Apple and Google are doing something they almost never do,

work together.

- Beginning next month,

Apple and Google are releasing software.

- [Newscaster] The two companies will roll out

a contact tracing system.

- [Newscaster] Will use Bluetooth to help notify someone

if they've been in contact with someone who's infected.

- On April 10th,

the companies announced a new project to halt

the spread of the novel coronavirus.

It's a system for automatically

and autonomously logging all

the people you've been in contact with.

So if one of those people gets diagnosed with coronavirus,

you'll get an alert saying you've been exposed

and should quarantine.

It's a really ambitious project

and we're only a couple weeks in,

but it could make a huge difference

in how we recover from the outbreak.

The system works by blasting out short codes over Bluetooth,

technically the Bluetooth low-energy beacon system.

Your phone collects a log of all the codes you've received,

representing all the people

who have been close enough to infect you.

Those codes are encrypted and constantly changing,

so you can't use them to work back to a person's identity.

Even if someone does test positive

and decides to share that diagnosis,

it's still pretty hard to figure out who the person is,

although it's not completely impossible.

More importantly,

the codes you collect never leave your phone.

So there's no master list of who's interacting with who.

The details here are a little complex,

and we'll link to a more thorough explanation

in the description,

but the important thing is

it's not collecting absolute location data,

and there are a lot of measures

to keep you anonymous while you're using it.

Apple and Google hope to make an API available

to public health agencies by mid-May,

which means that by the summer,

you could see an app using this system built

and distributed by your state government.

In the months after that,

they're gonna ship it as an update to iOS and Android.

So it'll still require explicit permission,

they're not trying to sign anyone up

for this against their will,

but don't be surprised

if you start seeing pop-up notifications asking

if you wanna join the project.

That's important because by the time the summer gets here,

we're gonna really need a system like this.

We don't know how the outbreak is gonna play out,

but optimistic projections show U.S. hospitalizations,

peaking in April and declining throughout May,

assuming we keep social distancing restrictions in place

and do everything else right.

As we start to open up again,

we're gonna need some way

to keep contagious people quarantined

while everyone else goes back to work.

And because people can be contagious for five days

before they show any symptoms of the disease at all,

that's gonna be really hard.

People who work with outbreaks have a system for doing this,

although we've never done it at this scale before,

it's called contact tracing.

Basically, when someone gets a positive diagnosis,

you sit them down and run through everything they did

during the contagious period.

Where they went, who they talked to,

anyone who might've been close enough to catch the disease.

Then you find all of those people

and get them into quarantine,

making sure this particular infection doesn't spread

any further than that circle of people.

If you're doing enough tests and quarantining enough people,

then the disease has nowhere to spread.

We've seen this system work for coronavirus

in countries like Singapore and South Korea,

and it's generally been through mobile alerts.

It's a lot easier to get 15 people's phone numbers

than to track down 15 people in person.

And if you cut out the interviewer

and just have an app do it, it's even simpler.

Outside of Singapore and South Korea,

most countries haven't been able

to launch a contact tracing app,

although a lot of places have tried.

But having Apple and Google onboard means you know

this system will ship to billions of phones

and you know there won't be any permissions problems

about collecting the Bluetooth data.

They're the only two companies in the world

that can do this,

so having both of them signed on makes

a huge difference in what you can do.

At the same time,

there's a lot that Apple and Google

are explicitly not gonna do.

They're not building the alert apps

or setting rules for how to quarantine.

They aren't even touching the question

of how you verify that everyone

who sends an alert through the app actually is infected,

weeding out the trolls and false positives.

All they've built is a way to log contacts and send alerts,

and then a way to get that system onto phones.

Everything else is gonna come down

to the public health agencies,

which have never dealt with anything on this scale before.

There's a real question as to how much people trust them

with this system.

And an even bigger question is

to whether they can pull it off.

So far, most of those agencies have been too busy scrambling

for hospital beds and ventilators to get much

of a contact tracing effort underway.

We still don't have nearly enough testing

and the federal response has given way

to a kind of free-for-all among the states

who are already running out of resources.

Apple and Google just can't solve that problem.

But if the system they've laid out is gonna work,

those agencies and the public sector in general

are gonna have to get better fast.

So we're doing a ton of reporting on this system

and there's a lot that didn't make it into this video,

so we're leaving a bunch of links in the description

and there's a bunch more stuff coming

that's gonna be on the site in the next week or so.

So stay tuned for that,

and otherwise, stay safe out there.