What Your Printer Knows That You Don't

The Real Reason You Can't Print Without Colour Ink: Printers Leave Tiny Yellow Dots for Authorities to Identify Documents

Joe Frost | September 24, 2015

With printers being cheap and in just about every home and office, it would seem the humble, letters-cut-out-of-magazines ransom note is now a thing of the past – print your demands in generic Times New Roman and no one would ever be able to identify you, right? Yeah, not so much.

The dots as printed by a HP Color Laserjet 3700. Source: http://www.techly.com.au/2015/09/24/real-reason-cant-print-without-colour-ink-printers-leave-tiny-yellow-dots-authorities-identify-documents/

Just about every printer on the planet leaves a digital footprint – tiny, almost invisible yellow dots on every page they print, featuring information such as the printer’s serial number and a timestamp. To pick up the dots, you’d need a microscope and a blue light.

<more at http://www.techly.com.au/2015/09/24/real-reason-cant-print-without-colour-ink-printers-leave-tiny-yellow-dots-authorities-identify-documents/; http://wayback.archive.org/web/20131021120012/http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=935180&isnumber=20242&url=http%3A%2F%2Fieeexplore.ieee.org%2Fstamp%2Fstamp.jsp%3Ftp%3D%26arnumber%3D935180%26isnumber%3D20242 (Digital steganography: hiding data within data. Internet Computing, IEEE. Volume 5, Issue 3. By D. Artz (Los Alamos National Lab). [Abstract: Digital steganography is the art of inconspicuously hiding data within data. Steganography's goal in general is to hide data well enough that unintended recipients do not suspect the steganographic medium of containing hidden data. The software and links mentioned in this article are just a sample of the steganography tools currently available. As privacy concerns continue to develop along with the digital communication domain, steganography will undoubtedly play a growing role in society. For this reason, it is important that we are aware of digital steganography technology and its implications. Equally important are the ethical concerns of using steganography and steganalysis. Steganography enhances rather than replaces encryption. Messages are not secure simply by virtue of being hidden. Likewise, steganography is not about keeping your message from being known - it's about keeping its existence from being known.]) and https://www.eff.org/issues/printers (Is Your Printer Spying On You? March 2, 2015)>