Random patterns of secret keys from sampled IR-UWB channel responses

Key generation from reciprocal physical layer measurements (e.g. received signal strength, channel responses etc.) is an alternative to infrastructure-dependent key distribution techniques. Quantization of these intrinsically deterministic metrics should produce sufficiently long and robust keys with good randomness properties. Recent studies [1], [2] have provided a proof of concept for exploiting oversampled ultra wideband signals to generate secret keys with practical lengths. In this paper, we investigate the random character of such keys [1] extracted in noiseless conditions and improve it with a more complex quantization algorithm. Lastly, we statistically test the algorithms in noisy scenarios and show that our algorithm achieves a satisfactory performance in medium to high SNR scenarios, while improving the random pattern of keys obtained from deterministic signals.