The document discusses Conditional Access (CA) systems, which use scrambling and encryption to prevent unauthorized access to digital content. It outlines their functionality, applications in pay-per-view and service restriction, as well as advantages such as seamless operation and protecting purchased content. Additionally, it provides models to help understand and evaluate CA systems for future digital video broadcasting services.

1. www.oeclib.in
Submitted By:
Odisha Electronic Control Library
Seminar
On
Conditional Access System

2. Conditional Access System

3. Index
• Introduction
• Functional requirements of a CA system
• Fundamentals Of CAS
• How Conditional Access Systems Work
• Applications
• Advantages
• Conclusions and recommendations
• References

4. Introduction
• A conditional access (CA) system comprises a
combination of scrambling and encryption to
prevent unauthorized reception.
• Scrambling is the process of rendering the
sound, pictures and data unintelligible.

5. Functional requirements of a CA
system
• Payment schemes:
• Multiple-decoder households:
 Sharing of the CA system
 Receivers/decoders
 Delivery system
 CA Systems

6. Fundamentals Of CAS
• A conditional access system comprises a combination
of scrambling and encryption to prevent
unauthorized reception.
• Encryption is the process of protecting the secret
keys that are transmitted with a scrambled signal to
enable the descrambler to work.

7. How Conditional Access Systems Work

8. Applications
• While Conditional Access Systems are
commonly used for Pay-Per-View applications,
they are also often used to restrict Internet
and telephone services from subscribers who
have not purchased them.
• For example, while data is constantly being
passed through a coaxial cable provided by a
cable company, the data is encrypted in order
to prevent it from reaching the user’s modem.

9. Advantages
• Conditional Access Systems are advantageous
because they are able to prevent
unauthorized users from accessing data they
have not purchased without interfering with
subscribers who have purchased service.
• Conditional Access Systems are also
advantageous because they are seamless and
work without the user’s knowledge.

10. Conclusions and recommendations
• A basic set of transactional and functional
models of CA systems for use with digital
video broadcasting systems has been outlined.
• These models are intended to help EBU
Members to understand and evaluate
practical CA systems for use with future DVB
services and, in particular, to understand the
functionality, technical terms, and trade-offs
in these systems.

11. References
• www.google.com
• www.wikipedia.org
• www.oeclib.in

12. THANKS