This paper presents novel methodologies which allow robust secret key extraction from radio channel measurements which suffer from real-world non-reciprocities and a priori unknown fading statistics. These methodologies have low computational complexity, automatically adapt to differences in transmitter and receiver hardware, fading distribution and temporal correlations of the fading signal to produce secret keys with uncorrelated bits. Moreover, the introduced method produces secret key bits at a higher rate than has previously been reported. We validate the method using extensive measurements between TelosB wireless sensors. Categories and Subject Descriptors C.2.0 [COMPUTER-COMMUNICATION NETWORKS]: General–Security and protection General Terms Security, Experimentation, Measurement, Performance Keywords bit extraction, radio channel, RSS