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Secret printer codes decrypted

Secret printer codes decrypted

Dogged consumer advocates at the Electronic Frontier Foundation have cracked the mysterious codes concealed within some color laser prints. Tiny yellow dots buried within pages printed by Xerox DocuColor models hide the date and time each print was made, as well as the machine's serial number. In the name of cracking down on counterfeit currency, many printer makers shook hands with the Secret Service to encrypt data in prints, within faint yellow circles. The EFF spotted such dots in prints made by color lasers from Brother, Canon, Dell, Epson, HP, Konica/Minolta, Kyocera, Lexmark, Ricoh, and Xerox--but could not decipher all of their meaning. If you're a curious DIYer with access to one of those printers, then you, too, can spy the yellow marks--just get a microscope or a strong magnifying glass, a blue light, and this open-source decoding app. "It's one thing to detect counterfeit dollar bills," writes Declan McCullagh of "But the hidden dots may erode Americans' right to anonymity." Slashdot has more.