A Portable and Stealthy Inaudible Voice Attack Based on Acoustic Metamaterials

TL;DR

This paper introduces METAATTACK, a portable and stealthy inaudible voice attack system utilizing acoustic metamaterials, capable of targeting popular voice assistants over extended distances with high accuracy.

Contribution

The work presents the first use of acoustic metamaterials for inaudible voice attacks, significantly improving range, portability, and practicality over previous methods.

Findings

Achieves an average word accuracy of 76% across assistants.

Can attack targets at distances up to 8.85 meters.

Uses a compact device suitable for real-world scenarios.

Abstract

We present METAATTACK, the first approach to leverage acoustic metamaterials for inaudible attacks for voice control systems. Compared to the state-of-the-art inaudible attacks requiring complex and large speaker setups, METAATTACK achieves a longer attacking range and higher accuracy using a compact, portable device small enough to be put into a carry bag. These improvements in portability and stealth have led to the practical applicability of inaudible attacks and their adaptation to a wider range of scenarios. We demonstrate how the recent advancement in metamaterials can be utilized to design a voice attack system with carefully selected implementation parameters and commercial off-the-shelf components. We showcase that METAATTACK can be used to launch inaudible attacks for representative voice-controlled personal assistants, including Siri, Alexa, Google Assistant, XiaoAI, and Xiaoyi. The average word accuracy of all assistants is 76%, with a range of 8.85 m.