PairSonic: Helping Groups Securely Exchange Contact Information

TL;DR

PairSonic is a new protocol that enables secure, user-friendly, and scalable exchange of contact information for online groups by leveraging acoustic channels on smartphones, improving upon existing authentication methods.

Contribution

It introduces a novel acoustic out-of-band protocol that automates verification, extending trust from physical encounters to online communication for group settings.

Findings

Successfully automates contact verification using acoustic channels

Enhances scalability and user-friendliness over existing methods

Open-source implementation available for adoption

Abstract

Securely exchanging contact information is essential for establishing trustworthy communication channels that facilitate effective online collaboration. However, current methods are neither user-friendly nor scalable for large groups of users. In response, we introduce PairSonic, a novel group pairing protocol that extends trust from physical encounters to online communication. PairSonic simplifies the pairing process by automating the tedious verification tasks of previous methods through an acoustic out-of-band channel using smartphones' built-in hardware. Our protocol not only facilitates connecting users for computer-supported collaboration, but also provides a more user-friendly and scalable solution to the authentication ceremonies currently used in end-to-end encrypted messengers like Signal or WhatsApp. PairSonic is available as open-source software: https://github.com/seemoo-lab/pairsonic