Secure and Efficient Federated Learning by Combining Homomorphic Encryption and Gradient Pruning in Speech Emotion Recognition -- FedLS: An Anti-poisoning Attack Mechanism for Federated Network Intrusion Detection Systems using Autoencoder-based Latent Space Representations -- Mitigating Sybil Attacks in Federated Learning -- Privacy-Preserving Authentication Scheme for 5G Cloud-Fog Hybrid with Soft Biometrics -- Obfuscation padding schemes that minimize Renyi min-entropy for Privacy -- Cross-border Data Security from the Perspective of Risk Assessment -- IoT-REX: A Secure Remote-Control System for IoT Devices from Centralized Multi-Designated Verifier Signatures -- CVAR-FL IoV Intrusion Detection Framework -- Transparent Security Method for Automating IoT Security Assessments -- DIDO: Data Provenance from Restricted TLS 1.3 Websites -- QR-SACP: Quantitative Risk-based Situational Awareness Calculation and Projection through Threat Information Sharing -- Dynamic Trust Boundary Identification for the Secure Communications of the Entities via 6G -- RTR-Shield: Early Detection of Ransomware using Registry and Trap Files -- MalXCap: A Method for Malware Capability Extraction -- Multimodal Software bug Severity Prediction Based on Sentiment Probability -- Recovering Multi-Prime RSA Keys with Erasures and Errors -- Performance Impact Analysis of Homomorphic Encryption: A Case Study Using Linear Regression as an Example -- Chosen Ciphertext Security for Blind Identity-based Encryption with Certified Identities -- A New Gadget Decomposition Algorithm with Less Noise Growth in HE schemes -- Malicious Player Card-based Cryptographic Protocols with a Standard Deck of Cards Using Private Operations -- Cryptanalysis of Human Identification Protocol with Human-Computable Passwords -- A Source Hiding Protocol for Cooperative Intelligent Transportation Systems (C-ITS) -- A Revocable Outsourced Data Accessing Control Scheme with Black-Box Traceability -- LocKey: Location-based Key Extraction from the WiFi Environment in the User's Vicinity -- BAHS: a Blockchain-Aided Hash-based Signature Scheme -- Lever: Making Intensive Validation Practical on Blockchain -- Tikuna: An Ethereum Blockchain Network Security Monitoring System -- Isogeny-based Multi-Signature Scheme -- Security Analysis of WAGE against Division Property based Cube Attack -- When MPC in the Head meets VC -- Quantum Key Distribution as a Service and Its Injection into TLS -- XFedGraph-Hunter: An Interpretable Federated Learning Framework for Hunting Advanced Persistent Threat in Provenance Graph -- XSS attack detection by attention mechanism based on script tags in URLs -- Mining for Better: An Energy-Recycling Consensus Algorithm to Enhance Stability with Deep Learning -- SIOCEN: Secure Integrity Verification of Outsourced Data in Cloud Storage using Blockchain.

This book constitutes the refereed proceedings of the 18th International Conference on Information Security Practice and Experience, ISPEC 2023, held in Copenhagen, Denmark, in August 2023. The 27 full papers and 8 short papers included in this volume were carefully reviewed and selected from 80 submissions. The main goal of the conference is to promote research on new information security technologies, including their applications and their integration with IT systems in various vertical sectors.