BC-SMS2: A BLAKE2bp-enabled Security Model for Medical Image Protection with AVISPA-based Analysis
S. Sindhu, R. Raja, Regina S. · IETE Journal of Research · 2026
The primary function of blockchain (BC) technology in healthcare (HC) is to securely and efficiently share patient medical images and sensitive data. Integrating BC with image encryption (IE) provides a robust system for sharing and storing medical images in clinical environments. This research introduces BC-SMS2 (Blockchain-Secure Medical Data Storage and Sharing), an integrity-based approach ensuring secure transmission of medical images via BC using encryption and hashing. The system protects image data privacy by encrypting and storing hash values on the BC. BC-SMS2's resistance against formal attacks, including Chosen Plaintext Attack (CPA), Known Plaintext Attack (KPA), differential, and adaptive attacks, is evaluated using Information Entropy Analysis (IEA), Unified Averaged Change Intensity (UACI), and Number of Pixels Change Rate (NPCR). The model demonstrates strong resistance to differential attacks and high randomness, achieving NPCR and UACI encryption strengths of 99.9% and 33.5%, respectively, with an entropy value close to 8. Image reconstruction is lossless, evidenced by PSNR and RMSE values of 59.78 dB and 0.066, respectively. A batch encryption strategy significantly improves restoration time, reducing it from 723 hours to 160 seconds for a 512*512 image (K = 6). The model's pseudocode is verified using the AVISP tool for both passive and active attacks, reducing decryption time by 74.9%. Compared to traditional models, BC-SMS2 offers superior attack resistance, improved key sensitivity, and enhanced encryption quality, making it an ideal solution for secure, scalable medical image storage.