More than a century after the first essay identifying that privacy, as a fundamental human right, was endangered by technological advances. This heightened awareness for privacy issues is mainly due to the ubiquity, the invisibility and the processing power of computation. The privacy preservation problem has a major effect on human communities, as it touches upon social, cultural, economic, and political aspects. There are strict regulations in place within many countries that impose rules for the collection, handling, and processing of personal data. Their main objective is to guarantee people the control on the flow of their personal data. We believe that there will be an increasing awareness of a fundamental need the development of technologies that can implement such policies. To that end, this book reports the results of a study that developed a three layered privacy preserving system for the use in the cloud-based ubiquitous computing. Our ambitious objective is to provide privacy protection for collaborative cloud data services, information services using relational database, and personal information usage.