Since the book does not make any assumptions about the reader’s background, it is suitable for newcomers to object-oriented analysis and design & trusted operating systems. This book is good as a primer and great as a knowledge booster for those already familiar with object-oriented concepts. However, since the scope goes well beyond essentials the book is also of interest to those who already know another programming language and want to learn object-oriented approach. Readers who already know object-oriented concepts will also find the book useful because the presentation is quite different from that of other books and includes material not found elsewhere. This includes examples of conventional abstract data types, UML diagrams, use case diagrams, use case descriptions, class diagrams, sequence diagrams, code generation in C++, and the use of the security performance flexibility model of trusted operating systems. Besides, object-oriented approach for secure software development is always worth looking at from a different perspective because there is never an end to learning something new about this rich and flexible object-oriented environment.