Communications in Computer and Information Science

This book constitutes the proceedings of the Fourth International Conference on Ubiquitous Security, UbiSec 2024, held in Changsha, China, during December 29–31, 2024.The 27 full papers and 5 short papers included in this book were carefully reviewed and selected from 73 submissions. These papers were organized in the followingsections: Cyberspace Security, and Cyberspace Privacy.