Researchers at the IMDEA Networks Institute, together with European partners, have discovered that tire pressure sensors in modern cars can expose drivers to unintentional tracking, raising privacy concerns. During a ten-week study, they collected signals from more than 20,000 vehicles, revealing a hidden privacy risk and underscoring the need for stronger security measures in future vehicle sensor systems.
Most modern cars are equipped with a Tire Pressure Monitoring System (TPMS), mandatory since the late 2000s in many countries for its contribution to road safety. This system uses small sensors on each wheel to monitor pressure and sends wireless signals to the vehicle’s computer to warn if a tire is underinflated.
However, the research found that these sensors also send a unique identification (ID) number in clear, unencrypted wireless signals. This means that anyone nearby with a simple radio receiver can capture the signal and recognize the same vehicle again some time later, posing serious privacy measures.
TPMS based tracking
Most vehicle tracking today uses cameras that need clear, direct visibility. TPMS tracking is different: The sensors automatically send radio signals that pass through walls and other vehicles, allowing small hidden wireless receivers to capture them without being detected. Since each sensor emits a fixed unique ID, the same car can be recognized repeatedly without needing to read the license plate. This makes TPMS-based tracking cheaper and harder to both detect and prevent than camera-based surveillance, posing a greater threat to privacy.
To test the severity of this risk, the researchers built a network of low-cost radio receivers located near roads and parking areas. Each receiver costs only $100. In total, they collected more than six million messages from sensors from more than 20,000 cars.
“Our results show that these signals can be used to track vehicles and understand their movement patterns,” says Domenico Giustiniano, Research Professor at IMDEA Networks. ‘This means that a network of inexpensive wireless receivers could discreetly monitor traffic in real-world environments. “Such information could reveal daily routines, such as work arrival times or travel habits.”
Identification accuracy
The researchers also developed methods to match the signals from all four tires on the same car. This increased accuracy by identifying specific vehicles arriving, leaving, or following regular schedules. The study proved that signals can be captured from moving cars and from distances greater than 50 meters, even when the sensors are inside buildings or hidden places. This makes covert tracking technically feasible.
Additionally, TPMS signals include pressure readings, which could reveal the type of vehicle or whether a car or truck is carrying heavy loads, allowing for more advanced forms of monitoring.
“As vehicles become increasingly connected, even safety-oriented sensors such as TPMS should be designed with cybersecurity in mind, as data that seems passive and harmless can become a powerful identifier when collected on a large scale,” highlights Dr. Alessio Scalingi, former PhD student at IMDEA Networks and now Assistant Professor at Universidad Carlos III de Madrid.
No encryption or authentication
Despite these risks, current vehicle cybersecurity regulations do not yet specifically address TPMS security. The research team warns that without encryption or authentication, tire sensors remain an easy target for passive surveillance.
Each receiver costs only $100. In total, they collected more than six million messages from sensors from more than 20,000 cars.
“TPMS was designed for road safety, not computer security,” adds Dr. Yago Lizarribar, who participated in the work during his PhD at IMDEA Networks and is currently a researcher at Armasuisse, Switzerland. “Our findings show the need for manufacturers and regulators to improve protection in future vehicle sensor systems.”
Therefore, the research team urges the industry and public policy makers to strengthen cybersecurity in the cars of the future, so that security systems do not become tracking tools. The paper, titled “Can’t Hide Your Stride: Inferring Car Movement Patterns from Passive TPMS Measurements,” has been accepted for publication at IEEE WONS 2026.
