4 ms·

Not very clever. Get two leaked copies, and mix them up. Use the credits from copy A, or hell, even chop off 11 milliseconds from them. Then mix and match scen

Not very clever. Get two leaked copies, and mix them up. Use the credits from copy A, or hell, even chop off 11 milliseconds from them. Then mix and match scenes... even chop off a few ms from some randomly selected scenes. I bet you wouldn't even need the two copies.

slayed0 12y ago
This assumes you know the method they are using. As the post mentioned, a few milliseconds + or - at the end of a scene would not be noticeable and the overall timestamp would still be constant if "self-compensating offsets" were used.
- TheLoneWolfling 12y ago
  You can figure out the method they are using by comparing two copies.
- bigiain 12y ago
  So how many video frames do I lop off a scene to subtract "a few milliseconds" from it?
  - NoMoreNicksLeft 12y ago
    If it's 30fps, each frame is about 33ms. One or two is sufficient. Most films are 24fps, or 23.99 for some weird NTSC->film->NTSC reason.
zapu 12y ago
Only if you knew that was already going on. Security by obscurity, but still, I don't believe this kind of watermarking was ever used. Maybe something like Cinavia[1] could be used instead? It's an analog watermarking system for detecting pirated copies and refusing to play them if player detects such copy is played on something else than bluray disc. Apparently this survives transcoding, and was/is major pain for people ripping their discs for various reasons and trying to play the files on certified players. [1] http://en.wikipedia.org/wiki/Cinavia http://en.wikipedia.org/wiki/Cinavia
- TheLoneWolfling 12y ago
  Step 1: setup an automated setup for playing video and detecting if the output was detected via the watermarking system. Step 2: Run the whole thing through an optimizer seeking to minimize error while not being detected. Step 3: Wait a few hours.
  - zapu 12y ago
    Still, we are talking about one-shot solutions for big events, like this Game of Thrones release. Obviously I can come up with anything and you would be able to present a strategy how to beat it. But that's not the point. If this kind of various copyright protections become norm, people might actually be afraid to leak stuff, because you will never know how safe it is and what kind of protection you might run into. Even after analyzing spectrogram and generally watching the media multiple times, trying to find anything weird. Well, obviously when you grab infinite number of watermarked copies, you might be able see where the irregularities are. But that's not how leaks happen.
laurencei 12y ago
That's just a suggestion. They could change the opening credits by 2ms. Or a specific scene. They could even add a single extra sword 'clang' noise in part of the audio track on one single scene. There are so many options.
- NoMoreNicksLeft 12y ago
  I'd wager $10 this was done by an intern who can barely use email correctly.
ipedrazas 12y ago
"Get two leaked copies" Not sure I understand this.
- jarman 12y ago
  Get two copies from two different sources, with different watermarks
- joncrocks 12y ago
  I think this means 'gets two copies from sources who have been given their copies legitimately'. Your job is then to make sure that those two people can't be traced/identified by the watermark on/in the video.
baq 12y ago
> Get two leaked copies this should be the biggest obstacle.
royjacobs 12y ago
Steganographic systems used for tracking screeners would have no problem identifying the two different sources you've used. They are robust against all sorts of attacks, timing changes and edits. Removing frames doesn't really affect this, since it's not doing dumb frame-by-frame matching. You'd have to degrade your audio and video to the point where they become unwatchable in order to remove the watermark. Disclaimer: I used to work for one of the companies providing these systems.

slayed0 12y ago

This assumes you know the method they are using. As the post mentioned, a few milliseconds + or - at the end of a scene would not be noticeable and the overall timestamp would still be constant if "self-compensating offsets" were used.

TheLoneWolfling 12y ago
You can figure out the method they are using by comparing two copies.
bigiain 12y ago
So how many video frames do I lop off a scene to subtract "a few milliseconds" from it?
- NoMoreNicksLeft 12y ago
  If it's 30fps, each frame is about 33ms. One or two is sufficient. Most films are 24fps, or 23.99 for some weird NTSC->film->NTSC reason.

zapu 12y ago

Only if you knew that was already going on. Security by obscurity, but still, I don't believe this kind of watermarking was ever used. Maybe something like Cinavia[1] could be used instead? It's an analog watermarking system for detecting pirated copies and refusing to play them if player detects such copy is played on something else than bluray disc. Apparently this survives transcoding, and was/is major pain for people ripping their discs for various reasons and trying to play the files on certified players. [1] http://en.wikipedia.org/wiki/Cinavia http://en.wikipedia.org/wiki/Cinavia

TheLoneWolfling 12y ago
Step 1: setup an automated setup for playing video and detecting if the output was detected via the watermarking system. Step 2: Run the whole thing through an optimizer seeking to minimize error while not being detected. Step 3: Wait a few hours.
- zapu 12y ago
  Still, we are talking about one-shot solutions for big events, like this Game of Thrones release. Obviously I can come up with anything and you would be able to present a strategy how to beat it. But that's not the point. If this kind of various copyright protections become norm, people might actually be afraid to leak stuff, because you will never know how safe it is and what kind of protection you might run into. Even after analyzing spectrogram and generally watching the media multiple times, trying to find anything weird. Well, obviously when you grab infinite number of watermarked copies, you might be able see where the irregularities are. But that's not how leaks happen.

laurencei 12y ago

That's just a suggestion. They could change the opening credits by 2ms. Or a specific scene. They could even add a single extra sword 'clang' noise in part of the audio track on one single scene. There are so many options.

NoMoreNicksLeft 12y ago
I'd wager $10 this was done by an intern who can barely use email correctly.

ipedrazas 12y ago

"Get two leaked copies" Not sure I understand this.

jarman 12y ago
Get two copies from two different sources, with different watermarks
joncrocks 12y ago
I think this means 'gets two copies from sources who have been given their copies legitimately'. Your job is then to make sure that those two people can't be traced/identified by the watermark on/in the video.

baq 12y ago

> Get two leaked copies this should be the biggest obstacle.

royjacobs 12y ago

Steganographic systems used for tracking screeners would have no problem identifying the two different sources you've used. They are robust against all sorts of attacks, timing changes and edits. Removing frames doesn't really affect this, since it's not doing dumb frame-by-frame matching. You'd have to degrade your audio and video to the point where they become unwatchable in order to remove the watermark. Disclaimer: I used to work for one of the companies providing these systems.