Researchers find way to track 'untraceable' 3D-printed guns

The 3D-printer leaves a hardware fingerprint.

Marrian Zhou Staff Reporter
Marrian Zhou is a Beijing-born Californian living in New York City. She joined CNET as a staff reporter upon graduation from Columbia Journalism School. When Marrian is not reporting, she is probably binge watching, playing saxophone or eating hot pot.
Marrian Zhou
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An image of 3D printed items from the research paper. 

Screenshot by Marrian Zhou/CNET

Untraceable 3D-printed guns may soon be traceable.

In a paper published earlier this week, a team of researchers said they had discovered a way to trace 3D-printed objects back to the 3D printers that made them. The team's identification system, dubbed "PrinTracker," uses patterns that are etched onto the surface of a 3D-printed object to identify the printer that made it.

"Two human beings can write the same thing, but they'll have different handwriting," Wenyao Xu, a computer science professor at the University at Buffalo, New York, and the lead author of the paper, said during a phone interview. "It's the same concept for [tracking] 3D printers."

Xu and his team came up with the idea after hearing about Cody Wilson, the man at the center of a legal battle over 3D-printed guns. Wilson had offered downloadable plans for 3D-printed guns, prompting a lawsuit by 19 states, in part because the guns might prove untraceable.

As part of their research, Xu's team found that 20 years ago the Federal Investigation Bureau had looked into fingerprinting paper -- recognizing patterns on paper -- in order to identify fake documents. That inspired Xu and his team to use the same concept to trace 3D printers.

The research is based on hardware variations in each printer that creates a unique pattern, akin to a fingerprint, on the objects it prints. Even different units of the same make and model of printer won't perform exactly the same way, Xu says, each leaving its discrete mark on whatever it prints. 

In addition to tracking 3D-printed guns, PrinTracker can be used to identify counterfeit products made with 3D printers.

Xu hopes 3D printers will be fingerprinted before they're sold so that law enforcement can track the objects they print, if that's necessary.

"I think [the] 3D printer is a revolutionary invention," Xu said. "So security and forensics will be very important."