Wireless sensing technologies leveraging the acoustic and RF sensors in smart devices have advanced to enable accurate contactless monitoring of vital signs such as breathing and heartbeat. Wireless signal monitoring can enable important health applications, such as determining emotional states, detecting critical health conditions, and providing suitable interventions. While offering non-invasiveness and privacy advantages over wearables and cameras, these technologies pose serious privacy risks. The improved sensing accuracy allows any unauthorized sensor to detect sensitive health data without consent. This paper proposes VitalHide, a novel approach to protect vital signs from unauthorized sensing while still enabling wireless sensing for authorized devices. The key idea of VitalHide is to obfuscate the user’s vital signs by generating a deceiving vital sign motion using a wearable mechanical device. The obfuscated signal can then only be decoded at authorized devices, while unauthorized devices receive deceiving vital signs. We show the feasibility of VitalHide by generating motion using a vibration sensor and shape memory alloy (SMA)-based smart textile, and the successful decoding of the obfuscated vital sign signal at the authorized receiver. This work advances privacy-preserving wireless sensing by securing personal health information against unauthorized access without affecting the utility of authorized devices.

Publication

Y Gao, T Ahmed, Z Chang, T Roumen, R Nandakumar, Accepted at ACM Workshop on Mobile Computing Systems and Applications (HotMobile), 2025.

https://doi.org/10.1145/3708468.3711880