Pay television system using a memory card in association with a decoder
CA 2028248 C · Owner: Kudelski, Andre · Inventors: Kudelski, Andre
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
According to the invention, on the emitter side a number generator (10) delivers a random code (XAL) which is sent to the input of a master card (11) which ciphers such code according to a predetermined key (100) the code thus ciphered is broadcast with the video signal a first device (17) receives on the one hand the random code (XA) and on the other hand the code ciphered by the master card (11) and effects a predetermined numerical combination of these two codes such combination forming the initialization word of a pseudo-random generator (12) intended to provide a table of codes for scrambling the video signal and on the receiver side, the ciphered code received is deciphered by a …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed February 21, 1990 and granted February 13, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 21, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 21, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.