This set of volumes constitutes the refereed proceedings of 28th International Conference on Information and Communications Security, ICICS 2026, held in Fukui, Japan, during October 27–30, 2026.

The 148 full papers, 69 short papers and 16 poster papers presented in this book were carefully selected and reviewed from 499 submissions. The papers are organized in the following topical sections:

Part I: Full Papers — Cryptography and Secure Protocols.
Part II: Full Papers — Federated Learning, AI Model Security and Blockchain.
Part III: Full Papers — LLM Security, Software Security and Malware Analysis.
Part IV: Full Papers — Network, IoT, Hardware Security and Privacy.
Part V: Short Papers I — Cryptography, Secure Computation and Blockchain.
Part VI: Short Papers II — AI and Systems Security, and Posters.