Bluetooth Secure Proximity

Enabling secure micro-location on Bluetooth devices

Next generation Bluetooth devices capable of accurately measuring distances between devices will empower diverse micro-location applications, such as secure keyless entry, contactless payments and medical asset tracking. However, the popularity of Bluetooth also makes it vulnerable to attack. We, imec at Holst Centre, are overcoming this flaw by teaching Bluetooth devices to securely detect physical proximity and mitigate wireless relay attacks and location spoofing.
Technology explained

The widespread deployment of Bluetooth makes it vulnerable to attack. In micro-location use cases, attackers who can decrease the measured proximity by manipulating the communications between two legitimate entities, for instance, your car key and your car, pose the biggest security threat. More accurate positioning capabilities based on phase measurements would make this technology safer, but future relay attacks need to be considered as well. The solution is to combine high-accuracy distance measurement techniques with countermeasures against relay attacks and cryptographic methods. That is the essence of our Bluetooth secure distance-bounding protocol. Furthermore, standardisation is a prerequisite to be able to unleash the full potential of secure positioning technologies within a large ecosystem of companies and application domains. Together with the Bluetooth Special Interest Group (Bluetooth SIG) that oversees the development of Bluetooth standards, imec at Holst Centre is focusing its efforts on creating an industrial standardisation for next-generation secure and high-accuracy positioning.

Over the past few years, imec at Holst Centre has taken big steps in developing the algorithms and chip technology that enable these new Bluetooth secure proximity capabilities. At this year’s International Solid-State Circuits Conference (ISSCC) in San Francisco, we demonstrated a new chip prototype that further speeds up these phase-based distance measurements. Up to ten times faster than today’s approach, they enable the tracking of more devices and reduce energy consumption.

Societal benefits

Next to ultra-wideband (UWB) radio technology and radar, the next generation of Bluetooth micro-location capabilities will create a wide array of new possibilities; particularly in logistics, which requires highprecision tracking of assets in warehouses or even individual packages and letters. But, also in the digital domain of medical applications, Bluetooth could offload routine tasks, such as locating equipment or navigating patients to the right place in the hospital, allowing staff to focus on the patient. The power of localisation with new levels of accuracy and safety will fundamentally change the way in which we interact with the world around us.