NIS08-5: Effectiveness of Rate Control in Slowing Down Worm Epidemics

Rate control is an automated defense to slow down a worm outbreak to buy time for conventional defenses to take effect. In this study, we apply the community of households model from biological epidemiology to evaluate rate control strategies. We find that rate throttling of outbound worm traffic, implemented in the network or hosts, can be effective in slowing down a new worm outbreak given sufficient coverage of hosts. An outbreak is slowed down exponentially as the fraction of protected hosts is increased. We also find that throttling both inbound and outbound traffic can be much more effective than rate throttling only outbound traffic.