Machine Identification Code – Wikipedia

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Hexagonal point marking on white paper, generated by a color laser printer (expression enlarged greatly, point diameter about 0.1 mm)

When Machine Identification Code (Mic) – too Color printing , yellow dots (yellow dots), tracking dots (Points for tracking) or secret dots (Secret dots) -is a digital watermark that is applied by color laser printers and copies on every printed page.

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The code can enable identification of the device to be used to create a copy or pressure piece, and thereby provide information on the creator of the document.

Marked Yellow Dots of an HP Color Laserjet CP1515N.

The marking consists of a grid that is distributed over the entire pressure field. The points are yellow, have a diameter of a tenth of a millimeter and a distance of about one millimeter. They can hardly be seen with the naked eye. Your arrangement contains the serial number of the device, date and time of the printing process as well as data for error correction.

For example, if the code consists of 8 × 16 points in a square or hexagonal arrangement, it occupies an area of ​​about four square centimeters. It appears about 150 times on a DIN A4 sheet. In this way, it can also be read out if only excerpts or fragments of the printed sheet are available.

Some printers also arrange yellow dots in apparently random point clouds.

In 2005, the Chaos Computer Club states that color copiers can mark a matrix of 32 × 16 points and thus accommodate a amount of data of 64 bytes. [first]

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Yellow Dots: The hidden code on the expression in the form of tiny yellow points using the example of an HP Color Laserjet 3700.

The Machine Identification Code can be made visible by printing a color side or photocopying and then scanning a small excerpt with a scanner with a high resolution. The yellow color channel can then be reinforced with a graphics program in order to make the points of the machine identification codes clearly recognizable if available. With good lighting, a magnifying glass can also be enough to see the tiny yellow dots.
The yellow dots are clearly recognizable under UV light. [2]

Machine Identification Code (Mic, Yellow Dots, Tracking Dots, Secret Dots) under UV light in regular (red and blue marked) and irregular arrangement (marked green).

With this steganographic process, high -quality printouts are also recognized as copies of an original template (e.g. a banknote) under blue light. Likewise, printed prints can be restored with these markings: The “Shredder Challenge” advertised by Darpa in 2011 was only completely solved by the team “All Your Shreds are Belong to U.S.” (Otávio Good and two colleagues). [3] [4]

Copies or printouts of sensitive documents, such as doctor’s letters, bank extracts, tax returns or company balance sheets, can be traced back to the printer owner and the time of creation can be determined.
The traceability is not known to many users and is also not accessible. The code is not announced by the manufacturers. It is therefore initially unclear which data with an expression or a copy will be reluctantly passed on. In particular, there are no information in the accompanying materials of most affected printers (exceptions see below). The Electronic Frontier Foundation tried to decryption and provided a python script for analysis. [5]

Xerox is one of the few manufacturers who indicate the marking of the pages: The digital color printing system is equipped according to the demands of numerous governments with a counterfeit-proof labeling and banknote recognition system. Each copy is provided with a label, which, if necessary, enables the printing system to be identified with which it was created. This code is not visible under normal conditions. [6]

Hewlett Packard Germany confirms that I have integrated mic in all of its own printers. According to HP Germany, no firmware can be provided without a MIC. MIC is not mentioned in user manuals from HP printers. A return of a device is accepted by dealers with reference to the consulting liability if the sales discussion has not been informed in relation to MIC (which is practically never happening).

The electronic Frontier Foundation’s civil rights group called out printing out in 2005 and subsequently decoded the pattern. [7] The pattern was detected on a wide range of printers from different manufacturers and models. [8]

Decoding by the Eff.

A team of researchers from the TU Dresden presented at a conference on 23/24. June 2018 in Innsbruck a freely available software, which “prints additional yellow points on the paper, the hidden information becomes unusable.” [9] [ten]

Compared to the “Yellow Dots” visible under UV light or with a magnifying glass, other procedures are not so obviously recognizable. For example, modulation of laser intensity and a variation of grayscale in texts are not only conceivable, but have long since been realized. It is not known whether manufacturers are already using these techniques. [11] With Video Encoded Invisible Light (Veil) there is a similar identification system for video recordings.

  1. ↑ Frank Rosengart: Data track paper . In: Chaos Computer Club (ed.): The data slingshot . The scientific journal for data travelers. No. eighty six , 2005, ISSN  0930-1054 , S. 19–21 ( Data track paper [PDF; 1.8 MB ; accessed on June 27, 2018]).
  2. ↑ Contribution at printing channel: Big Brother is Watching You: Code deciphered in color lasers
  3. ↑ CONGRATULATIONS to “All Your Shreds Are Belong To U.S.”! (No longer available online.) Defense Advanced Research Projects Agency, November 21, 2011, archived from Original am 25. August 2016 ; accessed on June 12, 2014 (English). Info: The archive link has been used automatically and not yet checked. Please check original and archive link according to the instructions and then remove this note. @first @2 Template: Webachiv/Iabot/Archive.Darpa.mil
  4. ↑ Tip for Bad Guys: Burn, Don’t Shred. Bloomberg Business Week, December 15, 2011, accessed on June 12, 2014 (English).
  5. ↑ Archived copy ( Memento from January 14, 2016 in Internet Archive ) docucolor.cgi – CGI script to interpret Xerox DocuColor forensic dot pattern
  6. ↑ Xerox GmbH (Hrsg.): Xerox DocuColor® 6060 Digitales Farbdrucksystem . Brochure. Neuss, section “Technical data of the digital color printing system Xerox Docucolor 6060”, S. 8 , Sp. 2 ( Xerox DocuColor® 6060 Digitales Farbdrucksystem [PDF; 1.4 MB ; accessed on February 27, 2011]).
  7. ↑ Decoding information from the electronics Frontier Foundation (English) ( Memento from January 14, 2016 in Internet Archive )
  8. ↑ Printer list examined on the code ( Memento from April 19, 2017 in Internet Archive )
  9. ↑ Researchers have hidden data in printing out orf.at, June 27, 2018, accessed June 27, 2018.
  10. ↑ Timo Richter, Stephan Escher, Dagmar Schönfeld, and Thorsten Strufe. 2018. Forensic Analysis and Anonymisation of Printed Documents. In Proceedings of the 6th ACM Workshop on Information Hiding and Multimedia Security (IH&MMSec ’18). ACM, New York, NY, USA, 127-138. doi:10.1145/3206004.3206019
  11. ↑ Purdue University poster Jan P. Allebach et al.: Identification, Authentication and Privacy

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