A Review of Intrusion Detection Systems in Cloud Computing

Introduction

Cloud computing (CC) is rapidly growing computational model in today’s IT world. It delivers convenient, on-demand network access to a shared pool of configurable computing resources (e.g. Networks, servers, storage, applications, etc.), “as service” on the Internet for satisfying computing demand of users (National Institute of Standards and Technology [NIST], 2011). It has three basic abstraction layers i.e. system layer (which is a virtual machine abstraction of a server), the platform layer (a virtualized operating system of a server) and application layer (that includes web applications). The characteristics of CC include:

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  Virtual: Physical location and underlying infrastructure details are transparent to users.

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  Scalable: Able to break complex workloads into pieces to be served across an incrementally expandable infrastructure.

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  Efficient: Services Oriented Architecture for dynamic provisioning of shared compute resources. (Bakshi & Dujodwala, 2010).

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  Flexible: Can serve a variety of workload types (consumer and commercial).

Cloud computing has also three service models namely Platform as a Service (PaaS), Infrastructure as a Service (IaaS) and Software as a Service (SaaS) models. IaaS model delivers services to users by maintaining large infrastructures like hosting servers, managing networks and other resources for clients. In PaaS, it offers development and deployment tools, languages and APIs used to build, deploy and run applications in the cloud, and in SaaS, systems offer complete online applications that can be directly executed by their users, making them worry free of installing and running software services on its own machines.