Touch ID: How Does It Affect iPhone Security?

Recently, Apple has introduced Touch ID, which allows a fingerprint-based authentication to be used for iPhone unlocking.

Touch ID

It’s positioned to allow users to use stronger passcodes for locking their iOS devices, without substantially sacrificing usability. It is unclear, however, if users take advantage of Touch ID technology and if they, indeed, employ stronger passcodes. In order to answer this question, at LERSSE, we conducted three user studies through which we found that users do not take an advantage of Touch ID and use weak unlocking secrets. To our surprise, we found that more than 30% of the participants did not know that they could use passwords instead of 4-digit PINs. Some other participants indicated that they adopted PINs due to better usability, in comparison to passwords. Most of the participants agreed that Touch ID, indeed, offers usability benefits, such as convenience, speed and ease of use. Finally, we found that there is a disconnect between users’ desires for security that their passcodes have to offer and the reality. In particular, only 12% of participants correctly estimated the security their passcodes provide.

Find more details in our SOUPS ’15 paper.