無線通信におけるガウス性相関情報に基づく秘密鍵共有の秘密鍵容量: その2: 移動通信路モデル

Abstract

Wireless physical layer security schemes such as secret key agreement and secret data transmission have attracted attention in current wireless community. For the secret key agreement from correlated information, a general formula of the secret key capacity is given, but a specific formula of the secret key capacity has not been presented for secret key agreement from correlated information in wireless channels. This paper deals with the theoretical analysis on the secret key capacity for the Gaussian correlated information in mobile communication channel. The analysis result shows that the upper bound of the secret key capacity is given with conditional mutual information and that the formulas of the upper and lower bounds are expressed as functions of the correlation of channel coefficient between eavesdropper and legitimate user, the signal-to-noise power ratio, and the noise power ratio of eavesdropper to legitimate user.