A Lightweight Hybrid Model for Securing Medical Images Using LSB Watermarking, ECIES and AES-CTR

Telemedicine requires the provision of medical images over unstable networks in a secure manner. Traditional hybrid cryptographic algorithms e.g. ECC-LSB watermarking provide confidentiality, but are often limited by a large computational cost hence limiting its use to real time. This paper, in turn, offers a lightweight security architecture that integrates Least Significant Bit (LSB) watermarking, Elliptic Curve Integrated Encryption Scheme (ECIES) and the Advanced Encryption Standard in Counter Mode (AES-CTR) to provide fast and secure encryption of medical images. The red channel of every image is watermarked through LSB watermarking to store Patient Electronic Health Records (EHR), and the RGB channels are encrypted with AES-CTR independently, making it possible to perform parallel processing. ECIES is used to transfer symmetric encryption keys. The security of the proposed framework is evaluated in terms of confidentiality, integrity preservation, and resistance to common attacks. Experimental results, validated against conventional ECC-based LSB watermarking schemes, demonstrate superior image quality with MSE of 0.0022, PSNR of 74.64 dB, and UIQI of 1.0, while achieving encryption and decryption times below 0.3 seconds, throughput at 1.51MB/s and 1.91MB/s respectively which makes it suitable to the real-time telemedicine and Picture Archiving and Communication System (PACS) settings.