Abstract
Wireless body area network (WBAN) is an emerging technology that focuses on healthcare monitoring in indoor and outdoor areas. WBAN technology allows medical sensors to collect vital physiological data and transfer it from a source to a destination via low-energy communication. To be able to encrypt and decrypt healthcare data, it is important for medical sensing and health-related devices to generate and extract the same secret keys at both end points. Recent studies show that two medical sensing devices can generate and share secret keys using their wireless channel properties, such as the received signal strength indicator (RSSI). However, existing approaches have low bit rate values and the key entropy is insufficient. These limitations pose a major threat to WBANs and must be addressed. In this paper, we first provide an overview of existing studies related to key extraction between two devices. We then describe the basic principles of wireless channel properties and the key parameters needed to generate secret keys. Finally, we propose a practical scheme to generate secret keys while avoiding information reconciliation and privacy amplification. The proposed scheme can generate 128 symmetric secret keys in a short time frame, and allows to secure the communication between sensor devices and improve the quality of services in WBANs.