This study analyzed the security architecture of a blockchain-based authentication protocol and identified major vulnerabilities in smart health and Internet of Things (IoT) environments. The analysis confirmed potential risks including replay attacks due to key synchronization delays, incomplete verification logic in smart contracts, trust imbalance among nodes, and privacy breaches from private key reuse. To address these, the study proposes an enhanced protocol that integrates a time- and nonce-based multi-layered key derivation structure with dynamic trust indicators. Performance evaluation confirmed that the proposed solution simultaneously improves both throughput and security.

Abstract
1. 서 론
2. 관련 연구
3. 방 법
4. 프로토콜의 분석 절차
    4.1 기존의 블록체인 기술에 대한 개요
    4.2 취약점 분석
5. 제안된 개선 방안
6. 모의 실험 결과와 향상된 프로토콜의성능
7. 결 론
References

• 변해원(Dept. of Future Technology, Korea University of Technology and Education, South Korea) | Haewon Byeon Corresponding author