The prevalence of 3D printing poses a significant risk to public safety, as any individual with internet access and a commodity printer is able to produce untraceable firearms, keys, counterfeit products, etc. To aid government authorities in combating these new security threats, several approaches have been taken to tag 3D-prints with identifying information. Known as fingerprints, this information is written into the object using various bit embedding techniques; examples include varying the height of the molten thermoplastic layers, and depositing metallic powder with different magnetic properties. Yet, the practicality of theses techniques in real-world forensic settings is hindered by the adversarial nature of this problem. That is, the 3D-printing process is out of reach of any law enforcement agencies; it is the adversary who controls all aspects of printing and possesses the printed object. To combat these threats, law enforcement agencies can regulate the manufacturing of 3D printers, on which they may enforce a fingerprinting scheme, and collect adversarially tampered remains (e.g., fragments of a broken 3D-printed firearm) during forensic investigation. Therefore, it is important to devise fingerprinting techniques so that the fingerprint could be extracted even if printing is carried out by the adversary. To this end, we present SIDE (Secure Information Embedding and Extraction), a fingerprinting framework that tackles the adversarial nature of forensic fingerprinting in 3D prints by offering both secure information embedding and secure information extraction.

翻译：三维打印技术的普及对公共安全构成了重大风险，任何能够访问互联网并拥有商用打印机的个体均可制造无法追踪的枪支、钥匙、仿冒产品等。为协助政府部门应对这些新型安全威胁，已有多种方法被提出用于在三维打印件中嵌入识别信息。这类信息被称为指纹，通过不同的比特嵌入技术写入物体；例如通过改变熔融热塑性塑料层的高度、或沉积具有不同磁特性的金属粉末来实现。然而，这些技术在实际法证场景中的实用性受限于该问题的对抗性本质。即三维打印过程不受任何执法机构的控制；由对手完全掌控打印的所有环节并持有打印成品。为应对这些威胁，执法机构可对三维打印机制造进行监管，强制实施指纹嵌入方案，并在法证调查期间收集遭受对抗性篡改的残留物（例如破碎的三维打印枪支碎片）。因此，设计能够在对手实施打印的情况下仍能提取指纹的嵌入技术至关重要。为此，我们提出SIDE（安全信息嵌入与提取）框架，该指纹方案通过同时提供安全信息嵌入和安全信息提取功能，以应对三维打印法证指纹识别中的对抗性挑战。