Biblio

Users receive a multitude of digital- and physical- security advice every day. Indeed, if we implemented all the security advice we received, we would never leave our houses or use the Internet. Instead, users selectively choose some advice to accept and some (most) to reject; however, it is unclear whether they are effectively prioritizing what is most important or most useful. If we can understand from where and why users take security advice, we can develop more effective security interventions.

As a first step, we conducted 25 semi-structured interviews of a demographically broad pool of users. These interviews resulted in several interesting findings: (1) participants evaluated digital-security advice based on the trustworthiness of the advice source, but evaluated physical-security advice based on their intuitive assessment of the advice content; (2) negative-security events portrayed in well-crafted fictional narratives with relatable characters (such as those shown in TV or movies) may be effective teaching tools for both digital- and physical-security behaviors; and (3) participants rejected advice for many reasons, including finding that the advice contains too much marketing material or threatens their privacy.

To help users create stronger text-based passwords, many web sites have deployed password meters that provide visual feedback on password strength. Although these meters are in wide use, their effects on the security and usability of passwords have not been well studied. We present a 2,931-subject study of password creation in the presence of 14 password meters. We found that meters with a variety of visual appearances led users to create longer passwords. However, significant increases in resistance to a password-cracking algorithm were only achieved using meters that scored passwords stringently. These stringent meters also led participants to include more digits, symbols, and uppercase letters. Password meters also affected the act of password creation. Participants who saw stringent meters spent longer creating their password and were more likely to change their password while entering it, yet they were also more likely to find the password meter annoying. However, the most stringent meter and those without visual bars caused participants to place less importance on satisfying the meter. Participants who saw more lenient meters tried to fill the meter and were averse to choosing passwords a meter deemed “bad” or “poor.” Our findings can serve as guidelines for administrators seeking to nudge users towards stronger passwords.