Connectivity patterns of multiple devices
belonging to a single user
Research project

David R. Cheriton School of Computer Science
University of Waterloo
Principal Investigator: Urs Hengartner
Student Investigators: Erinn Atwater

Participant Information Letter and Consent Form


You are invited to participate in a study as part of a research project at the University of Waterloo. The intent of the project is to study how participants make use of multiple electronic devices in their day-to-day lives. The study will be conducted by student investigator Erinn Atwater for her PhD thesis, under the faculty supervision of Dr. Urs Hengartner. The intention of this study is to investigate whether users' devices are online and interconnected frequently enough to enable the use of a technique from threshold cryptography that would allow us to add significant protections to users' personal data against theft and hacking. (Threshold cryptography is a technique by which information is protected by distributing it across multiple cooperating devices.)

The only requirement for participants is that they (a) are 18 years of age or older, and (b) have and regularly use two or more personal computing devices running Windows, OSX, Linux, or Android.

What You Will Be Asked To Do

Participation in this study is completely voluntary. If you agree to participate, we will provide you with an account name, password, and the address of a website which contains instructions for installing a measurement app on each of the devices you intend to use for the study.

The purpose of this study is to collect data on your usage of your personal devices. After installing our measurement app on your devices, it will record the following data for a period of two weeks:

By logging into the website address using the information provided above, you may view the information our apps have collected from your devices at any time. This information will be available for you to access at any time up to one month after the completion of the study. Your unique username and password are the only way to access this data, and they will not be provided to anyone other than you.


No data other than that explicitly listed above is collected by our measurement app. In particular we are not collecting internet traffic, information about what apps you are using or have installed on your device, or personal data such as emails or photos. It is possible that you may have some concerns about having data collected on your device connectivity during private events, such as visiting a doctor's office. For this reason, there is a prominently displayed control in the app which will allow you to pause all data collection temporarily.

Confidentiality and Data Retention

All data collected is considered confidential. Your data will be associated with the random identifier assigned to you, rather than your actual name. Even though we may present our findings and publish the results in papers, only the principal and student investigators of the study will have access to the data collected. Your name or any other personal identifying information will not appear in any publication resulting from this study, and will not be stored with the data collected. However, with your permission, anonymous quotations may be used in the final project report. The information collected during this study will be retained for up to 7 years and will then be deleted.

All data will be reported by our measurement app over an HTTPS-secured connection. It will then be stored on an encrypted hard drive that only the student investigator has access to, stored in DC 3332 in a locked cabinet. At the conclusion of the study, access to & physical control of the data will be transferred to Dr. Hengartner's locked office in DC 3526.

Your participation in this study is voluntary. You may decline to answer particular questions, if you wish, and may withdraw participation at any time. You may choose not to install the measurement app on any device for which you do not wish us to collect data. You may temporarily pause data collection by using the app on any of your devices. You may ask us not to include your data in the study at any point in time during this session or up until the final submission date of the project report in December 2017.

Benefits of the Project

The information you provide will help us better understand how people make use of multiple personal devices. This project may provide us with useful information that we hope will lead to usable privacy enhancing technologies for people around the world, and help advance the field of usable privacy and security.

Consent Form

By providing your consent, you are not waiving your legal rights or releasing the investigator(s) or involved institution(s) from their legal and professional responsibilities.

I agree to participate in a study being conducted by Erinn Atwater at the University of Waterloo. The faculty supervisor is Dr. Urs Hengartner. I have made this decision based on the information I have read in this Information-Consent Letter. I have had the opportunity to receive any additional details I wanted about the study. I understand that I may withdraw this consent at any time by telling the student or principal investigator.

I am aware that by installing the data collection app on my computing devices, information about my usage of the device including when it is on, when it is connected to the internet or bluetooth, when it is able to detect other nearby devices, and information listed in the Information-Consent Letter such as hardware identifiers and IP addresses will be collected and securely reported to the persons conducting the study.

I am aware that the data, minus any unique identifying information, may be included in any publications to come from this study, with the understanding that all data in publications or presentations will be anonymous.

I am aware that I may temporarily pause data collection on any particular device by using the measurement app's interface.

I was informed that I may withdraw my consent at any time without penalty by advising the student or principal investigator.

This study has been reviewed and received ethics clearance through a University of Waterloo Research Ethics Committee (ORE#21756). If you have questions for the Committee contact the Chief Ethics Officer, Office of Research Ethics, at 1-519-888-4567 ext. 36005 or

For all other questions contact Erinn Atwater at (519) 888-4567 ext. 31337 or via email at