I. Introduction
Cloud services offer an elastic and scalable IT task force in terms of storage space and computing capabilities which are essential to most business owners, especially small and medium sized businesses [22]. While this has fueled the large growth in Cloud services, the growing number of Cloud services make it difficult for the potential users to weigh and decide which options suit their requirements the best. There is clearly a need of an additional computing layer on top the base service provisioning to enable tasks such as discovery, mediation, and monitoring. This additional layer of computing is referred to as a brokerage system.