This book constitutes the proceedings of the 20th International Workshop on Security on Advances in Information and Computer Security, IWSEC 2025, held in Fukuoka, Japan, in November 25, 2025.

The 27 full papers were carefully reviewed and selected from 95 submissions. These papers were categorized into the following sections: Public-Key Encryption; Signature Schemes; Security and Analysis of Post-Quantum Cryptography; Card-Based Cryptography; Protocols; Privacy-Preserving Techniques; AI Attacks and Mitigations; Vulnerability Detection; Cache & Code-Execution: Attacks and Mitigations; Cyber Attack & Threat Analysis; Wireless Communication Security and Human Factors in Cyber Security.

Inhalt

.- Public-Key Encryption.

.- Dynamic Collusion Function-Private Functional Encryption.

.- Public Key Encryption with Equality Test from Tag-Based Encryption.

.- Approximate CRT-Based Gadget Decomposition for Fully
Homomorphic Encryption.

.- Signature Schemes.

.- Ordered Multi-Signatures with Public-Key Aggregation from SXDH
Assumption.

.- Multi-Designated Verifier Ring Signature: Generic Construction from
Standard Primitives.

.- Security and Analysis of Post-Quantum Cryptography.

.- An Extended Rectangular MinRank Attack against UOV and Its Variants.

.- Refined Analysis of the Concrete Hardness of the Quasi-Cyclic
Syndrome Decoding.

.- Practical Lattice Attack and Patched Parameters for 2F Multivariate
Encryption: Is 2F Still Better Than Standard Lattice Constructions for
Small Ciphertext Size?.

.- Cryptanalysis of the best HFE-LL' Constructions.

.- Card-Based Cryptography.

.- Efficient Card-Based Protocols for Symmetric and Partially Doubly
Symmetric Functions.

.- Minimum number of up-down cards for finite-time committed-AND
protocol without interlocking operations.

.- Protocols.

.- Improved Private Simultaneous Messages Protocols for Symmetric
Functions with Universal Reconstruction.

.- Blockchain-based Economic Voting with Posterior Security from Lattices.

.- Privacy-Preserving Techniques.

.- Non-Interactive Privacy-Preserving Record Linkage using Polynomial
Sparsity Testing.

.- Utility of the Non-Negative Wavelet Mechanism with Zero-Concentrated
Differential Privacy.

.- Accelerating Simulations of Bitvector-Based LDP Protocols via
Binomial Modeling.

.- AI Attacks and Mitigations.

.- Supply Chain Threats in the MCP Ecosystem: Attack Vectors and
Mitigation Strategies.

.- Evaluation of Adversarial Input Attacks in Retrieval-Augmented
Generation Using Large Language Models.

.- Vulnerability Detection.

.- Tracking Security Smell Diffusion Patterns in Ansible Playbooks Using
Metadata.

.- Detecting Fake Proof-of-Concept Codes on GitHub Using Static Code
Analysis.

.- Cache & Code-Execution: Attacks and Mitigations.

.- Detecting and Mitigating Conflict-Based Cache Side-Channel Attacks
by Monitoring Ping-Pong Accesses Patterns.

.- Analyzing and Mitigating the SSB Vulnerability in an MDP-Equipped
RISC-V Processor.

.- Cyber Attack & Threat Analysis.

.- Benign Activity Extraction for Dependency Reduction in Data
Provenance-based Attack Analysis.

.- Cyber Threat Intelligence Report Summarization with Named Entity
Recognition.

.- Wireless Communication Security.

.- One Antenna Is Enough For Neutralizing Jamming In IEEE 802.15.4
BPSK.

.- Human Factors in Cyber Security.

.- Nudges to Reduce the Spread of Online Disinformation: A Comparison
with the Educational Effect.

.- Sequence Length Aggregation and Behavioral Biometrics: A Case
Study in Professional Player Authentication via Tree-Based Classification.