Chen, JingchaoZhang, RongqingSong, LingyangHan, ZhuJiao, Bingli2020-05-112020-05-118/30/2011Copyright 2011 IEEE Transactions on Information Forensics and Security. This is a pre-print version of a published paper that is available at: https://ieeexplore.ieee.org/abstract/document/6004829. Recommended citation: Chen, Jingchao, Rongqing Zhang, Lingyang Song, Zhu Han, and Bingli Jiao. "Joint relay and jammer selection for secure two-way relay networks." IEEE Transactions on Information Forensics and Security 7, no. 1 (2011): 310-320. doi: 10.1109/TIFS.2011.2166386. This item has been deposited in accordance with publisher copyright and licensing terms and with the author's permission.https://hdl.handle.net/10657/6490In this paper, we investigate joint relay and jammer selection in two-way cooperative networks, consisting of two sources, a number of intermediate nodes, and one eavesdropper, with the constraints of physical-layer security. Specifically, the proposed algorithms select two or three intermediate nodes to enhance security against the malicious eavesdropper. The first selected node operates in the conventional relay mode and assists the sources to deliver their data to the corresponding destinations using an amplify-and-forward protocol. The second and third nodes are used in different communication phases as jammers in order to create intentional interference upon the malicious eavesdropper. First, we find that in a topology where the intermediate nodes are randomly and sparsely distributed, the proposed schemes with cooperative jamming outperform the conventional nonjamming schemes within a certain transmitted power regime. We also find that, in the scenario where the intermediate nodes gather as a close cluster, the jamming schemes may be less effective than their nonjamming counterparts. Therefore, we introduce a hybrid scheme to switch between jamming and nonjamming modes. Simulation results validate our theoretical analysis and show that the hybrid switching scheme further improves the secrecy rate.Cooperative jammingfriendly jammer selectionphysical-layer securityrelay selectiontwo-way relayArticle