A metamorphic cryptography approach towards securing medical data using chaotic sequences and Ramanujan conjecture

Medical Images has evolved from time to time and the need to protect sensitive information related to such images have also grown significantly. Nowadays data being the primary asset of an individual, protecting them has posed new challenges from time and again. With the advancement of the digital medium, the medical image has been at greater risk and there is an urgent need to protect the information and the raw pixel data of such images. This research focuses on ensuring the confidentiality of DICOM medical images and protecting the Electronic Patient Report (EPR) by applying both cryptographic and steganographic protection techniques. The encryption keys are generated using the Logistic Chaotic Map and Non-Linear Feedback Shift Register. the electronic patient report (EPR) is converted into a 9-space-format using Continued Fraction of Ramanujan conjecture and then using steganography techniques EPR is embedded into the Most Significant Bits of Medical Images. The final encrypted image contains the EPR as well as encrypted medical image. The key sequence used in order to encrypt the medical image is highly pseudo random and the Key Space Analysis depicted that the algorithm is very strong. This work has paved a better way of securely storing 16-bit DICOM medical images and EPR into the Picture Archive and Communication System repository. The proposed security model has shown promising results in comparison to other research and the various analysis did show significant improvements over past studies.