Abstract
Cooperative computation among peer mobile devices via device-to-device (D2D) links, a.k.a. D2D offloading, is a promising technology to enhance mobile computing performance and reduce core wireless network traffic. However, D2D offloading also creates new security risks as malware can relatively easily compromise mobile devices participating in D2D offloading and propagate across the entire network. In this article, we build an epidemic model to understand the malware propagation process in the D2D offloading-enabled mobile network where devices have heterogeneous computation demand and new devices can enter the system over time. This model also allows mobile devices to intentionally enter a "non-cooperative" state as a preventive defense strategy to thwart malware propagation. We prove a thresholding result of the malware propagation similar to that in classic epidemic models under given static defender (i.e. the network operator) and attacker strategies. We further model the strategic interaction between the defender and the attacker as a zero-sum differential game. The existence of a saddle-point equilibrium is proved, and the optimal dynamic defense and attack strategies are derived based on the Pontryagin's maximum principle, which are proven to be a bang-bang control strategy. Simulation results validate the proposed model and show that the dynamic optimal strategies significantly improve the system utility compared with baseline strategies.
