DCI Specs - Digital Cinema Initiatives

standard for Digital Cinema applications has been constrained in order to reduce thecomplexity and ambiguity that can occur in systems that use X.509 certificates.Detailed requirements for Digital Cinema Digital Certificates are given in Section 9.8.9.5.2. Robustness and Physical ImplementationsThis security system protects Digital Cinema content during transport and storage throughthe use of secret keys. Key secrecy is maintained in normal operations by cryptographictechniques dependent upon other secret keys. The physical protection afforded secret keys,and the content itself once decrypted, determine the robustness of the securityimplementation.Robustness is required for all modes of operation, both normal and abnormal. Robustness isa function of the quality of the implementation of security devices, Exhibition operationalprocedures, and the security system itself.9.5.2.1. Device Perimeter IssuesSecurity equipment design must provide physical perimeters around secrets notcryptographically protected. Secure Processing Block (SPB) security perimeterrequirements shall meet the following characteristics:• Tamper evident – Penetration of the security perimeter results in permanentalterations to the equipment that are apparent upon inspection. This is theleast robust perimeter, since it only reveals an attack after-the-fact, anddepends on a specific inspection activity.o SPB type 1 and SPB type 2 shall be tamper evident.• Tamper resistant – The security perimeter is difficult to penetratesuccessfully. Compromise of effective tamper resistant designs requires theattacker to use extreme care and/or expensive tooling to expose secretswithout physically destroying them and the surrounding perimeter(s).o SPB type 1 shall be tamper resistant, and SPB type 2 secure silicon shallbe tamper resistant.• Tamper detecting and responsive – The security perimeter and/or accessopenings are actively monitored. Penetration of the security perimetertriggers erasure of the protected secrets.o SPB type 1 shall be tamper responsive, and SPB type 2 secure siliconshall be tamper responsive.oSPB type 1 shall be permitted to have maintenance access doors orpanels, provided that their designs and tamper protections do not permitaccess (penetration) other than as specified in Section 9.5.2.3 Repair andRenewal.9.5.2.2. Physical Security of Sensitive DataSensitive data critical to the security of the Secure Processing Block (SPB) or SE (e.g.,private keys, LE/LD or content keys) is generically referred to as a Critical SecurityParameter (see Section 9.5.2.6 Critical Security Parameters and D-Cinema SecurityParameters). The security system defines levels of protection appropriate to each type ofCSP as well as plain text content. The levels of protection are described as follows:DCI Digital Cinema System Specification v.1.2 Page 135