  The increasing cost of integrated circuit (IC) fabrication has driven most
companies to "go fabless" over time. The corresponding outsourcing trend gave
rise to various attack vectors, e.g., illegal overproduction of ICs, piracy of
the design intellectual property (IP), or insertion of hardware Trojans (HTs).
These attacks are possibly conducted by untrusted entities residing all over
the supply chain, ranging from untrusted foundries, test facilities, even to
end-users. To overcome this multitude of threats, various techniques have been
proposed over the past decade. In this paper, we review the landscape of IP
protection techniques, which can be classified into logic locking, layout
camouflaging, and split manufacturing. We discuss the history of these
techniques, followed by state-of-the-art advancements, relevant limitations,
and scope for future work.
