SKA-PS: Secure key agreement protocol using physiological signals

In this paper, we propose SKA-PS, a novel Secure Key Agreement protocol using Physiological Signals, for Body Area Networks (BANs). Our protocol generates symmetric cryptographic keys using the physiological parameters derived from the physiological signals of the users, such as electrocardiogram, photoplethysmogram and blood pressure. In our construction, we reduce the problem of secure key agreement into the problem of set reconciliation by representing the physiological parameter sequences generated from the physiological signals of the BAN users with appropriate sets. When properly selected parameters are applied, biosensors of the same BAN user can agree on symmetric cryptographic keys with remarkably high true match and low false match rates (as much as 100% and 0.46% for pairwise execution, and 100% and 0.26% for group execution, respectively), and low communication, computational and storage costs. We implemented our model in an embedded system, thus the results show real implementation outcomes. Moreover, we comparatively analyze the performance of SKA-PS with two existing bio-cryptographic key agreement protocols and show that SKA-PS outperforms both in all performance metrics.