This book presents techniques and security challenges of chaotic systems and their use in cybersecurity. It presents the state-of-the-art and the latest discoveries in the field of chaotic systems and methods and proposes new models, practical solutions, and technological advances related to  new chaotic dynamical systems. The book can be used as part of the bibliography of the following courses:- Cybersecurity - Cryptography- Networks and Communications Security- Nonlinear Circuits - Nonlinear Systems and Applications