Access control is one of the fundamental services that any Data Management System should provide. Its main goal is to protect data from unauthorized read and write operations. This is particularly crucial in today's open and interconnected world, where each kind of information can be easily made available to a huge user population, and where a damage or misuse of data may have unpredictable consequences that go beyond the boundaries where data reside or have been generated. This book provides an overview of the various developments in access control for data management systems. Discretionary, mandatory, and role-based access control will be discussed, by surveying the most relevant proposals and analyzing the benefits and drawbacks of each paradigm in view of the requirements of different application domains. Access control mechanisms provided by commercial Data Management Systems are presented and discussed. Finally, the last part of the book is devoted to discussion of some of the most challenging and innovative research trends in the area of access control, such as those related to the Web 2.0 revolution or to the Database as a Service paradigm. This book is a valuable reference for an heterogeneous audience. It can be used as either an extended survey for people who are interested in access control or as a reference book for senior undergraduate or graduate courses in data security with a special focus on access control. It is also useful for technologists, researchers, managers, and developers who want to know more about access control and related emerging trends.