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Alaa Kadhim Farhan

Bio: Alaa Kadhim Farhan is an academic researcher from University of Technology, Iraq. The author has contributed to research in topics: Encryption & Computer science. The author has an hindex of 5, co-authored 21 publications receiving 83 citations.

Papers
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Journal ArticleDOI
30 Sep 2019-Entropy
TL;DR: This study presents a novel chaotic system with a unique feature of crossing inside and outside of a cylinder repeatedly, and shows that the encryption method using the proposed chaotic system has reliable performance.
Abstract: Designing chaotic systems with specific features is a hot topic in nonlinear dynamics. In this study, a novel chaotic system is presented with a unique feature of crossing inside and outside of a cylinder repeatedly. This new system is thoroughly analyzed by the help of the bifurcation diagram, Lyapunov exponents’ spectrum, and entropy measurement. Bifurcation analysis of the proposed system with two initiation methods reveals its multistability. As an engineering application, the system’s efficiency is tested in image encryption. The complexity of the chaotic attractor of the proposed system makes it a proper choice for encryption. States of the chaotic attractor are used to shuffle the rows and columns of the image, and then the shuffled image is XORed with the states of chaotic attractor. The unpredictability of the chaotic attractor makes the encryption method very safe. The performance of the encryption method is analyzed using the histogram, correlation coefficient, Shannon entropy, and encryption quality. The results show that the encryption method using the proposed chaotic system has reliable performance.

37 citations

Journal ArticleDOI
TL;DR: A new controller is introduced on the plasma system that can shift its equilibria away from each other, and subsequently break the symmetric double-wing that resembles a butterfly into several independent chaotic attractors, which provides a higher level of security than applying only one set of initial conditions.
Abstract: This paper investigates the dynamics of a 3D plasma system that has a single symmetric double-wing attractor moving around symmetric equilibria. Therefore, it is reasonable to assume that changing the space between these wings can degenerate them. Motivated by this concept, we introduce a new controller on the plasma system that can shift its equilibria away from each other, and subsequently break the symmetric double-wing that resembles a butterfly into several independent chaotic attractors. To show the advantage of generating coexisting attractors, we compare between the complexity performance of the multi-stable controlled plasma system and the original plasma system that has single chaotic attractor. Simulation results show that the complexity performance of the multi-stable controlled plasma system is higher than the original system. As a result, and from cryptographic point of view, chaotic ciphers with applying more than one set of initial conditions provide a higher level of security than applying only one set of initial conditions. As an example, we present a new approach for generating S-box based on the multistability behavior of the controlled plasma system. Performance analysis shows that the proposed S-box algorithm can achieve a higher security level and has a better performance than some of the latest algorithms.

37 citations

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a confident hash algorithm that has characteristics that enable it to succeed in the field of digital authentication and data integrity and the experimental results demonstrate its high resistance to hackers while maintaining a suitable duration.
Abstract: MD5 is a one-way cryptographic function used in various fields for maintaining data integrity. The application of a Hash function can provide much protection and privacy and subsequently reduce data usage. Most users are familiar with validating electronic documents based on a Hash function, such as the MD5 algorithm and other hash functions, to demonstrate the data integrity. There are many weaknesses of the current MD5 algorithm, mainly its failures and weaknesses against varying types of attacks, such as brute force attacks, rainbow table attacks, and Christmas attacks. Therefore, the method proposed in this paper enhances the MD5 algorithm by adding a dynamic variable length and a high efficiency that simulates the highest security available. Whereas the logistic system was used to encode ribonucleic acid (RNA) by generating a random matrix based on a new key that was created using the initial permutation (IP) tables used in the data encryption stander (DES) with the linear-feedback shift register (LFSR), this work proposes several structures to improve the MD5 hash function. The experimental results demonstrate its high resistance to hackers while maintaining a suitable duration. This paper discusses the design of a confident hash algorithm. This algorithm has characteristics that enable it to succeed in the field of digital authentication and data integrity.

23 citations

Journal ArticleDOI
TL;DR: In this article, the authors proposed a linear trigonometric transformation to generate dynamic and key dependent substitution boxes (S-boxes) with the help of a projected S-box projection scheme.
Abstract: Protection of data transmitted over the network from illegal access is one of the major challenges being posed by exponential growth of data in online digital communication. Modern cryptosystems assist in data sanctuary by utilizing substitution-boxes (S-boxes). This paper presents a modest and novel technique to erect dynamic and key dependent S-boxes with the help of a novel linear trigonometric transformation. A new optimization plan is also suggested to improvise the nonlinearity characteristic of the preliminary S-box generated through trigonometric transformation. The proposed technique has the competence to create significant quantity of cryptographic strong S-boxes with the help of projected scheme. A specimen S-box is procreated, and standard performance criteria is applied to appraise the cryptographic strength of the resultant S-box and other known S-boxes available in the literature. Comparative performance analyses validate the noteworthy contribution of the proposed scheme for the generation of dynamic and secure S-boxes. An image privacy preserving scheme based on the proposed S-box is also suggested to validate the fact that it holds strong candidature for modern cryptosystems to protect multimedia data.

21 citations

Journal ArticleDOI
TL;DR: In this work, a new NTRU-analog cryptosystem called QOBTRU is proposed based on a newly designed algebraic structure called Carternion algebra, which is intended to have an alternative security and performance attribute upon three chosen highly performed multidimensional N TRU-like Cryptosystems, which are QTRU, O TRU, and BITRU.
Abstract: NTRU public key cryptosystem relies on computations that are efficiently performed with insignificant storage and time complexity. Many researchers were motivated to improve NTRU performance by rep...

17 citations


Cited by
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Journal ArticleDOI
TL;DR: This paper introduces a non-ideal flux-controlled memristor model into a Hopfield neural network (HNN), a novel memristive HNN model with multi-double-scroll attractors that has excellent randomness and is suitable for image encryption application.
Abstract: Memristors are widely considered to be promising candidates to mimic biological synapses. In this paper, by introducing a non-ideal flux-controlled memristor model into a Hopfield neural network (HNN), a novel memristive HNN model with multi-double-scroll attractors is constructed. The parity of the number of double scrolls can be flexibly controlled by the internal parameters of the memristor. Through theoretical analysis and numerical simulation, various coexisting attractors and amplitude control are observed. Particularly, the interesting and rare phenomenon of the memristor initial offset boosting coexisting dynamics is discovered, in which the initial offset boosting coexisting double-scroll attractors with banded attraction basins are distributed in a line along the boosting route with the variation of the memristor initial condition. In addition, it is also found that the number of the initial offset boosting coexisting double-scroll attractors is closely related to the total number of scrolls and ultimately tends to infinity with increasing the total number of scrolls, meaning the emergence of extreme multistability. Then, the random performance of the initial offset boosting coexisting double-scroll attractors is tested by the NIST test suite. Moreover, an encryption scheme based on them is also proposed. The obtained results show that they have excellent randomness and are suitable for image encryption application. Finally, numerical simulation results are well demonstrated by circuit experiments, showing the feasibility of the designed memristive multi-double-scroll HNN model.

92 citations

Journal ArticleDOI
TL;DR: A novel simple modular approach, the very first time, is investigated to construct nonlinear S-box in this paper, which consists of three operations such as new transformation, modular inverses, and permutation.
Abstract: In modern-day block ciphers, the role of substitution-boxes is to transform the plaintext data nonlinearly to generate ciphertext data with sufficient confusion. It has been well-confirmed that the robustness and security of such block ciphers heavily based on the cryptographic strength of the underlying substitution-boxes. Reason being, they are the only components that are held responsible to bring required nonlinearity and complexity into the security system which can frustrate the attackers. Accordingly, a number of different concepts have been explored to construct strong S-boxes. To move forward with the same aim, a novel simple modular approach, the very first time, is investigated to construct nonlinear S-box in this paper. The proposed new modular approach consists of three operations such as new transformation, modular inverses, and permutation. A number of highly nonlinear S-boxes can be easily constructed with slight changes in the novel transformation parameters. An example S-box is presented whose critical performance assessment against some benchmarking criterions such as high nonlinearity, absence of fixed points, fulfillment of SAC and BIC properties, low differential uniformity and linear approximation probability and comparison with recent S-boxes demonstrate its upright cryptographic potentiality. In addition, an image encryption algorithm is also proposed wherein the generated S-box is applied to perform the pixels shuffling and substitution for strong statistical and differential encryption performance.

53 citations

Journal ArticleDOI
TL;DR: The proposed algorithm guarantees the generation of strong S-boxes that fulfill the following criteria: bijection, nonlinearity, strict avalanche criterion, output bits independence criterion, criterion of equiprobable input/output XOR distribution, and maximum expected linear probability.
Abstract: In this work, we present a simple algorithm to design n × n-bits substitution boxes (S-boxes) based on chaotic time series of the logistic map for different carrying capacities. The use of different carrying capacities in the chaotic map leads to low computational complexity, which is desirable to get high-speed communication systems. We generate a main sequence by means of two auxiliary sequences with uniform distribution via the logistic map for different carrying capacities. The elements of the main sequence are useful for generating the elements of an S-box. The auxiliary sequences are generated by considering lag time chaotic series; this helps to hide the chaotic map used. The U-shape distribution of logistic chaotic map is also avoided, in contrast with common chaos-based schemes without considering lag time chaotic series, and uncorrelated S-box elements are obtained. The proposed algorithm guarantees the generation of strong S-boxes that fulfill the following criteria: bijection, nonlinearity, strict avalanche criterion, output bits independence criterion, criterion of equiprobable input/output XOR distribution, and maximum expected linear probability. Finally, an application premised on polyalphabetic ciphers principle is developed to obtain a uniform distribution of the plaintext via dynamical S-boxes.

52 citations

Journal ArticleDOI
TL;DR: The results show that methodology adapted to design proposed key-based dynamic S-boxes entails near-optimal cryptographic properties so that proposed S- boxes are as stronger as AES S-box.
Abstract: This work reports a novel chaos-based affine transformation generation method, which is based on rotational matrices to design strong key-based S-boxes. Chaotic logistic map’s nonlinear trajectories are used to generate rotational matrices under given design conditions. Thus, the inherent logic is to generate key-based S-boxes, as strong as AES S-box, in terms of cryptographic properties using chaos in affine transformation. The randomness of chaotic sequences is tested using the National Institute of Standard and Technology (NIST) Statistical Test Suit (STS) 800–22 that validates the generated sequences for S-box design. The results show that methodology adapted to design proposed key-based dynamic S-boxes entails near-optimal cryptographic properties so that proposed S-boxes are as stronger as AES S-box.

40 citations

Journal ArticleDOI
20 Apr 2020-Entropy
TL;DR: A modification of the classic logistic map is proposed, using fuzzy triangular numbers, which successfully passes the National Institute of Standards and Technology (NIST) statistical tests, and it is then successfully applied to the problem of image encryption.
Abstract: A modification of the classic logistic map is proposed, using fuzzy triangular numbers. The resulting map is analysed through its Lyapunov exponent (LE) and bifurcation diagrams. It shows higher complexity compared to the classic logistic map and showcases phenomena, like antimonotonicity and crisis. The map is then applied to the problem of pseudo random bit generation, using a simple rule to generate the bit sequence. The resulting random bit generator (RBG) successfully passes the National Institute of Standards and Technology (NIST) statistical tests, and it is then successfully applied to the problem of image encryption.

35 citations