Fast and practical secret key extraction by exploiting channel response

Channel hopping scheme to mitigate jamming attacks in wireless LANs

“…Indeed, there are many approaches to ensure channel reciprocity in wireless systems, such as interpolation and filtering [28]. The interpolation methods emulate the identical channel measurement times at the nodes [29,30] and the filtering methods eliminate the high frequency components in noise [31,32]. Unfortunately, these techniques are not perfect.…”

Verification of Key Generation from Individual OFDM Subcarrier's Channel Response

“…Therefore, randomness is the most important feature of the generated key sequence. We use National Institute of Standards and Technology (NIST) randomness test suite [27] to verify the randomness of the key sequence, which is also used by many other researchers [9], [10], [12], [13], [18].…”

“…Our work differs from [12], [13], which also extract keys from CSI. The work in [12] generates key from all the subcarriers.…”

“…CSI-based systems can provide a higher KGR as CSI is a finer-grained channel parameter [21]. However, CSI is not available in most WiFi NICs with the current exception of Intel WiFi Link 5300 wireless NIC [22], which makes key generation from CSI feasible [12], [13]. As the Intel WiFi Link 5300 wireless NIC supports IEEE 802.11n, multiple-antenna diversity was used to exploit a finer-grained spatial channel characteristics [14].…”

“…The work in [12] generates key from all the subcarriers. However this approach can introduce redundancy whenever the channel experiences flat fading, as this can produce periodic runs of ones and zeros, leading to reduced randomness and hence security.…”