A Privacy-Preserving Scheme for Medical Diagnosis Records Based on Encrypted Image Steganography

Abstract

Healthcare diagnosis records are essential as they establish perpetual reports on the health of patients. These records are in nature meant to be kept confidential. It is for this reason that medical data should be secured before transmission. Steganography and cryptography are old concepts used to secure communications. Steganography is hiding data into a carrier, for instance, images, videos, texts, and files. It seeks to hide the existence of communications. Cryptography is communication in deciphering secret writings or ciphers. In our privacy-preserving scheme for healthcare records, a hybrid approach is used to ensure the maximum multi-level security of medical records before transmission. The proposed system utilizes AES-128 which is a symmetric key encryption algorithm to scramble the data. As compared to asymmetric key encryption, symmetric key encryption is faster as only one key is used for both encryption and decryption. To resolve the problem of key distribution that plagues symmetric cryptosystems, the proposed system makes use of the Diffie-Hellman key exchange algorithm for key agreement. In this way, the encryption essentials are securely exchanged before the actual transmission of the date. To ensure efficient and optimal steganography throughput, the Least significant bit (LSB) which involves the hiding of information in the most repetitive bits of each pixel of an image was implemented for steganography. The technique was chosen because the level of distortion made to the image is low hence the image quality change is minimal. As such, the resultant robust system, is highly impeccable, utilises efficient compression, and has improved capacity which are all desirable features for securing medical health records.