The last chapter of this book presents a summary of the logic locking defenses and attacks discussed throughout the book. The chapter also highlights the challenges faced by existing logic locking approaches and hints at the future research directions. This chapter concludes the book by summarizing the techniques discussed throughout the book and offering directions for future research. Section 11.1 revisits the attack/defense matrix introduced in Chap. 2, summarizing the relation among various classes of attacks and defenses. Section 11.2 offers insights into the challenges faced by logic locking techniques. Section 11.3 highlights the future research directions.