Cloud computing has changed the users thought as what is believed to be their system and their data is no longer the case. Because they are not anymore specifically stored on a set of computers and disks, instead the concept of system and data has shifted to something disperse and physically distributed. In order to realize this emerging computation paradigm comprehensively, this book will looks at what cloud computing entails and based on some question that clients might ask from cloud service providers; it will cover the major security concerns and limitations in cloud computing. In addition reviews mitigating methods and solutions provided in the literature. Next, identifies and evaluates the security requirements by looking at specific service delivery models and provides detailed security measures and appropriate configurations for system components in the IT infrastructure. The work should help shed some light on this new and exciting computing paradigm, and should be especially useful to researchers and professionals in computing and networking fields, or anyone else who may be reluctant in considering utilising cloud services at enterprise or even personal level.