Cloud computing moves computing and data away from desktop and mobile devices into large data center distributed around the world. As a result, this will create a need for a considerable risk assessment approach to manage the various types of risks. Risk assessment is a concept that has developed to the point where it has the potential to address current limitations in cloud computing assessment methodologies. The novelty of this book comes from the use of machine learning technique as a novel and efficient technique to assess risk in cloud computing environment. To build the model; first data mining algorithms are applied, then the ensemble method is used to combine the outputs of the data mining algorithms. The results of this research demonstrate the strengths of the use of data mining algorithms to assess risks, and it indicates that the methodology of using ensemble of machine learning algorithm represent a valuable alternative to existing methodologies.