ALTHOUGH SKY will never discuss security loopholes patents recently filed by NDS (the sister company that provides Sky's conditional access system) reveal that research done by the NDS laboratory in Israel shows a trick known as the McCormack hack to be a "more serious treat than previously supposed" hence the new cards. Swapping over six million cars is a very expensive move judged necessary to prevent the new hack attacks that Sky clearly expects.
McCormac points out that every smartcard-based system in operation is currently wide open to this kind of hack. If you put the ADSL nets into the equation, it is trivial to defeat any PPV/CA/DRM system in real time.
What Satellite & Digital TV, September 2003, p15
John McCormac is Hackwatch.