Performance of secret key generation in non stationary channels
Résumé
Secret key generation (SKG) from the randomness provided by random channels is currently considered as one way to improve security in wireless communications at the physical layer level. However, the relation between the performance of SKG schemes and the characteristics of the radio channel has been moderately investigated. In this work, we evaluate the security performance on the basis of a simple channel model based on scatterers distributed around terminals, which enables going beyond the common assumption of spatial stationarity between the legitimate terminal and the eavesdropper. This performance is assessed both from information theory metrics and from a practical key extraction algorithm. Owing to the model flexibility, we evaluate the impact of several major channel characteristics such as the distribution and density of scatterers or the existence of a dominant LOS path.