Search

Traditional encryption algorithms are inefficient when applied to image encryption because image data have the characteristics of large data sizes and strong correlations between adjacent pixels. The shortcomings of the traditional Data encryption standard (DES) encryption algorithm when applied to image encryption are analyzed, and a new image encryption algorithm based on the traditional DES encryption algorithm model, chaotic systems, DNA computing, and select cipher-text output is proposed. Select cipher-text output selects cipher image with the biggest entropy, and it can increase the randomness of cipher image and reduce the risk of encryption system being broken down. This algorithm overcomes the shortcomings of high computational complexity and inconvenient key management that the traditional text encryption algorithm has when applied to image encryption. The experimental results show that the security of this algorithm is verified by analyzing the information entropy, image correlation of adjacent pixels and other indexes. At the same time, this algorithm passes the noise attack test and the occlusion attack test, so it can resist common attacks.

The chaotic complex system is designed from the start of the chaotic real system. Dynamical properties of a chaotic complex system in complex space are investigated. In this paper, a compound synchronization scheme is achieved for four chaotic complex systems. According to Lyapunov stability theory and the adaptive control method, four chaotic complex systems are considered and the corresponding controllers are designed to realize the compound synchronization scheme. Four novel design chaotic complex systems are given as an example to verify the validity and feasibility of the proposed control scheme.

Some important dynamical properties of the memristor chaotic oscillator system have been studied in the paper. A novel hybrid dislocated control method and a general hybrid projective dislocated synchronization scheme have been realized for memristor chaotic oscillator system. The paper firstly presents hybrid dislocated control method for stabilizing chaos to the unstable equilibrium point. Based on the Lyapunov stability theorem, general hybrid projective dislocated synchronization has been studied for the drive memristor chaotic oscillator system and the same response memristor chaotic oscillator system. For the different dimensions, the memristor chaotic oscillator system and the other chaotic system have realized general hybrid projective dislocated synchronization. Numerical simulations are given to show the effectiveness of these methods.