How it works

KDM Technology

KDM Explained

Encryption of the Content

Content owners encrypt digital content in the JPEG 2000 format, which is developed specifically for the Cinema industry using unique encryption keys. In order to play the content, Cinemas require Key Delivery Messages (KDMs) which decrypt the content for playback on specific equipment and allows it to be played during the period the KDMs are valid. Furthermore – individual versions of the film can be unlocked by separate KDMs to provide control of which version is being shown at theatres.

Creation of the Key Delivery Message (KDM)

A KDM is a special kind of Digital Rights Management (DRM) component which contains the decryption key necessary to unlock the encrypted movie. It’s designed for a specific playback server, identified by a unique identifier known as the server’s public certificate. The KDM ensures that only authorized projection systems (servers) can decrypt and play the movie.
The KDM is created separately from the film, and will unlock the film only on the intended playback server. It includes rights information like the time period during which the movie can be played (start and end dates).

Key Delivery and Playback

Encrypted KDMs are sent to theatres by KDM issuing companies, preferably via secure electronic delivery using site integrations, but as the KDMs themselves are encrypted – any means of delivery is acceptable.
Once the KDM is present on the theatre’s server, the Servers private key (corresponding to the public certificate used to create the KDM)  to decrypt the KDM and retrieve the content decryption key.
The content decryption key is then used to decrypt the movie file so it can be played. The KDM ensures that the content can only be played back on the authorized projector server and within the time frame specified by the distributor, preventing unauthorized copying and viewing of the film.