Peer-to-peer track and trace networks are now a thing

Once governments lift their shelter-in-place orders, we’ll still need a way to track infections and trace the contacts of people who are infected, especially if we want to resume any sort of normalcy. Governments at the federal level around the world are trying to figure out how to implement some kind of track and trace system while also weighing the potential threats to privacy.

In China, the solution has been monitoring where citizens travel by tracking what they buy. If someone buys a bus ticket, for example, and later tests positive for COVID-19, they’ll be able to let that person know if they were exposed to the novel coronavirus by a fellow passenger. In Singapore, the government has ordered citizens to download an app called TraceTogether, which uses Bluetooth to track people and their contacts.

Privacy isn’t top of mind for the governments of either of those countries, and in the U.S. pundits have suggested that maybe the big tech companies have a role to play since they already have access to our phone’s location. But there’s another option. Nodle, a company that runs a peer-to-peer Bluetooth connectivity network, has built an app that can provide the ability to track and trace people’s movement while also protecting their identity.

Nodle is launching the so-called Coalition app this week, when it will be available in the Apple App Store and the Google Play Store. The app uses a phone’s Bluetooth connection to note the other phones nearby. If a user nearby is later infected and had self-reported their status to the Coalition app, then anyone who passed that person or spent time with them will get a notification that they have been exposed.

However, no one will know who the exposure came from because Nodle hides the identity of the app’s users. Obviously the success of the Coalition app depends on getting a significant number of people to download it. Currently, only 25,000 people are using the Nodle Cash app to share their Bluetooth location in return for a cryptocurrency token that may or may not be worth anything in the future. (I run the app, mostly because I like sharing network connectivity for sensors or devices that might need it.)

Additionally, the first iteration of the app will be a somewhat blunt tool. Bluetooth is a personal area network, but it can stretch the length of a large room and certainly beyond the CDC’s current recommendation of staying six feet away from other people. Getting a notification that you’ve been exposed simply because you walked past a particular person on the street for all of two seconds could incite a lot of unnecessary anxiety.

Micha Benoliel, CEO of Nodle, says that later iterations of the app will use signal strength to detect how far someone is from the handset, and will also take into account the amount of time that passes with a person in range. From there, he’d like to have the app calculate some type of exposure score so as to be able to offer a better indication of any potential risk.

Another issue is that the app depends on people self-reporting their status. Absent a government order mandating its use, along with some kind of related enforcement, Coalition will amount to little more than a nice-to-have attempt at being a good citizen. But the U.S. government and others are clearly interested in track and trace technology, and I like the idea of a solution that runs on most phones and can help protect user privacy.

Benoliel says the app was designed with the ethical guidelines suggested by the Community Epidemiology in Action Project in mind. He also says it’s designed to work with Singapore’s TraceTogether, so if someone is running that app on their phone it can share information (but not identity). I like the privacy protections woven into the app and believe that with a campaign to get more people to download it and then use it to help them determine if they need to self-quarantine, we could get a more democratic and privacy-protecting form of contact tracing.

However, I also know there are plenty of people out there who may not self-report, or who will ignore the recommendations of such an app unless the government steps in and forces them to stay home.