Having to enter a password to regain access to your touchscreen device is not always convenient. Biometric Touch Sensing by Christian Holz, Microsoft Research, is a research project that explores the idea of enabling touchscreens to biometrically identify and authenticate users on every touch. The touchscreen senses the 2D input coordinates with each touch and obtains data to authenticate users. Here is how researchers pulled it off:
our watch prototype Bioamp senses the impedance profile of the user’s wrist and modulates a signal onto the user’s body through skin using a periodic electric signal. This signal affects the capacitive values touchscreens measure upon touch, allowing devices to identify users on each touch.
More information about this project is available on Christian Holz’s website.