Printers Betray Document Secrets

Source: Metamorphosis
Date: October 19, 2004
Original Link


US scientists have discovered that every desktop printer has a signature style that it invisibly leaves on all the documents it produces. The scientists have now found a way to use this to identify individual laser printers.

The work will help track down printers used to make bogus bank notes, fake passports and other important papers. Before now it was thought that the differences between cheap, mass-produced desktop printers were not significant enough to make individual identification possible. Desktop printers coupled with scanners have become favourites with forgers as they produce high-quality copies of banknotes and personal documents that can fool a casual glance.

But a team of scientists from Purdue University in Indiana led by Professor Edward Delp has developed techniques that make it possible to trace which printer was used to produce which document. In 11 out of 12 tests, the team's methods identified which model of desktop laser printer was used to print particular documents. The researchers will present their detailed findings at the International Conference on Digital Printing Technologies in early November.