This two-volume set LNICST 335 and 336 constitutes the post-conference proceedings of the 16th International Conference on Security and Privacy in Communication Networks, Secure Comm 2020, held in Washington, DC, USA, in October 2020. The conference was held virtually due to COVID-19 pandemic. The 60 full papers were carefully reviewed and selected from 120 submissions. The papers focus on the latest scientific research results in security and privacy in wired, mobile, hybrid and ad hoc networks, in Io T technologies, in cyber-physical systems, in next-generation communication systems in web and systems security and in pervasive and ubiquitous computing.