Defense against DoS attack: PSO approach in virtualization

Cloud Computing is a catchword in today´s IT industry that nobody can escape. The technology offers reduced IT costs and provides on demand services to individual users as well as organizations over the internet. Cloud computing delivery its services through three different service models like Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). One of the important service is IaaS. IaaS provides infrastructure including software, hardware, storage space, network bandwidth to users on demand over the internet. Cloud computing relies upon virtualization to provide services. Physical characteristics of resources are hide from end users by virtualization. Cloud environment faces threats from confidentiality, integrity, and availability (CIA). But availability considered as one of the most important threat in cloud environment. The vulnerability of Denial of Service (DoS) attack can affect the availability of cloud. One form of the DoS attack is Transmission Control Protocol (TCP)-SYN flood attack. TCP SYN flood attack is an attempt to make a machine or networked resource unavailable to its intended users. The actual users of cloud can´t use the resources. It is necessary to identify the exact position when TCP-SYN flood starts. Therefore the proposed framework uses the Particle Swarm Optimization (PSO) algorithm to identify the optimized position of SYN flood attack in the traffic flow.