We’ve been thinking a lot about contact tracing apps in recent weeks. There are ongoing debates about whether a centralised or decentralised model is superior, and how the ensuing discussions around privacy will impact their takeup.
More details of the UK's controversial NHSX contact tracing app are being released as the app starts a wider scale trial on the Isle of Wight this week. NHSX is a digital transformation group associated with the UK National Health Service.
Why controversial? There are many reasons, some to do with how the app development was initially procured, but also specifically from a technical perspective as the UK has opted for a centralised contact tracing approach rather than the decentralised model being championed by Apple and Google amongst others (including ourselves).
Recent years have seen a move towards cloud platforms and mobile health apps for citizens -- applications and data processing systems that enable ordinary people to interact with their health providers, make appointments with medical professionals, order prescriptions, and gain on-demand access to their medical records. The ongoing COVID-19 pandemic is putting greater emphasis on this trend, as citizens clamour for the latest news, advice, and best practices, while government and health organisations look to digital technologies to help them develop treatment protocols, track the progress of the virus spread, and monitor the condition of all those affected.
Last Friday, there was an unusual joint announcement from Apple and Google providing details of a new phone API for Covid-19 contact tracing via Bluetooth. The protocol allows mobile phones to continually transmit Bluetooth advertisements to one another. This includes a proximity identifier derived from randomly generated keys that can be held secretly on each device. If a phone user is later diagnosed with Covid-19, they are able to upload the daily tracing keys for those days when they might have been infectious.