Cost-Effective Defense Timing Selection for Moving Target Defense in Satellite Computing Systems

Lin Zhang, Yunchuan Guo, Siyuan Leng, Xiaogang Cao, Fenghua Li, Liang Fang

Abstract: Satellite computing system (SCS), with its huge economic value, is suffering from increasing attacks. Moving Target Defense (MTD) can create the asymmetric situation between attacks and defenses by changing the attack surface. As SCS’s limited defense resources, current MTD defense timing selection methods are not suitable for SCS. This paper proposes a Markov Game based Defense Timing Selection (MGDTS) approach for MTD in SCS. MGDTS formulates attack-defense adversarial relationship as a Markov game with incomplete information, and explicit costs are used to define the resource consumption of a defender. For defense timing decision, MGDTS uses a Markov decision process to construct the defense timing decision equation, and a real-time dynamic programming to solve the equation. Experimental results show that compared with other MTDs, MGDTS can improve the security of MTD while reducing its costs.