Some printers arrange yellow dots in seemingly random point clouds.Īccording to the Chaos Computer Club in 2005, color printers leave the code in a matrix of 32 × 16 dots and thus can store 64 bytes of data (64×8). Thus, it can be analyzed even if only fragments or excerpts are available. For example, if the code consists of 8 × 16 dots in a square or hexagonal pattern, it spreads over a surface of about 4 square centimetres (0.62 sq in) and appears on a sheet of size A4 paper about 150 times. Their arrangement encodes the serial number of the device, date and time of the printing, and is repeated several times across the printing area in case of errors. The dots have a diameter of a tenth of a millimeter (0.004") and a spacing of about one millimeter (0.039"). The pattern consists of a dot-matrix spread of yellow dots, which can barely be seen with the naked eye. Yellow dots produced by an HP Color LaserJet CP1515n The Central Bank Counterfeit Deterrence Group (CBCDG) has denied that it developed the feature.
In November 2004, PC World reported the machine identification code had been used for decades in some printers, allowing law enforcement to identify and track counterfeiters. The public first became aware of MIC in October 2004, when it was used by Dutch authorities to track counterfeiters who had used a Canon color laser printer.
Patent No 5515451 describing the use of the yellow dots to identify the source of a copied or printed document. Xerox developed the machine identification code "to assuage fears that their color copiers could be used to counterfeit bills" and received U.S. In the mid-1980s Xerox pioneered an encoding mechanism for a unique number represented by tiny dots spread over the entire print area. 5 Protection of privacy and circumvention.
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