A novel chaotic image encryption algorithm based on content-sensitive dynamic function switching scheme

Abstract

This paper proposes a novel chaotic image encryption algorithm based on a content-sensitive dynamic function switching mechanism. The proposed encryption algorithm is a symmetric cipher, operating on 1D byte sequence. Three independent chaotic maps are utilized for scrambling plain image bytes in order to realize confusion and diffusion properties. The first chaotic map is used for choosing one out of previously encrypted bytes, the second for choosing one out of remaining bytes not encrypted yet, and the last for determining a stochastic value to be externally injected into the stream simply by exclusive-or operation. An innovative content-sensitive dynamic function switching mechanism introducing more random behavior is incorporated in order to ensure high sensitivity to slight changes in plain image bytes. The proposed cryptosystem has gone through various common security analyses and tests to prove its validity. The results demonstrate that the proposed method achieves high security level regarding information entropy, key space, key sensitivity, and resistance to differential, data loss and noise attacks.