This book presents 48 selected papers focused on Information and Network Security from the 23rd International Conference on Hybrid Intelligent Systems and 19th International Conference on Information Assurance and Security (IAS 2023), which was held in five different cities namely Olten, Switzerland; Porto, Portugal; Kaunas, Lithuania; Greater Noida, India; Kochi, India and in online mode. The 23rd International Conference on Hybrid Intelligent Systems (HIS 2023) was focusing on synergistic combinations of multiple approaches to develop the next generation of intelligent systems. HIS-IAS 2023 had contributions by authors from 44 countries. This book offers a valuable reference guide for all network and security specialists, scientists, academicians, researchers, students, and practitioners in the field of artificial intelligence and information/network security.