Shake well before use: Authentication based on Accelerometer Data

Small, mobile devices without user interfaces, such as Bluetooth headsets, often need to communicate securely over wireless networks. Active attacks can only be prevented by authenticating wireless communication, which is problematic when devices do not have any a priori information about each other. We introduce a new method for device-to-device authentication by shaking devices together. This paper describes two protocols for combining cryptographic authentication techniques with known methods of accelerometer data analysis to the effect of generating authenticated, secret keys. The protocols differ in their design, one being more conservative from a security point of view, while the other allows more dynamic interactions. Three experiments are used to optimize and validate our proposed authentication method

ivPair: context-based fast intra-vehicle device pairing for secure wireless connectivity

The emergence of advanced in-vehicle infotainment (IVI) systems, such as Apple CarPlay and Android Auto, calls for fast and intuitive device pairing mechanisms to discover newly introduced devices and make or break a secure, high-bandwidth wireless connection. Current pairing schemes are tedious and lengthy as they typically require users to go through pairing and verification procedures by manually entering a predetermined or randomly generated pin on both devices. This inconvenience usually results in prolonged usage of old pins, significantly degrading the security of network connections. To address this challenge, we propose ivPair, a secure and usable device pairing protocol that extracts an identical pairing pin or fingerprint from vehicle\u27s vibration response caused by various factors such as driver\u27s driving pattern, vehicle type, and road conditions. Using ivPair, users can pair a mobile device equipped with an accelerometer with the vehicle\u27s IVI system or other mobile devices by simply holding it against the vehicle\u27s interior frame. Under realistic driving experiments with various types of vehicles and road conditions, we demonstrate that all passenger-owned devices can expect a high pairing success rate with a short pairing time, while effectively rejecting proximate adversaries attempting to pair with the target vehicle

On the Security of Ultrasound as Out-of-band Channel

Ultrasound has been proposed as out-of-band channel for authentication of peer devices in wireless ad hoc networks. Ultrasound can implicitly contribute to secure communication based on inherent limitations in signal propagation, and can additionally be used explicitly by peers to measure and verify their relative positions. In this paper we analyse potential attacks on an ultrasonic communication channel and peer-to-peer ultrasonic sensing, and investigate how potential attacks translate to application-level threats for peers seeking to establish a secure wireless link. Based on our analysis we propose a novel method for authentic communication of short messages over an ultrasonic channel

Shake Well Before Use: Intuitive and Secure Pairing of Mobile Devices

A challenge in facilitating spontaneous mobile interactions is to provide pairing methods that are both intuitive and secure. Simultaneous shaking is proposed as a novel and easy-to-use mechanism for pairing of small mobile devices. The underlying principle is to use common movement as a secret that the involved devices share for mutual authentication. We present two concrete methods, ShaVe and ShaCK, in which sensing and analysis of shaking movement is combined with cryptographic protocols for secure authentication. ShaVe is based on initial key exchange followed by exchange and comparison of sensor data for verification of key authenticity. ShaCK, in contrast, is based on matching features extracted from the sensor data to construct a cryptographic key. The classification algorithms used in our approach are shown to robustly separate simultaneous shaking of two devices from other concurrent movement of a pair of devices, with a false negative rate of under 12 percent. A user study confirms that the method is intuitive and easy to use, as users can shake devices in an arbitrary pattern

Using a Spatial Context Authentication Proxy for Establishing Secure Wireless Connections

Spontaneous interaction in wireless ad-hoc networks is often desirable not only between users or devices in direct contact, but also with devices that are accessible only via a wireless network. Secure communication with such devices is difficult because of the required authentication, which is often either password- or certificate-based. An intuitive alternative is context-based authentication, where device authenticity is verified by shared context, and often by direct physical evidence. Devices that are physically separated cannot experience the same context and thus cannot benefit directly from context authentication. We introduce a context authentication proxy that is pre-authenticated with one of the devices and can authenticate with the other by shared context. This concept is applicable to a wide range of application scenarios, context sensing technologies, and trust models. We show its practicality in an implementation for setting up IPSec connections based on spatial reference. Our specific scenario is ad-hoc access of mobile devices to secure 802.11 WLANs using a mobile device as authentication proxy. A user study shows that our method and implementation are intuitive to use and compare favourably to a standard, password-based approach

A Context Authentication Proxy for IPSec Using Spatial Reference

Spontaneous interaction in ad-hoc networks is often desirable not only between users or devices in direct contact, but also with devices that are accessible only via a wireless network. Secure communication with such devices is di#cult because of the required authentication, which is often either password- or certificate-based. An intuitive alternative is context-based authentication, where device authenticity is verified by shared context, and often by direct physical evidence. Devices that are physically separated can not experience the same context and can thus not benefit directly from context authentication. We introduce a context authentication proxy that is pre-authenticated with one of the devices and can authenticate with the other by shared context. This concept is applicable to a wide range of application scenarios, context sensing technologies, and trust models. We show its practicality in an implementation for setting up IPSec connections based on spatial reference. Our specific scenario is ad-hoc access of mobile devices to secure 802.11 WLANs using a PDA as authentication proxy

An Architecture for Context Prediction

Today's information appliances appear very powerful, featuring on-device storage and processing power, communication technology and supporting many different applications. Context awareness is currently considered as one of the key issues for future device generations, with context prediction being the next step in research. The goal is not only to recognize the current context of an information appliance or its user, but also to predict the future context and thus enable the device to become proactive. In this paper, an approach to recognize and predict high level context information from low level sensor data is presented. Targeting a wide range of platforms, this approach has also been implemented in a software framework for on-line, un-supervised context prediction

USING A SPATIAL CONTEXT AUTHENTICATION PROXY FOR ESTABLISHING SECURE WIRELESS CONNECTIONS ∗

Spontaneous interaction in wireless ad-hoc networks is often desirable not only between users or devices in direct contact, but also with devices that are accessible only via a wireless network. Secure communication with such devices is difficult because of the required authentication, which is often either password- or certificate-based. An intuitive alternative is context-based authentication, where device authenticity is verified by shared context, and often by direct physical evidence. Devices that are physically separated cannot experience the same context and thus cannot benefit directly from context authentication. We introduce a context authentication proxy that is pre-authenticated with one of the devices and can authenticate with the other by shared context. This concept is applicable to a wide range of application scenarios, context sensing technologies, and trust models. We show its practicality in an implementation for setting up IPSec connections based on spatial reference. Our specific scenario is ad-hoc access of mobile devices to secure 802.11 WLANs using a mobile device as authentication proxy. A user study shows that our method and implementation are intuitive to use and compare favourably to a standard, password-based approach.

The candidate key protocol for generating secret shared keys from similar sensor data streams

Abstract. Secure communication over wireless channels necessitates authentication of communication partners to prevent man-in-the-middle attacks. For spontaneous interaction between independent, mobile devices, no a priori information is available for authentication purposes. However,traditionalapproachesbasedonmanualpasswordinputorverificationofkeyfingerprintsdonotscaletotenstohundredsofinteractions a day, as envisioned by future ubiquitous computing environments. One possibility to solve this problem is authentication based on similar sensor data: when two (or multiple) devices are in the same situation, and thus experience the same sensor readings, this constitutes shared, (weakly) secret information. This paper introduces the Candidate Key Protocol (CKP) to interactively generate secret shared keys from similar sensor data streams. It is suitable for two-party and multi-party authentication, and supports opportunistic authentication.