Abstract—We analyze the fundamental limits of key generation
and describe an implementation based on error correcting codes.
We show that key extraction based on channel coefﬁcients
signiﬁcantly outperforms key extraction based on received signal
strength indicators (RSSI). The development in this paper is
based on an IEEE 802.11a orthogonal frequency-division multiplexing (OFDM) model and We demonstrate that it is feasible to
use the sampled channel coefﬁcients in OFDM as the key source.
The key extraction problem is cast as a Slepian-Wolf coding and
decoding problem. We construct regular and irregular forms of
binary and non-binary low-density parity check (LDPC) codes
to prototype our key extraction.