Ubiquitous Security

This volume constitutes selected papers presented at the First Inernational Conference on Ubiquitous Security, UbiSec 2021, held in Guangzhou, China, in December 2021. The presented 26 full papers and 2 short papers were thoroughly reviewed and selected from the 96 submissions. They focus on security, privacy and anonymity aspects in cyberspace, physical world, and social networks.