The primary role of the Digital Cinema Initiatives (DCI) specification is to establish the mechanisms that define trusted devices for the playback of first release movies. Up to now, DCI has relied on the US Federal Information Processing Standards (FIPS) 140-2 specification for the specific requirements and testing protocol of secure processing blocks, governing everything aspect of security from key generation and use to a device’s response to physical tampering.
The US National Institute of Standards and Technology (NIST) is responsible for FIPS 140-2, and for many years has openly discussed a transition to an updated version of the specification, FIPS 140-3. However, this may change. NIST is instead considering the adoption of a parallel standard, ISO/IEC 19790:2012, as recently announced below:
ISO/IEC 19790 2nd Edition was published 2012-08-15
It was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 27, IT Security techniques. ISO/IEC 19790 1st Edition was derived from NIST Federal Information Processing Standard (FIPS) PUB 140-2, Security Requirements for Cryptographic Modules.
The CMVP [Cryptographic Module Validation Program] does not validate cryptographic modules tested for conformance to ISO/IEC 19790. The CMVP is studying the adoption of this International Standard as the revision of FIPS 140-2.
In response, DCI this month issued an advisory that ISO/IEC 19790:2012 may replace the security requirements of the DCI specification now established by FIPS 140-2. Figuratively, this would be a good move for non-US manufacturers of digital cinema media blocks, as reliance on ISO would better internationalize DCI’s core security requirements. For manufacturers, however, it could be a different story, as the updated specification is expected to impose somewhat stricter rules. One of the changes that could occur is the requirement for more thorough documentation from the manufacturer regarding operation of its security modules.
If DCI were to have its way, its updated requirements, including any imposed by ISO/IEC 19790:2012, could impact all products sold in the market. DCI asks that all designs having undergone more than 4 updates be rested every 3-4 years. (Devices with 4 updates would include every media block in the market.) However, revising and retesting to updated DCI requirements is an expense that is likely to lead to a silent revolt by manufacturers. Given that DCI’s security requirements, even its older ones, are more likely to overshoot than undershoot, mandatory retesting would seem to be unnecessary. In truth, DCI places far more trust in the manufacturers of digital cinema equipment than it is willing to admit. After all, it is the security data directly supplied by manufacturers that populate the Trusted Device List (TDL) databases from which Key Delivery Messages (KDMs) are generated. (KDMs supply the keys needed to decrypt movies for playout.)
None of this means that manufacturers can sit on their laurels when it comes to revised DCI security requirements. It is the ability of the manufacturer to demonstrate that it can produce products that can be trusted that counts. In that light, ISO/IEC 19790:2012 is worth a study.
