Contact tracing is essential to controlling the spread of infectious disease and plays a central role in plans to safely loosen Covid-19 physical distancing measures and begin to reopen the economy. Contact tracing apps, used in conjunction with established human contact tracing methods, could serve as part of Canada’s “test, trace, and isolate” strategy. In this brief, we consider the potential benefits of using contract tracing apps to identify people who have been exposed to Covid-19, as well as the limitations of using this technology. We also consider the privacy implications of different app design choices. Finally, we consider how the privacy impacts of contact tracing apps could be evaluated under the Canadian Charter of Rights and Freedoms, which provides a framework for balancing competing rights and interests. We argue that so long as apps are carefully constructed and the information they reveal is appropriately safeguarded, tracing apps may have a role to play in the response of a free and democratic society to the Covid 19 pandemic.
1. Improving the Efficiency of Human Contact Tracing: The public health goal of a contact tracing app should be to integrate with human contact tracing and make it more efficient rather than replace it. We need to keep humans in the loop to ensure accuracy and to maintain the important social functions of contact tracing, which includes educating people about risks and helping them access social supports.
2. Privacy Choices: Currently, the most privacy-protective design for contact tracing apps makes use of proximity data (via Bluetooth) through a decentralized design. This method is receiving significant technical support from Apple and Google. However, this method fails to integrate with the human contact tracing system. Other options, such as the use of location logs or a centralized registration system, are more aligned with the public health goal of integration with human contact tracing but raise additional privacy questions. In addition to the constitutional questions raised by these privacy choices, there are two important considerations. First, social trust is important. If individuals do not feel comfortable with using a particular contact tracing app there will not be the large-scale uptake needed to make these an effective addition to human contact tracing. Second, due to various technical challenges, it is difficult to make effective contact tracing apps utilizing proximity data unless one uses the method supported by Apple and Google. However, Google and Apple prohibit app developers both from utilizing centralized methods and from utilizing location data.
3. Constitutional Balancing: Our privacy commissioners have discussed the need to assess these privacy choices according to the principles of necessity and proportionality. The Canadian Charter provides an important framework for thinking about these principles as it provides us with a framework for how to balance rights and interests in a free and democratic society. The Charter requires that we choose the most privacy-protective app design that meets the public health goal, so long as the benefits of meeting this goal outweigh its deleterious effects on privacy. This requires a reasonable belief in the efficacy of such an app. It also requires an assessment of the nature of the benefits, which are not just the economic benefits of reopening the economy. The currently prevailing restrictions on movement and work are themselves limitations of basic rights and liberties. Individuals who self-isolate in situations of poverty, precarious housing, mental health challenges, abusive relationships, or other vulnerabilities face challenges that affect their security of the person. There are also broader effects on equality and human flourishing. If contact tracing, enhanced by an app, reduces the need for restrictions in the form of self-isolation, it promotes other Charter rights and values (e.g., security of the person) which must be balanced against the potential infringement of privacy rights.
Tanguay-Renaud, François; Austin, Lisa M.; Chiao, Vincent; Coleman, Beth; Lie, David; Shaffer, Martha; and Slane, Andrea, "Test, Trace, and Isolate: Covid-19 and the Canadian Constitution" (2020). Articles & Book Chapters. 2797.