Video watermarking/tracking on CH videos

[torachan]

If you can acquire two copies of the same file from the same source with different credentials (accounts, ip addresses, etc.), it should be easy to determine if they are being altered. Just generate and compare checksums for the two files (e.g. see https://stackoverflow.com/questions/105 ... powershell). If they match, they should be safe to use.

I doubt this will work since the videos are using completely different bitrates/fps. Also the metadata is different. :/

I kind of don't get why it'd be impossible for you to find a torrent or so of a given scene at given resolution and then downloading that same scene at same resolution from the website. That or do it the other way around.

Because even the slightest difference in anything will give a completely different hash. I doubt any of the torrents are in 100% without any modifications. Thus, the only way to do this really would be to download the same video with 2 different users, delete the metadata and then do the md5 checksum.

[rawrrawr300]

Because even the slightest difference in anything will give a completely different hash. I doubt any of the torrents are in 100% without any modifications. Thus, the only way to do this really would be to download the same video with 2 different users, delete the metadata and then do the md5 checksum.

Yes, you'd want to go the two different users route rather than comparing it to a torrent. I don't know the particulars of the service, obviously, but if it's a subscription, canceling and signing up again under an alias is an option. Or, if that isn't possible and it's prohibitively expensive to register for a second account, you could provide more information about the particular service: perhaps another Milovanian would be able to corroborate your hash.

[pl3b]

Because even the slightest difference in anything will give a completely different hash. I doubt any of the torrents are in 100% without any modifications. Thus, the only way to do this really would be to download the same video with 2 different users, delete the metadata and then do the md5 checksum.

Yeah I know how hashes work. I mean the thing is, I thought you wanted to compare whether the content alone is watermarked (you mentioned using the videos for CH which means they'll get re-encoded which means metadata is lost either way). Therefore, in my eyes, you want to do the following:
- get two copies of the same file at same resolution - one downloaded by you, one downloaded either by another user or from torrent
- strip metadata from both files
- compare the files
If they come out the same, that means the video content is not watermarked, which is what you asked for I guess. I don't see why it'd matter if the file comes from torrent or is downloaded by another user. Unless the person making a torrent decided to re-encode it, stripping metadata from both files should result in both files being the same. People posting torrents rarely re-encode anyway, all they really do (if anything) is to change the metadata, which you want to strip anyway.

From what I understand, your real question is "how much do I need to strip from the file to be safe", which all it really comes down to is getting an equal hash of files coming from two different sources.

[torachan]

Yes, you are right. My worry was just that. With torrent I cannot be sure that it hasn't been re-encoded etc. so cannot trust in the results, but by downloading the file with 2 different accounts I can be 100% sure what steps has been taken.

[hosenguy]

These are just observations of a technician and software manager level individual, me.

The intent of the watermarks on videos and such appear intent on tracing theft to the source of distribution. An example would be that Hulu gets a specific encoded mark and Netflix gets a different one. When one of those sites has a breech of content each pirated copy can be tracked to the it's source. Individuals are not intended to be the target because it is evident when an individual has a copy that is not legit in other ways. It always has been. The intent is to track the large volume of copies and verify them to a specific leaked source. (As I interpret the Pallycon website posted before.)

This also means that if you use a clip in a CH, and it pisses off a porn producer, they could find evidence how far your production has spread. So the danger is there but not much more than it always has been.

So you go on Ebay or Craigslist and buy a laptop with operating system and never use it from your IP. Set in some parking lot and use a free access internet. Set up a free and secret account on Gmail. Use that to join some sites via debit cards. Download what is needed. Make your CH and use the secret laptop to upload somewhere from an unknown location. If the CH is really good and it is caught in a copyright net, of all the people that downloaded it you will be the only one that cannot be caught!

[torachan]

These are just observations of a technician and software manager level individual, me.

The intent of the watermarks on videos and such appear intent on tracing theft to the source of distribution. An example would be that Hulu gets a specific encoded mark and Netflix gets a different one. When one of those sites has a breech of content each pirated copy can be tracked to the it's source. Individuals are not intended to be the target because it is evident when an individual has a copy that is not legit in other ways. It always has been. The intent is to track the large volume of copies and verify them to a specific leaked source. (As I interpret the Pallycon website posted before.)

This also means that if you use a clip in a CH, and it pisses off a porn producer, they could find evidence how far your production has spread. So the danger is there but not much more than it always has been.

So you go on Ebay or Craigslist and buy a laptop with operating system and never use it from your IP. Set in some parking lot and use a free access internet. Set up a free and secret account on Gmail. Use that to join some sites via debit cards. Download what is needed. Make your CH and use the secret laptop to upload somewhere from an unknown location. If the CH is really good and it is caught in a copyright net, of all the people that downloaded it you will be the only one that cannot be caught!

Thanks for the input! Yes this is also what I think they do. But there is always a possibility that they user your userID and other information to generate a unique encrypted ID, which they will then watermark to the video. They could then in turn, if video was caught, run the decryption software on the video to get the userID. File a copyright infringement lawsuit to through the payment provider to get my information. Puf, anonymity lost.

But as you said. I doubt this is the case. They would need some futuristic quantum computer to process the video fast enough to encode some watermark there while downloading.

But paranoia is real man. What if I made a mistake, what if they do have something :D Can't lose my night's sleep over this

[pl3b]

Thanks for the input! Yes this is also what I think they do. But there is always a possibility that they user your userID and other information to generate a unique encrypted ID, which they will then watermark to the video. They could then in turn, if video was caught, run the decryption software on the video to get the userID. File a copyright infringement lawsuit to through the payment provider to get my information. Puf, anonymity lost.

But as you said. I doubt this is the case. They would need some futuristic quantum computer to process the video fast enough to encode some watermark there while downloading.

But paranoia is real man. What if I made a mistake, what if they do have something :D Can't lose my night's sleep over this

It's funny because I do quite a bit of security-related things as part of my every-day job and I don't see how going through my process above would leave you exposed. Again, if you get the same file from two different sources - one downloaded by you, another downloaded by someone else - then remove metadata and then compare them and you get the same result -> there's absolutely no way to trace given file back to you as there's no data in the file left that identifies you exactly.

What you're probably trying to refer to is steganography, which is indeed about hiding data inside the contents of an image. There are MANY possible ways to achieve this - for example something simpliest but also easiest to understand would be to set 0 for least significant bit for each color in each pixel, then storing 3 bits of information per-pixel, let's say in first X pixels every 10000th frame of the video. That's a quite a bit of data that you can hide this way and the change of the image is so minimal that nobody is ever going to notice. I'm not saying that anybody does this, just trying to give an example. Either way, no matter which method you use, they all result in content being modified and therefore each file being different, even after you remove its metadata. Therefore again, remove metadata from files from two sources and compare.