Modeling and Analysis for Thwarting Worm Propagation in Email Networks

Email worm has long been a critical but intractable threat to Internet users. In this paper, we propose an analytical model to present the propagation dynamics of email worms using difference equations. Based on this model, we further investigate the quarantine conditions for the number of infected users decreasing as soon as possible. In this field, previous works have found that a static threshold for worms fast dying out does not exist. In our work, we extend the modeling with dynamical quarantine processes to see if the previous viewpoint is still supported or not. By contrast, the results suggest that it is possible to have a sharp decline in the number of infected users within a short period of time. In the experiments, we implement both the empirical and theoretical methods to support our analysis. The work of this paper can provide practical values on protecting email networks.