Privacy is becoming more and more precious in mod ern society. A viewer's T
V- watching habits may reveal information about him/her that will make the
viewer uncomfortable or cause him/her inconvenience. People should have the
right to assert their privacy about the TV-programs they are in the habit
of watching. This article will develop a practical CAS mechanism for Pay-TV
systems to secure such personal privacy in watching TV-programs. Disputes
about transactions are usually unavoidable and can endanger the life of any
business, including commercial TV systems. In order to prevent possible di
sputes or settle existing disputes, Pay-TV systems need non-repudiation ser
vices to provide some evidence-digital signatures, for example-such that a
fairer environment can be created. The conventional approaches for Pay-TV s
ystems have not provided any non-repudiation services to facilitate dispute
resolution. This article also intends to demonstrate the use of digital si
gnature techniques to make Pay-TV systems fairer than before.