Image Encryption Based on a Four-Dimensional Chaotic System

An image encryption algorithm based on a four-dimensional chaotic system is presented in this paper, in view of the existing problems in the image encryption. Firstly, the characteristics of the chaotic system are analyzed. This system has more parameters and is more complex than the low-dimensional chaotic systems. The chaotic sequences are improved to be suitable for image encryption. Secondly, a generation method of the binary sequence is reported in accordance with the requirement of the encryption algorithm. Through theoretical and statistical analysis, we can see the binary sequence generated by the chaotic system meets the requirement of the pseudo-random sequence and has the high security. Finally, a mixed airspace encryption algorithm is presented. The chaotic sequences are used to the image encryption. The algorithm has very good effect because of increasing the key space and resisting the exhaustive attacks and statistical attacks.