VideoGuard
VideoGuard, produced by
NDS, is a digital
encryption system for use with
conditional access television broadcasting. It is used almost exclusively on digital
satellite television () systems operated by
News Corporation, which owns the majority of NDS. Its most widely used implementation is
BSkyB's
Sky Digital (popular in Britain and Ireland) which adopted the system in
1998. Several other broadcasters around the world use the VideoGuard system, including:
Viasat (Scandinavia),
Sky Italia, and
Foxtel (Australia).
Since the majority of content provided by companies like BSkyB requires subscription, VideoGuard protects that content by encrypting both standard subscription channels and
pay-per-view movies and events. Access flags can be downloaded to the subscriber's card either over the air (via 'hidden' channels) or by using the
box's built in
modem, thereby allowing rapid changing of channel packages and ordering of events.
The VideoGuard system was introduced by News Corporation to replace the analogue
VideoCrypt system. To date, the current encryption method has yet to be broken, even to an extent where successful cloning of cards is possible. It is suspected that the version initially used by Sky Digital was either insecure or close to being broken, as a software update rolled out to all boxes required replacement of the BSkyB subscriber's viewing card.
Despite being designed to protect pay-TV, VideoGuard is used by BSkyB to encrypt
Channel 4, and
Five (To prevent these channels being viewed outside the UK for copyright reasons). These channels are
free-to-air in the UK, either using analogue PAL or digital terrestrial () receivers, and can also be viewed using any working VideoGuard card from the correct area, even if expired. Until November 2005, all of
ITV's channels were also encrypted using VideoGuard, but switched to becoming unencrypted like the
BBC's channels. All these channels can also be viewed using the popular
FreeSat scheme which, due to the easy availability of cheap cards, potentially increases the risk of VideoGuard becoming cracked through experimentation.
Unlike many other satellite broadcasters, News Corporation's encrypted output can only be viewed using a designated Set-Top Box (STB) in which VideoGuard is embedded into the circuitry. Due to News Corporation's control of VideoGuard, it is impossible to get a licenced VideoGuard
Conditional Access Module (CAM) for a third-party STB, or to obtain VideoGuard routines for a software CAM. This is seen by many as an example of
vendor lock-in, often to protect NewsCorp's preferred suppliers of boxes, eg
PACE. In contrast, CAMs and even software CAMs are available for all other encryption systems, including
Irdeto,
Nagravision and
Viaccess. The CAM monopoly may be broken due to
Italian inter-operability laws, which are forcing
Sky Italia to allow other boxes read their cards for legally acquired services.
As of 2005, one maker of hardware has managed to reverse-engineer VideoGuard to the point where a legitimate subscriber's card can be used in a generic STB with upgraded
firmware to decrypt only those channels that subscriber is authorised to view. A software CAM emulator for the
DreamBox Linux-powered satellite receiver can also do the same. However, many broadcasters choose to
pair their cards to a specific STB serial number, meaning that a paired (also called "married") card can only be used in a broadcaster-supplied STB, or by using the serial number from said receiver with one of the reverse-engineered solutions.
*
BSkyB*
DirecTV*
Foxtel*
Sky Italia*
Yes DBS*
HOT*
Viasat*
IndovisionLink to NDS website with more technical and business information on VideoGuard [
1].
