Showing papers on "Coupled map lattice published in 2018"
TL;DR: The security analysis demonstrates the effectiveness of the proposed encryption system and the simulation results verify that the cryptosystem is enough against the traditional attacks, such as statistical attack, differential attack, brute force attack, and entropy attack.
Abstract: According to the DNA encryption algorithm and the double-chaotic system which contains the optical chaos and the coupled map lattice chaotic system, a novel image encryption-then-transmission system is proposed. In the system, with identical chaotic injection from a master laser with two optical feedbacks, two slave lasers (SL1 and SL2) can output similar chaotic signals served as chaotic carrier to transmit image and used to generate the core part of the encryption scheme. A 128-b key is selected to generate the original value of the double-chaotic system, which decides the DNA complementary rule, hence, the key is hypersensitive in encryption and decryption process. The security analysis demonstrates the effectiveness of the proposed encryption system. The simulation results verify that the cryptosystem is enough against the traditional attacks, such as statistical attack, differential attack, brute force attack, and entropy attack. Moreover, the encrypted image can be the optical message and transmitted in 10 km single-mode fiber channel from SL1 to SL2. In order to ensure the security, we use the chaos masking technique to modulate and demodulate the optical message. Through numerical simulations of the cross-correlation function, the chaos synchronization between SL1 and SL2 is desired. The Q-factor is 9.559 and the bit error rate is $5.771\times 10^{-22}$ .
81 citations
TL;DR: In this paper, a new spatiotemporal dynamics with mixing degrees of nonlinear chaotic maps for spatial coupling connections based on 2DCML is investigated, where the coupling methods are including with linear neighborhood coupling and the non-linear chaotic map coupling of lattices.
Abstract: We investigate a new spatiotemporal dynamics with mixing degrees of nonlinear chaotic maps for spatial coupling connections based on 2DCML. Here, the coupling methods are including with linear neighborhood coupling and the nonlinear chaotic map coupling of lattices, and the former 2DCML system is only a special case in the proposed system. In this paper the criteria such Kolmogorov–Sinai entropy density and universality, bifurcation diagrams, space-amplitude and snapshot pattern diagrams are provided in order to investigate the chaotic behaviors of the proposed system. Furthermore, we also investigate the parameter ranges of the proposed system which holds those features in comparisons with those of the 2DCML system and the MLNCML system. Theoretical analysis and computer simulation indicate that the proposed system contains features such as the higher percentage of lattices in chaotic behaviors for most of parameters, less periodic windows in bifurcation diagrams and the larger range of parameters for chaotic behaviors, which is more suitable for cryptography.
32 citations
TL;DR: This paper is devoted to designing a pseudo-random number generator based on coupled map lattice with time-varying delay, analyzing the random properties of the generated pseudo- random numbers and discussing the dynamical degradation of the system under finite precision of computer simulation.
Abstract: Chaos has been widely combined with cryptography in the field of information security, especially, a considerable amount of studies of generating pseudo-random numbers based on chaotic systems have been proposed in recent decades. However, many of them are easy to be attacked via utilizing the nonlinear prediction method based on phase space reconstruction and other analysis. Furthermore, under the finite precision environment of computer simulation, there does not exist a random sequence which is truly non-periodic. Unfortunately, few researches had made a related analysis on the above two discussions. This paper is devoted to designing a pseudo-random number generator based on coupled map lattice with time-varying delay, analyzing the random properties of the generated pseudo-random numbers and discussing the dynamical degradation of the system under finite precision of computer simulation. The proposed scheme merely depends on the determining equation; thus, the algorithm itself is not complex, which does not impose high demand on computer hardware and its efficiency is excellent. In order to meet the requirements of using the proposed pseudo-random number generator in cryptography and other practical engineering applications, the proposed pseudo-random number generator is subjected to statistical tests utilizing the well-known test suites, such as NIST SP800-22 and TestU01. Moreover, other related properties, such as permutation entropy, invariant distribution, degradation of dynamical characteristics and parameter test, are also investigated. All results illustrate that the new pseudo-random number generator can generate a high percentage of available pseudo-random numbers for scientific computer simulation and practical applications in the field of information security.
31 citations
01 Dec 2018
TL;DR: A number of analysis performed suggest the proposed model a potential candidate for image encryption application, incorporates mixing based on randomly generated secret key, sub-keys based substitution, confusion algorithm and coupled map lattice based diffusion process to enrich the security, sensitivity and robustness of the model.
Abstract: In this study, a novel cryptographic model that uses coupled map lattice is proposed for securing image. It incorporates mixing based on randomly generated secret key, sub-keys based substitution, confusion algorithm and coupled map lattice based diffusion process to enrich the security, sensitivity and robustness of the model. The control parameters of coupled map lattice and initial condition of chaotic systems are deduced using externally generated random secret key of 280-bit length. To make the encryption process more dependent on confusion and more sensitive to the encryption key, pixels of a channel are XOR-ed with pixels of other channel with an intelligent mix of sub-keys. Finally, the diffusion model based on coupled map lattice, binds the pixels in a way such that a single-bit change is reflected into a large number of pixels in the cipher image. Resistance to various kinds of attacks like plain text, brute force and statistical attacks are the important features observed in the proposed cryptographic model. Several studies related to correlation coefficients, histogram, anti-noise attacks, plain text analysis, NPCR, key sensitivity, UACI and key space analysis were carried out and corresponding results are given in detail. The simulation results yield an average NPCR score to be about 99.63% and UACI value 33.46%. A number of analysis performed and mentioned here, suggests the proposed model a potential candidate for image encryption application.
21 citations
TL;DR: This paper presents a novel approach called " permutation in a pixel-level plane based on various chaotic systems" that automates the very labor-intensive and therefore time-heavy and expensive process of designing and implementing image encryption algorithms.
Abstract: Most of the existing image encryption algorithms had two basic properties: confusion and diffusion in a pixel-level plane based on various chaotic systems. Actually, permutation in a pixel-level pl...
17 citations
TL;DR: It is demonstrated that the extended CML can generate complex fractal patterns representing spatiotemporal divergence which can be controlled by the coupling parameter between the nodes.
Abstract: The extension of the Coupled map lattice (CML) model by replacing scalar nodal variables by matrix variables is investigated in this paper. The dynamics of the extended CML is investigated using formal analytical and computational techniques. Necessary conditions for the occurrence of the effect of explosive divergence in the extended CML are derived. It is demonstrated that the extended CML can generate complex fractal patterns representing spatiotemporal divergence which can be controlled by the coupling parameter between the nodes.
8 citations
TL;DR: In this article, the chaotic motions of a class of single-machine-infinite bus power systems are investigated both analytically and numerically for the case of a single-bus power system and the critical curves separating chaotic and non-chaotic regions are presented.
Abstract: The chaotic motions are investigated both analytically and numerically for a class of single-machine-infinite bus power systems. The mechanism and parametric conditions for chaotic motions of this system are obtained rigorously. The critical curves separating the chaotic and non-chaotic regions are presented. The chaotic feature of the system parameters is discussed in detail. It is shown that there exist chaotic bands for this system, and the bands vary with the system parameters. Some new dynamical phenomena are presented. Numerical results are given, which verify the analytical ones.
8 citations
01 Apr 2018
TL;DR: This paper deals with a problem of key diffusion in chaotic image encryption algorithms by usage of Coupled Map Lattice which introduces dependencies between chaotic maps used for generation of the pseudo-random sequences.
Abstract: This paper deals with a problem of key diffusion in chaotic image encryption algorithms. Usually, these approaches use multiple pseudo-random sequences for operations done during encryption and decryption. As each of these sequences is generated by part of selected key, in case that only small portion of key is changed, some of sequences could remain the same. This problem is solved by usage of Coupled Map Lattice which introduces dependencies between chaotic maps used for generation of the pseudo-random sequences. Paper also mentions other approaches, and compares their results with those achieved by the proposed algorithm by means of commonly used measures. The main advantages of our proposal include high values of entropy and Unified Average Changing Intensity.
5 citations
4 citations
TL;DR: In this paper, the authors derive from the Perron-Frobenius equation the corrections to ordinary Fokker-Planck equations in leading order of the time scale separation parameter.
Abstract: We consider discrete-time dynamical systems with a linear relaxation dynamics that are driven by deterministic chaotic forces. By perturbative expansion in a small time scale parameter, we derive from the Perron–Frobenius equation the corrections to ordinary Fokker–Planck equations in leading order of the time scale separation parameter. We present analytic solutions to the equations for the example of driving forces generated by Nth order Chebychev maps. The leading order corrections are universal for but different for N = 2 and N = 3. We also study diffusively coupled Chebychev maps as driving forces, where strong correlations may prevent convergence to Gaussian limit behavior.
3 citations
01 Jun 2018
TL;DR: The proposed pseudo-random number generator is subjected to statistical tests and shows that it holds better pseudo- random characteristics and suggests strong candidate for cryptographic applications.
Abstract: This paper proposes a new algorithm of generating pseudo-random numbers where delay coupled map lattice is utilized as a pseudo-random function. k-order Chebyshev map embedded time-varying delay is introduced as the dynamic function of delay coupled map lattice to improve random performance of the system. The proposed pseudo-random number generator is subjected to statistical tests which is the well-known NIST 800–22 and TestU01 test in the field of security and other related properties are also investigated. The result shows that the proposed pseudo-random number generator holds better pseudo-random characteristics and suggests strong candidate for cryptographic applications.
TL;DR: In this paper, a spatiotemporal discrete predator-prey system is investigated for understanding the pattern self-organization on the route to chaos in a coupled map lattice and shows advection of populations in space.
Abstract: A spatiotemporal discrete predator–prey system is investigated for understanding the pattern self-organization on the route to chaos. The discrete system is modelled by a coupled map lattice and shows advection of populations in space. Based on the conditions of stable stationary states and Hopf bifurcation, Turing pattern formation conditions are determined. As the parameter value is changed, self-organization of diverse patterns and complex phase transition among the patterns on the route to chaos are observed in simulations. Ordered patterns of stripes, bands, circles, and various disordered states are revealed. When we zoom in to observe the pattern transition in smaller and smaller parameter ranges, subtle structures for transition process are found: (1) alternation between self-organized structured patterns and disordered states emerges as the main nonlinear characteristic; (2) when the parameter value varies in the level from 10−3 to 10−4, a cyclic pattern transition process occurs repeatedly; (3) when the parameter value shifts in the level of 10−5 or below, stochastic pattern fluctuation dominates as essential regularity for pattern variations. The results obtained in this research promote comprehending pattern self-organization and pattern transition on the route to chaos in spatiotemporal predator–prey systems.
TL;DR: This approach reveals great diversity and complexity of pattern self-organization and pattern transition in predator–prey interactions, promoting comprehending on the spatiotemporal complexity of spatially extended predator-prey system.
TL;DR: In this paper, the structural stability of random coupled map lattice models of hyperbolic type under certain metrics was studied and the existence of equilibrium states for equi-Holder continuous random functions was proved under the conditions of random weak interaction and translation invariance.
Journal Article•
01 Jan 2018
TL;DR: A simulation of mosquito population dynamics and Plasmodium vivax malaria transmission in the Brazilian Amazon is described combining techniques of cellular automata and coupled map lattices to provide a stable platform for investigating the role of human migration and asymptomatic malaria in perpetuating transmission cycles.
Abstract: End stage malaria elimination efforts will require interventions against transmission that is sparse, cryptic and spotty, situations suited for explicitly spatial simulation. A simulation of mosquito population dynamics and Plasmodium vivax malaria transmission in the Brazilian Amazon is described combining techniques of cellular automata and coupled map lattices. Within a 200x200 grid, 64 dispersed communities of 50 households each are represented with larval breeding sites following a random Gaussian distribution. Discrete representation of individual humans allows examination of the effect of circulation and migration. Continuous representation of mosquito abundance allows for more realistic scaling over space. Simulations (n=100) reach equilibrium within 200 daily time steps. Adult mosquito populations range between 230-241,000 individuals. An average parous rate of 56.5% for stable mosquito populations is consistent with values reported in local field studies of the primary vector, Anopheles darlingi. Equilibrium prevalence of P. vivax infections averages 3% (1.8-3.9%) and is highly sensitive to treatment seeking behaviour of asymptomatics. This simulation provides a stable platform that may be useful for investigating the role of human migration and asymptomatic malaria in perpetuating transmission cycles in this region and interventions supporting malaria elimination
01 Oct 2018
TL;DR: The proposed hybrid encryption model enhances security and provides negligible correlation among pixels of cipher image and high NPCR, UACI scores.
Abstract: An image encryption model as a diffusion model for image encryption is proposed using coupled map lattice. It incorporates mixing process based on pseudo random number generator to ensure shuffling even if all image pixels are same. Further, Confusion is based on intertwining logistic map to enhance sensitivity with respect to key or data. Finally, coupled map lattice based diffusion model is used to modify the image pixels such that even a small change in one pixel of the original image affects most of the pixels in encrypted image. The proposed hybrid encryption model enhances security and provides negligible correlation among pixels of cipher image and high NPCR, UACI scores. The performance matrices of the proposed diffusion model enhance the performance as compared with other diffusion models used in image encryption methods.
01 Mar 2018
TL;DR: In this article, a space-and time-discrete predator-prey model with Holling type II function response is investigated, where the mortality of predator is variable, which is related to the population density.
Abstract: In this paper, a spaceand time-discrete predatorprey model with Holling type II function response is investigated. The mortality of predator is variable, which is related to the population density. The model is given by a coupled map lattice framework, it takes a nonlinear relationship between predatorprey reaction stage and dispersal stage. The stability of equilibrium point and the parameter conditions for the Hopf bifurcation are obtained when the diffusion is absent. After adding the diffusion, we obtained the parameter conditions for the Turing instability. Numerical simulations verify the theoretical analysis and show a series of spatial patterns with the change of the parameters. Keywords—discrete model; coupled map lattice; hopf bifurcation; turing instability; pattern formation