Can digital fingerprint put an end to counterfeit components?

According to Fraunhofer scientist, Dominik Merli, electronic components or chips can be made counterfeit proof using physical unclonable functions (PUFs). "Every component has a kind of individual fingerprint since small differences inevitably arise between components during production. Printed circuits, for instance, end up with minimal variations in thickness or length during the manufacturing process. While these variations do not affect functionality, they can be used to generate a unique code." Merli explained a PUF module is integrated directly into a chips, fpgas, microchips or smartcards for example. "At its heart is a measuring circuit, for instance a ring oscillator. This oscillator generates a characteristic clock signal which allows the chip's precise material properties to be determined. Special electronic circuits then read the measurement data and generate the component specific key from the data." Unlike conventional cryptographic processes, the secret key is not stored on the hardware but is regenerated as and when required. According to Merli, since the code relates directly to the system properties at any given point in time, it is virtually impossible to extract and clone it. Invasive attacks on the chip would alter physical parameters, thus distorting or destroying the unique structure. The Garching based researchers have already developed two prototypes - a butterfly PUF and a ring oscillator PUF, which are currently being optimised for practical applications. Hall 11, Stand 203