Protecting VoD the easier way

1. ABSTRACT Various on-demand systems require that large numbers of customers are provided with the same multimedia stream content or different but closely related content in short temporary sequence but not at exactly the same time. This includes video on demand and news on demand. A typical approach to increase the performance of such systems is caching. However in current commercial on-demand streaming applications in the Internet caches are used very rarely because a mechanism to protect the content from resale by the cache owners does not exist. A typical solution is to transfer all content via protected unicast transmissions, which is an approach that does not scale. We want to present a trivial scheme that provides similar protection for the content but be used efficiently with multicasting and caching. In this approach, the major part of the video is intentionally corrupted and can be distributed via multicast connections, while the part for reconstruction of the original is delivered to each receiver individually. We propose also means to discourage resale of the multimedia content by customers. One proposal introduces receiver-sided introduction of watermarks into the video, the other uses infrequent corrupt bytes to achieve uniqueness of each copy.