Requirements for enforcing digital rights management in multicast content distribution

In this paper, we have collected the requirements for Digital Rights Management from various sources, and presented them as a set of 11 requirements, associated with five categories. We discuss each requirement, provide the motivation for each entry, and illustrate how each one could be achieved. Four example commercial DRM systems are briefly explained, and the requirements that they meet are presented in tabular format. None of the example systems meet all the requirements that we have listed. The security threats that are faced by DRM systems are briefly discussed. All of the example systems are based on unicast data distribution. The use of multicast data distribution can help the source of the data and the underlying network to reduce their resource requirements when distributing high-quality content at minimum cost and delay. Up to now, there has been little motivation to use standard Internet Protocol multicast because it does not support any protection mechanisms for the delivered data. Given that significant progress has been made by other researchers in providing "secure" multicast data distribution, we explore how the use of secure multicast as a distribution technology can bring significant improvement for some requirements, while making the achievement of others more difficult. We review how the architecture of the distribution must change to permit capturing the advantages of multicast distribution while retaining as much as possible the features of unicast systems. Some open problems are identified.