1. A method to authenticate a product comprising a parameter settings phase, an acquisition phase and an identification phase; the parameter setting phase comprising: selecting an imaging lighting orientation, an imaging resolution and a region of interest on the reference product surface; the acquisition phase comprising the steps of: lighting, with an imaging device, the surface of a first reference product item with the imaging lighting orientation; capturing, with the imaging device, an image of a microstructure of the region of interest on the reference product surface, wherein the image has sufficient resolution to show a least one product surface microstructure feature at the pixel level; computing, with the imaging device, an image feature to characterize the captured image; and storing, with the imaging device, the image feature in a database; the identification phase comprising the steps of: lighting, with an imaging device, the surface of a product to authenticate with the imaging lighting orientation; capturing, with the imaging device, an image of a microstructure of the region of interest on the surface of the product to authenticate, wherein the image has sufficient resolution to show a least one microstructure feature at the pixel level; computing, with the imaging device, an initial image feature to characterize the captured image of the region of interest on the surface of the product to authenticate; querying, with the imaging device, for a reference product item, a reference image feature in the database; comparing the initial image feature and the reference image feature, with an image matching technique; responsive to the comparison, computing, with the imaging device, a refined image feature to characterize the captured image; measuring a correlation metric between the refined image feature and the reference image feature; and identifying a match between the product to authenticate and the reference product item when the correlation metric is above a predefined threshold.