Why Lasers Inject Perceived Sound Into MEMS Microphones: Indications and Contraindications of Photoacoustic and Photoelectric Effects
Why Lasers Inject Perceived Sound Into MEMS Microphones: Indications and Contraindications of Photoacoustic and Photoelectric Effects
复制标题
为什么激光器将感知声音注入 MEMS 麦克风：光声和光电效应的适应症和禁忌症
DOI：
10.1109/sensors47087.2021.9639744
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Fu Kevin
中科院分区：
文献类型：
--
作者：
Cyr Benjamin;Sugawara Takeshi;Fu Kevin
最近发表在网络安全研究界的工作展示了一个令人惊讶的发现：调制的低功率激光器可以可靠地将错误感知的声学信号注入MEMS麦克风。然而，这项工作对基于物理学的因果关系保持沉默，只对为什么这项技术有效进行了简短的说明。在理解能量转移的物理学之前，很难设计出具有令人信服的有效性和可靠性证据的防御系统。在这项工作中，我们提供了一种方法来测试的存在和贡献的光声和光电效应的激光信号注入MEMS麦克风。我们在真空室中对MEMS器件进行的可编程、精确的激光实验创造了条件，可以充分隔离各种麦克风中的光声效应和光电效应。结果表明，光声效应的优势，同时也提供了光电效应的禁忌症。这对激光注入防御产生了深远的影响，因为现代MEMS设计不考虑通过光声现象防止激光信号注入的安全要求。
Recent work published in the cybersecurity research community demonstrated a surprising discovery: modulated, low-power lasers can reliably inject falsely-sensed acoustic signals in MEMS microphones. However, the work remained mute on the physics-based causality with only passing conjectures on why the technique works. Until the physics of the energy transfer is understood, it will be difficult to design defenses with convincing evidence of effectiveness and reliability. In this work, we provide a methodology to test the presence and contribution of the photoacoustic and photoelectric effects to laser signal injection in MEMS microphones. Our programmable, precise laser experiments on MEMS devices in a vacuum chamber creates conditions to sufficiently isolate photoacoustic effects from photoelectric effects in a diverse set of microphones. The results indicate a dominance of photoacoustic effects while also providing contraindications of photoelectric effects. This leads to profound implications on laser injection defenses as modern MEMS designs do not consider security requirements to protect against laser signal injection via photoacoustic phenomena.