Key agreement method based on multi-dimensional advantage distillation over mmWave MIMO channels

To achieve efficient physical layer secure secret key agreement in millimeter wave (mmWave) multiple input multiple output (MIMO) communication systems, a key agreement method was proposed based on multi-dimensional advantage distillation (AD) exploiting the multi-dimensional characteristics of mmWave MIMO channel parameters. The mmWave MIMO channel was modeled as a high-dimensional tensor spanning the space, time, and frequency domains. The legitimate communication parties alternately sent pilot symbols, based on the uniqueness property of tensor decomposition, simultaneously acquired estimates of multiple channel parameters, i.e. amplitude, angle, and delay, in a single shot. The legitimate communication parties used the common information contained in the estimates of the multiple channel parameters as the source of common randomness for advantage distillation, thus significantly improving the overall efficiency of key agreement. Further, a correlation model between the legitimate and eavesdropping channel parameters was derived through a joint geometric and statistical analysis of the channels. Simulation studies were conducted to evaluate the key rate performance of the proposed method under different channel correlation scenarios and to investigate the impact of different factors on the key rate.