A New Algorithm for Digital Image Encryption Based on Chaos Theory

In recent decades, image encryption, as one of the significant information security fields, has attracted many researchers and scientists. However, several studies have been performed with different methods, and novel and useful algorithms have been suggested to improve secure image encryption schemes. Nowadays, chaotic methods have been found in diverse fields, such as the design of cryptosystems and image encryption. Chaotic methods-based digital image encryptions are a novel image encryption method. This technique uses random chaos sequences for encrypting images, and it is a highly-secured and fast method for image encryption. Limited accuracy is one of the disadvantages of this technique. This paper researches the chaos sequence and wavelet transform value to find gaps. Thus, a novel technique was proposed for digital image encryption and improved previous algorithms. The technique is run in MATLAB, and a comparison is made in terms of various performance metrics such as the Number of Pixels Change Rate (NPCR), Peak Signal to Noise Ratio (PSNR), Correlation coefficient, and Unified Average Changing Intensity (UACI). The simulation and theoretical analysis indicate the proposed scheme’s effectiveness and show that this technique is a suitable choice for actual image encryption.

CHAOTIC INITIALIZED MULTIPLE OBJECTIVE DIFFERENTIAL EVOLUTION WITH ADAPTIVE MUTATION STRATEGY (CA-MODE) FOR CONSTRUCTION PROJECT TIME-COST-QUALITY TRADE-OFF

Time, cost and quality are three factors playing an important role in the planning and controlling of construc­tion. Trade-off optimization among them is significant for the improvement of the overall benefits of construction pro­jects. In this paper, a novel optimization model, named as Chaotic Initialized Multiple Objective Differential Evolution with Adaptive Mutation Strategy (CA-MODE), is developed to deal with the time-cost-quality trade-off problems. The proposed algorithm utilizes the advantages of chaos sequences for generating an initial population and an external elitist archive to store non-dominated solutions found during the evolutionary process. In order to maintain the exploration and exploitation capabilities during various phases of optimization process, an adaptive mutation operation is introduced. A numerical case study of highway construction is used to illustrate the application of CA-MODE. It has been shown that non-dominated solutions generated by CA-MODE assist project managers in choosing appropriate plan which is other­wise hard and time-consuming to obtain. The comparisons with non-dominated sorting genetic algorithm (NSGA-II), multiple objective particle swarm optimization (MOPSO), multiple objective differential evolution (MODE) and previ­ous results verify the efficiency and effectiveness of the proposed algorithm.

Combining a chaos system with an Arnold cat map for a secure authentication scheme in wireless communication networks

Purpose – Wu et al.'s scheme has a security problem that is related to anonymity: attackers can determine by interception the identity of a legal user. This paper aims to propose a new secure authentication which combines a chaos system with an Arnold cat map. The scheme improves upon that of the Wu et al.'s scheme. The scheme proposed herein provides for full anonymity and improves the security of authentication messages for wireless communications. Design/methodology/approach – A novel scheme that integrates a chaos sequence is used with an Arnold cat map for authentication messages. Authentication messages are shuffled using an Arnold cat map to improve the security of authentication in wireless communications. An analytic approach based on a chaos sequence with an Arnold cat map is developed to secure authentication. The proposed scheme is presented in this study to overcome the inherent drawbacks of existing designs. Findings – The integrated scheme involves two steps. First, a chaos map is used to generate a set of chaos sequences that is added to the authentication messages. Second, the authentication messages are shuffled using an Arnold cat map. The main feature of the proposed design is such that the chaos systems are sensitive to the initial values of conditions. Sensitivity will lead to long-term behavior unpredictability to reflect the non-linear dynamic systems. Furthermore, to increase the complexity of the authentication message, the authors also use an Arnold cat map. Originality/value – The proposed scheme provides functions that include full anonymity properties, protection of the real identity of the user, one-time password properties, timestamp benefits and sufficient complexity of the password. The analysis shows that the proposed scheme exhibits the advantages of the chaos system and is more secure than previous schemes. Notably, the proposed scheme is effective for wireless communications.

RFID Mutual Authentication Protocol Based on Chaos Key

While radio frequency identification (RFID) is evolving as a major technology enabler for identifying and tracking goods and assets around the world, its security issues are also increasingly exposed. A Hash-based RFID mutual authentication protocol was put forward. The key was joined into the hash algorithm, and chaos sequences were used to update the key. The protocol enhances the security of the RFID system with low cost. Experiments show that the chaos system has the character of initial value sensitivity, which can be used to distribute and update the secret key. Safety analysis show that the mutual authentication protocol can solve security issues including eavesdropping, illegal access, masquerade, spoofing attack, position tracking.

Planar Four-Linkage Guide Mechanism Synthesis Based on Mechanical Chaos System Methods

The problem of four-linkage guide mechanism synthesis is transformed into nonlinear equations to be found, Newton iterative method is an important technique to one dimensional and multidimensional variables and iterative process exhibits sensitive dependence on initial guess points. For the first time, the mechanical chaos methods of mechanism synthesis and all solutions of the nonlinear questions of mechanism synthesis were found by utilizing chaos sequences of chaos motions of mechanical system to obtain locate initial points. As an example the problem of function generation for planar four-linkage guide mechanism was considered. This makes that multi-projects selecting could be possible. This method is adaptive to planar multi-linkage and spatial mechanism. This provides a new simple realization method for mechanics design.

Two-Dimensional Hyper-Chaotic Mapping Interval Newton Iterative Method to Mechanism Synthesis

Mechanism synthesis questions can be transformed into nonlinear equations to be found. Interval Newton iterative method is an important technique to one dimensional and multidimensional variables and iterative process exhibits sensitive dependence on initial guess point. The characteristic of hyper-chaotic sequences produced by two dimensional hyper-chaotic discrete systems was analyzed. Making use of the advantage of giving rigorous bounds for the exact solution, for the first time, combining hyper-chaos sequences and interval Newton iteration with Krawczyk operator, a new method to find all solutions was proposed. The numerical examples in linkage synthesis and approximate synthesis show that the method is correct and effective.

A Novel Encryption Scheme for Digital Images Based on Compound Chaos Algorithm

A compound Chaos encryption algorithm for digital images is designed in this paper. Lorenz Chaotic system and Logistics map are linked in cascade to generate Chaos sequences. Then the permutation matrix is constructed to encrypt the digital image. The new algorithm can expand the key space and improve anti-aggressive ability. Matlab7.0 is used for simulation testing of the image encryption. Experimental results show that the algorithm is feasible and it can satisfy the security requirement for image transmission and storage. The compound Chaos algorithm can be also used for color digital image encryption.

The Research of Chaos Mapping Method with Infinite Collapses to Mechanism Synthesis

Many questions in natural science and engineering are transformed into nonlinear equations to be found, Newton iterative method is an important technique to one dimensional and multidimensional variables and iterative process exhibits sensitive dependence on initial guess point. The property of chaos sequences produced by one dimensional simple chaos mapping method with infinite collapses in finite interval was analyzed. For the first time, a new method based on utilizing one dimensional chaos mapping method with infinite collapses to obtain locate initial points to find all solutions of the nonlinear questions was proposed. The numerical examples in linkage synthesis and approximate synthesis show that the new method is correct and effective.