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.