PaperSpeckle: microscopic fingerprinting of paper

Paper forgery is among the leading causes of corruption in many developing regions. In this paper, we introduce PaperSpeckle, a robust system that leverages the natural randomness property present in paper to generate a fingerprint for any piece of paper. Our goal in developing PaperSpeckle is to build a low-cost paper based authentication mechanism for applications in rural regions such as microfinance, healthcare, land ownership records, supply chain services and education which heavily rely on paper based records. Unlike prior paper fingerprinting techniques that have extracted fingerprints based on the fiber structure of paper, PaperSpeckle uses the texture speckle pattern, a random bright/dark region formation at the microscopic level when light falls on to the paper, to extract a unique fingerprint to identify paper. In PaperSpeckle, we show how to extract a "repeatable" texture speckle pattern of a microscopic region of a paper using low-cost machinery involving paper, pen and a cheap microscope. Using extensive testing on different types of paper, we show that PaperSpeckle can produce a robust repeatable fingerprint even if paper is damaged due to crumpling, printing or scribbling, soaking in water or aging with time.