Role-Based Access Control for Secure Retrieval of Triple-Watermarked DICOM Medical Images

The rapid adoption of digital medical imaging has increased the need for secure storage, transmission, retrieval, andcontrolled access to medical images. Digital Imaging and Communications in Medicine (DICOM) is widely used forstoring and exchanging medical images together with associated patient and clinical information. However,unauthorized access, modification, duplication, and disclosure of sensitive medical information remain importantsecurity concerns. This paper proposes a role-based access control framework for the secure retrieval of triplewatermarked DICOM medical images. The proposed framework combines Discrete Wavelet Transform (DWT) andSingular Value Decomposition (SVD) with Role-Based Access Control (RBAC). Three independent watermarks areembedded into selected DWT-SVD coefficients to provide authentication, integrity verification, and ownershipprotection. RBAC is then applied to control which watermark or associated information can be retrieved by differentcategories of authorized users. Doctors, radiologists, technicians, researchers, and administrators are assigneddifferent permissions according to their operational requirements. The framework separates authentication fromauthorization and limits sensitive information exposure according to user roles. Performance can be evaluated usingPeak Signal-to-Noise Ratio (PSNR), Structural Similarity Index (SSIM), Normalized Correlation (NC), Bit ErrorRate (BER), extraction accuracy, and execution time. The proposed approach provides a combined mechanism forimage protection and controlled information retrieval while maintaining the visual quality of DICOM images.