This book constitutes the refereed proceedings of the 16th International Symposium on Foundations and Practice of Security, FPS 2023, held in Bordeaux, France, during December 11–13, 2023.The 27 regular and 8 short papers presented in this book were carefully reviewed and selected from 80 submissions.

Short Papers.- UCAT: the Uniform Categorization for Access Control.- Collectively Enhancing IoT Security: A Privacy-Aware Crowd-Sourcing Approach.- Comparative Analysis of Reduction Methods on Provenance Graphs for APT Attack Detection.- Evaluating Deep Learning for Cross-Domains Fake News Detection.- Accurify: Automated New Testflows Generation for Attack Variants in Threat Hunting.- Trade-off between Authentication Performance and Detection Time for Zero-effort Attack in Location-based Authentication.- SADIS: real-time sound-based anomaly detection for industrial systems.- A resilience Component for a Digital Twin.