The physical structure of a device, viewed at high enough magnification, can reveal the information stored inside. Typical steps in IC reverse engineering involve removing the chip packaging (decapsulation) then using various imaging techniques ranging from high resolution x-ray microscopy to invasive techniques involving removing IC layers and imaging each layer using a scanning electron microscope. The goal of such activities is to recover secret keys, unique device identifiers, and proprietary code and circuit designs embedded in hardware that the attacker has been unsuccessful at accessing through other means.

These secrets may be stored in non-volatile memory or in the circuit netlist. Memory technologies such as masked ROM allow easier to extraction of secrets than One-time Programmable (OTP) memory.