Comment They really put a lot of thought into the security (Score 5, Interesting) 124
I actually had a chance to meet with Walt Ordway, the head of DCI's technology branch, at my school a few years ago (he's a Northeastern University Alumnus). He gave a really nice presentation about what they're doing to secure the distribution masters and minimize piracy. Basically, they have a Digital Source Master (DCM) which is a final cut of the movie in a high definition format taken directly from post-processing. From this, they make various distribution masters in different formats for DVD, TV, Airline showings, and also conversion to film masters. One of the masters they make is a Digital Cinema Distribution Master. After processing, this is what is actually sent to the cinemas.
After all the video, audio, subtitle, and auxiliary data channels (things like cues for curtains, theater lighting, etc.) are compressed and packaged, it's encrypted via AES with a 128-bit key. Along with the compression and encryption process, a watermark is embedded into the video source. The Digital Cinema Package (DCP), as it is now called, is delivered to the theater via satellite uplink, hard drive delivery, internet, etc. However, the encryption key is delivered separately, via secure courier, and each theater will get a different key. The DCP is uploaded into a central server in the theater, where it will then be scheduled by the manager to be loaded into a specific screen on a set schedule. Each screen will have a digital projector along with its own server to store a local copy of the DCP.
Key entry and decryption only actually happens when the movie is played, and as everything is decrypted, the forensic watermark is added to the video as well as the audio. This watermark is unique not only to the theater, but to the specific projector and even the time that it was played. This ensures that if anyone is sitting in a theater with a camcorder, they can trace it back to the exact showing using the embedded watermarks.
If anyone is interested in checking out the Digital Cinema System Specifications, they were awarded final approval on July 20, 2005 and can be found at http://www.dcimovies.com/DCI_Digital_Cinema_System _Spec_v1.pdf
After all the video, audio, subtitle, and auxiliary data channels (things like cues for curtains, theater lighting, etc.) are compressed and packaged, it's encrypted via AES with a 128-bit key. Along with the compression and encryption process, a watermark is embedded into the video source. The Digital Cinema Package (DCP), as it is now called, is delivered to the theater via satellite uplink, hard drive delivery, internet, etc. However, the encryption key is delivered separately, via secure courier, and each theater will get a different key. The DCP is uploaded into a central server in the theater, where it will then be scheduled by the manager to be loaded into a specific screen on a set schedule. Each screen will have a digital projector along with its own server to store a local copy of the DCP.
Key entry and decryption only actually happens when the movie is played, and as everything is decrypted, the forensic watermark is added to the video as well as the audio. This watermark is unique not only to the theater, but to the specific projector and even the time that it was played. This ensures that if anyone is sitting in a theater with a camcorder, they can trace it back to the exact showing using the embedded watermarks.
If anyone is interested in checking out the Digital Cinema System Specifications, they were awarded final approval on July 20, 2005 and can be found at http://www.dcimovies.com/DCI_Digital_Cinema_Syste
