# Managing Access to Confidential Documents: A Case Study of an Email Security Tool
## 4 Methodology
### Study Design  
We conducted online interviews with 19 participants. Each participant was reminded of the importance of the consent form at the beginning of the interview. Once the par ticipants reconfirmed their interest in participating in our study, we began recording the interview sessions. Zoom's recording feature was used to record the audio and video. The participants were first asked a set of questions on how they perceived the security and privacy of Gmail. After that, we asked the participants to perform three tasks. In the first task, we aimed to explore the participants' first impressions of receiving a secured email as shown in Figure 1(a). We told the participants that we would send an email to their email address (without saying anything related to this investigated email security tool). Since these participants were receiving an encrypted email for the first time, we asked them to state their impression after opening this email, their rating of how easy they thought it was for them to understand the text in that email, and their rating of how familiar they were with the concept of \"encrypted email\" as described in the email. In the second task, we wanted to make sure that the participants were able to compose an email using the email security tool and explore its security features. Thus, the participants were first asked to watch a video that included security- and privacy-related information about this email security tool, the importance of using it, and a demo on adding the email security extension to their Google Chrome browser. The video transcript is available in Appendix B. Then, we asked them to think aloud while composing an email with this email security tool and explore its security features. In the third task, the participants were provided with three hypothetical scenarios to understand how users manage the access control using the tool's security features in the encrypted email and how they rated their satisfaction and concern once they shared their confidential information via standard email and encrypted email. To perform this task, the participants were first asked to download three sensitive documents and forms (employee information form, medical history form, and W-9 (tax) form) on their personal devices. These forms were filled with fake information as an example. We asked the participants to imagine that the information in all these forms, including sensitive information such as social security numbers, belonged to them and that there was no need to change these forms. The three scenarios are described below:  
* For the employee information form, we included employee information such as employee IDs and contact information. The given scenario was between the participants and the human resource department (HR). We asked them to imagine that they were newly hired by a company, and they were asked to email their employee information form to HR a week before they joined the company so HR could review it anytime during this week. * For the medical history form, we included information about a person's health history (e.g., unhealthy habits and the patient's medical history). The given scenario was between the participants and a doctor's office. We asked them to imagine visiting a  
Figure 2: Email security tool (Virtru’s) sender and recipient window after email is sent. (**a**) Recipient window. (**b**) Sender window showing revoke access option. new doctor for the first time, and the new doctor's office needed their medical history form before they went to their appointment, which was three days later. * For the W-9 form, we included information about a person's tax information (e.g., account number, taxpayer identification number, and employer identification). The email was between the participants and a certified public accountant.