For Covid-19 Apps, a Tug of War Between Privacy and Efficiency

(Bloomberg Businessweek) -- As the global pandemic stretches into its ninth month and governments around the world seek to create contact-tracing apps, they’re grappling with a fundamental dilemma: how to design a program that’s effective without compromising the privacy of those using it. “Many people don’t trust these apps,” says Annelies Blom, a researcher at Germany’s University of Mannheim who has studied the willingness of people to install such technology. “They fear they will be traced somehow.”.The difficulty is in identifying people who have spent time near someone who has been infected without tracking exactly where they’ve been at every moment. Of the roughly 40 countries with such apps, more than a third—most of them with questionable democratic credentials—use location-tracking technology that could compromise privacy..But for others such as Germany, where privacy is a national obsession, it’s more difficult. The solution most privacy-minded countries have come up with is a decentralized approach using Bluetooth, which researchers acknowledge is less than ideal but the best they’ve got..With Bluetooth, each phone sends a code to other handsets it comes close to, information that’s stored only on a user’s phone and only for about two weeks. People who test positive are asked to register their infection in the app, which sends a message out to the system. Periodically, each phone checks in to see if it’s holding the codes of any infectious people. If so, the phone alerts the user without disclosing when or where the contact took place..So far, there’s only been modest uptake of such technology in most countries. An Oxford University study found that an app installed by about 60% of the population could stop the pandemic, though smaller numbers could reduce infections and deaths. In Qatar, where the government has required use of its app, more than 90% of the population has installed it. Next is Singapore, which requires all migrant laborers to use the app, with 41%..In countries with greater social pressure for privacy, the numbers tend to be lower. In Ireland and Switzerland, roughly a quarter of the population has downloaded the app. In Germany, it’s about a fifth and in Italy it’s less than one-tenth. France is unusual among its western European neighbors in storing data on a central server. Just 4% of the population has downloaded its app..There’s considerable debate about how effective these apps can be. In Switzerland, where health authorities say 17% of the population uses the app daily, 12% of Covid-19 cases have been reported via the program—meaning the contacts of those people could be traced. In the Australian state of New South Wales, the app has found more than 50 cases, including 14 that wouldn’t have been discovered through manual contact tracing. In Germany, by contrast, tight privacy rules make it impossible to say how many infections the app has helped find..At least two countries have scrapped their programs because of privacy concerns. Iceland and Norway went for an approach that stored data on central servers and used location tracking, which privacy advocates in those countries objected to. “We thought it was a great intrusion and we did not feel that they had documented why this was necessary,” says Susanne Lie, an attorney with the Norwegian Data Protection Agency, which was instrumental in bringing about the ban..Douglas Leith, a computer science professor at Trinity College in Dublin, says there’s a fundamental flaw with the Bluetooth apps: The type of phone, where it’s being carried (say in a bag or pocket), and the direction it’s facing can influence signals. And in a train or bus, he says, the waves can bounce off the walls, making the system even less reliable. “All the apps running on Bluetooth have the same problems,” Leith says..Carmela Troncoso, a researcher who worked on the SwissCovid program, acknowledges that Bluetooth isn’t perfect. But she says the apps are still useful because they can anonymously alert people that they’ve been near an infected stranger in, say, a train station or mall—something in-person contact tracing could never reveal. And even for easily identified contacts, an app is likely to be faster. “We’ve done a lot of tests, and we don’t think the error makes a big difference for the overall goal of saving lives,” Troncoso says..And researchers say that using the apps should only be one part of the campaign against the virus. Masks, social distancing, quarantines, and interview-based contact tracing are just as important. Using an app “is pretty good for where we are now,” says Marc Zissmann, a computer scientist at MIT studying coronavirus apps. “But we have to remember that it is only one part of the puzzle in fighting the pandemic.” Read next: Covid Gag Rules at U.S. Companies Are Putting Everyone at Risk.©2020 Bloomberg L.P.

For Covid-19 Apps, a Tug of War Between Privacy and Efficiency

Bluetooth is the technology of choice, but it’s far from perfect.

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