I can imagine some cypherpunks in this sci-fi world creating a crypto-system where the keying data is sent as media files (possibly requiring a new movie studio

I can imagine some cypherpunks in this sci-fi world creating a crypto-system where the keying data is sent as media files (possibly requiring a new movie studio to be created as a cover story). Unfortunately I can also imagine that the NSA give themselves backdoors that can even get past the legally-mandated DRM, and the media industries would accept this.