This book constitutes the revised selected papers from the 24th International Conference on Information Security Applications, WISA 2023, held in Jeju Island, South Korea, during August 23-25, 2023. The 25 papers included in this book were carefully reviewed and selected from 76 submissions. They were organized in topical sections as follows: Cryptography; network and application security; privacy and management; attacks and defenses; post-quantum cryptography and quantum cryptanalysis.