Without getting too deep into the physics, a PUF is based on the fact every chip is slightly different due to deep sub-micron manufacturing variability, even though two or more chips might have been produced with the same manufacturing process. As a result, when a chip is initially powered up, its threshold voltages and other physical characteristics are slightly different from all other chips, enabling us to derive the PUF for that chip, and therefore its unique identity. In the case of the SRAM PUF, it is embodied in the start-up behavior specifically of the SRAM memory on the chip. Since SRAM is a standard semiconductor component that exists in all technology nodes and processes, and that is present on almost every digital chip, the SRAM PUF scales very well. It can be used on almost every embedded device independent of whether the chip was built in old technology nodes such as 180 nm or very new ones, such as 7 nm, which is the leading edge in today’s semiconductor technology. Furthermore, the SRAM PUF can be instantiated by software and can be easily evaluated on existing devices. Intrinsic ID enables this with our BroadKey.