SonarSnoop: Active Acoustic Side-Channel Attacks

TL;DR

This paper introduces SonarSnoop, an active acoustic side-channel attack that uses inaudible sounds and echoes to infer user interactions on smartphones, revealing significant security vulnerabilities.

Contribution

It presents the first active acoustic side-channel attack method that employs inaudible signals and echo analysis to profile user behavior on mobile devices.

Findings

Reduced unlock pattern candidate space by up to 70%

Demonstrated applicability to various device types

Highlights new security threat family

Abstract

We report the first active acoustic side-channel attack. Speakers are used to emit human inaudible acoustic signals and the echo is recorded via microphones, turning the acoustic system of a smart phone into a sonar system. The echo signal can be used to profile user interaction with the device. For example, a victim's finger movements can be inferred to steal Android phone unlock patterns. In our empirical study, the number of candidate unlock patterns that an attacker must try to authenticate herself to a Samsung S4 Android phone can be reduced by up to 70% using this novel acoustic side-channel. Our approach can be easily applied to other application scenarios and device types. Overall, our work highlights a new family of security threats.