Communications in Computer and Information Science

This three-volume set CCIS 2637-2639, constitutes the refereed proceedings of the 7th International Conference on Blockchain and Trustworthy Systems, BlockSys 2025, held in Zhuhai, China, during May 30–31, 2025. The 110 full papers included in this book were carefully reviewed and selected from 254 submissions. They were organized in topical sections as follows:Part I: Blockchain Security & Attack Mitigation; Identity Authentication & Data Privacy; Blockchain Applications & Industry Solutions; Part II: Deep Learning Architectures & Optimization; Computer Vision & Medical Image Analysis; Natural Language Processing & Multimodal Learning; Reinforcement Learning & Edge Computing Systems;Part III: Blockchain & Smart Contract Trustworthiness; Federated Learning & Edge Computing Security; Industrial & IoT System Reliability; Privacy-Preserving & Secure Data Management;