Microscopic dots that leave a “spy trail” on printed documents can be traced back to the original printer.
An article by Tech Featured discusses the technology that has been monitoring printing activities for 20 years ,and has only recently “come to light”. The technology was developed to prevent counterfeiting of “money, official certificates and classified documents”, and to trace it back to the printer.
The information is still classified, but the method was through a “microscopic dot pattern encryption”, and the article noted that “it is still possible to discover if a printer still possesses the means to secretly encode a page of printed text by carefully examining the page under a strong, bright light”. The light should expose a “a barely visible pattern of yellow dots” which would cover the whole page.
These tiny dots are “encoded, date and time stamped” so that security agencies or officials from government could trace and locate the original printer that printed the page. The official secrecy is still being upheld, although in the periods between 2004 and 2008 there were some reports about the “yellow dot code”.
Even though this technology was for tracking counterfeiting, there could be laser printers being used in businesses and the home that contain this tracking method, and there is there is nothing to counteract it, but it is almost certain that a “new-generation of highly sophisticated and impossible-to-detect encrypted tracking sensors would have replaced the original yellow dots”.
The article concludes that, although not impossible, it is “highly unlikely” that modern home or business users still own an ink printer that contains the encrypted “yellow dot tracking technology”.