While the embedded security research community aims to protect systems by reducing analog sensor side channels, our work argues that sensor side channels can be beneficial to defenders. This work introduces the general problem of synthesizing virtual sensors from existing circuits to authenticate physical sensors' measurands. We investigate how to apply this approach and present a preliminary analytical framework and definitions for sensor side channels. To illustrate the general concept, we provide a proof-of-concept case study to synthesize a virtual inertial measurement unit from a camera motion side channel. Our work also provides an example of applying this technique to protect facial recognition against silicon mask spoofing attacks. Finally, we discuss downstream problems of how to ensure that side channels benefit the defender, but not the adversary, during authentication.

翻译：尽管嵌入式安全研究界旨在通过减少模拟传感器侧信道来保护系统，但本文认为传感器侧信道可对防御者有益。本文提出了一个通用问题：如何从现有电路中合成虚拟传感器，以认证物理传感器的被测对象。我们探索了该方法的适用性，并提出了传感器侧信道的初步分析框架与定义。为阐明这一通用概念，我们通过概念验证案例研究，从相机运动侧信道中合成了虚拟惯性测量单元。此外，本文提供了将该技术应用于保护人脸识别免受硅面具欺骗攻击的示例。最后，我们讨论了在认证过程中如何确保侧信道有利于防御者而非攻击者的下游问题。