Color Laser Printers and Tracking Dots
Did you know that a lot of newer color laser printers create yellow tracking dots on their output which can be used to identify the printer and probably even the person that printed the document?
It's not a fictional scenario and the EFF, the Electronic Frontier Foundation, started creating a list of color laser printers that do and do no create the tracking dots.
Update: The list is no longer being updated by the EFF as of 2017. The reason for that according to the EFF is that it believes that all recent commercial laser printers do print forensic tracking code on printout. They may even use different methods and not necessarily yellow dots as mentioned in the article.End
It's interesting that the Electronic Frontier Foundation states that its researchers cannot be sure that the printers that do not create the tracking dots are not using another way to add a tracking code to the printed documents. The printer manufacturers apparently gave in to the demands of the US Government in a "purported effort to identify counterfeiters".
Currently there is not enough information to validate a tracking dot with a 100% certainty unless the manufacturer stated that the printer would indeed make use of it. The EFF has been using three sources of information to compile the list:
We looked at printer output under a blue light and/or a computer microscope; we consulted press reports about printers (e.g. at Druckerchannel); we relied on printer manuals and other manufacturer statements.
The two companies that have a completely green - meaning no yellow dots to be seen - listing are Okidata and Samsung. As the EFF states this does not necessarily mean that they do not use another method to add the information to the printouts but as of know nothing of this kind could be spotted.
The best course of action for uses who don't want to risk being identified through printouts is to use inkjet printers.
