Evolution of SSL/TLS Indicators and Warnings in Web Browsers [SPW 2019]

The creation of the World Wide Web (WWW) in the early 1990’s finally made the Internet accessible to a wider part of the population. With this increase in users, security became more important. To address confidentiality and integrity requirements on the web, Netscape—by then a major web browser vendor—presented the Secure Socket Layer (SSL), later versions of which were renamed to Transport Layer Security (TLS). In turn, this necessitated the introduction of both security indicators in browsers to inform users about the TLS connection state and also of warnings to inform users about potential errors in the TLS connection to a website. Looking at the evolution of indicators and warnings, we find that the qualitative data on security indicators and warnings, i.e., screen shots of different browsers over time is inconsistent. Hence, in this paper we outline our methodology for collecting a comprehensive data set of web browser security indicators and warnings, which will enable researchers to better understand how security indicators and TLS warnings in web browsers evolved over time.