PUF with dissolvable conductive paths

The generation of "fingerprints", also called challenge-response pairs (CRPs) of Physically Unclonable Functions (PUFs), can often stress electronic components, leaving behind traces that can be exploited by crypto-analysts. A non-intrusive method to generate CRPs based on Resistive RAMs may instead be used, which does not disturb the memory cells. The injection of small electric currents (magnitude of nanoAmperes) in each cell causes the resistance of each cell to drop abruptly by several orders of magnitudes through the formation of temporary conductive paths in each cell. A repeated injection of currents into the same cell, results in an almost identical effect in resistance drop for a single cell. However, due to the small physical variations which occur during manufacturing, the cells are significantly different from each other, in such a way that a group of cells can be used as a basis for PUF authentication.