Topics covered in include secrecy metrics for physical layer security over fading channels; trusted wireless communications with spatial multiplexing; directional modulation enabled physical layer wireless security; secure waveform for 5G systems; confidential and energy efficient communications using physical layer security; secure data networks with channel uncertainty; antenna selection strategies for wiretap channels; physical layer security for massive MIMO systems, millimeter wave cellular networks, non-orthogonal multiple access, multiuser relay networks, cognitive radio networks, MIMOME-OFDM systems; wirelessly powered communication systems and D2D-enabled cellular networks; and security solutions and applications at the physical layer, including case studies of secret key generation and secrecy coding in communication nodes and terminals.