The SwitchWare Active Network Architecture

D. Scott Alexander, William A. Arbaugh, Michael W. Hicks, Pankaj Kakkar, Angelos D. Keromytis, Jonathan T. Moore, Carl A. Gunter, Scott M. Nettles, and Jonathan M. Smith University of Pennsylvania July 7, 1998 Abstract Active networks must balance the exibility of a programmable network infrastructure against the safety and security requirements inherent in sharing that infrastructure. Furthermore, this balance must be achieved while maintaining the usability of the network. The SwitchWare active network architecture is a novel approach to achieving this balance using three layers: active packets, which contain mobile programs that replace traditional packets; active extensions, which provide services on the network elements, and which can be dynamically loaded, and; a secure active router infrastructure, which forms a high integrity base upon which the security of the other layers depends. In addition to integrity-checking and cryptography-based authentication, security in our architecture depends heavily on veri cation techniques from programming languages, such as strong type checking.