GuardLens: Supporting Safer Online Browsing for People with Visual Impairments.

Visual cues play a key role in how users assess the privacy/security of a website, but often remain inaccessible to people with visual impairments (PVIs), disproportionately exposing them to privacy and security risks. We employed an iterative, user-centered design process with 25 PVIs to design and evaluate GuardLens, a browser extension that improves the accessibility of privacy/security cues and helps PVIs assess a website's legitimacy (i.e., if it is a spoof/phish). We started with a formative study to understand what privacy/security cues PVIs find helpful, and then improved GuardLens based on the results. Next, we further refined Guardlens based on a pilot study, and lastly, conducted our main study to evaluate GuardLens' efficacy. The results suggest that GuardLens, by extracting and listing pertinent privacy/security cues in one place for faster and easier access, helps PVIs quickly and accurately determine if websites are legitimate or spoofs. PVIs found cues such as domain age, search result ranking, and the presence/absence of HTTPS encryption especially helpful. We conclude with design implications for tools to support PVIs with safe web browsing.