Watching What You Print

The Electronic Frontier Foundation(EEF) said that currently only the U.S. Secret Service and now itself had the ability to decrypt the imprint. It said that although the Secret Service claims to use this information only for cornering counterfeit crimes, there is no legal framework to prevent the information from being put to other uses. A secret code embedded in many color laser jet printers allows the U.S. government and any other organization capable of reading the cipher to identify when the copies were made and on which particular machine, according to research conducted by the EFF.
The San Francisco-based privacy organization said Tuesday it had detected almost invisible patterns of yellow dots on every document printed on the affected machines. The dots could indicate when and where the print was made. Among the copiers found to include the secret yellow dots are ones made by Brother, Canon , Dell, Epson, HP, Konica/Minolta, Kyocera , Lexmark, Ricoh, Tektronix/Toshiba and Xerox.
The foundation cautioned that although it had deciphered the code on Xerox machines, it had not done the same for the yellow dots found on other copiers, but that it was likely that they too represented a sophisticated document tracking system. "So far, we've only broken the code for Xerox DocuColor printers, but we believe that other models from other manufacturers include the same personally identifiable information in their tracking dots," said EFF Staff Technologist Seth David Schoen.
The dots are yellow, less than one millimeter in diameter, and are typically repeated over each page of a document. The pattern can be seen using a blue light, a magnifying glass, or a microscope. The group said that currently only the U.S. Secret Service and now itself had the ability to decrypt the imprint. It said that although the Secret Service claims to use this information only for cornering counterfeit crimes, there is no legal framework to prevent the information from being put to other uses.