Honey, I Shrunk the keys: Influences of mobile devices on password composition and authentication performance

In this paper, we present the results of two studies on the influence of mobile devices on authentication performance and password composition. A pre-study in the lab (n = 24) showed a lower performance for password-entry on mobile devices, in particular on smartphones. The main study (n = 450) showed a trend that alphanumeric passwords are increasingly created on smartphones and tablets. Moreover, a negative effect on password security could be observed as users fall back to using passwords that are easier to enter on the respective devices. This work contributes to the understanding of mobile password-entry and its effects on security in the following ways: (a) we tested different types of commonly used passwords (b) on all relevant devices, and (c) we present analytic and empirical evidence for the differences that (d) are likely to influence overall security or reduce secure behavior with respect to password-entry on mobile devices.