DCI Specs - Digital Cinema Initiatives

each key will be part of the normal engagement negotiation between Exhibition andDistribution. The Security Manager will authenticate the identity and integrity of theauditorium security equipment for each showing, and thereafter enable the use of theappropriate keys during the authorized play window.9.3.3. Security Messaging and Security EntitiesThe security system described herein implements a standardized open architecture in whichequipment used at exhibition facilities can be sourced from multiple, competing suppliers. Inorder to achieve interoperable security operation, the security system design for Exhibition,specifies a standard message set for interoperable communications between standardizedsecurity devices.9.3.3.1. Security MessagesThere are two classes of messages in the architecture:• Extra-theater Messages (ETM) – These are self-contained one-waymessages that move Security Data and information outside or within thetheater. These specifications have defined a fundamental message structurefor a generic ETM, the requirements for which are normative and given inSection 9.8• Intra-theater Message (ITM) – Messages that move security informationwithin the auditorium over a real-time two-way channel. Requirements for theITM infrastructure are given in Section 9.4.5 Intra-Theater Communications.Figure 14: shows typical locations of SM functions 14 , ETM 15 and ITM messageinterfaces. ETM message types are labeled with a black 1 and ITM messages with ared 2.14 There may be various types of SM functions. These specifications are focused on the auditorium SM and its securitymanagement roles. SM functional and behavioral requirements are specified in Section 9.4.3 Theater Security Operations15 The KDM is a type of ETM, and its creation location may vary. The KDM is normatively specified in Section 9.8DCI Digital Cinema System Specification v.1.2 Page 95