Crypto-Steganographic Validity for Additive Manufacturing (3D Printing) Design Files.

Additive Manufacturing (AM) is an important up and coming manufacturing technology which creates three-dimensional objects based on digital design files. While these digital files simplify outsourcing, it also raises security concerns of technical data theft by malicious actors. We propose a novel approach for steganographically embedding validity marks to identify the design owner and outsourced manufacturer in the widely used STL (STereoLithography) file format. It exploits redundancies in STL file encoding and applies basic cryptography to generate a mark that is detectable if illegally modified. While deforming watermarks for 3D-printed objects have been explored, our approach is the first to watermark STL files without affecting the manufactured geometry - a prerequisite for safety-critical functional parts.