ABSTRACT
There has been an increase in the use of obfuscation as a means for providing hardware security. Obfuscation on a circuit can be provided either structurally or functionally. Structural obfuscation is provided with the use of various high-level transformation techniques, whereas functional obfuscation is provided by encryption of the circuit. It enables the circuit to operate on two distinct modes based on the key entered. If the entered key is correct, the circuit operates in normal mode, whereas if the entered key is incorrect, the circuit operates in an obfuscated mode which hides the functionality. This selection of the mode is done by the use of finite-state machine. The key generated is mainly done by using a physical unclonable function. It is a device that is known for its unique property for generating the unclonable key, as the generated key is based on the variation in silicon properties. In this chapter, we will see the advent of logic obfuscation and development of it and provide a review on this topic to help the researchers understand the basic idea of it.
