Abstract: Aiming at the situation of lacking research on Distributed Denial of Service (DDoS) attack under multi-clouds environment,a user behavior analysis model based on game theory under multi-clouds environment was proposed from the perspective of cloud service provider．The model firstly constructs a payoff matrix based on game theory,and then it judges user behavior through fuzzy membership function,and evaluates the resource consumption and profit of cloud service provider under non-cooperation and cooperation scenarios．Simulations show that the proposed cooperation model can reduce resource consumption,lower the risk of DDoS attack for cloud service providers,and prompt the profit of each resource unit for more than three times,which takes an effective significance.

Key words: Cloud computing,Multi-clouds,Fuzzy membership function,Game theory,Cooperation