  In this paper, we explore graphical passwords as a child-friendly alternative
for user authentication. We evaluate the usability of three variants of the
PassTiles graphical password scheme for children, and explore the similarities
and differences in performance and preferences between children and adults
while using these schemes. Children were most successful at recalling passwords
containing images of distinct objects. Both children and adults prefer
graphical passwords to their existing schemes, but password memorization
strategies differ considerably between the two groups. Based on our findings,
we provide recommendations for designing more child-friendly authentication
schemes.
