Forensic experts track printer fingerprints
Researchers at Purdue University have developed image analysis techniques that may one day help tie counterfeit money and forged documents to the printers that produced them.
In lab experiments, the researchers examined documents that came from 12 different models of printers and were able to correctly link a document to its printer 11 times. The techniques currently let forensic investigators match a document with only a specific printer model, but will be honed so that a document can be matched to a particular printer.
"That means we will be able to tell the difference between counterfeit bills created on specific printers even if they are the same model," Edward Delp, professor of electrical and computer engineering at Purdue, said in a statement.
Delp and other professors and graduate students who worked on the project will present papers detailing the technology in November at the International Conference on Digital Printing Technologies in Salt Lake City. The group will also work with the U.S. Secret Service to develop new methods for tracing documents and counterfeit bills.
Software developed by Delp can identify "intrinsic signatures" of printers, or the subtle differences in the output of printers based on the small differences in their mechanics. To cut costs, printer manufacturers use plastic gears and other parts that create variations in printed sheets. These variations could be attenuated, but it would raise manufacturing prices considerably.
