A Comprehensive Study of Frequency, Interference, and Training of Multiple Graphical Passwords

Graphical password systems have received significant attention as one potential solution to the need for more usable authentication, but nearly all prior work makes the unrealistic assumption of studying a single password. This paper presents the first study of multiple graphical passwords to systematically examine frequency of access to a graphical password, interference resulting from interleaving access to multiple graphical passwords, and patterns of access while training multiple graphical passwords. We find that all of these factors significantly impact the ease of authenticating using multiple facial graphical passwords. For example, participants who accessed four different graphical passwords per week were ten times more likely to completely fail to authenticate than participants who accessed a single password once per week. Our results underscore the need for more realistic evaluations of the use. of multiple graphical passwords, have a number of implications for the adoption of graphical password systems, and provide a new basis for comparing proposed graphical password systems.