This book constitutes the refereed proceedings of the 5th International Conference on Science of Cyber Security, SciSec 2023, held in Melbourne, VIC, Australia, during July 11–14, 2023. The 21 full papers presented together with 6 short papers were carefully reviewed and selected from 60 submissions.

Session 1 Network and System Security​.- ACDroid: Detecting Collusion Applications on Smart Devices.- DomainIsolation: Lightweight Intra-enclave Isolation for Confidential Virtual Machines.- Keeping Your Enemies Closer: Shedding Light on the Attacker's Optimal Strategy.- Cyber Attacks against Enterprise Networks: Characterization, Modelling and Forecasting.- Session 2 Cryptography and Authentication.- MCVDSSE: Secure Multi-Client Verifiable Dynamic Symmetric Searchable Encryption.- A Graphical Password Scheme based on Rounded Image Selection.- Implementation of the Elliptic Curve Method.- Almost Injective and Invertible Encodings for Jacobi Quartic Curves.- SeeStar: an Efficient Starlink Asset Detection Framework.- Privacy-enhanced Anonymous and Deniable Post-Quantum X3DH.- Session 3 AI for Security.- Fractional Dynamic: Analysis for Network Malware Propagation.- Enhancing the Anti-steganalysis Ability via Multiple Adversarial Network.- An Empirical study of AI model’s Performance for Electricity Load Forecasting with Extreme Weather Conditions.- Session 4 Threat Detection and Analysis.- AST2Vec: A Robust Neural Code Representation for Malicious PowerShell Detection.- Real-time Aggregation for Massive alerts based on Dynamic Attack Granularity Graph.- Decompilation Based Deep Binary-Source Function Matching.- Event-based Threat Intelligence Ontology Model.- Session 5 Web and Privacy Security.- Optimally Blending Honeypots into Production Networks: Hardness and Algorithms.- WebMea: A Google Chrome Extension for Web Security and Privacy Measurement Studies.- Quantifying Psychological Sophistication of Malicious Emails.- SVFL: Secure Vertical Federated Learning on Linear Models.- Session 6: Cryptography and Authentication II.- Multiprime Strategies for Serial Evaluation of eSIDH-Like Isogenies.- Adaptively Secure Constrained Verifiable Random Function.- A Robust Reversible Data Hiding Algorithm Based on Polar Harmonic Fourier Moments.- Session 7: Advanced Threat Detection Techniques and Blockchain.- VaultBox: Enhancing the Security and Effectiveness of Security Analytics.- Two-stage Anomaly Detection in LEO Satellite Network.- Hydra: An Efficient Asynchronous DAG-based BFT Protocol.- Redactable Blockchain in the Permissioned Setting.- Session 8: Workshop Session.- A MULTI-LEVEL Sorting Prediction Enhancement-based two-dimensional Reversible Data Hiding Algorithm for Jpeg Images.- Research on Encrypted Malicious 5G Access Network Traffic identification based on Deep Learning.- A Design of Network Attack Detection Using Causal and Non-causal Temporal Convolutional.