Somewhat yes: Whoever wants to deliver content keys to a digital cinema server will need that server's certificate (which contains the public part of the server's key pair) and the signing chain of certificates down to its root authority from a trusted location. The higher the content's value the more trust you want to have in that location.
Wrt the DC20: Wasn't aware of the vendor, interesting. Contacted them (firstname.lastname@example.org) and asked where to get their certs. Update: techsupport writes "The DC20 certificates can be found on ftp://certificates.qubecinema.com. They are located in the SMPTE directory."
Doremi keeps server certificates at ftp://doremilabs.com/dcp2000/Certificates/ (user: service, pass: t3chn1c1an)
Wrt Dolby: Terrence had contacted Dolby about access to server certs. They'll answer inquiries sent to email@example.com. Update: Dolby writes they need site and screen info, serial and the CAT862 serial (should be a 6 digit number starting with 51).
Say, will you need KDMs from my side or are you going to run cinemaslides yourself? Content keys for the test DCP are up at https://github.com/wolfgangw/digital...0-8760d746f6a3. Anyway, see https://github.com/wolfgangw/digital...r/kdm/vincentb for your Doremi's and DC20's certificates and KDMs for the test DCP CRYPT-BLUE_TST_F_2K_20101208_WOE_OV (https://github.com/wolfgangw/digital...208_WOE_OV.zip).