3D Printing Security

As more 3D printed products reach the markets so does the increased risk for counterfeit parts. Nikhil Gupta is an Associate Professor of Mechanical and Aerospace Engineering at New York University’s Tandon School of Engineering. He joins Hari Sreenivasan to discuss a new security measure using three dimensional quick response codes.


As more 3-D-printed products reach the market, so does the increased risk for counterfeit parts.

Nikhil Gupta is an associate professor of mechanical and aerospace engineering at New York University's Tandon School of Engineering.

He joins us now to discuss a new security measure -- three-dimensional quick response codes, QR codes, and we've seen them.

If you've taken a flight, you've seen now that you can do most of your boarding passes with QR codes, and you see them in other countries a lot.

How would you use a QR code, and how would you 3-D print it?

QR code is an example, but you can do the same thing with bar code or any other code given our method.

So what 3-D printing is doing is giving us a method where we layer material in order to build a large-scale part, and this layer-by-layer printing process is very important because we can hide information, or encode information inside, when the part is being printed.

So we take advantage of this method, and we put a QR code in one of the layers, and then the part keeps building.

Eventually this part -- from outside this code is invisible.


...so you will need a method like ultrasonic imaging or CT scan in order to get that code and validate the part.

So when I look at an object now -- you have a couple of samples here -- essentially, if I looked at... This sample is... What is it, titanium?

This is our titanium part, and after printing the QR code in one layer, we cut it open so that you can see and validate the code exists there.


...but if this was completely built.

Like, from the back side, if you look at it, there's no sign of a code being there.

But basically if you scanned it somehow, you'd be able to see that there's a code inside.


If you scan it using CT scan, which is a common technique people already use on 3-D-printed parts to look for defects inside or any abnormalities...


...so you can also catch some of these codes.

Because I guess the concern is, is that as 3-D printers become more common, that you could actually create more and more counterfeit product.

Exactly, and it's not just creating counterfeit product, but people can actually genuinely buy products and then reverse-engineer them using 3-D scanners and just make copies.

So just like we take a paper and we make a photocopy of it, a similar process is now feasible for 3-D-printed parts also.

But people can also copy QR code.

That's a legitimate worry as well...


...if they know that the code exists, so what we did in an example like this that if you look at it, it just looks like a cloud of points.


Inside the cube, there's tons of little pink dots here, so as soon as I look at it, I can see, and I look at it dead-on.

I can see exactly what looks like a QR code, but that's a composite of all of these different layers that have gone into it.


So you've printed each of those dots but at different layers in the cube.

Right, and their distance is also controlled.

Their location is controlled, so if this was printed as a sphere, then you would really have a hard time to figure out from which direction you have to see inside.

So besides the security component, what else does a QR code help?

At this point, tracking of authentic 3-D-printed parts is a big problem because people can just make copies.

And think of examples like prosthetics or implants that go inside people's body.


So there's no way to figure out if the implant was genuine or counterfeit if it is inside somebody's body already, but the CT scan can still figure out even inside the body whether the part was genuine or not.


So there is a lot of value in this kind of technology.

What inspired this?

So we started working into design-based security method, so people have been working on securing the 3-D printing chain for a long time, but being a mechanical engineer and material scientist, my thinking was that there needs to be something in the design itself because the most secure resources have been breached very easily in recent past for computers.

So now what we are trying to do is we are going to put all of this information in the design stage, so even if the password is breached, you still have a method inside which is very difficult to either copy or decode by the hackers who stole the files.

So this is something that let's say a company, a medical device manufacturer, that is going to start printing 3-D implants, they would use this at a sort of functional design layer before they even started printing, right?

Exactly, yes, so it has to go within the design process somewhere.

All right.

Nikhil Gupta, thanks for joining us.