Here's How Hackers Could Cripple NYC's Streets

NEW YORK — Hackers have stolen social security numbers, emails and surveillance photos — and your commute could be next. Cyberattackers could bring Manhattan's streets to a grinding halt if enough New Yorkers drive cars connected to the internet, a new study warns.

Hackers would only have to disable 20 percent of the cars on the borough's roads during rush hour to stop traffic completely, physicists from the Georgia Institute of Technology and the materials firm Multiscale Systems, Inc. argue in their paper published Tuesday.

At midday, attackers would have to stall about 30 percent of all vehicles on the streets — or 13 cars per kilometer in each lane, according to a synopsis of the study in the journal Physical Review E. But it could be even easier to wreak havoc in other big cities.

"Manhattan has a nice grid, and that makes traffic more efficient," Peter Yunker, an assistant professor at Georgia Tech's School of Physics who co-led the study, said in a news release. "Looking at cities without large grids like Atlanta, Boston, or Los Angeles, and we think hackers could do worse harm because a grid makes you more robust with redundancies to get to the same places down many different routes."

The study stands as a warning of how cyberattacks could cause a physical mess in the city amid a reported rise in data breaches, such as the recent Capital One hack involving about 100 million people's personal information.

The researchers simulated how traffic would react if some vehicles suddenly stopped and became obstacles to others on the road. They chose Manhattan for their case study because there is ample data available on the borough's traffic patterns, according to Georgia Tech's news service.

They determined that hackers would only have to stall 20 percent of all vehicles to create a "total traffic freeze" at rush hour, said David Yanni, a Georgia Tech graduate assistant who coauthored the paper.

"At 20 percent, the city has been broken up into small islands, where you may be able to inch around a few blocks, but no one would be able to move across town," Yanni said in the news release.

That means an attack would only have to hit half of Manhattan's internet-connected vehicles if they accounted for 40 percent of all cars on the road, researchers say. That might sound like an ambitious hack, but more and more cars are getting online: The size of the global "connected car" market is expected to grow from about $73 billion in 2018 to $219 billion in 2025.

The physicists based their study on percolation theory, which scientists use to judge whether a certain quality will spread throughout a substance. While they did not draw any conclusions about the likelihood of a traffic-halting hack, they said their estimates are conservative because they did not factor in blocked cars turning onto different roads — or the panic that would ensue if vehicles randomly came to a halt.

To prevent a traffic disaster, the researchers suggested breaking up the digital network on which many cars run and working to protect nearby cars from being hacked at the same time.

"With cars, one of the worrying things is that currently there is effectively one central computing system, and a lot runs through it," another co-author, Multiscale Systems's Jesse Silverberg, told Georgia Tech's news service.

"You don’t necessarily have separate systems to run your car and run your satellite radio," he added. "If you can get into one, you may be able to get into the other."