Biblio

We performed a large-scale online survey (n=1,880) to study the padlock icon, an established security indicator in web browsers that denotes connection security through HTTPS. In this paper, we evaluate users’ understanding of the padlock icon, and how removing or replacing it might influence their expectations and decisions. We found that the majority of respondents (89%) had misconceptions about the padlock’s meaning. While only a minority (23%-44%) referred to the padlock icon at all when asked to evaluate trustworthiness, these padlock-aware users reported that they would be deterred from a hypothetical shopping transaction when the padlock icon was absent. These users were reassured after seeing secondary UI surfaces (i.e., Chrome Page Info) where more verbose information about connection security was present.We conclude that the padlock icon, displayed by browsers in the address bar, is still misunderstood by many users. The padlock icon guarantees connection security, but is often perceived to indicate the general privacy, security, and trustworthiness of a website. We argue that communicating connection security precisely and clearly is likely to be more effective through secondary UI, where there is more surface area for content. We hope that this paper boosts the discussion about the benefits and drawbacks of showing passive security indicators in the browser UI.

Converged Multi-Level Secure systems allow users to interact with and freely move between applications and data of varying sensitivity on a single user interface. They promise unprecedented usability and security, especially in security-critical environments like Defence. Yet these promises rely on hard assumptions about secure user behaviour. We present initial work to test the validity of these assumptions in the absence of deception by an adversary. We conducted a user study with 21 participants on the Cross Domain Desktop Compositor. Chief amongst our findings is that the vast majority of participants (19 of 21) behave securely, even when doing so requires more effort than to behave insecurely. Our findings suggest that there is large scope for further research on converged Multi-Level Secure systems, and highlight the value of user studies to complement formal security analyses of critical systems.