Abstract
A digital home network is a cluster of digital audio/visual (A/V) devices including set-top boxes, TVs, VCRs,
DVD players, and general-purpose computing devices such as personal computers. The network may receive
copyrighted digital multimedia content from a number of sources. This content may be broadcast via satellite or
terrestrial systems, transmitted by cable operators, or made available as prepackaged media (e.g., a digital tape
or a digital video disc). Before releasing their content for distribution, the content owners may require
protection by specifying access conditions. Once the content is delivered to the consumer, it moves across
home the network until it reaches its destination where it is stored or displayed. A copy protection system is
needed to prevent unauthorized access to bit streams in transmission from one A/V device to another or while it
is in storage on magnetic or optical media. Recently, two fundamental groups of technologies, encryption and
watermarking, have been identified for protecting copyrighted digital multimedia content. This paper is an
overview of the work done for protecting content owners