No, Your 3D Printer Doesn’t Have a Fingerprint

Hackers and makers see the desktop 3D printer as something close to a dream come true, a device that enables automated small-scale manufacturing for a few hundred dollars. But it’s not unreasonable to say that most of us are idealists; we see the rise of 3D printing as a positive development because we have positive intentions for the technology. But what of those who would use 3D printers to produce objects of more questionable intent?

We’ve already seen 3D printed credit card skimmers in the wild, and if you have a clear enough picture of a key its been demonstrated that you can print a functional copy. Following this logic, it’s reasonable to conclude that the forensic identification of 3D printed objects could one day become a valuable tool for law enforcement. If a printed credit card skimmer is recovered by authorities, being able to tell how and when it was printed could provide valuable clues as to who put it there.

This precise line of thinking is how the paper “PrinTracker: Fingerprinting 3D Printers using Commodity Scanners” (PDF link) came to be. This research, led by the University at Buffalo, aims to develop a system which would allow investigators to scan a 3D printed object recovered from a crime scene and identify which printer was used to produce it. The document claims that microscopic inconsistencies in the object are distinctive enough that they’re analogous to the human fingerprint.

But like many of you, I had considerable doubts about this proposal when it was recently featured here on Hackaday. Those of us who use 3D printers on a regular basis know how many variables are involved in getting consistent prints, and how introducing even the smallest change can have a huge impact on the final product. The idea that a visual inspection could make any useful identification with all of these parameters in play was exceptionally difficult to believe.

In light of my own doubts, and some of the excellent points brought up by reader comments, I thought a closer examination of the PrinTracker concept was in order. How exactly is this identification system supposed to work? How well does it adapt to the highly dynamic nature of 3D printing? But perhaps most importantly, could these techniques really be trusted in a criminal investigation?

Continue reading “No, Your 3D Printer Doesn’t Have a Fingerprint”

Hackaday Links: September 9, 2018

Octoprint is one of those must-have apps for 3D printers. All you need is a Raspberry Pi, an SD card, and a USB cable, and you can control your 3D printer from anywhere in the house. Of course, some people take it too far and open up their Octoprint to the greater Internet. Gizmodo reports thousands of people are doing so, with possible dire consequences. Choice quotes: “Imagine waking up in the morning to find that your 3D printer was used to produce a gun” and “Once again, 3D guns come to mind”. Yes, they referenced 3D printed guns twice in a story. Call me when you can 3D print bullets. Or when bioprinters can print airborne HIV, which was also suggested in the story.

ARS Electronica is going on in Linz this weekend, and it’s the largest new media art festival where cyber artists are recognized for their innovations. One of the more interesting exhibits is [Sarah Petkus]’ Noodlefeet. Its [Sarah]’s kid, that’s a robot, that’s made out of pool noodles. She’s talked about it at the Hackaday Superconference, and now there’s an entire exhibit behind it. You can check out her ‘making of’ post right here.

A mirror is a useful survival tool, if only for signalling people. Here’s a video showing long-distance mirror signalling, over a distance of 27.5 miles. The mirror used was 330 x 254mm, but the real challenge here is pointing the mirror in the right direction. For that, [Andy] used a bamboo pole a few meters in front of the mirror. By reflecting sunlight onto the pole, he knew it was going in about the right direction. Accuracy versus precision, or something like that.

Last week, a slow leak was detected aboard the International Space Station. The leak was quickly traced to a 2mm hole in the upper orbital module of a visiting Soyuz spacecraft. prompting call of micrometeoroid damage and plenty of speculation on what would have happened if this hole appeared anywhere else on the station. Now, it looks like this hole was put there by a drill, probably during assembly or testing, and was somehow plugged until the Soyuz was in space for a few weeks. Why this hole just magically appeared one night is anyone’s guess, but there you go.