Hey Siri – Are You There?: Jamming of Voice Commands Using the Resonance Effect (Work-in-Progress)

Abstract

Micro Electro-Mechanical Systems (MEMS) microphones have become popularly used in portable devices thanks to their numerous advantages over other types of microphones. However, MEMS microphones introduce their own vulnerabilities, and in this paper we discuss the possibility of new attacks that impact devices equipped with a MEMS microphone. We found that these devices can be vulnerable to a new jamming attack based on the resonance effect inherent in the vibrating nature of MEMS devices. For example, a user’s voice commands can be canceled by a jamming attack by broadcasting carefully crafted audio signals. When these signals are generated with a frequency that matches the inherent frequency of the target MEMS microphone, the microphone’s membrane will resonant at a significantly large amplitude which prevents the device from receiving the victim’s command.