Abstract Cyber-physical security is a major concern in the modern environment of digital manufacturing, wherein a cyber-attack has the potential to result in the production of defective parts, theft of IP, or damage to infrastructure or the operator have become a real threat that have the potential to create bad parts. Current cyber only solutions are insufficient due to the nature of manufacturing environments where it may not be feasible or even possible to upgrade physical equipment to the most current cyber security standards, necessitating an approach that addresses both the cyber and the physical components. This paper proposes a new method for detecting malicious cyber-physical attacks on additive manufacturing (AM) systems. The method makes use of a physical hash, which links digital data to the manufactured part via a disconnected side-channel measurement system. The disconnection ensures that if the network and/or AM system becomes compromised, the manufacturer can still rely on the measurement system for attack detection. The physical hash ensures protection of the intellectual property (IP) associated with both process and toolpath parameters while also enabling in situ quality assurance. In this paper, the physical hash takes the form of a QR code that contains a hash string of the nominal process parameters and toolpath. It is manufactured alongside the original geometry for the measurement system to scan and compare to the readings from its sensor suite. By taking measurements in situ, the measurement system can detect in real-time if the part being manufactured matches the designer’s specification. In this paper, the overall concept and underlying algorithm of the physical hash is presented. A proof-of-concept validation is realized on a material extrusion AM machine, to demonstrate the ability of a physical hash and in situ monitoring to detect the existence (and absence) of malicious attacks on the STL file, the printing process parameters, and the printing toolpath.

中文翻译：

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用于预防和检测增材制造系统中的网络物理攻击的物理哈希

摘要 网络物理安全是现代数字制造环境中的一个主要问题，其中网络攻击有可能导致生产有缺陷的零件、IP 被盗或对基础设施或运营商的损害已成为真正的威胁。有可能产生坏零件。由于制造环境的性质，当前的纯网络解决方案是不够的，在这种环境下，将物理设备升级到最新的网络安全标准可能不可行，甚至不可能，因此需要一种同时解决网络和物理组件的方法。本文提出了一种检测对增材制造 (AM) 系统的恶意网络物理攻击的新方法。该方法使用物理散列，它通过断开连接的侧通道测量系统将数字数据链接到制造的零件。断开连接确保如果网络和/或 AM 系统受到威胁，制造商仍然可以依靠测量系统进行攻击检测。物理散列可确保保护与工艺和刀具路径参数相关的知识产权 (IP)，同时还能实现原位质量保证。在本文中，物理散列采用二维码的形式，其中包含标称工艺参数和刀具路径的散列字符串。它与原始几何形状一起制造，供测量系统扫描并与其传感器套件的读数进行比较。通过原位测量，测量系统可以实时检测正在制造的零件是否符合设计者的规格。本文介绍了物理哈希的整体概念和底层算法。在材料挤出 AM 机器上实现了概念验证验证，以展示物理哈希和原位监控检测 STL 文件是否存在（和不存在）恶意攻击、打印工艺参数和打印刀具路径。