Efficient Kerberized Multicast in a Practical Distributed Setting

Abstract

Many of today's distributed applications are based on group communication. Given the openness of today's networks, communication among group members must be secure and, at the same time, efficient. In this paper we consider a realistic distributed setting modeling general networks, including the Internet, that suggests the use of Kerberos, and, more specifically, a distributed mode of operation of Kerberos, called corssrealm authentication protocol, as a desirable choice for distributed applications. We design an efficient protocol for secure group communication via multicast, using Kerberos. While developing the main components of our protocol, we construct an efficient paradigm for crossrealm authentication protocols that decreases communication over the Internet, makes most operations local, and reduces the workload of the involved components. We also design extensions of single-center multicast encryption schemes to multiple-center schemes. Our main protocol is obtained by combining these two contributions.