Security improvement of the pixel-shuffle-encryption by bit-chaos-rearrangement

The dynamic trajectory of a chaotic system has high sensitivity to the variance of initial system values. Therefore, a chaotic system is applied to image encryption for high security. This study discusses pixel-shuffle-encryption (PSE) technologies in Arnold's cat map, Baker map, and line map. The PSE can delete image contours, but it cannot disorder a gray-level spectrum for easy decryption of hackers. This study correspondingly proposes a chaotic, code-based, quasi-three-dimensional encrypting system that combines PSE and bit-chaos-rearrangement to scatter image contours and to disorder gray-level distribution. Statistical analyses of entropy and mean square error are used to verify encryption security through a demonstration of the effects of hybrid encryption.