The desire for exible networking services has given rise to the concept of active networks." Active networks provide a general framework for designing and implementing network-embedded services, typically by means of a programmable network infrastructure. A programmable network infrastructure creates signi cant new challenges for securing the network infrastructure. This paper begins with an overview of active networking. It then moves to security issues, beginning with a threat model for active networking, moving through an enumeration of the challenges for system designers, and ending with a survey of approaches for meeting those challenges. The Secure Active Networking Environment SANE realizes many of these approaches; an implementation exists and provides acceptable performance for even the most aggressive active networking proposals such as active packets sometimes called capsules". We close the paper with a discussion of open problems and an attempt to prioritize t...
D. Scott Alexander, William A. Arbaugh, Angelos D.