Mitigating Inaudible Ultrasound Attacks on Voice Assistants With Acoustic Metamaterials
Mitigating Inaudible Ultrasound Attacks on Voice Assistants With Acoustic Metamaterials
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DOI：
10.1109/access.2023.3266722
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发表时间：
2023
期刊：
影响因子：
3.9
通讯作者：
J. S. Lloyd;Cole G. Ludwikowski;Cyrus Malik;Chen Shen
中科院分区：
文献类型：
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作者：
J. S. Lloyd;Cole G. Ludwikowski;Cyrus Malik;Chen Shen
语音助手在促进人机交互方面发挥着重要作用，并已广泛应用于音频消费电子产品中。然而，已经表明它们容易受到听不见的攻击，其中恶意信号处于超声状态并且不能被人耳听到。在这项研究中，我们表明，一个明智的设计声学超材料滤波器可以减轻这种攻击，通过调制麦克风接收到的信号。超材料滤波器由具有单独孔的刚性板组成，这些孔表现出抑制特定频率的入射波的局部共振现象。实验证实了超材料滤波器的有效性，这些实验表明，这些孔的组合可以共同扭曲攻击信号并保护智能扬声器。此外，正常的可听信号不受所提出的超材料的影响，这增加了设备的灵活性。超材料滤波器占地面积小，可轻松安装在各种音频产品上。我们提出的策略扩展了声学超材料的能力，并提高了使用语音助手的设备的安全性。
Voice assistants play an important role in facilitating human–machine interactions and have been widely used in audio consumer electronic products. However, it has been shown that they are susceptible to inaudible attacks in which the malicious signals are in the ultrasound regime and cannot be heard by human ears. In this study, we show that a judiciously designed acoustic metamaterial filter can mitigate such attacks by modulating the received signals by the microphones. The metamaterial filter is composed of rigid plates with individual holes which exhibit local resonance phenomena that suppress incoming waves at specific frequencies. The effectiveness of the metamaterial filter is confirmed by experiments that show a combination of the holes can collectively distort the attack signals and protect the smart speakers. Moreover, normal audible signals are not affected by the proposed metamaterial, which adds to the flexibility of the device. The metamaterial filter has a small footprint and can be easily installed on various audio products. Our proposed strategy expands the capacity of acoustic metamaterials and improves the security of devices that use voice assistants.