In "Acoustic Emanation of Haptics as a Side-Channel for Gesture-Typing Attacks" we demonstrated an update to the classical technique of analysing acoustic emanations from keyboards that applied to touchscreen typing now standard in mobile devices. Specifically, the technique applies to gesture typing and the acoustic emanation is from the haptic feedback motor, rather than from individual key presses.
With a related patent, "Data Interception Protection" we propose modifications to input and feedback mechanisms to mitigate the risk associated with such an attack.
The main claim is as follows:
A computer implemented method to protect data input to a user input device from detection, the device including an artificial haptic feedback mechanism arranged to generate an occurrence of haptic feedback for sensing by a user of the device in response to each input gesture on the device by the user, characterised in that at least a subset of each occurrence of haptic feedback is adjusted with respect to a previous occurrence of haptic feedback by one or more of: a timing of the haptic feedback with respect to a time of occurrence of a corresponding input gesture; an adjustment to a duration of haptic feedback relative to a duration of the previous occurrence of haptic feedback; and a generation of one or more addition occurrences of haptic feedback.