Encryption-free Authentication and Integrity Protection in Body Area Networks through Physical Unclonable Functions

Abstract

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 between sensor pairs or among sensor groups has not been carefully studied. In this paper, we propose to design several mutual authentication mechanisms for BAN sensor pairs and sensor groups with physical unclonable functions (PUF). Using control unit as a middle point, the body sensors can establish shared secrets so that authenticity of exchanged data can be protected. In sensor groups of BAN, we design both control unit based and sensor based sender authentication mechanisms. To reduce hardware demand and overhead, the proposed approaches do not require sensors to conduct any encryption operations, which suits the restricted resources available to BAN nodes. We design probability based schemes to defend against collusive sender impersonation attacks. We formally prove the safety of the protocols. The analysis and simulation results show that the proposed approaches have low overhead and are robust against multiple types of attacks.