[J20] A Lightweight and Efficient Key Generation Scheme From OFDM Subcarriers’ Channel Responses

This letter presents a physical layer secret key generation (PLSKG) protocol utilizing the amplitude of channel frequency response (CFR) of Orthogonal Frequency Division Multiplexing (OFDM) subcarriers. Firstly, least squares estimation estimates the CFR. Next, a partition moving average (PMA) algorithm encodes the CFR. PMA re-uses the CFR within a partition by encoding at different overlap sizes, thus increasing the key generation rate (KGR). Then, a 2-bit differential-based quantization at every overlap for each partition is followed for an improved KGR and randomness. Finally, a cyclic redundancy check is performed to select strings with consistent results as candidate key, eliminating streams from less correlated measurements, thus ensuring a 0-bit mismatch. Simulation results have verified that our scheme achieves random 0-bit disagreement keys with a high average key length and reduced complexity compared to the other existing lightweight schemes.

Recommended citation: A. F. Kawoya, H. Wang, and D. He, "A Lightweight and Efficient Key Generation Scheme From OFDM Subcarriers’ Channel Responses," IEEE Wireless Commun. Lett., vol. 13, no. 11, pp. 3177–3181, Nov. 2024.
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