FastZIP

Abstract

With the advent of the Internet of Things (IoT), establishing a secure channel between smart devices becomes crucial. Recent research proposes zero-interaction pairing (ZIP), which enables pairing without user assistance by utilizing devices' physical context (e.g., ambient audio) to obtain a shared secret key. The state-of-the-art ZIP schemes suffer from three limitations: (1) prolonged pairing time (i.e., minutes or hours), (2) vulnerability to brute-force offline attacks on a shared key, and (3) susceptibility to attacks caused by predictable context (e.g., replay attack) because they rely on limited entropy of physical context to protect a shared key. We address these limitations, proposing FastZIP, a novel ZIP scheme that significantly reduces pairing time while preventing offline and predictable context attacks. In particular, we adapt a recently introduced Fuzzy Password-Authenticated Key Exchange (fPAKE) protocol and utilize sensor fusion, maximizing their advantages. We instantiate FastZIP for intra-car device pairing to demonstrate its feasibility and show how the design of FastZIP can be adapted to other ZIP use cases. We implement FastZIP and evaluate it by driving four cars for a total of 800 km. We achieve up to three times shorter pairing time compared to the state-of-the-art ZIP schemes while assuring robust security with adversarial error rates below 0.5%. CCS CONCEPTS• Security and privacy → Security services; • Computer systems organization → Embedded and cyber-physical systems.

GPSKey: GPS based Secret Key Establishment for Intra-Vehicle Environment

“…We assume that the adversary knows how the proposed secret key establishment works, however she cannot be within the target vehicle during the key establishment process. We note that this is a common assumption in other context-based secret key establishment schemes [11], [6], [16], where a moving vehicle provides a physical security boundary. Instead, the adversary attempts to observe the target vehicle's velocity from outside of the target vehicle to get the same key as the legitimate devices.…”

“…The IMU-based device pairing schemes for vehicular environments [6], [16] extract secret keys from the vehicle movement or environmental changes obtained from IMU sensor readings. However, they introduce two limitations: (1) As IMU sensor data can be easily interfered with by device movement or orientations, they require the legitimate devices to be fixed (e.g., taping the devices) inside of the vehicle.…”

“…As such devices often carry privacy-sensitive information, they are required to establish secure communication channels [7], [17], [33]. For example, there is a growing number of smart devices inside modern cars [6], and users may need to pair such a device with the vehicle's IVI system or another in-vehicle device. Existing device pairing schemes, however, are not user-friendly and may be unsafe to be performed while driving.…”

“…Recent research efforts propose context-based pairing schemes for vehicular environments [6], [16]. They focus on a fact that devices located in the same vehicle experience highly similar movement, which can be captured by inertial measurement unit (IMU) sensors (e.g., accelerometer, gyroscope, and magnetometer).…”

“…For example, [16] derives a key from the vertical acceleration (perpendicular to lateral and longitudinal acceleration) of a vehicle, which is affected by vehicle type and road condition. [6] employs three different sensors, where a vehicle's lateral and longitudinal accelerations are captured by an accelerometer, a gyroscope is utilized for measuring the vehicle's turns, and a barometer monitors altitude changes. However, these schemes present two limitations: (1) IMU sensor data can be easily disturbed by device movement, thus may not be robust or provide a consistent performance when the user uses or wear the device during key establishment.…”