In this chapter, we provide an overview of the ReBO approaches discussed throughout the book. The chapter also highlights the challenges faced by existing ReBO approaches, discusses the ReBO design methods, and emphasizes the need for automation of CAD tools. It addresses the lack of bitstream protection and the necessity for further silicon validation. Additionally, we note the common consideration of SAT attacks in security analysis, emphasize the lack of further security evaluation methods and common security metrics to meet the needs of the research community. Lastly, we explore potential future research directions.