Tamper-Resistant Secure Medical Image Carrier: An IWT-SVD-Chaos-FPGA Combination

Medical images are widely used for diagnostic and therapeutic purposes during the detection of abnormalities in various organs of the human body. A huge number of medical images are handled every day by the hospitals as well as medical practitioners. Medical images need a strong mechanism for rightful patient identification and confidential sharing. The proposed work addresses both these issues through watermarking, encryption and hardware storage. In the proposed work, the important credentials of the patient such as their treatment history, ID and thumb impression are integrated in the form of a 256 x 256 watermark image. This watermark is embedded into the DICOM image of size 512 x 512 using Singular Value Decomposition on Integer Wavelet Transform domain. The watermarked DICOM image was further encrypted using Tent map and Lu chaotic attractors. Further, Stratix FPGA has been used to carry the bitstream format of encrypted images. The extracted watermark achieves a PSNR of 30 dB after subjecting to 17 different noise and image processing attacks on the encrypted image. For a payload of 0.25, the normal cross-correlation reached is 0.99. Keyspace of the encrypted DICOM image is 10(136) achieving an average entropy of 15.68 and near-zero correlation. The proposed solution also overcomes the False Positive Problem. Various error metrics and statistical analyses have been performed to validate the robustness of the proposed secure medical image carrier.