The privacy issue has become very important more than ever with the diffusion of Cloud Computing. The large amount of data the users store at online data storage service providers make a concern about who can access and read user's information. This book presents the idea on how to protect user's data in a Desktop as a Service environment and the same concept can be extended for the Cloud Computing environment as well. The basic idea is a lightweight client-side proxy named Hedge Proxy that has been designed such that non-intelligible user contents and non-traceable user actions are guaranteed by enabling homomorphic encryption in the proxy. The book also proposes an implementation and evaluation of the Hedge Proxy based on a specific DaaS environment developed at the University of Rome and called Virtual Distro Dispatcher (VDD). Results of such evaluation are discussed and aim at assessing the performances experienced by users of VDD against the progressive privacy achievements that can be obtained.