UCL Faculty of Laws


UCL research enables privacy-preserving COVID-19 tracing technology

Research at UCL Laws was instrumental in developing contact tracing technology during the pandemic that protected people’s privacy.

Person looking at their phone while walking down a flight of stairs.jpg
As the advent of COVID-19 forced the rapid development of contact tracing technology, new questions were raised around digital privacy and rights. How could governments develop technology to trace people exposed to a COVID-positive individual, while still keep their data safe?

It was clear all digital contact tracing approaches were vulnerable to privacy threats, but that centralised systems would involve greater risks, with the potential for abuse of data.

Dr Michael Veale (UCL Laws) was the main legal researcher contributing to a groundbreaking project in this area, called Decentralised Privacy Preserving Proximity Tracing Protocol (DP-3T).

Dr Veale worked with an international consortium of universities to facilitate notification of exposure to a COVID-positive individual without individuals being identifiable to anyone else. The new protocol used the idea of rotating codes, which meant tracing apps could notify people who may have been exposed to the virus, without having to know their identity.

The team’s work inspired Apple and Google’s approach to building decentralised proximity tracing capability into their operating systems, called ‘Exposure Notification’.

It also led to the UK government abandoning its centralised app, and using a decentralised design instead based on the DP-3T protocol.

From its launch until its retirement in May 2023, the app had been downloaded over 31m times. This corresponds to ~64% of the adult population of England and Wales (although some may be re-downloads), and its use is thought to have averted around 594,000 cases of COVID-19.

At least 65 official national or regional COVID-19 contact tracing apps have since been developed globally, using the privacy-preserving technology, covering over 90% of smartphones and 372m people.

Read more on the UCL Research Impact website

Find out more 

Image credit: © UCL Digital Media