Preserving Confidentiality and Integrity of Medical Images over IoMT Networks: A Secure Transmission Approach for Smart Healthcare Systems

Abstract

This study targets increased security threats in the growing number of healthcare data records available digitally around the world via the Internet, making it essential to protect data against any unauthorized access. In order to solve this problem, two different fields are used in combination to protect the data: cryptography, which ensures the unreadable data format via mathematical manipulation, and steganography that hides the secret messages within the carriers. In this paper, a two-layer model combining DCT-based JPEG Steganography and substitution cipher Cryptography is proposed for safe transmission of sensitive healthcare information in IoMTs. Encrypted data are then embedded into cover medical images by employing DCT with the minimum perceivable and statistical alterations to avoid detection and guarantee accurate transmission of data. Six types of medical images were tested for the performance of the developed system by analyzing PSNR, SNR, MSE, and SC measures, showing successful capacity for embedding medical data of various image size (from 30 KB to 400 KB). The two-layer structure greatly improves security by not letting anyone access the encrypted message in case the first layer was breached. Clinically acceptable PSNR values are between 24 and 36 dB.