Secure Conversation: A View from Physical Layer

In this paper, we investigate the performance of a two-way secure conversation among users under the threat of an eavesdropper. To be more specific, we assume that the source and destination engage in a conversation to exchange confidential information. An eavesdropper exists, seeking to exploit the conversation illicitly. The messages of sender are split into multiple packets and then delivered to the receiver via wireless channels. To ensure communication security, we introduce a new concept called the “secure conversation constraint” to analyze the trade-off between security and system performance. Most importantly, the proposed approach can be extended to the study of other wireless networks such as cognitive radio, non-orthogonal multiple access communication, and cooperative relay networks.