[Sadoun]

They are all systems of encoding:

- Viaccess was developed by France Telecom and is used in Europe by many diffusers (TPS, NTV, HRT, SRG-ssr inter alia).

- Mediaguard was developed by the SECA and is used in Europe by the Canal+ group.

- Irdeto was developed by Nethold is used by DF1, Telepiu, Stream, Nova.

- Cryptoworks was developed by Philips and is used by Wizja, Deutsche Telekom, British Telecom, Viacom.

- Betacrypt was developed by Beta DIGITAL

- Nagravision was developed by Nagra-Kudelski (Swiss) and is used by Via DIGITAL.

- Conax was developed by Telenor and is used by Canal DIGITAL on the Thor satellites.

- Powervu was developed by Scientific-Atlanta and is used for the transmissions professionels (Retevision, Bloomberg, Discovery, AFRTS).