What if you could print your own driver's license at home, instead of having to wait in line all day at the DMV? That's the potential of an emerging technology in the works at Purdue University.

Although it may not be apparent, all laser printers leave specific markings on each document they print, a process called banding. Purdue's School of Electrical and Computer Engineering has pioneered a tracking system that uses banding to trace a document back to the printer from which it originated.

"(Each printer) has its own forensic fingerprint," says Edward J. Delp, a professor of electrical and computer engineering at Purdue and one of the architects of the project.

That fingerprint is detected by closely analyzing the bands a printer leaves behind. "It's a combination of using image-analysis tools and pattern recognition," Delp says.

The printer's "signature" is then digitally loaded into a database. This database could be used by forensic examiners, law-enforcement agencies, and government officials to spot forged documents. The Secret Service has already expressed interest in the technology for its potential to track forgeries and improve homeland security, Purdue says.

The technology won't merely be a tracking tool; it could also add secure data to a printout to create an official document, Delp says. The printers of the future, Delp says, could encode data in printouts that could be scanned and verified by a bank, an airline, or a police officer. Thus, users could print their licenses, boarding passes, or ID cards from the comfort of their own homes.

"There is the need for the average person to be able to print secure documents," Delp says.

Jonathan Zittrain, codirector of the Berkman Center for Internet and Society at Harvard Law School, says that the tracking technology likely won't receive too much legal opposition.

"The world of consumer commerce is desperate for more ways than personal signatures and ID cards" to create official documents, Zittrain says, but admits some legal issues are bound to occur.

"It could definitely raise challenges, he says, adding "I don't know if they're insurmountable."

"I have some faith in the legal system," he says.

Delp says he is very concerned with privacy issues and says one graduate student works full time on "attack" scenarios for the project.

"It's something that we think about every day," Delp says.

Delp and his colleagues will present the project at the International Conference on Digital Printing Technologies in Salt Lake City, Utah, on November 5.

Tuohey writes for the Medill News Service.