Defending against Contagious Attacks on a Network with Resource Reallocation


  • Rufan Bai IoTSC, University of Macau,
  • Haoxing Lin IoTSC, University of Macau,
  • Xinyu Yang IoTSC, University of Macau,
  • Xiaowei Wu IoTSC, University of Macau,
  • Minming Li City University of Hong Kong,
  • Weijia Jia BNU(Zhuhai) & UIC,


Game Theory, Security, Games, Constraint Optimization


In classic network security games, the defender distributes defending resources to the nodes of the network, and the attacker attacks a node, with the objective to maximize the damage caused. Existing models assume that the attack at node u causes damage only at u. However, in many real-world security scenarios, the attack at a node u spreads to the neighbors of u and can cause damage at multiple nodes, e.g., for the outbreak of a virus. In this paper, we consider the network defending problem against contagious attacks. Existing works that study shared resources assume that the resource allocated to a node can be shared or duplicated between neighboring nodes. However, in real world, sharing resource naturally leads to a decrease in defending power of the source node, especially when defending against contagious attacks. To this end, we study the model in which resources allocated to a node can only be transferred to its neighboring nodes, which we refer to as a reallocation process. We show that this more general model is difficult in two aspects: (1) even for a fixed allocation of resources, we show that computing the optimal reallocation is NP-hard; (2) for the case when reallocation is not allowed, we show that computing the optimal allocation (against contagious attack) is also NP-hard. For positive results, we give a mixed integer linear program formulation for the problem and a bi-criteria approximation algorithm. Our experimental results demonstrate that the allocation and reallocation strategies our algorithm computes perform well in terms of minimizing the damage due to contagious attacks.




How to Cite

Bai, R., Lin, H., Yang, X., Wu, X., Li, M., & Jia, W. (2021). Defending against Contagious Attacks on a Network with Resource Reallocation. Proceedings of the AAAI Conference on Artificial Intelligence, 35(6), 5135-5142. Retrieved from



AAAI Technical Track on Game Theory and Economic Paradigms