A Multi-Layered Security Framework for Medical Imaging: Integrating Compressed Digital Watermarking and Blockchain

In electronic healthcare, patient medical imaging data is critical for remote diagnostic procedures. The increasing demand to harness the potential of these medical images necessitates their secure sharing among various entities, including hospitals, medical institutions, and insurance companies. However, third-party access and possible manipulation make it challenging to maintain the ownership and integrity of this data. This study introduces a novel approach that combines compression, digital watermarking, symmetric encryption, and blockchain technology to protect medical images from unauthorized third-party interventions. Using the Discrete Wavelet Transform, our proposed technique embeds a compressed watermark into the host image. Specifically, the watermark is encoded into vectors and inserted into the second-level approximation, i.e., the Low-Low of the image using the Least Significant Bit, producing a watermarked image. The watermarked data is encrypted and stored on a blockchain to further safeguard these images' integrity. This multi-layer security framework not only preserves the integrity and confidentiality of the data but also facilitates transparent and secure sharing among stakeholders. The proposed method achieves a peak signal-to-noise ratio of 63.24dB and a structural similarity index of 1. These results demonstrate the robustness of our solution in protecting and exchanging medical images within the digital healthcare ecosystem, positioning it as an advanced and reliable option for secure data management.