Yeah, I don’t know much about them. I’m sure modern day ones do things like expire and have great encryption and a million ways of watermarking things. 2002 though? Maybe less crazy. But I’ve never heard of someone having such a thing.
Check this out:
http://sohodigitalcinema.com/info/digital-cinema-mastering-faqs/
“A digital cinema package can be encrypted. This is an anti-piracy measure and it means the DCP can only be played back with the use of a KDM (Key Delivery Message). This is a small XML file we send to the cinema via email. It is ingested onto the Digital Cinema Server along with the DCP. The KDM will only work on the server it has been made for. It contains the time and date when the DCP can be played back and, if required, an expiry date.”