Printer 'fingerprints' to collar counterfeiters

Source: PC Pro
Date: Thursday, October 19, 2004
Writer: Simon Aughton Original Link

Scientists in the US are developing a technology that will enable law enforcement agencies to track down the laser or inkjet printer used to produce forged and counterfeit documents.

Software installed on printers would embed a unique band in the printed image which would be invisible to the eye but detectable using image analysis techniques.

The technology is a consequence of two separate sets of research. Edward J Delp, professor of electrical and computer engineering at Purdue University, Indiana, discovered that printed documents can be matched to the precise device on which they were printed because of tiny fluctuations in the manufacturing process.

'We will be able to identify not only which model printer was used but specifically which printer was used,'

Delp said. 'That means we will be able to tell the difference between counterfeit bills created on specific printers even if they are the same model.'

However, there is one drawback: as soon as a toner or ink cartrdige is changed, the characteristics of the printer are altered and documents can no longer be traced to their source.

Nonetheless, Jan Allebach, a professor of electrical and computer engineering and George Chiu, a professor of mechanical engineering, realised that printers also have a unique banding pattern - slight horizontal variations in the image quality.

'We have observed variability from printer to printer within a single model,' Allebach said. 'That's because for a company to make printers all behave exactly the same way would require tightening the manufacturing tolerances to the point where each printer would be too expensive for consumers.'

Allebach and Chiu realised that software could be used to artificially create a band unique to each printer.

The researchers are now working with US Government bodies to find ways to develop their discoveries to track forged documents such as passports and counterfeit currency.