"My phone's lying out on Thanksgiving and Grandma picks it up." User Threat Models for Using Vault Applications

Contributor(s)

Chris Geeng, Natalie Chen, Kieron Ivy Turk, Jevan Hutson, Damon McCoy

Session

Cryptography and Privacy for the People

Abstract

Vault apps and hidden albums are tools used to encrypt and hide sensitive photos, videos, and other files. There is little research to understand how and why users use vault apps, and whether these tools meet their needs. To understand vault app user threat models, we conducted interviews with U.S. adult vault app users. We find our participants store intimate media, non-sexual body images, photos of partying and drinking, identification documents, and other sensitive files. Participants primarily used vault apps to prevent accidental content exposure from shoulder surfing or phone sharing, whether in public or with and around close ties. Users were generally aware vault apps could not prevent a technically proficient adversary from accessing their files. We find that vault apps prevent context collapse when sharing devices, similar to how privacy settings prevent context collapse on social media.