No abstract

In this paper, a novel image encryption algorithm based on chaotic synchronization is proposed. First, a digital-redesign sliding mode controller (SMC) is developed to guarantee the chaos synchronization. The digital redesign method makes it possible to transform a proposed continuous-time SMC to discrete-time SMC whilst maintaining the performance of the robust synchronization. Then, the secret keys are embedded in the state equations of the master chaotic system, such that the secret keys do not appear in the public channel, and utilize the chaotic synchronization to achieve secure communication for transmitting the secret keys from transmitter to receiver. Second, an image encryption algorithm integrating the S-box with chaotic synchronization is established, where the S-box is created by the secret key transmitted from the transmitter. Finally, a detailed analysis of the image encryption algorithm based on chaos synchronization is included to verify the feasibility and effectiveness of this proposed approach.

This paper is concerned with the robust control for a general class of discrete chaotic systems with unmatched uncertainties. It is implemented by using discrete sliding mode control (DSMC). The proposed DSMC ensures the existence of the sliding mode. The chaotic behavior can be inhibited in an estimated bound in the state space even with unmatched uncertainties, which is not well addressed in the literature. The numerical simulation results demonstrate the feasibility and effectiveness of the proposed scheme.