TV/COM, based in the Netherlands, obtained a patent in 1981 for
means of encrypting broadcast transmissions. Encryption is used by
digital broadcasters to prevent free access to pay-per-view
programmes.
According to Silicon.com, TV/COM is trying to secure licensing
deals with ONDigital, Telewest and viewer access software
suppliers, failing which the company will look to the courts to
enforce the patent. TV/COM is owned by a rival company to the
software suppliers in question, CanalPlus and Nagra Kudelski.
What is not yet clear is how much longer the patent will be in
force. A patent right normally exists for a maximum of 20 years in
Europe and this period is measured not from the grant of the patent
itself but from the date on which the application is filed, which
can be over four years earlier.
