BRANDEN GHENA pulls his car up under a traffic light in a city in Michigan. He plugs a radio transmitter into the car鈥檚 power adapter, connects it to his laptop and, with a few keyboard strokes, takes control of every traffic light in town.
鈥淲e were able to advance the light,鈥� Ghena says of the experiment, which took place in May. 鈥淲e could make it turn green.鈥�
Ghena, an electrical engineer at the University of Michigan, and his team were exploiting a vulnerability in the light鈥檚 traffic controller. Present at every signalled intersection, the controller switches between red, yellow and green lights according to its programming. It can be set to change at regular intervals, or based on input from external traffic sensors.
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These controllers are often networked across a city, and receive commands via a sequence of data packets. This allows engineers to manage them remotely, but anyone with network access can send these commands. All Ghena had to do was figure out which sequences of packets corresponded to which controller commands, and he gained full control.
鈥淚t鈥檚 great research,鈥� says Cesar Cerrudo, a professional hacker and chief technology officer for IOActive Labs. Cerrudo earlier this year. He showed that it was possible to spoof the sensors that feed into the traffic controller, making the lights think that cars are waiting at a light when they aren鈥檛, for instance. 鈥淸Ghena鈥檚 work] and my research make me scared of driving in the US,鈥� he says.
Part of Ghena and his colleagues鈥� agreement with the traffic department that authorised their study was that they wouldn鈥檛 reveal the name of the city concerned, or who made the vulnerable equipment. But Ghena says the vendor in question has traffic controllers installed at 100,000 intersections across the US. The Federal Highway Administration .
The US government has recognised the country has a problem with its infrastructure 鈥� in 2013, President Barack Obama signed an executive order that called for for critical systems like electricity grids, water utilities and transport networks.
An attack can do more than create havoc for its own sake. 鈥淚f you were robbing a bank, you could cause a lot of congestion between you and the police station,鈥� says Ghena. And thieves or even just an impatient commuter could easily set up a corridor of green lights for themselves. Ghena will present the work at on 19 August in San Diego, California.
聯If you were robbing a bank, you could cause a lot of congestion between you and the police station聰
This isn鈥檛 the first time that traffic infrastructure has been shown vulnerable to digital attack. In October last year, the signalling systems in the Carmel Tunnels in Haifa, Israel, were taken over, with the attackers gaining control through a weakness in the traffic cameras. The , causing massive congestion.
鈥淭he attack space is growing every day,鈥� says Cerrudo. 鈥淚n the past you had viruses that affected PCs. In the future we鈥檙e going to see malware for everyday objects, because they鈥檙e all like small computers.鈥�
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This article appeared in print under the headline 鈥淕ridlock alert鈥�
