a watermarking scheme for Grayscale image isproposed based on a family of the chaotic maps and discretecosine transform. Jacobian Elliptic mapis employed to encrypt ofwatermarked logo. Piecewise nonlinear chaotic map is also usedto determine the location of DCT coefficients for the watermarkembedding. The purpose of this algorithm is to improve theshortcoming of watermarking such as small key s...

In the recent years, researchers developed image encryption methods based on chaotic systems. This paper proposed new image encryption technique based on new chaotic system by adding two chaotic systems: the Lorenz chaotic system and the Rössler chaotic system. The main advantage of this technique is stronger security, as is shown in the encryption tests.

In this study, we investigate synchronization phenomena observed in coupled chaotic circuits as a ring topology when two types of the bifurcation parameters to generate chaotic and three-periodic attractors are arranged. By using computer simulations and circuit experiments, we observe a collision between chaotic and periodic attractors depending on the number of chaotic attractors and the loca...

Evolutionary technique differential evolution (DE) is used for the evolutionary tuning of controller parameters for the stabilization of set of different chaotic systems. The novelty of the approach is that the selected controlled discrete dissipative chaotic system is used also as the chaotic pseudorandom number generator to drive the mutation and crossover process in the DE. The idea was to u...

First, this paper announces a seven-term novel 3-D chaotic system with a cubic nonlinearity and two quadratic nonlinearities. The phase portraits of the novel 3-D chaotic system are displayed and the mathematical properties are discussed. The proposed novel 3-D chaotic system has three equilibrium points, which are all unstable. We shall show that the equilibrium point at the origin is a saddle...

An important problem in nonlinear science is the unknown parameters estimation in Loranz chaotic system. Clearly, the parameter estimation for chaotic systems is a multidimensional continuous optimization problem, where the optimization goal is to minimize mean squared errors (MSEs) between real and estimated responses for a number of given samples. The Bees algorithm (BA) is a new member of me...

-Although the motions of independent chaotic systems are uncorrelated with each other, it is possible under some conditions to synchronize a subsystem of one chaotic system with a separate chaotic system by sending a signal from the chaotic system to the subsystem. We describe here the conditions necessary for synchronization and demonstrate synchronization with a chaotic circuit.

Secure communication using synchronization between chaotic systems(chaotic secure communication, for short) is a new concept of secure communication. The great potentials of this kind of “hardware key” secure communication systems had driven the progress of this field rapidly. Since 1992, chaotic secure communication had evolved four generations. In this paper, a detailed history of chaotic sec...

Since chaos systems generally have the intrinsic properties of sensitivity to initial conditions, topological mixing and density of periodic orbits, they may tactfully use the chaotic ergodic orbits to achieve the global optimum or their better approximation to given cost functions with high probability. During the past decade, they have increasingly received much attention from academic commun...