Enterprise cybersecurity empowers organizations of all sizes to defend themselves with next-generation cybersecurity programs against the escalating threat of modern targeted cyberattacks. This book presents a comprehensive framework for managing all aspects of an enterprise cybersecurity program. It enables an enterprise to architect, design, implement, and operate a coherent cybersecurity program that is seamlessly coordinated with policy, programmatics, IT life cycle, and assessment. Fail-safe cyber defense is a pipe dream. Given sufficient time, an intelligent attacker can eventually defeat defensive measures protecting an enterprise's computer systems and IT networks. To prevail, an enterprise cybersecurity program must manage risk by detecting attacks early enough and delaying them long enough that the defenders have time to respond effectively.