A Secure PLAN (Extended Version)

Active Networks promise greater flexibility than current networks, but threaten safety and security by virtue of their programmability. In this paper, we describe the design and implementation of a security architecture for the active network PLANet [22]. Security is obtained with a two-level architecture that combines a functionally restricted packet language, PLAN [20], with an environment of general-purpose service routines governed by trust management [11]. In particular, we employ a technique which expands or contracts a packet’s service environment based on its level of privilege, termed namespace-based security. As an application of our security architecture, we present the design and implementation of an active-network firewall. We find that the addition of the firewall imposes an approximately 34% latency overhead and as little as a 6.7% space overhead to incoming packets.