Critical Infrastructure

Traffic cybersecurity gets a red light

Shutterstock image: traffic light.

Cybersecurity vulnerabilities in autonomous motor vehicles have worried federal researchers and automakers for years, but a new study warns that the traffic light infrastructure already offers easy pickings for hackers.

Five researchers in the University of Michigan's Electrical Engineering and Computer Science Department teamed up with a Michigan road agency to see if they could hack into wirelessly networked traffic light systems. The results of their work, published in August and aptly titled "Green Lights Forever," show that those systems have few barriers to stopping hackers from seizing control of the traffic devices and possibly wreaking havoc.

"The critical nature of traffic infrastructure requires that it be secure against computer-based attacks, but this is not always the case," the researchers wrote.

In its work with the unnamed Michigan agency, the team found that the systems, which controlled as many as 100 traffic lights, lacked encryption, had no secure authentication requirement and were vulnerable to known exploits. Any one of those weaknesses could open the door to a denial-of-service attack, traffic congestion or hackers seizing command of the control system, researchers said.

The report comes as the National Highway Traffic Safety Administration is moving forward with a plan for a crash-avoidance system for networked vehicles on U.S. highways. On Aug. 18, NHTSA issued an advance notice of proposed rulemaking to solicit public comments on the technical specifics of its plans for a system that would use onboard wireless devices to transmit and share critical safety information among vehicles on the road. Skeptics continue to voice concerns about the implications for physical safety and cybersecurity.

In July, the Alliance of Automobile Manufacturers created a voluntary information sharing and analysis center aimed at protecting the cybersecurity of increasingly Internet-wired vehicles. The organization said the center would collect and share information about existing or potential cybersecurity threats and vulnerabilities in motor vehicle electronics or associated in-vehicle networks.

The Michigan research shows that cybersecurity remains a tough issue for future autonomous vehicles and traffic control infrastructure. "With the appropriate hardware and a little effort, an adversary can reconfigure a traffic controller to suit her needs," the report states. "She can execute a denial-of-service attack to cripple the flow of traffic in a city, cause congestion at intersections by modifying light timings, or even take control of the lights and give herself clear passage through intersections."

The report noted that the U.S. Transportation Department has invested heavily in vehicle-to-vehicle (V2V) and vehicle-to infrastructure systems since 2002 and has recently started the Connected Vehicle Safety Pilot Program as a way of testing those systems in the field.

"This paper shows that these types of systems often have safety in mind but may forget the importance of security," the authors wrote. "Depending on how information is transferred in these systems, adversaries may be able to inject falsified data into the V2V network. Even if such systems are designed with safety in mind, a lack of security could have dangerous consequences."

About the Author

Mark Rockwell is a staff writer covering acquisition, procurement and homeland security. Contact him at or follow him on Twitter at @MRockwell4.

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Reader comments

Fri, Aug 29, 2014

Encrypted or unencrypted, the stoplights know when I am coming its way! :(

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