Side Auth: Synthesizing Virtual Sensors for Authentication

TL;DR

This paper proposes synthesizing virtual sensors from existing hardware to enhance authentication methods, demonstrating applications in protecting facial recognition and detecting spoofing, thus turning side channels into defensive tools.

Contribution

It introduces a novel framework for creating virtual sensors from side channels, with a proof-of-concept for inertial measurement and facial recognition security.

Findings

Successful synthesis of a virtual inertial measurement unit from camera side channels

Application of virtual sensors to defend against silicon mask spoofing

Discussion of security considerations in using side channels for authentication

Abstract

While the embedded security research community aims to protect systems by reducing analog sensor side channels, our work argues that sensor side channels can be beneficial to defenders. This work introduces the general problem of synthesizing virtual sensors from existing circuits to authenticate physical sensors' measurands. We investigate how to apply this approach and present a preliminary analytical framework and definitions for sensor side channels. To illustrate the general concept, we provide a proof-of-concept case study to synthesize a virtual inertial measurement unit from a camera motion side channel. Our work also provides an example of applying this technique to protect facial recognition against silicon mask spoofing attacks. Finally, we discuss downstream problems of how to ensure that side channels benefit the defender, but not the adversary, during authentication.