This book constitutes the refereed post-proceedings of the 9th and 10th International Conference on Information Systems Security and Privacy, ICISSP 2023 and 2024, held in Lisbon, Portugal, and in Rome, Italy during February 22-24, 2023 and February 26-28, 2024, respectively. The 15 full papers included in this book were carefully reviewed and selected from 285 submissions. These papers have been organized under the following topical sections: Management and operations; Applications and services; and Technologies and foundations.