E2PKA: An Energy-Efficient and PV-Based Key Agreement Scheme for Body Area Networks

Recently, several types of body sensors have been developed and adopted to monitor health conditions of patients. Because health-related information is very sensitive, this information should be handled securely. Key agreement is the first basic step that should be performed to provide body sensors with security services such as encryption and authentication. In particular, key agreement using physiological values (PVs) as the source of a secret key (termed PV-based key agreement) has attracted much attention because it does not require any pre-shared secret information. Key agreement among body sensors should be extremely efficient because the battery lifetime is considered the same as that of the body sensors. Unfortunately, in the design of previous PV-based key-agreement methods, power consumption was not adequately considered, making them impractical. In this paper, we propose a key-agreement method between body sensors, the energy-efficient and PV-based key agreement scheme (E2PKA), which is extremely efficient in terms of reducing the power consumption. The significant savings in power consumption of body sensors come from the reduced communication, which is the main reason for battery drain. As a result, E2PKA results in a power consumption savings of at least 90% for body sensors when compared to previous PV-based key-agreement methods.