Chua's diode and strange attractor: a three-layer hardware-software co-design for medical image confidentiality

Medical image security relies upon the arrival of improved techniques for enhancing the confusion as well as diffusion processes in the pixel level manipulations. Non-linear circuits constructed with hardware components can be employed for hardware-software co-design in medical image encryption. The proposed approach has adopted Chua diode circuit for the generation of 256 x 256 random synthetic image with the entropy of 7.9972. This synthetic image has been utilised to scramble the DICOM image for the second level of diffusion as the cellular automata provides the first level of scrambling and diffusion. The average correlation coefficients of encrypted pixels are 0.00204, -0.00298 and -0.00054 in three directions. The encrypted pixels pass the NIST SP 800-22 test suite and offer resistance to statistical, differential and chosen plain text attacks.