Privacy and non-repudiation on pay-TV systems

Privacy is becoming more and more precious in modern society. A viewer's TV-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 develops a practical conditional access system (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 disputes or settle existing disputes, pay-TV systems need non-repudiation services to provide some evidence-digital signatures, for example-such that a fairer environment can be created. The conventional approaches for pay-TV systems have not provided any non-repudiation services to facilitate dispute resolution. This article also intends to demonstrate the use of digital signature techniques to make pay-TV systems fairer than before.