LOBBY: A Novel Physical-layer Key Generation Method

Physical-layer key generation (PKG) relying on wireless channel reciprocity has become a potential research topic as it can provide information-theoretic security guarantees. Various PKG protocols have been proposed to improve key generation rate. However, as a key generation scheme, key rate is not the only important feature. Availability in practical scenario and security resistance are also valuable to be focused on. In order to achieve the availability under quasi-static environment and nearby attack, a scheme named loop-one-block-back key (LOBBY) key generation is proposed. Compared with algorithms raised before, LOBBY only needs one time-frequency block to transmit signal back which saves a quarter energy than conventional algorithms, but still has a powerful bit generation rate (BGR) as before. The simulation of LOBBY shows that correlation of subsequent keys keeps flat near 0.5 in quasi-static environment. As for bit disagreement ratio (BDR) between authorized users, it is less than 0.05 when SNR is 15dB.