTSchnitzel wrote: post #114

Earlier quoted context omitted.

Add a series of random names in the middle of Special Thanks. The names are in a list stored somewhere, so are actually (large base) digits of a serial number.

Trivially detectable. Find two screeners. Search for different frames. Oh look, the credits are different! Let's delete the credits to be safe! You want to make it so that the entire binary content of the film looks different for each person, so there can be no point of reference apart from what it looks like (which is the same).

Oh of course. I don't doubt something more sophisticated would be used in practice.
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