We design and explore the usability and security of two geographic authentication schemes: GeoPass and GeoPassNotes. GeoPass requires users to choose a place on a digital map to authenticate with (a location password). GeoPassNotes-an extension of GeoPass-requires users to annotate their location password with a sequence of words that they can associate with the location (an annotated location password). In GeoPassNotes, users are authenticated by correctly entering both a location and an annotation. We conducted user studies to test the usability and assess the security of location passwords and annotated location passwords. The results indicate that both the variants are highly memorable, and that annotated location passwords may be more advantageous than location passwords alone due to their increased security and the minimal usability impact introduced by the annotation.

We provide a simple yet powerful demonstration of how an unobtrusive change to a graphical password interface can modify the distribution of user chosen passwords, and thus possibly the security it provides. The only change to the interface is how the background image is presented to the user in the password creation phase--we call the effect of this change the "presentation effect". We demonstrate the presentation effect by performing a comparative user study of two groups using the same background image, where the image is presented in two different ways prior to password creation. Our results show a statistically different distribution of user's graphical passwords, with no observed usability consequences.

We design, implement, and evaluate GeoPass: an interface for digital map-based authentication where a user chooses a place as his or her password (i.e., a "location-password"). We conducted a multi-session in-lab/at-home user study to evaluate the usability, memorability, and security of location-passwords created with GeoPass. The results of our user study found that 97% of users were able to remember their location-password over the span of 8-9 days and most without any failed login attempts. Users generally welcomed GeoPass; all of the users who completed the study reported that they would at least consider using GeoPass for some of their accounts. We also perform an in-depth usability and security analysis of location-passwords. Our security analysis includes the effect of information that could be gleaned from social engineering. The results of our security analysis show that location-passwords created with GeoPass can have reasonable security against online attacks, even when accounting for social engineering attacks. Based on our results, we suggest GeoPass would be most appropriate in contexts where logins occur infrequently, e.g., as an alternative to secondary authentication methods used for password resets, or for infrequently used online accounts.