Security researchers have demonstrated that it is possible for hackers to make undetectable changes to 3D printed parts that could introduce defects and possibly safety risks, too.
Scientists at Rutgers University-New Brunswick and the Georgia Institute of Technology have shown that cyberattacks on 3D printers were likely to pose threats to health and safety. The researchers have also developed ways to combat them.
In a research paper, See No Evil, Hear No Evil, Feel No Evil, Print No Evil? Malicious Fill Pattern Detection in Additive Manufacturing, the researchers used cancer imaging techniques to detect intrusions and hacking of 3D printer controllers. The study was recently presented at the 26th USENIX Security Symposium held in Vancouver, Canada.
“Imagine outsourcing the manufacturing of an object to a 3D printing facility and you have no access to their printers and no way of verifying whether small defects, invisible to the naked eye, have been inserted into your object,” said Mehdi Javanmard, study co-author and assistant professor in the Department of Electrical and Computer Engineering at Rutgers University-New Brunswick. “The results could be devastating and you would have no way of tracing where the problem came from.”
The risks in undetected defective parts come from the increased use of external 3D printing facilities and services to manufacture goods. Items can be made here but there is no standard way to verify them for accuracy, the study said. The firmware in these printers may be hacked.
The study showed that 3D printers could be hacked to print out defective objects. Researchers have devised a way of detecting and combating 3D printing cyberattacks.
First, the sound and movement of the 3D printer’s extruder is monitored. “Just looking at the noise and the extruder’s motion, we can figure out if the print process is following the design or a malicious defect is being introduced,” said Saman Aliari Zonouz, an associate professor in the Department of Electrical and Computer Engineering at Rutgers University-New Brunswick.
Researchers said that they could then use MRIs or CT scans to check for defects. Tiny gold nanoparticles, acting as contrast agents, are injected into the filament and sent with the 3D print design to the printing facility. Once the object is printed and shipped back, high-tech scanning reveals whether the nanoparticles – a few microns in diameter – have shifted in the object or have holes or other defects.
“This idea is kind of similar to the way contrast agents or dyes are used for more accurate imaging of tumours as we see in MRIs or CT scans,” Javanmard said.
In the next five years, researchers will also look at other possible methods of attack on 3D printers, as well as possible defences.