Encipherment and Conditional Access

This article discusses modeling conditional access in any television environment (terrestrial broadcasting, cable, and satellite). After conditional access has been defined, two models are presented that correspond to two different systems, widespread in Europe: • Distribution of control words. This model is illustrated by a proprietary system of Canal-Plus, used by about 3.5 million subscribers in France. This proprietary system is known as Discret 1. • Distribution of authorizations. This model is illustrated by an open system used by about 1 million receivers throughout Europe: Kinnevik (500,000); FilmNet (250,000); France Telecom (60,000); Canal-Plus (60,000); Polycom; Maxat; KabelKanal, and others. Known as Eurocrypt, this open system is standardized by CEN/CENELEC (Eurocrypt, EN 50 094:1992). — The emergence of digital signals technically facilitates the design of open systems, and the use of strong cryptography becomes justified. The encipherment techniques appear at three different levels: for managing entitlements (updating authorization keys and distributing access rights); for checking entitlements; and for scrambling program components. This modelization emphasizes the impact of standardization and the reserve for further evolution. The knowledge gained from existing systems allows the determination of the axes for additional developments, specifically in relation to digital television.

Print ISSN

0036-1682

Published

1994-06

Content type

Information

DOI

10.5594/J09673