User Behaviors and Attitudes Under Password Expiration Policies.

Policies that require employees to update their passwords regularly have become common at universities and government organizations. However, prior work has suggested that forced password expiration might have limited security benefits, or could even cause harm. For example, users might react to forced password expiration by picking easy-to-guess passwords or reusing passwords from other accounts. We conducted two surveys on Mechanical Turk through which we examined people's self-reported behaviors in using and updating workplace passwords, and their attitudes toward four previously studied password-management behaviors, including periodic password changes. Our findings suggest that forced password expiration might not have some of the negative effects that were feared nor positive ones that were hoped for. In particular, our results indicate that participants forced to change passwords did not resort to behaviors that would significantly decrease password security; on the other hand, their self-reported strategies for creating replacement passwords suggest that those passwords were no stronger than the ones they replaced. We also found that repeating security advice causes users to internalize it, even if evidence supporting the advice is scant. Our participants overwhelmingly reported that periodically changing passwords was important for account security, though not as important as other factors that have been more convincingly shown to inuence password strength.