Scalable multicast security with dynamic recipient groups

Abstract

In this article we propose a new framework for multicast security based on distributed computation of security transforms by intermediate nodes. The involvement of intermediate nodes in the security process causes a new type of dependency between group membership and the topology of the multicast network. Thanks to this dependency, the containment of security exposures in large multicast groups is ensured. The framework also ensures both the scalability for large dynamic groups and the security of individual members. Two different key distribution protocols complying with the framework are introduced: an extension of the EIGamal encryption scheme, and one based on a multiexponent version of RSA.