A credit card or sheet of paper might look smooth, but under a microscope, these surfaces teem with ridges, pits, and other irregularities. Now, researchers in England have devised a way to translate those random artifacts of manufacturing into unique identification codes. Such codes are difficult, if not impossible, to forge, the developers claim.
Russell P. Cowburn of Imperial College London and his colleagues describe their authentication scheme in the July 28 Nature. A London-based start-up company, to which some of the researchers have financial ties, is already manufacturing a laser-based coding system that applies the new strategy.