This book provides a look into the future of hardware and microelectronics security, with an emphasis on potential directions in security-aware design, security verification and validation, building trusted execution environments, and physical assurance. The book emphasizes some critical questions that must be answered in the domain of hardware and microelectronics security in the next 5-10 years: (i) The notion of security must be migrated from IP-level to system-level; (ii) What would be the future of IP and IC protection against emerging threats; (iii) How security solutions could be migrated/expanded from SoC-level to SiP-level; (iv) the advances in power side-channel analysis with emphasis on post-quantum cryptography algorithms; (v) how to enable digital twin for secure semiconductor lifecycle management; and (vi) how physical assurance will look like with considerations of emerging technologies. The main aim of this book is to serve as a comprehensive and concise roadmap for new learners and educators navigating the evolving research directions in the domain of hardware and microelectronic securities. Overall, throughout 11 chapters, the book provides numerous frameworks, countermeasures, security evaluations, and roadmaps for the future of hardware security.