This book constitutes the refereed proceedings of the 20th International Conference on Provable Security, ProvSec 2026, held in Queenstown, New Zealand, during September 2426, 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.

Inhalt

.- Machine Learning Security and Privacy

.- Latency-Optimal Adaptive Split Inference for Privacy-Preserving Cloud-Edge-End Collaboration.
.- FedFD: Semantics-Guided Feature Diffusion for Federated Learning with Private Extractors.
.- Caliber: Cross-Architecture Extraction-Cost Control for Score-Returning APIs.
.- Membership Inference Attacks against LDP-Based PPML.

.- Machine Learning for Security Applications

.- Vul4Py: An Automated Vulnerability Repair Benchmark for Python Exploitable Vulnerabilities.

.- Database Security

.- Search-Efficient Public-Key Authenticated Encryption with Keyword Search Made Easy.
.- Disjunctive Searchable Encryption with Comprehensive Forward and Backward Privacy.
.- Storage-optimized Stateful Private Information Retrieval with Constant Response Size.

.- Blockchain and Cryptocurrency

.- A Consortium Blockchain Architecture for Cross-Organisational Security Log Integrity Verification.
.- TCRWal: A Threshold Collusion-Resistant Wallet for Deterministic Key Derivation.
.- TornaLink: Toward Linking Tornado Cash Deposits to Withdrawals via DeFi Fingerprints.
.- Statistical Zero-Knowledge of Verifier-Efficient PLONKish SNARKs.

.- Signatures and Watermarking

.- Ring Adaptor Signatures for Atomic Swaps: Formalization and Efficient Construction.
.- Privacy-Preserving Multi-Signatures: Achieving Transcript-Aware Privacy.
.- Unique Ring Signatures from Isogeny-based Group Actions: Improved Framework and Constructions.
.- Towards Public-Key Watermarking Schemes for Pseudorandom Functions with Black Box Extraction.

.- Encryption Schemes

.- Analyzing Bootstrapping in Approximate Homomorphic Encryption Through the Lens of Optimization.
.- Batched Attribute-Based Encryption from Bilinear Pairings.
.- Constant-Time Modular Inversion with Tight Iteration Bounds.

.- Short Papers

.- Estimating the Cost of Partial Key Exposure Attacks on ML-KEM and ML-DSA.
.- Distributed Polynomial-in-the-Action VRFs with Proactive Refresh.
.- An MPC-in-the-Head-Inspired Isogeny-Based Identification Protocol.
.- MoLM-KEM: A Decryption-Failure-Free Module-Lattice KEM from Linear Masking.