Multiple Chaotic Map Based Selective Image Encryption Scheme for Medical Images

Securing medical images is essential to protect patient privacy, particularly with the rise of telemedicine and eHealth/mHealth services, necessitating rapid and effective security measures. However, research on securing medical images with minimal processing time remains limited. This paper presents a selective encryption approach aimed at reducing processing time while ensuring robust security. In the developed scheme of the present study, a selective image security system, using multiple chaotic maps has been incorporated. The Region of Interest is selected either manually or a histogram based global threshold is used. The selected region is then subjected to a 2D logistic map and then XORed with the pseudo random series generated by a 3D Lorentz map. The applying of the diffused image over the input image gives a selectively encrypted image. The proposed novel image encryption scheme in this paper combines both logistic and Lorenz maps to improve the encryption capacity. Our experimental results demonstrate that the proposed method enhances the security performance more effectively than other methods in terms of entropy and correlation coefficients. The adopted encryption strategy also reveals high reliability against the brute force attacks with low processing delay required achieving high entropy and nearly zero correlation coefficients making it appropriate for real-time medical image applications.