You can add “contact tracing” to your list of newfound medical terms. This method for slowing down the spread of disease is going high-tech with Apple and Google’s plan to turn your smartphone into a coronavirus tracker. We’ve recoiled against advertisers, tech companies and even the government tracking us for years. But what about when that tracking is for the greater good? Here’s a look at how smartphone contact tracing works and what it means for your privacy.

Wait, what’s contact tracing?

Contact tracing isn’t a tech term but a medical one. In a nutshell, the process involves interviewing infected individuals to find out who they’ve been in contact with recently. Healthcare workers contact those people and advise them to self-quarantine or take precautions. It’s part detective work, part medical process and all for the good of fighting disease. Things get a little trickier when it comes to COVID-19. The virus has a long incubation period and it can spread quickly. Coronavirus is more contagious than the seasonal flu but less contagious than measles. The World Health Organization says the average patient infects at least two people. With social distancing and shelter-in-place in effect, people are likely to have encountered far fewer people than they would have otherwise. This makes it easier to narrow down at-risk people before they have a chance to infect others. But what happens when business reopen and people start leaving their homes more? That brings us to the high-tech side of things.

How digital contact tracing works

Big Tech companies want to make the process of identifying those infected with COVID-19 — and notifying people around them — as simple as opening your smartphone. Apple and Google have teamed up to develop this technology for iPhone and Android users. In the U.S. alone, we’re talking a combined 230 million devices. But instead of calling it contact tracing, the two companies decided to start referring to it “exposure notification.” The tech will use Bluetooth and an app from “public health authorities” to alert you if you come in contact with someone who might be infected with COVID-19 — if you opt-in. Here’s how it would work:

Phones enrolled in contact tracing will send signals to one another using Bluetooth.If someone is within a close enough range for a sufficient period of time (around five minutes), the phones will register one another as a contact.Anyone who has tested positive for the coronavirus can input that info, and that data is anonymously broadcast to phones marked as contacts. If you’ve been exposed to the virus, you’ll be alerted. The timeframe will be set by local authorities.From here, it’s up to the individual to self-isolate or seek medical attention.

Recent advances in Bluetooth, like the Bluetooth 5 bands found in the iPhone 8 and above, make this system possible. These new Bluetooth standards have shorter latency times, wider ranges and are able to switch between devices much quicker than older antennas. All the particulars aren’t clear yet, but the system appears to be cross-platform compatible — meaning Android phones and iPhones will be able to talk to each other over Bluetooth.

When is this coming to my phone?

Apple and Google are projecting a release date within the next few months. Developers will get early access to the program starting as early as April 28. Not all devices will be eligible, however. Of the 3.5 billion smartphones in use around the world, the Financial Times reports as many as 2 billion of those won’t be able to use the new system, either because they’re too old to have the necessary Bluetooth standard or the latest operating system. Not only that, but Google may also only be able to include newer Android devices in the program — which will potentially leave out millions of Android owners. This is because so many different manufacturers make Android devices, and software releases from Google are fragmented. As many as 500 million Android users could be left out.

A privacy nightmare for the greater good?

Now, if your phone is eligible, should you opt-in? Third-party apps will do the tracking and communicate between iPhones and Google’s Android software, which powers all the other big smartphone brands. Are there privacy concerns here? You bet. But both companies emphasize that participation will be both anonymous and voluntary. As far as Bluetooth privacy is concerned, Apple and Google released a few new details late this week. First, Bluetooth metadata will be encrypted, meaning it can’t be used to identify your phone. And there will be two kinds of keys generated to protect your identity. One is created every 24 hours, and other keys will be randomly generated every 10 to 20 minutes. Still, someone is building a vast database of who’s had the virus, who hasn’t and who is contagious right now. Users will upload health data to servers owned by Apple and Google, and this data will explicitly be shared with state healthcare systems. In China, state-run firms pushed mandatory apps to citizens that not only traced contacts but tracked movement in quarantine zones. Most likely, this kind of policy wouldn’t fly all too well here in America. That said, handing data over to state officials and tech companies on such a massive scale could set a dangerous precedent for the future. The government could mandate location-tracking applications like China does to prevent large-scale public gatherings. While this can help prevent the spread of diseases like COVID-19, it could also be used in other ways. Then there’s the issue of storage. Even if the data is truly anonymized and heavily encrypted, such a large cluster of personal information would be an insanely valuable target for cybercriminals. A single misplaced password or misconfigured server would put millions of people in harm’s way. It’s no exaggeration to say that Apple and Google have their work cut out for them. But early attempts at contact tracing in countries like South Korea have shown positive results in flattening the curve. Once we reach the tail-end of this pandemic, it will be critical in containing the disease. Until then, it’s up to the users: Will you opt-in or not? Your health could be at stake. The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have regarding a medical condition, advice, or health objectives.