Can a technological intervention stem the pandemic while avoiding the privacy pitfalls of location tracking?
The UK Government recently announced that it was ceasing development of its current contact-tracing app; on the same day, the Canadian Government stated that it was developing one. All this in the same week that the Norwegian health authority had to delete all data gathered via its contact-tracing app and suspended further use due to a ruling by the Norwegian Data Protection Authority. And if these examples are not enough to demonstrate the utter confusion, the Australian app is reported to have a bug that stops iPhones from reporting possible close contacts.
It’s clear that there is no single or quick solution that is going to resolve the individual needs of the world’s health and government agencies that are attempting to use technology to assist in reducing the infection rates of COVID-19.
According to Wikipedia, more than 30 countries have, or are planning to release, apps designed to contact trace or geo fence their users, for the purposes of limiting and managing the spread of COVID-19. The development cycle and distribution of these time-sensitive solutions is itself unprecedented. Ask the members of any app development team if they could develop an app and the infrastructure to support 100 million or more users in under three months and they would say no – and that’s after they stop laughing at the suggestion.
Coming to a phone near you
The concept of contact tracing is to inform people that they may have come into contact with another person who has contracted or is showing symptoms of an infectious ailment, in this case COVID-19. The recipient of the notification can then take precautionary measures, such as self-isolation. This has proven a successful tool to assist in eradicating other diseases such as smallpox and has been used to control others such as tuberculosis, measles and HIV. With large portions of the world population now carrying a smartphone, technology should be able to play an important role, which is why we are seeing a surge in the development of contact-tracing apps.
The majority of apps available are government sponsored and use a variety of different methods to fulfill their purpose, such as Bluetooth vs. GPS, centralized vs. decentralized, and not all are sensitive to maintaining the privacy of the user.
There are two main methods being used to glean the physical proximity of users. The first is the global positioning system (GPS): this uses satellite-based radio-navigation to approximate the individual’s location and the location of other app users. The second, more prominent, solution uses Bluetooth and signal strength to identify other app users’ proximity, allowing the devices to exchange handshakes rather than track actual location. There are some solutions that use a mix of both Bluetooth and GPS and some even use network-based location tracking, but these methods have significant location-tracking privacy issues and are fortunately limited to only a few developments. The primary technology in use by COVID-19 contact-tracing apps is Bluetooth, as it provides a higher level of privacy protection.
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There is an underlying issue though: Bluetooth discovery is not enabled while a phone is locked and the app requesting it is not primary. Until now there has been no reason for this to be enabled. Early versions of apps such as BlueTrace, the Singapore government’s solution, relied on its users keeping their phones unlocked. The UK NHS beta app had a unique solution to this, at least for Android, but it would appear the limits implemented by Apple in iOS have meant that this was unachievable and has required developers to work with the official Apple and Google Exposure Notifications API.
The joint Google and Apple solution, Exposure Notifications API, preserves privacy and provides a method of using Bluetooth Low Energy and cryptography to provide a contact-tracing infrastructure. Use of the API is limited to public health authorities and access is only granted when specific criteria around privacy, security and data are met. However, this API is only part of a solution that an app needs to deliver the functionality needed. If an app requests personal information, either directly or by other methods, it could render this privacy-friendly solution questionable. The perception of a potential user of a contact-tracing app using this solution may be that the app, due the Google and Apple solution, has been developed to preserve the privacy of the individual; this could give a false sense of security.
There is also speculation that the use of the Exposure Notification API and Bluetooth for proximity and distance measuring in iOS may not be accurate; this was alluded to by the UK Government when announcing the cessation of the development of its own solution. Some of the potential issues are detailed in an article published by MIT Technology Review: it claims that if a phone is standing up in your pocket in portrait rather than landscape, then this alone can adjust the received power and make it look like someone is across the room as opposed to being next to you. The research also mentions the issue of signals passing through bodies – for example, if two people are standing back to back, the signal may appear weak, and thus record an incorrect distance. The UK Government claims to have developed algorithms that alleviate some of these issues; let’s hope the tech giants at Apple are willing to at least explore the potential solution the NHS team claims to have.
Google and Apple’s solution joins eight other frameworks that have been created since the beginning of the pandemic. The frameworks have been created in parallel by a mix of technology companies, privacy organizations, academia and governments. If the world adopted one framework there would of course be standardization, but this also adds a single point of failure if the framework is compromised or fails to deliver the expected results. As frameworks have evolved,