The team from digital rights lobby group Electronic Frontier Foundation have cracked the “secret” forensic tracking codes Fuji Xerox DocuColor laser printers embed in their prints.
The foundation examined the small yellow dots printed onto documents under a microscope, noting that they could be used to encode up to 14 seven-bit bytes of tracking data, IT News reported.
The codes are allegedly used by the United States Secret Service and other national government agencies to link printed out documents with specific devices, revealing the date, time, and device serial numbers.
The EFF has since made the source code available as a free download, licensed under the GNU general public licence (GPL). Further testing showed that some devices from HP, OKI, Samsung and Xerox’ Phaser range did not include the yellow tracking dots in documents. Last month the group produced a list of 200 devices that show the yellow dots under blue light.