Powering for Privacy: Improving User Trust in Smart Speaker Microphones with Intentional Powering and Perceptible Assurance


Youngwook Do and Nivedita Arora, Georgia Institute of Technology; Ali Mirzazadeh and Injoo Moon, Georgia Institute of Technology and Massachusetts Institute of Technology; Eryue Xu, Georgia Institute of Technology; Zhihan Zhang, Georgia Institute of Technology and University of Washington; Gregory D. Abowd, Georgia Institute of Technology and Northeastern University; Sauvik Das, Georgia Institute of Technology and Carnegie Mellon University


Smart speakers come with always-on microphones to facilitate voice-based interaction. To address user privacy concerns, existing devices come with a number of privacy features: e.g., mute buttons and local trigger-word detection modules. But it is difficult for users to trust that these manufacturer-provided privacy features actually work given that there is a misalignment of incentives: Google, Meta, and Amazon benefit from collecting personal data and users know it. What's needed is perceptible assurance — privacy features that users can, through physical perception, verify actually work. To that end, we introduce, implement, and evaluate the idea of "intentionally-powered" microphones to provide users with perceptible assurance of privacy with smart speakers. We employed an iterative-design process to develop Candid Mic, a battery-free, wireless microphone that can only be powered by harvesting energy from intentional user interactions. Moreover, users can visually inspect the (dis)connection between the energy harvesting module and the microphone. Through a within-subjects experiment, we found that Candid Mic provides users with perceptible assurance about whether the microphone is capturing audio or not, and improves user trust in using smart speakers relative to mute button interfaces.

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@inproceedings {291152,
author = {Youngwook Do and Nivedita Arora and Ali Mirzazadeh and Injoo Moon and Eryue Xu and Zhihan Zhang and Gregory D. Abowd and Sauvik Das},
title = {Powering for Privacy: Improving User Trust in Smart Speaker Microphones with Intentional Powering and Perceptible Assurance},
booktitle = {32nd USENIX Security Symposium (USENIX Security 23)},
year = {2023},
isbn = {978-1-939133-37-3},
address = {Anaheim, CA},
pages = {2473--2490},
url = {https://www.usenix.org/conference/usenixsecurity23/presentation/do},
publisher = {USENIX Association},
month = aug

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