Provable and Practical Security

This book constitutes the refereed proceedings of the 20th International Conference on Provable Security, ProvSec 2026, held in Queenstown, New Zealand, during September 24–26, 2026.The 19 full papers, 4 short papers included in this book were carefully reviewed and selected from 66 submissions. They were organized in topical sections as follows: Machine Learning Security and Privacy,Machine Learning for Security Applications,Database Security,Blockchain and Cryptocurrency,Signatures and Watermarking,Encryption Schemes and Short papers.