InaudibleKey: Generic Inaudible Acoustic Signal based Key Agreement Protocol for Mobile Devices

TL;DR

InaudibleKey is a novel acoustic signal-based key agreement protocol for mobile devices that leverages acoustic channel reciprocity to generate secure keys, significantly improving key rate and pairing distance over prior methods.

Contribution

The paper introduces InaudibleKey, a new inaudible acoustic key generation protocol that enhances performance and security for device-to-device communication in IoT environments.

Findings

Key generation rate improved by 3-145 times

Pairing distance extended by 3.2-44 times

Energy-efficient implementation on smartphones and IoT devices

Abstract

Secure Device-to-Device (D2D) communication is becoming increasingly important with the ever-growing number of Internet-of-Things (IoT) devices in our daily life. To achieve secure D2D communication, the key agreement between different IoT devices without any prior knowledge is becoming desirable. Although various approaches have been proposed in the literature, they suffer from a number of limitations, such as low key generation rate and short pairing distance. In this paper, we present InaudibleKey, an inaudible acoustic signal-based key generation protocol for mobile devices. Based on acoustic channel reciprocity, InaudibleKey exploits the acoustic channel frequency response of two legitimate devices as a common secret to generating keys. InaudibleKey employs several novel technologies to significantly improve its performance. We conduct extensive experiments to evaluate the proposed system in different real environments. Compared to state-of-the-art works, InaudibleKey improves key generation rate by 3-145 times, extends pairing distance by 3.2-44 times, and reduces information reconciliation counts by 2.5-16 times. Security analysis demonstrates that InaudibleKey is resilient to a number of malicious attacks. We also implement InaudibleKey on modern smartphones and resource-limited IoT devices. Results show that it is energy-efficient and can run on both powerful and resource-limited IoT devices without incurring excessive resource consumption.