App promises privacy with contact tracing

A new phone app that would let users know if they were exposed to someone infected with coronavirus — but designed to address privacy concerns users have had with other techbased contact tracing options — will soon be tested at UCSF’s hospital and medical school complex in San Francisco.

California public health officials are running the pilot program with UCSF and UC San Diego and are betting that app users who get an alert will quickly call their doctor, get tested and quarantine. It’s a system they hope can make a dent in the

pandemic.

It’s “designed to be completely anonymous,” Dr. Erica Pan, the state’s interim public health officer, said in a statement.

Phone apps have been less successful than anticipated in facilitating contact tracing, or finding who people have come in contact with to slow the spread of COVID19. Privacy concerns are one reason; getting people to download and use them is another. Tech companies are developing apps to address these issues.

Concerns about privacy and public health often collide in the era of COVID19, as state officials try to stop its spread through tests and personal questions. Yet some people are reluctant to respond, perhaps because they are in the country illegally or simply don’t like the intrusion. If an app tracks where you are and who you’re with, that can also be a dealbreaker.

And then there are concerns about health data from an app being leaked or hacked.

“When I think about privacy concerns with any health app, I think of the government and what they might do if they weaponize it against people,” said privacy expert Eric Goldman, a law professor at Santa Clara University who codirects the High Tech Law Institute and supervises the Privacy Law Certificate.

“The government could do things that could change my life: change my benefits, my immigration status,” Goldman said. “They could literally lock me up in jail and prosecute me.”

It’s dark stuff. But not beyond the possible, perhaps even in the U.S.

The new app promises to deliver contact tracing results without compromising privacy.

The petri dish for testing California COVID Notify in the Bay Area is UCSF, a medical center and university where thousands of essential workers cross paths: doctors, nurses, maintenance crews, vendors and countless others. And if any of them became infected, most couldn’t tell a contact tracer the name of everyone they came in contact with even if they wanted to.

The new app is intended to take care of that problem without naming a single person. It works like this:

As you go about your day, the app wirelessly seeks similar signals from the same app on nearby phones using Bluetooth, said Dr. Robert Kosnik, head of occupational health services at UCSF. He’s leading the rollout. At each encounter, the app generates a unique number that is stored in each phone and vanishes after 14 days. That’s the virus’ incubation time.

That’s about it — unless someone you’ve been near tests positive for the coronavirus. In that case, your app notifies you that you’ve had contact with someone who has tested positive. The app can tell you when the contact occurred and what to do next. But it can’t tell you where the contact happened because it’s not equipped with geolocation software. Nor can it identify whom you were exposed to.

If it’s you who tested positive, then you call a number on the app — under the pilot program,

it’s at UCSF — to get a code to tap into your phone. That triggers each unique number collected by the app over the last 14 days to notify the phones’ owners that they have been exposed. And so on.

“Holy cow,” said Bruce Mace, who, as director of facilities and support services at UCSF Health, oversees 175 essential workers — carpenters, plumbers, electricians and others — who show up at the hospital on Parnassus Avenue every workday. “We’ve had multiple COVID encounters.”

But when contact tracers ask for details, “all those things become blurry on busy days and over time,” said Mace, who has a beta version of California

COVID Notify on his phone. “It pinged me at 4 o’clock and said: ‘You’ve had no exposures.’ When I saw that, it shocked me, although it was because no one has the app yet. But I think this is going to be a big benefit of this product. It’s going to help.”

The app rests on a platform developed by Google and Apple called Exposure Notification Technology. From there, UCSF doctors and public health officials have been working to tailor the technology to the particular needs of essential workers, for example, calibrating how far away the wireless signals should be before they exchange unique numbers.

“The app does not collect, store or transmit any personally identifiable user information,” the state’s public health department said in announcing the pilot programs, which are expected to last a month.

“After reviewing the results of the pilot projects, the state will consider making the technology available to all people statewide,” Amy Tong, director of the California Department of Technology, said in a statement.

Myriad coronavirusrelated apps have not proved that they are the savior many had hoped. The widely quoted Oxford study found in April that 60% of people would have to use an app to actually vanquish the virus. At the same time, far fewer users could still slow the virus: For every one or two users, one infection will be averted, the study found.

Yet Goldman is skeptical that the new app being tested could achieve even that.

“It’s a pretty wellknown problem that the more privacy you have, the less useful” a thing is, he said. The new app, for example, simply tells you when you’ve been near someone who has tested positive — but that person may have been behind plexiglass or wearing a mask and gloves.

In other words, posing little risk but prompting the app user to get tested and worry. The app also may invite unscrupulous people to try to submit a false report.

“Neither are really privacy problems,” he said. “They are more ‘app design’ problems. Navigating away from the privacy problems potentially makes the app unhelpful.”

But those pilottesting the new app hope it will, in fact, be very useful.

Using it at UCSF will be voluntary, said Kosnick, adding that California COVID Notify will be just another one of many tools to improve safety until an effective vaccine is developed.

And Kosnick is confident that the new app will be more popular than people think, since it’s private, decentralized and generates only random numbers.

It’s anonymous, he said. “That seems to matter.”