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How encryption for Cinema Movies works

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Re: How encryption for Cinema Movies works

#41

Post by lern_too_spel »

kmeisthax wrote: post #12
ddtaylor wrote: post #5

How are groups getting the high quality digital dumps of some movies then?

Hollywood is stupid and eroded its own economic advantage by putting everything on streaming. This was already known, but it also makes antipiracy operations much, much harder. Ripping a stream is always going to be easier than getting any unprotected video footage out of a movie theater. The stream is in your own home, you own and can tamper with all the equipment involved in playing it, and the economics of CDNs pr…

> Hollywood is stupid and eroded its own economic advantage by putting everything on streaming.

If moving to streaming made them less money, they wouldn't have done it.

Re: How encryption for Cinema Movies works

#42

Post by tverbeure »

shmerl wrote: post #38

"Standards that have to be purchased". Someone is just trying to fleece the participants. That's what whole DRM is about most of the time.

Standards are often cheap. Many tech companies have a subscription to all IEEE papers and standards. The incremental cost of downloading one standard more is in the noise. But even if you don't have a subscription, the price for, say, the 802.11n standard is only $381.

Re: How encryption for Cinema Movies works

#43

Post by tverbeure »

jeffbee wrote: post #23

It's remarkable that they do all this in the context of box office revenues cratering. In 2024 American theaters has less gross ticket sales than they did in 1982, in constant dollars. The whole thing of movie theaters is just over.

Why does that context matter? It's not as if the use of DRM for movie theater distribution influences whether or not somebody goes to see a movie.

Re: How encryption for Cinema Movies works

#44

Post by plastic3169 »

kelnos wrote: post #37
tptacek wrote: post #29

Earlier quoted context omitted.

Most importantly, the industry concerns itself primarily with the new-release window; that high fidelity copies will eventually be widely available doesn't break the model.

I suppose this would help keep pirated copies from getting out before the theatrical release date (presumably theaters are given these digital releases at least days before their first projection date). But it seems that more and more releases are straight-to-streaming, and/or sometimes simultaneous with the theatrical release. High-quality pirated copies often show up within a day of a streaming release. Sure, many…

There are no high quality pirated versions though. The streaming version and even blu-ray is compressed way heavier than these DCP files. I’d buy these cinema versions of films in a heartbeat if they were availble.

Re: How encryption for Cinema Movies works

#45

Post by kmeisthax »

thaumasiotes wrote: post #31
kmeisthax wrote: post #12

Earlier quoted context omitted.

Hollywood is stupid and eroded its own economic advantage by putting everything on streaming. This was already known, but it also makes antipiracy operations much, much harder. Ripping a stream is always going to be easier than getting any unprotected video footage out of a movie theater. The stream is in your own home, you own and can tamper with all the equipment involved in playing it, and the economics of CDNs pr…

> Problem is, the number of people who actually have the password that unlocks the projector is really small[2] > [2] This is also why the 3D era of film made movies way too fucking dark. What is the relationship between these two things?

3D requires inserting an extra device into the image path to split the projector light into polarized halves, otherwise the 3D glasses don't work. Because of how light works, half the light is thrown away. So you either have a darker picture or you jack up the light (which, according to theater owners, means more wear on the projector's light source).

Now, in an ordinary scenario, you'd just have the projectionist remove the extra polarizing step from the image path for 2D showings. Except, remember, all of these projectors have DRM specifically to control who is allowed to put things in the image path of the projector. So now management has to be called in every time a theater needs to change over from a 2D or a 3D film.

Or you follow the path of least resistance and just leave all the 3D crap on the projectors all the time, keeping it at the same brightness for 2D (to save money on maintenance), which results in everything being darker.

Re: How encryption for Cinema Movies works

#46

Post by loeg »

plastic3169 wrote: post #44
kelnos wrote: post #37

Earlier quoted context omitted.

I suppose this would help keep pirated copies from getting out before the theatrical release date (presumably theaters are given these digital releases at least days before their first projection date). But it seems that more and more releases are straight-to-streaming, and/or sometimes simultaneous with the theatrical release. High-quality pirated copies often show up within a day of a streaming release. Sure, many…

There are no high quality pirated versions though. The streaming version and even blu-ray is compressed way heavier than these DCP files. I’d buy these cinema versions of films in a heartbeat if they were availble.

1080p/4k as encoded by the streaming sites / blu-ray is sufficiently high quality for virtually all of the viewing public. You're weird (no offense).

Re: How encryption for Cinema Movies works

#47

Post by kmeisthax »

mysteria wrote: post #20
kmeisthax wrote: post #12

Earlier quoted context omitted.

Hollywood is stupid and eroded its own economic advantage by putting everything on streaming. This was already known, but it also makes antipiracy operations much, much harder. Ripping a stream is always going to be easier than getting any unprotected video footage out of a movie theater. The stream is in your own home, you own and can tamper with all the equipment involved in playing it, and the economics of CDNs pr…

To be clear, traitor-tracing each stream would require a unique encode per account to inject the stegotext; that's computationally unfeasible. Doing one encode per movie theater would still be a struggle, but less so by three orders of magnitude. If the movie is streamed in chunks, only certain short segments would need to be reencoded to add watermark data. Alternatively it might be possible to splice in a short seg…

If you were only watermarking short sections of the video, wouldn't that make it possible to analyze the stegotext and erase it? You could have a handful of people rip the same video and then compare them, and if different sections get watermarked then you can reassemble an unwatermarked file. This also applies to splicing in short segments of watermarked video.

If you have the whole thing watermarked then all you can do to fix that is averaging; which might not even destroy the stegotext.

Audio watermarking is definitely an option; hell, there's already a DRM scheme called Cinavia that relies on watermarking[0]. If you cam a movie and play it on a Blu-Ray player, it'll actually trip this DRM scheme and, at a minimum, mute the audio or refuse to play the file. I would argue this is probably the most successful use of watermarking, at least in terms of "how much piracy does this frustrate"; but even then you can just play your cams on something else and get around it.

And this is all assuming your CDN provider offers cheap-enough edge compute to inject watermarks before the video hits the user's device. I haven't looked into this recently, but I remember early DRM schemes having very silly bypasses[1] because CDNs could only serve static files. Someone else linked to Akamai documentation about watermarking, but I have no idea how much extra that costs or how much it might complicate other parts of the setup.

[0] https://en.wikipedia.org/wiki/Cinavia

[1] e.g. Remember when someone made an iTunes Music Store client that just didn't encrypt anything, because all the encryption was done on your own device?

Re: How encryption for Cinema Movies works

#48

Post by jeffbee »

tverbeure wrote: post #43
jeffbee wrote: post #23

It's remarkable that they do all this in the context of box office revenues cratering. In 2024 American theaters has less gross ticket sales than they did in 1982, in constant dollars. The whole thing of movie theaters is just over.

Why does that context matter? It's not as if the use of DRM for movie theater distribution influences whether or not somebody goes to see a movie.

No, the other direction. Clearly the problem is that nobody wants their product, not that everyone wants to steal it.

Re: How encryption for Cinema Movies works

#49

Post by navigate8310 »

loeg wrote: post #46
plastic3169 wrote: post #44

Earlier quoted context omitted.

There are no high quality pirated versions though. The streaming version and even blu-ray is compressed way heavier than these DCP files. I’d buy these cinema versions of films in a heartbeat if they were availble.

1080p/4k as encoded by the streaming sites / blu-ray is sufficiently high quality for virtually all of the viewing public. You're weird (no offense).

There is nothing weird about it. If a single person has the resource to decrypt and manage the logistics, then obviously DCP is the intended way a director wants his audience to experience his creativity.

Re: How encryption for Cinema Movies works

#50

Post by KaiserPro »

dherls wrote: post #28

I'm confused why it's encrypted as a JPEG image per frame instead of one AES encrypted video file. Since the same AES key is used for each frame it wouldn't add any additional security imo

DCPs were designed to be jpeg200 streams with a bunch of audio streams as well.

The idea was that they wanted up to 16bit colour (per channel) lossless imagery. The encryption was (or so I recall) was an extra feature.

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