Patent attributes
The disclosure features methods and systems that include illuminating a candidate structure with radiation linearly polarized along a first polarization direction and obtaining a first image of the dendritic structure, illuminating the candidate structure with radiation linearly polarized along a second polarization direction and obtaining a second image of the dendritic structure, where an angle between the first and second polarization directions is at least 10, for a set of pixels corresponding to a first region of the candidate structure in the first and second images, determining a first change in average pixel intensity between the first and second images, and authenticating the candidate structure as a dendritic structure based on the first change in average pixel intensity.