This book provides a high-level discussion on the roles and responsibilities of a CISO or an equivalent authority that is in-charge of protecting the confidentiality of information in a typical organization. It supplies the knowledge base and experience required for a CISO. It includes several case studies developed based on real-world experiences of CISOs. For an incumbent or an aspiring CISO, the book includes the necessary training material. For an experienced CISO, this book serves as a guide for best practices in the industry.