Protecting Large Size Medical Images with Logistic Map Using Dynamic Parameters and Key Image

This paper presents a faster and efficient algorithm to encrypt large size 24-bit color medical images. The algorithm generates permutation sequences which shuffles the image pixels and color bytes. The generated masking sequences alters the value of the pixels and color bytes. The dynamic chaotic parameters initialisation is one of the key factors in the proposed cryptosystem. Further, the key image enhances efficiency of the encryption algorithm and the whole cryptosystem becomes complex by executing XOR operation with the shuffled pixels and bytes. The proposed algorithm yields final cipher images of the test medical images that have good confusion diffusion properties and validated through series of tests to ensure the high security level.