Multi-tier network secrecy in the ether

Communications in the ether are highly susceptible to eavesdropping due to the broadcast nature of the wireless medium. To improve communication confidentiality in wireless environments, research efforts have been made to complement cryptography with physical layer security. A recent view of the role of interference, especially in multi-tier wireless networks, suggested that interference engineering can increase the level of communication confidentiality. The design of interference engineering strategies (IESs) requires a thorough characterization of concurrent effects of wireless emissions on legitimate and eavesdropping receivers. This article advocates IESs for achieving a new level of communication confidentiality in multi-tier wireless networks (namely multi-tier network secrecy) with different degrees of coordination among the tiers. Insights on how IES benefits wireless network secrecy are provided, guiding the design of such strategies for a new level of communication confidentiality.