Cryptic movie cache

Hollywood has long seen broadband video-on-demand (VoD) as a great way to make renting movies simpler. But delivering movies on demand by satellite or online takes time and gobbles up bandwidth. CSIR, a company based in Pretoria, South Africa, has an answer (WO 03/041383). A hard-disc recorder steadily downloads digital movies by the dozen from a satellite channel, while building an on-screen index of everything stored. All the films are encrypted, so nothing can be viewed unless the viewer buys a movie from the list. The VoD service provider then sends a decryption key that unlocks the movie.