关键词: 干扰, 安全图, 随机几何, 无线网络

Abstract: The intrinsically secure communications graph, iS-graph, is a random graph which describes the connections that can be securely established over a wireless network by exploiting the physical properties of the wireless medium. Secrecy capacity of iS-graph can be increased by reducing the SINR (signal to interference plus noise ratio) of the eavesdroppers by adding controlled interference. Inspired by recent results on information-theoretic security, this paper considers the transmission of secret messages over wireless networks in which the legitimate communication nodes are aided by cooperative jamming nodes, and proposes a secure communication graph model with jamming, namely jS-graph, on the basis of iS-graph. This paper aims to characterize the security properties of the jS-graph in the protocol model and the threshold model, proposes jamming strategies to handle unknown eavesdropper locations. The results show that, with the aid of jamming, the secure communication graph can lead to significant secrecy gains compared to its counterpart iS-graph without the aid of jamming. These results help clarify how the presence of eavesdroppers and the cooperative jamming can influence secure connectivity in wireless networks.

Key words: jamming, secrecy graph, stochastic geometry, wireless networks