Lightweight mutual authentication among sensors in body area networks through Physical Unclonable Functions

Abstract

Medical sensors are usually attached to or implanted inside patient body. Since sensing results of Body Area Networks (BAN) can directly impact the control of medical equipment, the authenticity and integrity of sensing data is essential for safety of patients. Restricted by the limited resources available to BAN sensors, researchers have referred to Physical Unclonable Function of the nodes to achieve authentication. Existing approaches focus on the authentication between control unit and sensors. Mutual authentication among body sensors has not been carefully studied. In this paper, we propose to design a lightweight mutual authentication mechanism for BAN sensors with physical unclonable functions (PUF). Using control unit as a middle point, a pair of body sensors can establish shared secrets so that authenticity of exchanged data can be protected. The proposed approach does not require sensors to conduct any encryption operations, which suits the restricted resources available to BAN nodes. The analysis shows that the proposed approach has very low overhead and does not introduce new vulnerabilities into the system.