4 ms·

I'm no expert on DCP or encryption. But from what I've read DCP uses AES 128, they probably didn't crack that. But also each projector gets its own unique key t

by rblatz 10y ago

I'm no expert on DCP or encryption. But from what I've read DCP uses AES 128, they probably didn't crack that. But also each projector gets its own unique key to decode the movie. Which I assume is somehow combined with the key in the projector to create the real decryption key. So my first guess is that they had the ability to snoop on multiple key exchange messages and some how used that knowledge to find a shortcut to solve AES based on the gleaned knowledge from all the gathered keys, or they broke into a projector and took its internal key.

wmf 10y ago
It sounds like no projectors are involved here.
- sprocket35 10y ago
  Some of the projectors are connected to the DCP playback server via encrypted HD-SDI. The content is link-encrypted between the server and projector using Texas Instrument's "Cinelink" technology. If the TI "Enigma" module's private key was leaked, this would enable recording the plaintext SMPTE 292M video stream in real-time. The audio is un-encrypted obviously and easy to record, but it is watermarked so they would be able to trace back the recording to a specific KDM.
  - wyager 10y ago
    Jesus, they put so much effort into "encrypting" this data when it fundamentally needs to be available in a decrypted format for the users to watch it. At the end of the day, there's always the analog hole (or, more likely, the digital hole between the rendering chip and the MEMS array or LCD or whatever other mechanism lives inside the projector). No matter how many convoluted layers of encryption they throw at these things, there's always somewhere you can stick a camera or a few high-bandwidth digital signal analyzers and recover the content with at worst slightly degraded quality.
    - sprocket35 10y ago
      DCP isn't a consumer format (yet), it's only intended to protect the movie before it comes out on Bluray. And the encryption isn't convoluted at all, the private/public key system is essentially the same as what protects your information when you log into your bank's website.
    - aaron695 10y ago
      > there's always somewhere you can stick a camera or a few high-bandwidth digital signal analyzers and recover the content with at worst slightly degraded quality And hence you have a safer product? The exact thing they are trying for? The objective is to slow down pirate release. Seems to be working exactly as planned.

by rblatz 10y ago

wmf 10y ago

It sounds like no projectors are involved here.

sprocket35 10y ago
Some of the projectors are connected to the DCP playback server via encrypted HD-SDI. The content is link-encrypted between the server and projector using Texas Instrument's "Cinelink" technology. If the TI "Enigma" module's private key was leaked, this would enable recording the plaintext SMPTE 292M video stream in real-time. The audio is un-encrypted obviously and easy to record, but it is watermarked so they would be able to trace back the recording to a specific KDM.
- wyager 10y ago
  Jesus, they put so much effort into "encrypting" this data when it fundamentally needs to be available in a decrypted format for the users to watch it. At the end of the day, there's always the analog hole (or, more likely, the digital hole between the rendering chip and the MEMS array or LCD or whatever other mechanism lives inside the projector). No matter how many convoluted layers of encryption they throw at these things, there's always somewhere you can stick a camera or a few high-bandwidth digital signal analyzers and recover the content with at worst slightly degraded quality.
  - sprocket35 10y ago
    DCP isn't a consumer format (yet), it's only intended to protect the movie before it comes out on Bluray. And the encryption isn't convoluted at all, the private/public key system is essentially the same as what protects your information when you log into your bank's website.
  - aaron695 10y ago
    > there's always somewhere you can stick a camera or a few high-bandwidth digital signal analyzers and recover the content with at worst slightly degraded quality And hence you have a safer product? The exact thing they are trying for? The objective is to slow down pirate release. Seems to be working exactly as planned.