There are STB for viewing only uncoded channel (Free to Air — FTA), as well as with the support of different conditional access systems (CAS). Rather a great amount of such systems are currently represented on the market of digital broadcasting. The most popular among them are VIACCESS, IRDETO, CONAX, MEDIAGUARD and NAGRAVISION. Regional conditional access systems are worth noticing as well. They have become widely used in the CIS: CryptOn, DVCrypt, NordE, MSA, DRE.
For most end users of digital telecommunications systems, CAS embodied in the form of smart cards or CAM-modules (Conditional Access Module), which are inserted into the appropriate STB slot and allow the user to access a variety of information services: TV channels, radio, Internet resources, teleconferences, "video on demand" (VoD), etc.
Promwad’s engineers use two different technologies for a conditional access implementation in STB: