2018-11-06 Authentication and Pairing Using Human Body Impedance

Abstract

The electrical properties of the human body are an unexplored source of much potential in Computer Science and Biometrics. The body is an electric conductor with veryn interesting features: at lower frequencies it can be treated like a resistive cable and at higher frequencies it behaves similar to an electric antenna. These physical phenomena allow the construction of electrical circuits that interface the human body or even build on it as the core element. In particular, one can use the human body as a transmission medium for electromagnetic signals. Using so-called body channel communication techniques, it is possible to send information wirelessly through the body of a person. In addition, the electrical properties of the body can be measured and constitute physiological characteristics unique to the every individual.

Although these properties could prove very useful in the context of Computer Security, their potential for security applications is largely unexplored. However, extracting the body's distinctive impedance characteristics or using the body as a communication medium entails many interesting application scenarios. The human body can serve as an additional layer to augment the security in existing protocols or enable the design of entirely new methods.

This talk presents solutions to two challenging problems in the area of System Security: user authentication and secure device pairing. In order to address these problems, the talk explores the use of the electrical properties of the human body. Keeping usability and universality in mind, the primary focus is on applications where the human body can be interfaced in ways that require little to no user involvement and are completely noninvasive.

It is most natural, even for novice users, to interface the body through the person's hands. The proposed solutions therefore connect to the body through (capacitive) electrodes that the user has to touch with their hands. In case of user authentication, a method that measures human body impedance from one hand to the other is proposed, and for device pairing, the talk presents a novel approach that allows two devices to communicate with each other when a person touches them both, one with each hand.

The speaker was invited by Panagiotis Papadimitratos  and is visiting the NSS group.

About Marc Roeschlin

Marc Roeschlin is a recent PhD student under the supervision of Kasper Rasmussen and Ivan Martinovic in the System Security Lab at Oxford University. Before starting his PhD, he was a visiting student researcher in the Security and Privacy Research Group led by Gene Tsudik at University of California, Irvine. Prior to that, he received his BSc and MSc in Computer Science from ETH Zurich. His interests include user authentication, wireless network security, key generation and Biometrics. Besides his academic interests, Marc has been exposed to a variety of industry projects. He worked for PricewaterhouseCoopers, the Swiss National Bank and the Swiss Stock Exchange.