This book constitutes the proceedings of the 20th International Conference on Risks and Security of Internet and Systems, CRiSIS 2025, held in Gatineau, QC, Canada, during October 22-24, 2025.The 25 full papers and 3 short papers presented here were carefully selected and reviewed from 52 submissions. These papers were organized in the following topical sections: AI for Software Security; Cyber Threats and Prediction; Distributed Systems and IoT Security; Intrusion Detection Systems (IDS); Privacy and Digital Trust; Vulnerabilities and Resilience; Privacy, Threat Analysis, and Explainable Cybersecurity; Advanced Attacks and Strategic Detection; Security Governance, Compliance, and Adaptive Systems.

This book constitutes the proceedings of the 20th International Conference on Risks and Security of Internet and Systems, CRiSIS 2025, held in Gatineau, QC, Canada, during October 22-24, 2025.The 25 full papers and 3 short papers presented here were carefully selected and reviewed from 52 submissions. These papers were organized in the following topical sections: AI for Software Security; Cyber Threats and Prediction; Distributed Systems and IoT Security; Intrusion Detection Systems (IDS); Privacy and Digital Trust; Vulnerabilities and Resilience; Privacy, Threat Analysis, and Explainable Cybersecurity; Advanced Attacks and Strategic Detection; Security Governance, Compliance, and Adaptive Systems.