ENHANCED CRYPTOGRAPHIC INTEGRITY: INTEGRATING MODIFIED SHA-256 FOR SECURE DISTRIBUTED LEDGER-BASED MEDICAL RECORD SYSTEMS

Abstract

The integration of a Modified SHA-256 algorithm into distributed ledger-based medical record systems enhances cryptographic security, data integrity, and computational efficiency. The proposed model optimizes padding, message scheduling, and compression functions. A public repository containing 50,000 de-identified Electronic Health Records (EHRs) was utilized for evaluation under a Python-based AWS cloud environment with Intel Core i9 (3.6 GHz), 32 GB RAM, and NVIDIA RTX 3080 GPU. Results demonstrate that the Modified SHA-256 outperforms Standard SHA-256 and related models, reducing hash computation time by 33.6%, latency by 35.6%, encryption/decryption time by 28.2%, and storage overhead by 31.4% on average. The system also lowers computational complexity and energy consumption without compromising cryptographic robustness. Integration with distributed ledger ensures immutability, Merkle tree validation, and verification digest mechanisms, providing real-time consistency. Overall, the proposed Modified SHA-256-based distributed ledger framework establishes a secure and efficient foundation for healthcare data management and privacy preservation.