An MTD-driven Hybrid Defense Method Against DDoS Based on Markov Game in Multi-controller SDN-enabled IoT Networks

The widespread deployment of low-cost, vulnerable IoT devices allows attackers to exploit them to generate botnets and launch distributed denial-of-service (DDoS) attacks, which has become a serious security challenge for ensuring quality of service (QoS). For cost-effective defense against DDoS, we propose a novel hybrid defense method that includes proactive moving target defense (MTD) and passive security control to resist DDoS threats at different stages in IoT networks in this paper. We construct a multi-stage Markov game model to portray the game as a competition between the attacker and the defender for the control duration of the attack surface, and design an optimal defense strategy algorithm. In particular, we introduce a new parameter of action execution interval expectation in the game and add node importance evaluation in the reward quantification so that the optimal action execution interval of each defense technique can be output. We also consider the possibility that advanced attackers may launch DDoS on the SDN controller in the game. The experimental results demonstrate that our proposed method can defend against DDoS cost-effectively and ensure the QoS in IoT networks with acceptable overhead.