An Innovative Technique for Constructing Highly Non-Linear Components of Block Cipher for Data Security against Cyber Attacks

Efficient high nonlinearity S-box generating algorithm based on third-order nonlinear digital filter

Block cipher has been a standout amongst the most reliable option by which data security is accomplished. Block cipher strength against various attacks relies on substitution boxes. In literature, extensively algebraic structures, and chaotic systems-based techniques are available to design the cryptographic substitution boxes. Although, algebraic and chaotic systems-based approaches have favorable characteristics for the design of substitution boxes, but on the other side researchers have also pointed weaknesses in these approaches. First-time multilevel information fusion is introduced to construct the substitution boxes, having four layers; Multi Sources, Multi Features, Nonlinear Multi Features Whitening and Substitution Boxes Construction. Our proposed design does not hold the weakness of algebraic structures and chaotic systems because our novel s-box construction relies on the strength of true random numbers. In our proposed method true random numbers are generated from the inevitable random noise of medical imaging. The proposed design passes all the substitution box security evaluation criteria including Nonlinearity, Bit Independence Criterion (BIC), Strict Avalanche Criterion (SAC), Differential Approximation Probability (DP), Linear Approximation Probability (LP), and statistical tests, including resistance to Differential Attack, Correlation Analysis, 2D, 3D histogram analysis. The outcomes of the evaluation criteria validate that the proposed substitution boxes are effective for block ciphers; furthermore, the proposed substitution boxes attain better cryptographic strength as compared to very recent state-of-the-art techniques.

Algebraic structures play a vital role in securing important data. These structures are utilized to construct the non-linear components of block ciphers. Since constructing non-linear components through algebraic structures is crucial for the confusion aspects of encryption schemes, relying solely on these structures can result in limited key spaces. To address this issue, a complex non-chain ring with combination of Henon map based algorithm is presented. This proposed work aims to enhance both security and key space by utilizing complex algebraic structures. In this study, we investigate the use of unit elements from non-chain rings, establishing a mapping from the group of units to Galois fields to enhance the algebraic robustness of the scheme. A substitution box is constructed from Galois field and is applied in image processing. For pixel mixing, the Henon map is employed, and the exclusive OR operation is performed using a key generated from image pixels and the substitution box. The algorithm’s performance is evaluated using standard parameters such as histograms, Structural Similarity Index Measure (SSIM), correlation analysis, and National Institute of Standards and Technology (NIST) tests. For S-box analysis, we apply the strict avalanche criterion (SAC), bit independence criterion (BIC), linear approximation probability (LAP), and differential approximation probability (DAP). This algebraic approach utilizes a robust and state-of-the-art image encryption system that is highly effective against potential attackers.

Region of interest-based medical image encryption technique based on chaotic S-boxes

In this modern era, where technologies are being evolved day by day and data is shared on various communication platforms in a huge volume and variety. There is a need of implementing security and privacy in every technology. The files that are being shared need to be protected with strong encryption. So that the confidential data will remain, secure and protected from unauthorized access. Data is a raw form of information that can be stored or transferred digitally over the network. Cybersecurity is applied to protect data from unauthorized access in order to maintain its integrity and availability. Information security refers to the use of defensive computerized protection measures to prevent unauthorized access to computers, databases, and websites. It protects customers by making the encrypting of communications and the validation of distinct clients helpful. This allows us to communicate critical data in a surprising manner. Nevertheless, there are several approaches available; the current state of the data security framework includes categorization, trustworthiness, and righteousness while accessing or modifying confidential internal records. This paper proposes an approach for securing the data from unauthorized access using color-coding authentication. It secures confidential data from being mishandled and information from being passed into the wrong hands by encrypting it and securing it using a process of automated passwords. Security is about the assurance of benefits. The validation model depends on some shading mixes. Thus, this paper aims for making sure about classified documents for conveying data utilizing encryption, unscrambling, and shading code validation.KeywordsAuthenticationCybersecurityConfidentialityCryptographyEncryptionSecurityPrivacy

The multiplicative complexity of an S-box over a finite field is the minimum number of multiplications needed to implement the S-box as an arithmetic circuit. In this paper we fully characterize bijective S-boxes with multiplicative complexity 1 up to affine equivalence over any finite field. We show that under affine equivalence in odd characteristic there are two classes of bijective functions and in even characteristic there are three classes of bijective functions with multiplicative complexity 1. Moreover, in (Jeon et al., Cryptogr. Commun., 14(4), 849-874 (2022)) A-boxes where introduced to lower bound the differential uniformity of an S-box over F2n\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb {F}_{2}^{n}$$\\end{document} via its multiplicative complexity. We generalize this concept to arbitrary finite fields. In particular, we show that the differential uniformity of a (n, m)-S-box over Fq\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb {F}_{q}$$\\end{document} is at least qn-l\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$q^{n - l}$$\\end{document}, where ⌊n-12⌋+l\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\lfloor \\frac{n - 1}{2} \\rfloor + l$$\\end{document} is the multiplicative complexity of the S-box.

Image Encryption is a technique where an algorithm along with a set of characters called key encrypts the data into cipher text. The cipher text can be converted back into plaintext by decryption. This technique is employed for the security of data such that confidentiality, integrity and authenticity of data is maintained. In today's era security of information has become a crucial task, unauthorized access and use of data has become a noticeable issue. To provide the security required, there are several algorithms to suit the purposes. While the use and transferring of images has become easy and faster due to technological advancements especially wireless sensor network, image destruction and illegitimate use has become a potential threat. Different transfer mediums and various uses of images require different and appropriately suiting encryption approaches. Hence, in this paper we discuss the types of image encryption techniques. We have also discussed several encryption algorithms, their advantages and suitability.

The growing use of e-learning systems has been documented by numerous studies (Levy, 2005). Yet in spite of this enormous growth, little attention has been given to the issue of security of e learning systems both in research and in practice. Security of e-learning systems has a unique challenge as these systems are accessed and managed via the Internet by thousands of users over hundreds of networks. However, the Internet can pose security threats such as unauthorized access, hacking/cracking, obtaining sensitive information, and altering data and configuration, as well as enabling academic misconduct incidents (Freeh, 2000; Ramim, 2005; Sridhar & Bhasker, 2003). At the same time, cyber attacks have proliferated significantly in recent years. As a result, proper IT policies and procedures, in particular ones related to security of information systems, have become critical for organizations. This case study was written from the IS consultant’s point of view and addresses the issues related to insider cyber attacks combined with novice IT management knowledge in a small university. After a year of substantial growth to its online learning program, the university in this case study experienced a devastating event that halted all academic activities enabled by the institution’s e-learning system. This case reveals that internal cyber attack as well as lack of proper IT policies and procedures all resulted in multiple instances of damage to the e-learning system. The case provides detailed documentation on the security audit performed as well as stimulation for class discussions on actions to be taken as a result of the insider’s cyber attack. Additionally, this case study attempts to provide a starting point on discussions in the area of security related to e-learning systems. It is hoped that this case study will stimulate discussions among practitioners and researchers related to e-learning systems security, and that it will help prevent such incidents from occurring at other academic institutions.

Efficiency is essential in lightweight cryptography to ensure robust protection within constrained environments. This paper introduces a lightweight block cipher built on a Non-Linear Feedback Shift Register (NFSR), referred to as the NFSR-Based Block Cipher (NFBC). The cipher is designed for constrained environments where both efficiency and strong security are critical. NFBC operates as a Nonce-based Authenticated Encryption with Associated Data (NAEAD) scheme, providing confidentiality and authenticity within a single framework. The design achieves robust protection while maintaining minimal hardware overhead. NFBC operates on 128-bit data, key, and nonce sizes, fully aligning with National Institute of Standards and Technology (NIST) lightweight cryptography requirements. The design integrates a Non-Linear Feedback Shift Register (NFSR) for generating high-entropy round subkeys, dynamic chaotic substitution box (S-boxes) for strong confusion, and a Group Permutation (GRP) mechanism that ensures rapid diffusion with hardware-friendly efficiency. Security is rigorously evaluated across multiple dimensions. NFBC passes all 15 NIST Statistical Test Suite (STS) tests, achieves near-ideal avalanche and Bit Independence Criterion (BIC), and demonstrates consistently high nonlinearity across 200 independent chaotic S-box instances. The S-box achieves a maximum differential probability of 10/256 and maximum linear probability of (72/256)^{2}, confirming strong resistance to classical attacks. To strengthen theoretical guarantees, a provable branch-number analysis is introduced, establishing conservative lower bounds on active S-boxes (ge 45 across 20 rounds), with corresponding differential and linear probabilities that are vanishingly small. Formal AEAD security is ensured through an Encrypt-then-MAC (EtM) construction. Implementation on a Xilinx Artix-7 FPGA confirms practicality: NFBC achieves superior throughput-per-area compared to several NIST Round-2 lightweight candidates (SPOC, SPOOK, GIFT-COFB, ESTATE, SAEAES, Oribatida) and CAESAR finalists (Ascon-128, Ascon-small, CLOC-AES, SILC-AES). Estimated countermeasure overheads for masking and fault detection demonstrate feasibility against side-channel and fault attacks. These results confirm NFBC as a secure, efficient, and practically deployable lightweight cryptographic solution.

In block ciphers, the substitution boxes (S-boxes) are used with the purpose to induce confusion in cryptosystems. For the last three decades most of algebraic and chaotic S-boxes are based on the associative algebras of Galois fields. However, recently a little but remarkable work on the designing of S-boxes over some local associative algebras have been published, which is in fact a mock of the associative algebras of Galois fields. The main purpose of these establishments is to hide data and improve the security levels of crypto algorithms. In this study we redesign S-boxes over the elements of inverse property loop. The fascinating features of this structure are; it’s non-associativity and the existence of the inverse of zero element. These properties not only increase the availability of the number of structures but also provide easy approach in constructing S-boxes. The newly designed S-boxes are assessed by various analyses, which include nonlinearity, strict avalanche criterion, bit independence criterion, linear approximation probabilities, and differential approximation probabilities. Majority logic criterion is also performed to evaluate its application in various encryption systems.

In today's world of rapid increasing of technology, Data privacy and Ethics has become a major concern. The complexity of data and ethics poses incredible issues by collecting user personal information in digital world. the Digital service company usually bear responsibility of protecting users' personal data from unauthorized access however issue arise when service provider and platforms do not protect user collective data, and this led to data misuse and exposing sensible data of the person. To handling once data responsibly and ethically is important for safeguarding people's rights and preserving public trust. This study examines the ethical challenges in emerging technologies, including data privacy and ethics. The paper aims to provide awareness of data privacy and ethics in technology.

For functions over the finite field $$\mathbb {F}_{p^n}$$ , we study a generalization of affine equivalence. Two functions of algebraic degree d are equivalent if, when ignoring monomials of algebraic degree $$d-1$$ or less, they coincide with two affine equivalent functions. This equivalence appears naturally for functions defined by the properties of their derivatives of order $$d-1$$ . In order to test this equivalence, as usual, invariants can be used as a first approach. We describe several such invariants, based on the kernel/image of the derivatives of order $$d-1$$ and on the set of vectors orthogonal to those images (similar to the orthoderivatives used as invariants for quadratic APN functions). We also define a canonical form with respect to left composition with linear transformations, which decreases the computational effort of testing for equivalence. We then apply these techniques and computer search to classify all GAPN (generalized APN) functions of algebraic degree 3 over $$\mathbb {F}_{3^3}$$ . We determined that there are exactly 31 equivalence classes; for each class we list, firstly, a representative in multivariate algebraic normal form which is in canonical form with respect to left composition with linear transformations; secondly, we also list a representative with a shortest univariate representation. Moreover, our computations show that all of the GAPN functions of algebraic degree 3 over $$\mathbb {F}_{3^3}$$ have optimal second-order differential uniformity. While this is not always the case for other values of p and n , we show that the GAPN functions of algebraic degree p over $$\mathbb {F}_{p^n}$$ of the form $$x^{p-1+p^{\ell }}$$ with $$\gcd (\ell ,n)=1$$ do have optimal order- $$(p-1)$$ differential uniformity.

We consider the boomerang uniformity of an infinite class of (locally-APN) power maps and show that their boomerang uniformity over the finite field $$\mathbb {F}_{2^n}$$ is 2 and 4, when $$n \equiv 0 \pmod 4$$ and $$n \equiv 2 \pmod 4$$ , respectively. As a consequence, we show that for this class of power maps, the differential uniformity is strictly greater than their boomerang uniformity.

In this article coset diagrams of the action of PSL(2, Z) on a PL(F_p) are obtained, through parametrization, which yields one of the eight finite generalized triangle groups which are homomorphic images or quotients of PSL(2, Z). Other than this we analyzed the coset diagrams for the parameter for three finite generalized triangle groups. One of the most dependable methods for achieving data security has been the block cipher. S-Boxes constructed using algebraic structure have gained popularity recently because of their advantageous cryptographic properties and high non-linearity have been found in these structures, which attract researchers. With the help of these parametrized actions, a novel algebraic method to create 2^8 S-Boxe was established. The S-Box provides strong cryptographic qualities of nonlinearity 112, differential uniformity 6, linear approximation probability of 0.0576 and differential attack probability of 0.0039. To assess the practical applicability of our S-box, we integrate it into an image encryption scheme and present experimental results to showcase its efficacy in real-world scenarios. When used with an image encryption framework, the following results were obtained: NPCR = 0.9959, UACI = 0.3348, and approx. Entropy 7.98. Therefore, GTG based parametrisation has been shown to be an effective and secure alternative to traditional algebraic construction method for S-Boxes.

Substitution-boxes are the main deciding components in symmetric-key cryptosystems for resisting many cryptanalytic attacks. It has been a challenging task for the designers to construct strong S-box which satisfies multiple cryptographic properties simultaneously. A number of S-box studies have been investigated in literature; but, the generated S-box found to exhibit one single property with good score. This paper proposes a novel creation of S-boxes which possess excellent scores of multiple cryptographic properties instead of only one property. The suggested hybrid S-box method explores the science of two-dimensional cellular automata theory, discrete chaotic maps, and algebraic group structure. The proposed anticipated 8×8 S-box holds excellent security performance features such as: minimum nonlinearity as high as 110, no fixed points, satisfaction of strict avalanche and bits independence criterions, differential uniformity as low as 6, linear approximation probability as low as 0.0703, and auto-correlation function (absolute indicator) of 40. The performance comparison indicates the proposed S-box has superior features, greater inherent security and robustness strength than many available state of the art S-box methods.