Selective Plane Replacement Watermarking and Cryptography (SPRWC)

Abstract

Background/Objectives: Telemedicine is an innovative system of healthcare provision from long distance. Though the technology adds to facilitating in reducing the patients’ visit, but requires innovative techniques to prevent illegal intruders during the transaction of medical images. Methods/Statistical Analysis: This paper introduces Selective Plane Replacement Watermarking with RSA Cryptography (SPRWRC) that combines bit plane slicing technique with a standard public key cryptographic algorithm by embedding the hospital logo as invisible watermark. The medical image that is to be shared over the public network is subjected to bit plane slicing. The hospital logo is encrypted by the standard public key cryptographic algorithm namely Rivest Shamir Adleman (RSA). The encrypted hospital logo is embedded into the MSB plane of the medical image. The LSB plane of the medical image is replaced with the embedded MSB plane. The image is reconstructed and transmitted over the public network. Findings: The hybrid algorithm explores a watermarking approach in spatial domain with hospital logo as the watermark. The maximum Entropy, NPCR and UACI values are 7.988, 0.998 and 0.46 respectively which are closer to the upper limit of theoretical values. The effectiveness of the proposed algorithm is verified against various attacks. The proposed method with encryption gives better result than without encryption due to scrambling of the watermark and embedding into the cover image does not show perceptible change on watermarked image. Application/Improvements: Protection of the integrity and confidentiality of medical images transactioned over public networks.