The more products created on 3D printers are on sale, the faster they will begin to counterfeit - on the same printers, but in violation of the technological process for the sake of cheaper prices and greater margins. New York University has already started developing security measures and came up with what they called a "deceptive QR code."
A special add-on algorithm for a 3D printer instructs him to insert microelements from inert materials into its structure during the printing of a product. Their location is calculated so as not to affect the structural integrity or other properties of the product, they are just separate droplets of paint, and even hidden in the thickness of the material. But their relative position in three-dimensional space creates a code that can be read with a simple x-ray micro-CT scanner.
The question is how to read a three-dimensional picture - at different "angles of attack" we get completely different projections of points onto the two-dimensional field of the screen. The manufacturer preselects the desired angle and fixes the form of a two-dimensional QR code that is read in this position. And a criminal who gets a finished product in his hands will have to guess how to apply the scanner and therefore with a high probability will not be able to repeat the protective sign, although the utilities for printing it for 3D printers will be freely available.
The technology has already been successfully tested on products in the form of a cube, a rod and a ball made of photopolymers, thermoplastics and metal alloys. Of course, there is always a risk of data leakage on the correct scanning angle, but if insiders are wound up in a company, then this is already a completely different kind of problem. And who prevents to increase the number of particles in a three-dimensional drawing in order to get millions of combinations, choosing only a dozen of the correct ones? Here, simple "brute-force" is no longer enough.