Information and Communications Technology (ICT)] has come to stay. As a result, most of our institutions have decided to move their important files to the cloud and do online transactions – allocation of resources to reviewer, proper storage of the big data from hackers. Cloud also involves multi-mesh distributed and service oriented paradigms, multi-tenancies, multi-domains, and multi-user autonomous administrative infrastructures which are more vulnerable and prone to security risks.

Cloud computing service architecture combines three layers of inter-dependent infrastructure, platform and application; each layer may suffer from certain vulnerabilities which are introduced by different programming or configuration errors of the user or the service provider. A cloud computing system can be exposed to several threats including threats to the integrity, confidentiality and availability of its resources, data and the virtualized infrastructure which can be used as a launching pad for new attacks. The problem becomes even more critical when a cloud with massive computing power and storage capacity is abused by an insider intruder as an ill-intention party which makes cloud computing a threat against itself.

It is efficient and cost economical for consumers to use computing resources as much as they need or use services they want from Cloud Computing provider. Especially, Cloud Computing has been recently more spotlighted than other computing services because of its capacity of providing unlimited amount of resources. Moreover, consumers can use the services wherever Internet access is possible, so Cloud Computing is excellent in the aspect of accessibility. Cloud Computing systems have a lot of resources and private information, therefore they are easily threatened by attackers (Enisa, 2009). Especially, System administrators potentially can become attackers. Therefore, Cloud Computing providers must protect the systems safely against both insiders and outsiders.