The motive for this research book is to provide relevant theoretical frameworks that include device physics, modeling, circuit design, and the latest developments in experimental fabrication in the field of nanotechnology for hardware/software security. There are numerous challenges in the development of models for nanoscale devices (e.g., FinFET, gate-all-around devices, TFET, etc.), short channel effects, fringing effects, high leakage current, and power dissipation, among others. This book will help to identify areas where there are challenges and apply nanodevice and circuit techniques to address hardware/software security issues.