Documents you print contain your identity: Your printer spying on you

Spy-printers

As we know that the government can read our emails, and listen to our phone conversations and track us but you might have never thought that government can also track you by your printers and every page printed by your printer. Every time we print a document, a secret code also gets printed all over the page. This code can be used to identify the serial number of the printer, brand and date when it was printed and much more information.

NSA is already working with many printer manufacturers like HP, Epson, Brother, Canon, Lexmark, Ricoh, Toshiba, Xerox. US government started this program in early 1990 to prevent counterfeit money printing. The printer prints a yellow dots grid all over the printed page. The size of one rectangular grid is normally of 15 by 8 miniscule and is printed parallel to the edges of the page. The dots track up to 14 7-bit bytes of tracking information. Digital forensics experts and Researchers from Electronic Frontier Foundation were able to decode this encoding.

The little yellow dots in the grid cannot be seen by naked eye under white light. However with the help of magnifying glass or microscope or by illuminating the page with blue light instead of white light, we can see the dots easily. Blue light causes the yellow dots to appear black in dark.

Here is the sample of normal paper and the same paper under microscope and under blue light.

 

Normal printout

faint EFF

 

 

The paper under microscope with dots visible

 

60x EFF

The paper under microscope but under blue lights now the yellow dots grid is easily visible.

 

Blue Light EFF

The same images but with black dots colored as yellow so that you can clearly identify them.

yellow EFF

Digital forensic expert mentions that the topmost row and leftmost column are for error correction. The rows and columns all have odd parity: that is, every column contains an odd number of dots, and every row (except the topmost row) contains an odd number of dots.

guide EFF

Each column is read top-to-bottom as a single byte of seven bits (omitting the first parity bit); the bytes are then read right-to-left. The columns (which we have chosen to number from left to right) have the following meanings:

• 15: unknown (often zero; constant for each individual printer; may convey some non-user-visible fact about the printer’s model or configuration)
• 14, 13, 12, 11: printer serial number in binary-coded-decimal, two digits per byte (constant for each individual printer; see below)
• 10: separator (typically all ones; does not appear to code information)
• 9: unused
• 8: year that page was printed (without century; 2005 is coded as 5)
• 7: month that page was printed
• 6: day that page was printed
• 5: hour that page was printed (may be UTC time zone, or may be set inaccurately within printer)
• 4, 3: unused
• 2: minute that page was printed
• 1: row parity bit (set to guarantee an odd number of dots present per row)

The printer serial number is a decimal number of six or eight digits; these digits are coded two at a time in columns 14, 13, 12, and 11 (or possibly just 13, 12, and 11); for instance, the serial number 00654321 would be coded with column values 00, 65, 43, and 21.

Below is the list of printers and their corresponding EFF test results. As we can see most of the printers except Samsung proved to have some kind of watermarking says digital forensics expert, Jack Williams of International Institute of cyber security. Jack says that you can check your printouts from your home printers and if you can find yellow dots, it means you are being tracked. If you don’t find any dots you can mail your samples to EFF for testing.

 

Table of printers

Manufacturer	Model	Dots?	Comments
Brother
	HL-2700CN	yes	volunteer test
	HL-4200CN	yes	EFF test
Canon
	CLC 1000	yes	EFF test
	CLC 2400	yes	EFF test
	CLC 3002	yes	EFF test
	CLC 4000	yes	EFF test
	CLC 5000+	yes	EFF test
	CLC-iR 3200-C1	yes	EFF test
	Color imageRUNNER C2570	yes	EFF test
	Color imageRUNNER C3100CN	yes	EFF test
	Color imageRUNNER C3200	yes	EFF test
	Color imageRUNNER C3200N	yes	EFF test
	Color imageRUNNER C3220	yes	EFF test
	Color Laser Copier 1150	yes	EFF test
	Imageclass MF8170C	yes	EFF test
	LBP 2410	pendiente	faint dots; could be artifacts
Dell
	3000CN	yes	EFF test
	3100CN	yes	EFF test
	5100CN	yes	EFF test
Epson
	AcuLaser C900	yes	EFF test
	AcuLaser C1100	yes	EFF test
	AcuLaser C1500	yes	EFF test
	AcuLaser C1900	yes	EFF test
	AcuLaser C3000	yes	EFF test
	AcuLaser C4000	yes	EFF test
Fuji: see Xerox
Hewlett-Packard
	Color LaserJET 1550L	yes	EFF test
	Color LaserJET 1600	yes	EFF test
	Color LaserJET 2250LN	no (??)	EFF test
	Color LaserJET 2500	yes	EFF test
	Color LaserJET 2500L	yes	EFF test
	Color LaserJET 2500N	yes	EFF test
	Color LaserJET 2550	yes	EFF test
	Color LaserJET 2550L	yes	EFF test
	Color LaserJET 2550N	yes	EFF test
	Color LaserJET 2600N	yes	EFF test
	Color LaserJET 2680	yes	EFF test
	Color LaserJET 2700N	yes	volunteer test
	Color LaserJET 2840	yes	EFF test
	Color LaserJET 3500	yes	EFF test
	Color LaserJET 3550	yes	EFF test
	Color LaserJET 3600DN	yes	EFF test
	Color LaserJET 3700	yes	EFF test
	Color LaserJET 3700DN	yes	EFF test
	Color LaserJET 3700N	yes	EFF test
	Color LaserJET 4500	no	EFF test
	Color LaserJET 4500DN	no	EFF test
	Color LaserJET 4500N	no	EFF test
	Color LaserJET 4550	no	EFF test
	Color LaserJET 4550N	no	EFF test
	Color LaserJET 4600	yes	EFF test
	Color LaserJET 4600DN	yes	EFF test
	Color LaserJET 4600HDN	yes	EFF test
	Color LaserJET 4600N	yes	EFF test
	Color LaserJET 4650	yes	EFF test
	Color LaserJET 4650DN	yes	EFF test
	Color LaserJET 4650DTN	yes	EFF test
	Color LaserJET 4700	yes	volunteer test
	Color LaserJET 4700DN	yes	volunteer test
	Color LaserJET 4700DTN	yes	volunteer test
	Color LaserJET 5M	no	EFF test
	Color LaserJET 5100CN	yes	EFF test
	Color LaserJET 5500	yes	EFF test
	Color LaserJET 5500ATN	yes	EFF test
	Color LaserJET 5500DN	yes	EFF test
	Color LaserJET 5500HDN	yes	EFF test
	Color LaserJET 5550	yes	EFF test
	Color LaserJET 5550DN	yes	EFF test
	Color LaserJET 5550DTN	yes	EFF test
	Color LaserJET 8500	no	EFF test
	Color LaserJET 8500DN	no	EFF test
	Color LaserJET 8550	no	EFF test
	Color LaserJET 8550DN	no	EFF test
	Color LaserJET 8550GN	no	EFF test
	Color LaserJET 9500	yes	EFF test
	Color LaserJET 9500HDN	yes	EFF test
	Color LaserJET 9500MFP	yes	EFF test
IBM
	Infoprint Color 1454	pendiente	dithering?
	Infoprint Color 1464 PS3	yes	dithering?
Konica (Konica/Minolta)
	Bizhub C252	yes	EFF test
	Bizhub C350	yes	EFF test
	Colorforce 1501	yes	EFF test
	Colorforce 8050	yes	EFF test
	DialtaColor CF 2001	pendiente	dithering?
	DialtaColor CF 2002	pendiente	dithering?
	Ikon CPP500E	yes	EFF test
	Magicolor 2 Desklaser	no	EFF test
	Magicolor 2200 DL	yes	EFF test
	Magicolor 2210	yes	EFF test
	Magicolor 2300 DL	yes	EFF test
	Magicolor 2300 W	yes	EFF test
	Magicolor 2350	yes	EFF test
	Magicolor 2350 EN	yes	EFF test
	Magicolor 2400 W	yes	EFF test
	Magicolor 2430 DL	yes	EFF test
	Magicolor 2450	yes	EFF test
	Magicolor 3100	yes	EFF test
	Magicolor 3300	yes	EFF test
	Magicolor 5450	yes	EFF test
	Magicolor 7300	yes	EFF test
Kyocera
	C2630D	yes	EFF test
	FS-C5016N	yes	EFF test
	FS-C5020N	yes	EFF test
	FS-C5030N	yes	EFF test
	FS-C8008	yes	EFF test
	Mita KM-C2230	yes	EFF test
Lanier
	LD238C	yes	EFF test
	LP125CX/LP126CN	yes	EFF test
Lexmark
	C510	yes	EFF test
	C720	pendiente	retest
	C752	yes	EFF test
	C752N	yes	EFF test
	C760	yes	EFF test
	C910	yes	EFF test
	C912	yes	EFF test
Minolta:
NRG
	DSc38	yes	EFF test
OkiDATA
	C5100	no	EFF test
	C5150	no	EFF test
	C5150N	no	EFF test
	C5200	no	EFF test
	C5300	no	EFF test
	C7200	no	EFF test
	C7350	no	EFF test
	C7400	no	EFF test
	C7400N	no	EFF test
	C9200	no	EFF test
	C9300	no	EFF test
	C9400	no	EFF test
	MIP C5540	no	EFF test
	OkiLAN 8100E	no	EFF test
Panasonic
	Workio KXCL-500	yes	EFF test
Ricoh
	Aficio 1224C	yes	EFF test
	Aficio 1232C	yes	EFF test
	Aficio CL 2000	yes	press report
	Aficio CL 3000	yes	EFF test
	Aficio CL 3000E	yes	EFF test
	Aficio CL 6010	yes	EFF test
	Aficio CL 7000	yes	EFF test
	AP 206	yes	EFF test
	Infotec/Danka ISC 2838	yes	EFF test
Samsung
	CLP-500	no	EFF test
	CLP-510	no	EFF test
	CLP-550	no	EFF test
	CLP-550N	no	EFF test
Savin
	C3210	yes	EFF test
	CLP35	yes	EFF test
Toshiba
	eStudio 210c	yes	mfr. statement
	eStudio 211c	yes	mfr. statement
	eStudio 310c	yes	mfr. statement
	eStudio 311c	yes	mfr. statement
	eStudio 2100c	yes	mfr. statement
	eStudio 3100c	yes	mfr. statement
	eStudio 3511	yes	EFF test
	FC15	yes	mfr. statement
	FC15i	yes	mfr. statement
	FC22	yes	mfr. statement
	FC22i	yes	mfr. statement
	FC25P	yes	mfr. statement
	FC25Pi	yes	mfr. statement
	FC70	yes	mfr. statement
Xerox
	DocuColor 12	yes	EFF test
	DocuColor 40	yes	EFF test
	DocuColor 1521	yes	EFF test
	DocuColor 1632	yes	EFF test
	DocuColor 2000	yes	mfr. statement
	DocuColor 2045	yes	EFF test
	DocuColor 2240	yes	EFF test
	DocuColor 3535	yes	EFF test
	DocuColor 5252	yes	EFF test/mfr. statement
	DocuColor 6060	yes	EFF test/mfr. statement
	Phaser 560	no	EFF test
	Phaser 740	no	EFF test
	Phaser 750 (Z750V)	no	EFF test
	Phaser 750P	no	EFF test
	Phaser 790	yes	EFF test
	Phaser 850DP	no	EFF test
	Phaser 860DP	no	EFF test
	Phaser 1235	no	EFF test
	Phaser 6100	no	EFF test
	Phaser 6200	no	EFF test
	Phaser 6200DP	no	EFF test
	Phaser 6250DP	no	EFF test
	Phaser 6350DP	no	EFF test
	Phaser 7300DN	no	EFF test
	Phaser 7300DT	no	EFF test
	Phaser 7700	no	EFF test
	Phaser 7750DN	no	EFF test
	Phaser 8200DP	no	EFF test
	Phaser 8200DX	no	EFF test
	Phaser 8400	no	dithering?
	Phaser 8400B	pendiente	dithering?
	Phaser 8400DP	pendiente	dithering?
	Phaser 8400DX	pendiente	dithering?
	Phaser 8400N	pendiente	dithering?
	Phaser 8440DP	pendiente	dithering?
	Phaser 8550	no	EFF test
	Phaser 8550DP	no	EFF test
	Phaser 8560MFP/D	no	EFF test
	WorkCentre M24	yes	EFF test
	WorkCentre Pro (all models)	yes	mfr. statement

 

Here is video from a computer forensic experts explaining the logic

Source: http://www.eff.org