Als machine identification code (MIC) -Color mark, yellow dots (yellow dots), tracking dots (Points tracking) or secret dots (secret points) -is called a digital watermark, It is attached by certain colour laser printers and copiers on each printed page.

The code could allow an identification of the device, a particular document was created with the, and this information on the manufacturer of the document type.

Background

The background is an agreement of the manufacturer with the U.S. Government, to print an invisible code on each color page, to track back documents.

These devices print a tiny dot pattern in yellow colour on the sides. These points are hardly be discerned with the naked eye.

From the arrangement of the points are time, Date and the serial number of the printer to find out. Only color lasers are affected- and color LED printers and color copiers. Ink printers us black and white copiers is this code so far still not surfaced.

Technical realization

The mark consists of a dot grid, It is spread over the whole field. The points are yellow, have a diameter of one tenth millimeter and a distance of about one millimeter. They are hard to see with the naked eye.

For example, consists of the code 8 × 16 Points in a square or hexagonal arrangement, It occupies an area of about four square centimeters. He appears ca on an A4 sheet. 150 Time. So it can be read even, If only snippets or Fragments of printed sheet available.

Specifies the chaos computer Club, current color copier is a marker in a matrix of 32 × 16 Noble and thus a lot of data points from 64 Byte can accommodate.

Visualize points

You can make the points visible in different ways:

The paper scanning with a resolution of at least 600 DPI. Then zoom in and with Photoshop or GIMP the colors/contrast manipulate so that the points are visible.

The blade in a dark room under ultraviolet light and look with a magnifying glass on the sheet. The yellow dots are now black and more visible.

Instructions found in the sources.

List of manufacturers use the MIC:

Brother

Canon

Dell

Epson

HP

IBM

Konica

Lanier

Lexmark

Ricoh

Toshiba

Xerox

For details see: Printers which do or do emergency of display tracking dots

Sources:

https://www.eff.org/press/archives/2005/10/16

https://www.youtube.com/watch?v=izMGMsIZK4U

http://www.druckerchannel.de/artikel.php?ID=1239

https://de.wikipedia.org/wiki/Machine_Identification_Code