Summary: | 碩士 === 臺灣大學 === 資訊管理學研究所 === 96 === As the popularity of networks is increasing, network attack events occur frequently, especially Distributed Denial-of-Service (DDoS) attacks. Upon such attacks, system resources are dramatically consumed and the Quality-of-Service (QoS) perceived by users significantly degrades. In order to achieve the objective of “continuity of services”, it is then essential that a network be well designed by spare resource allocation so as to maintain acceptable QoS levels upon such attacks.
In this thesis, the problem of defense against intelligent DDoS attacks by routing and budget allocation (RB) under QoS constraints is considered. This problem is formulated as a max-min integer programming problem, where the inner (minimization) problem is for network administrators to determine the minimum amount of defense budget required and effective internal routing policies so as to defend the network against a given pattern of DDoS attacks under given QoS requirements, while the outer (maximization) problem is for network administrators to evaluate the worst-case defense resource required when attacks adjust the patterns of DDoS attack flows (AF) under a fixed total attack power. A Lagrangean relaxation-based algorithm is proposed to solve the inner problem, while a subgradient-based algorithm is proposed to solve the outer problem. It is expected that efficient and effective algorithms be developed accordingly.
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