Several countries have been experimenting, or have rolled out, mobile-phone-based efforts to track the spread of Coronavirus – often based on GPS. While the US government is in discussion with leading tech companies, policymakers, data security experts and legal consultants have gone back and forth on the concept. There are concerns that such apps might not be well adopted, could possibly discriminate between cases owing to insufficient data,and potentially introduce privacy or security issues. However, tech giants are re-purposing the data already in their store to track and contain the pandemic, while the debate rages on. Both Google and Facebook have published maps and reports on human movement, collective and individual behaviour patterns and potential contacts within specific regions.
A low-profile 21-year-old wireless technology has been at the crux of all such efforts. Bluetooth, best known so long for pairing audio devices, is the backbone of most contact-tracing apps that are being designed to track possible exposures to the Coronavirus.
The principle is beguilingly simple. While turned on, Bluetooth constantly scans for other devices. To do this, your phone uses wireless signals to see who you’ve been near. Anyone who tests positive for COVID-19 can feed the information to the tracking app, which will alert everyone else close by through Bluetooth wireless signals.
Researchers at MIT is playing along with the possibilities offered by Bluetooth. The multi-organization Private Automatic Contact Tracing (PACT) team from MIT is leveraging the short-range data strings known as “chirps” that smartphones regularly emit over the Bluetooth functionality to connect with other devices.
Anyone who installs the PACT appenable their phone to continuously send out such random data strings and keep a log of similar incoming strings from other registered phones. If a member ever tests positive for the Coronavirus, they would receive a QR code that notifies their status to a Cloud system. The tool also keeps track of the distance between participating devices and their contacts, and how long they remain within warning range throughout the day.
MIT Professor Ron Rivest, principal investigator of the PACT project,said in an interview with MIT News:“…for these broadcasts, we’re using cryptographic techniques to generate random, rotating numbers that are not just anonymous, but pseudonymous, constantly changing their ‘ID,’ and that can’t be traced back to an individual.”
However, Bluetooth-based tracking has its own pitfalls. Getting correct information is going to be difficult, because disclosure cannot be monitored 100 percent. Accurate measurement from Bluetooth signals is another issue; a host of disruptions can interfere – even changing the position of the phone from horizontal to vertical. While authorities need to strike a balance between privacy and disclosure, developers must analyze more data before such tracking systems become truly effective, and not mere tools to while away idle times.