Bringing PHY-Based Key Generation into the Field: An Evaluation for Practical Scenarios

The need for secured communication between computationally weak wireless devices has driven the development of novel key generation protocols. Various schemes for extracting symmetric cryptographic keys out of wireless channel properties have been proposed during recent years, making the generation protocol more and more efficient for individual applications. However, often these schemes were evaluated based on theoretical models and without considering practical effects. We present a system for PHY-based key generation with two legitimate users as well as a passive attacker of equivalent power and analyze results from practical measurements in real world scenarios. Furthermore we extend practical constraints by considering heterogeneous setups and show the impact onto representative performance indicators.