Security in Multi-UAV Networks Figure 3. Moves of attacker and defender in the proposed game. Table 1. (a) Computation of ROI, (b) ROA, and (c) RPN. matrix for the formulated attack-defense game is constituted. Furthermore, RPN values corresponding to each leaf node of the attack- defense tree model is computed in Table 1(c). The attack that is most likely to occur can be easily determined by performing the preemptive evaluation of the network using this measure. 40 CONCLUSION A tree-based attack-defense model in a multi-UAV environment is presented is this paper. In this model, a game-theoretic scheme is designed to analyze the impact of ROI and ROA on attacker and defender moves. An RPN-based assessment is used to calculate the level of risk associated with each attack. After analyzing IEEE Consumer Electronics Magazine