IP multicast and its security

IP multicasting is the ability to send IP datagrams to a set of nodes, or a group, in such a way as to minimize the number of packets. A large body of work exists about IP multicast, both as established standards and ongoing research. Applications such as video/audio distribution are the natural users of this type of networking primitive. However, for multicast communication to be a viable solution for such applications, security services should also be available. In this chapter, we review the core concepts of IP multicast, with particular attention to addressing, routing, and group management. We illustrate the security requirements a secure multicast protocol should satisfy, including data confidentiality and secure group management. We then present an overview of key management protocols, as they are central to any security service.