Hey Alexa, what's my PIN? Voice assistants can figure out the taps made on a smartphone keyboard

Smart speakers like Google Home and Amazon Alexa could be used by criminals to listen to and decipher a password or PIN being typed in on a nearby phone. Researchers from the University of Cambridge built their own version of a smart speaker to closely resemble those which are commercially available. Sound recordings from the gadget were inputted into a computer for analysis and experts investigated if the sound and vibrations caused by typing on a smartphone screen could be used to guess a five-digit passcode. When the phone was placed within 20cm (7.8inches) of the custom-built device, the computer was able to guess the code with 76 per cent accuracy in three attempts. This graphic outlines the general flow of the experiment.