24 Oct
2016
24 Oct
'16
8:07 p.m.
Am 24.10.2016 um 18:06 schrieb Wolfgang Woehl via DCPomatic:
Note that in the Digital Cinema use case there is no
such thing as a 'NullSignature’.
Hi Wolfgang,
I was probably referring from memory to the usage of 'zero' in this passage of
this document:
(1) http://isdcf.com/papers/ISDCF-Doc5-Guideline-formulations-Interop-and-SMPTE…
'Note: Role of Certificate that Signs the KDM: The KDM shall be signed using a leaf
certificate with a SubjectName having zero to many role(s) (See SMPTE ST 430-2 for more
information about certificate roles). DCI requires the use of CPL signature in those cases
where the CPL references encrypted track files (See DCI Specification v1.2, section 5.2.3
"Packaging Concepts"). The rationale for KDM interpretation presented above
explains why this is a desirable practice. It should be noted however that DCI does not
require that a player reject a CPL that is not signed, even in the case where the CPL
references encrypted track files - except in the special case where the
ContentAuthenticator element is present in the KDM.'
- Carsten