Cloud computing is a thriving technology that most organizations here in Kenya are considering for adoption as a cost effective strategy for managing IT. However, organizations also still consider the technology to be associated with many business risks that are not yet resolved. In this era of cloud computing where all the software, platform and infrastructure are virtualised and provided as services typically exploited using pay-per-use model, the data and processes are maintained by some third party vendors and hence the control is lost. Internet is the communication channel for cloud computing which is open to everyone. If weak points are identified by attackers, it could be exploited to a great extent. Hence it is the tempting target for cyber crime. Most of the companies would like to embrace cloud computing services due to the huge cost savings it provides. But they are taken aback due to one main reason "Security". It is against this backdrop therefore that this book was written to critically analyse the security concerns Software as a Service (SaaS), Platform as a Service (PaaS) and Infrastructure as a Service (IaaS) with their respective deployment models.