Paper Patterns and Smartphones Foil Forgers
22nd October 2011
The system, called PaperSpeckle, is based on the microscopic patterns of light and shadow that appear when light shines on paper. Subramanian and his colleagues encoded these patterns with an equation known as a Gabor transform, which is also used in iris and fingerprint recognition. This creates a unique “fingerprint” that allows the software to distinguish between 1030 different sheets of paper.
The software runs on an Android smartphone, ownership of which is on the rise in India, connected to a USB microscope. The components can be bought for around $100 each, making it accessible to small organisations and some individuals.
As well as analysing the unique speckle pattern, the software can generate a QR code – a type of matrix barcode – that corresponds to it. If this is on the document, users can authenticate it even if they do not have access to an online database. While someone could easily copy the QR code to another sheet of paper, the speckles would no longer match.
As soon as governments use it for currency, banks will be on this like politicians on tax money.