Description

In this work, efficient algorithms are designed and simulated for secret
key generation from the wireless channel, where key bits
are not only generated by amplitudes of the subcarriers but
also by the indices of subcarriers corresponding to highest
channel gains. Specifically, in the first step, the communicating
nodes convert the correlated frequency response of the channel
at them into random order by exploiting random interleaver.
Afterwards, the estimated channel response in the frequency
domain at them is partitioned into small subblocks. Finally,
the key bits are generated by both amplitudes of individual
subcarriers by comparing them with their mean as well as by
indices/positions of good sub-channels in each subblock by
employing a look-up table. The proposed novel dimensions
for secret key generation results in the enhancement of overall
KGR without degrading overall performance as shown by simulation
results. More specifically, there is a 50 % increase in
key rate as shown by JKG performance compared to the CKG
approach due to the involvement of the proposed dimensions
of key generation. For future work, different variations of
the proposed algorithm assuming different activation ratios
and block sizes can be considered. In addition, the proposed
algorithm of secret key generation can be extended to other
domains such as time, space, and code domains.