"We've found that the dots from at least one line of printers encode the date and time your document was printed, as well as the serial number of the printer," said EFF Staff Technologist Seth David Schoen. The serial number of the printer could be used to track the customer who bought it. The code is a series of dots printed onto the pages. The dots are yellow and less than one millimeter in diameter but can be seen on the pages.
A blue light, magnifying glass or microscope can be used to see the dots properly. The manufacturers never really say anything on record about the code but this is what was said to OUT-LAW Magazine earlier this year: "Epson is cooperating closely with industry groups and the relevant authorities in each country to prevent counterfeiters use [sic] its products in illegal activities. However, due to the sensitive nature of this issue we are unable to comment about the exact measures that are being taken."
If you want to check out how to read the dots yourself, there is a very interesting article provided by the EFF. You can view that by clicking here.
Sources:
The Register
EFF
Written by: James Delahunty @ 20 Oct 2005 3:40
