Date, time and printer serial number: enough to trace the author of a document . That is the hidden meaning of the notorious yellow dots , the yellow dots that lurk between the characters of the pages produced by a large number of models of laser printers for many manufacturers. revealed by PcWord in 2004 and later became the subject of an investigation Electronic Frontier Foundation in 2005, their meaning was revealed in part by the same organization. But now, back in the spotlight after Paul Weihe, a graph of known German study, it revealed the presence in the prints of his company. the method adopted by Weihe is quite simple: after printing una pagina con la Xerox DC-12 dell'ufficio, ha provveduto a digitalizzarne a 3200 dpi una sezione da 7,5 centimetri di lato con uno scanner professionale. Un po' di lavoro in Photoshop, per saturare il colore giallo e aumentare il contrasto, e la trama segreta è ben evidente.
Più complesso, almeno in apparenza, decifrare il codice: l'interpretazione è invece immediata. La prima riga indica la parità delle colonne, mentre la prima colonna indica la parità delle righe. La seconda e The fifth column shows the time of printing, while the sixth, seventh and eighth indicate day, month and year. Finally, column 11 to 14 is the serial number of the printer.
concludes sarcastically Erik Spiekermann, who described the method in the pages of his company's blog: "It's nice to discover we can always prove the paternity of a color laser printing, without using the letterhead. " currently no still no response came from either the EFF, which has compiled a list of color laser printers burn after or site seeing yellow - an initiative launched by MIT students to raise awareness on question. I wonder if the study SpiekermannPartner undergo the visit of U.S. intelligence, just as happened to the hacker who first revealed the play.
from Point Computer ( LINK)
