A Side-channel Analysis of Sensor Multiplexing for Covert Channels and Application Fingerprinting on Mobile Devices. / Shepherd, Carlton; Kalbantner, Jan; Semal, Benjamin; Markantonakis, Konstantinos.

2022.

Research output: Contribution to conferencePaper

E-pub ahead of print

Documents

  • Accepted Manuscript

    Accepted author manuscript, 4.59 MB, PDF document

Abstract

Mobile devices often distribute measurements from a single physical sensor to multiple applications using software-based multiplexing. On Android devices, the highest requested sampling frequency is returned to all applications even if other applications request measurements at lower frequencies. In this paper, we comprehensively demonstrate that this design choice exposes practically exploitable side-channels based on frequency-key shifting. By carefully modulating sensor sampling frequencies in software, we show that unprivileged malicious applications can construct reliable spectral covert channels that bypass existing security mechanisms. Moreover, we present a novel variant that allows an unprivileged malicious observer app to fingerprint other victim applications at a coarse-grained level. Both techniques do not impose any special assumptions beyond accessing standard mobile services from unprivileged applications. As such, our work reports side-channel vulnerabilities that exploit subtle yet insecure design choices in mobile sensor stacks.
Original languageEnglish
Publication statusE-pub ahead of print - 22 Mar 2022

ID: 45835628