This book addresses the question of how deep learning methods can be used to advance cyber security objectives. This book fills an important gap between Deep Learning and Cyber Security communities. The topics cover a wide range of modern and practical deep learning techniques, frameworks and development tools enabling the audience to innovate with those cutting-edge research advancement in various cyber security use cases. The book aims at preparing the readers with essential Deep Learning knowledge and tools to solve practical Cyber Security use cases. The scope is limited to mature and proven techniques with ample examples for readers to digest the core knowledge.