This text is a clearly-written guide to building secure distributed applications with CORBA. It helps securing CORBA applications, integrating security infrastructure with CORBA applications, and evaluating the security effectiveness of distributed applications. The book provides a comprehensive study of the CORBA security architecture, allowing for a better understanding of its goals and limitations. It is designed to serve as a complete reference for understanding security in distributed systems. The book also illustrates the usage of the MICOSec CORBA security services implementation, including important information on the installation and configuration of MICOSec, the usage of two different kinds of application-facing interfaces, and the configuration of CORBA security for applications that do not contain any security-related modifications.