[DCP-o-matic] Getting Doremi server key from serial number

Hi all. Apologies that this is a bit of a "noob" question and not actually related to DCP-o-matic, but Google is not my friend today it seems, and I'm sure someone here know the answer. I'm co-ordinating delivery of an encrypted DCP feature made by someone else to a cinema. The filmmakers need the server cert to make a KDM. The only information the cinema has been able to give me is "Doremi DCP-2K4 serial no. <six digit number>". Is there any online database to look up the server cert from the serial number? I really hope that this information is not proprietary. The clue that it shouldn't be is the word "public" in "public key cryptography"! Many thanks, Jim