This paper introduces an FPGA design methodology of a sample and bit permutation speech encryption system. Pipelining method is used to build the proposed system, which can have different number of permutation levels. The security of the system is evaluated using entropy, Mean Squared Error (MSE) and correlation coefficients comparing the different permutation levels. The results demonstrate the

This paper proposes a current-/voltage-controlled universal emulator that can realize any fractional-order memelements (FOME). The proposed emulator consists of second-generation current conveyors (CCII) block, two switches, and a multiplier/divider block. The first switch controls the emulator mode (voltage or current), while, the other controls the type of the emulated FOME. The influence of the

In this paper, we proposed a new technique for designing a dynamic S-box depended on the idea of DNA module and Chaotic system to increase its security. Lorenz chaotic generator is utilized as the chaos part of the proposed design. This design is Tested on the Field Programmable Gate Array (FPGA) for the use of offline speech encryption and decryption in real time. The experimental results are

In this work, we demonstrate the possibility of performing two-dimensional rotation on a chaotic system. This enables the rotation of its attractor in space without changing its chaotic dynamics. In particular, the rotated system preserves the same eigenvalues at all equilibrium points and its largest Lyapunov exponent remains unchanged. Two chaotic systems, one of which is the classical Lorenz

In this paper, the application of the theory of Lissajous figures to the creation of pinched hysteresis loops, considered to be a characteristic of memristive systems, is demonstrated and experimentally verified using designed electronic circuits in the form of an input impedance. The relationship between the Lissajous-based model of the pinched hysteresis loop and a previously reported integrator

In this paper, a new realization of the fractional capacitor (FC) using passive symmetric networks is proposed. A general analysis of the symmetric network that is independent of the internal impedance composition is introduced. Three different internal impedances are utilized in the network to realize the required response of the FC. These three cases are based on either a series RC circuit

In this paper, an enhanced version of the improved Howland circuit is proposed. An improvement in output impedance to a maximum factor of two is obtained. The theoretical derivation is presented, including analysis from a two-port network perspective, and both simulation and experimental results using a general purpose opamp confirm the expected result. © 2019 John Wiley & Sons, Ltd.

The fractional-order model of a phantom electroencephalographic system, at various distances between electrodes, is realized using appropriate decomposition of the rational transfer functions which approximate the highpass filters that describe its dynamics. The main offered benefits, in comparison to the corresponding straightforward implementations of the rational transfer functions, are the

Fractional-order chaotic systems (FOCS) parameter identification is an essential issue in chaos control and synchronization process. In this paper, different recent Meta-heuristic Optimization Algorithms are used to estimate the parameters and orders of three FOCS. The investigated systems are Arneodo, Borah rotational attractor and Chen double- and four-wing systems. The employed algorithms are

Optimization routines are widely used to numerically determine a set of model parameters that best fit collected experimental data. One recent application of these methods is to extract the fractional-order circuit model parameters that accurately characterize the transient behavior of discharging supercapacitors. However, the variability that these methods introduce to the extracted model