Biblio

Secret key generation from wireless channel is an emerging technique of physical layer security. At present, most of the secret key generation schemes use information reconciliation to obtain symmetric keys. This paper introduces a non-interactive information reconciliation scheme based on channel coding and stream encryption, and considering the error correction capability, we design a concatenated code of BCH and RS codes as channel coding. The performance of concatenated error correction code has been analyzed in this scheme. Then, we compare the concatenated code with first-level error correction code in different test environments. Extensive numerical simulations and experiments demonstrate that the decoding performance of this second-level concatenated code is better than the first-level error correction code, and it can also effectively eliminate third-party eavesdropping.

In recent years, secret key generation based on physical layer security has gradually attracted high attentions. The wireless channel reciprocity and eavesdropping attack are critical problems in secret key generation studies. In this paper, we carry out a simulation and experimental study of channel reciprocity in terms of measuring channel state information (CSI) in both time division duplexing (TDD) and frequency division duplexing (FDD) modes. In simulation study, a close eavesdropping wiretap channel model is introduced to evaluate the security of the CSI by using Pearson correlation coefficient. In experimental study, an indoor wireless CSI measurement system is built with N210 and X310 universal software radio peripheral (USRP) platforms. In TDD mode, theoretical analysis and most of experimental results show that the closer eavesdropping distance, the higher CSI correlation coefficient between eavesdropping channel and legitimate channel. However, in actual environment, when eavesdropping distance is too close (less than 1/4 wavelength), this CSI correlation seriously dropped. In FDD mode, both theoretical analysis and experimental results show that the wireless channel still owns some reciprocity. When frequency interval increases, the FDD channel reciprocity in actual environment is better than that in theoretical analysis.