Nowadays, the notion of virtualization infrastructures is making significant headway in the computing landscape. The business-push to these infrastructures stemming from the Cloud computing paradigm resulted in a more sophisticated concept of rent-a-technology that enabled a series of new-networked business models. This emerging digital globalization has not only raised the legal stakes and ownership concerns ; but also highlight the need of providing effective security solutions. These security solutions should be able to scale the application requirements without undue performance and quality overheads to ensure security and privacy of data in the federated Cloud deployments. This paper presents a formal way of testing the impact of scalability and heterogeneity on the federated Cloud security services. The work presented in this paper aims to develop a mean of quantifying the impact on security functions under various operating conditions and parameters of federated Cloud deployments. The results of this work will help businesses to identify the best security architecture that will fit their Cloud architectures and performance requirements.