A movie is an artwork. Artwork can be copyrighted.
A master key is a binary INTEGER. Integers cannot be copyrighted.
Oddly, product identification codes such as ISBN numbers and UPC barcode numbers can be protected, at least in the US
you are not allowed to generate your own and claim it's UPC's or ISBN's. that could be fraud depending on xyz. might apply to GeoHot here provided Sony can successfully claim that only they have the right to generate and distribute their security keys for their products and services.
Proud Sony Rear Admiral