Trackpad interaction inference from MacBook IMU vibrations

Determine whether vibrations captured by the built-in MacBook inertial measurement unit from Force Touch taps, clicks, and swipes reveal users’ click targets or gestures, thereby extending side-channel analysis beyond keystroke inference.

Background

The paper demonstrates that the built-in MacBook IMU captures mechanical vibrations generated by keyboard input and that these vibrations can support unprivileged keystroke inference. The same chassis-coupled sensor may also capture mechanical signals produced by Force Touch trackpad taps, clicks, and swipes.

The unresolved issue is whether those trackpad-induced vibrations contain sufficient information to identify the location of a click or distinguish specific gestures. Establishing this would determine whether the disclosed IMU side channel threatens additional forms of user interaction beyond keyboard input.

References

The built-in IMU can capture vibrations from Force Touch taps, clicks, and swipes; whether they reveal click targets or gestures remains future work.

— Et Tu, MacBook? Unprivileged Keystroke Inference and Context Profiling via the Built-in IMU Side Channel  (2609.21569 - He et al., 18 Sep 2026) in Section 6, Discussion, subsection “Other Exploitations,” paragraph “Trackpad side channel”