Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2026Scopus SJRQ1Real-time photovoltaic voltage data-driven dynamic green s-box generation framework for smart grid security
Aydın, Yılmaz; Garipcan, Ali Murat; Özkaynak, Fatih
In this study, a dynamic substitution box (s-box) generation method is proposed using real-time voltage data obtained from photovoltaic (PV) panels as an environmentally sensitive entropy source. These data, affected by environmental conditions such as solar radiation and temperature, exhibit irregular and unpredictable temporal behavior, offering strong potential for cryptographic randomness generation. In this context, the 0–1 test, Kolmogorov Entropy (KE), scale-index analysis, and the National Institute of Standards and Technology (NIST) SP 800-22 test suite are applied to PV voltage data collected at 1-minute intervals, experimentally confirming their chaotic dynamics and high-entropy characteristics. Following appropriate preprocessing and nonlinear mathematical transformations, the validated data are utilized to generate 8-bit s-box structures. The cryptographic strength of the generated s-boxes is quantitatively evaluated using standard security metrics, including nonlinearity (NL), Differential Probability (DP), Linear Probability (LP), Strict Avalanche Criterion (SAC), and Bit Independence Criterion (BIC). The findings reveal that PV data can serve as a functional resource not only for energy monitoring but also for randomness-based cryptographic construction. This approach enables lightweight cryptographic solutions for resource-constrained edge devices requiring <1 KB of memory and supports context-aware data security in renewable energy infrastructures.
- MakaleAçık Erişim2026Scopus SJRQ1A new key generator algorithm based on sine map and SHA-3 for image encryption
Artuğer, Fırat; Özkaynak, Fatih
In recent years, the need for secure cryptographic keys for various purposes has been constantly increasing. One of these areas is undoubtedly image encryption. In this study, a new key generation algorithm has been developed for use in image encryption algorithms. The proposed generator has a hybrid structure based on the chaotic sine map and the SHA-3 algorithm. It is aimed to produce strong keys by using the benefits of these two structures. To do this, first, bit sequences of the desired length are generated using the basic parameters of the sine map. Then, bit sequences of the same length are obtained using the SHA-3 algorithm. These two bit sequences are then subjected to an XOR operation to generate key values of the desired length. With this structure, 3 different bit sequences of 1 million length were produced. All of these bit sequences successfully passed NIST SP 800 − 22 tests. This key value obtained in this study has been successfully applied to a new image encryption algorithm. The results of the study demonstrate that the proposed algorithm meets important cryptographic criteria such as information entropy, correlation-histogram analysis, NPCR, and UACI values. In addition, the simple and fast structure of the algorithm in key generation was the most important difference from other studies.
AtıfScopus3OpenAlex2
İncele - MakaleAçık Erişim2025Scopus SJRQ1A Novel Secure S-box Design Methodology Based on FPGA and SHA-256 Hash Algorithm for Block Cipher Algorithms
Aydin, Yilmaz; Garipcan, Ali Murat; Özkaynak, Fatih
In this study, a novel robust design methodology that successfully meets the performance and security criteria for substitution-boxes (s-boxes), critical component in block cipher systems, is proposed. Unlike traditional methods providing low-level randomness, the proposed method utilizes physical true randomness as the entropy source, significantly improving the robustness and effectiveness of the s-box design. Phase noise (jitter) occurring on ring oscillators (ROs) is used for true randomness inputs with high security and unpredictability properties in the proposed method. The success of the proposed method is evaluated by considering key performance metrics of s-boxes such as bijectivity, strict avalanche criterion (SAC), bit independence criterion (BIC), nonlinearity (NL), and differential probability (DP). In the novel method, including the integration of the secure hashing algorithm (SHA)-256 hash function for cryptographic usage adequacy of the noise signal, 106.75 NL, 0.4995 SAC, and 105.7 average BIC-NL values can be obtained for s-boxes without any additional optimization process. Considering the low DP value, the analysis results confirm that the s-boxes produced by the proposed method can provide remarkable resistance against linear and differential cryptanalysis scenarios. Numerical findings also show that the proposed s-boxes are competitive and superior compared to other s-box designs in the literature. In conclusion, we believe that the methodology producing robust and reliable s-box solutions for block cipher systems contains important contributions inspiring future research regarding design principles.
AtıfScopus23WoS27OpenAlex20
İncele - MakaleAçık Erişim2025Scopus SJRQ1A novel s-box generation method based on metastable inducing over FPGA for block ciphers
Garipcan, Ali Murat; Aydın, Yılmaz; Özkaynak, Fatih
Substitution boxes (s-boxes) providing the nonlinearity property are fundamental components of modern encryption systems. The security of these systems directly depends on the quality of the s-boxes ensuring a high level of resistance to advanced attacks. Although there is no perfect method in the literature, improving the cryptographic properties of s-boxes, such as nonlinearity and differential independence remains an important area of interest for many researchers. In this paper, we propose a new s-box generation method based on the reinforcement of the randomness obtained from the metastable states of the R-S latch. In the proposed method, a Field Programmable Gate Array (FPGA) chip is used to obtain design inputs based on physical reality obtained from the hardware level. Design inputs with poor statistical adequacy are transformed into s-boxes by passing them through four different hash functions (Blake2b, Blake2 s, SHA3 and Shake). A total of 333,328 s-boxes are generated with the proposed method for four different scenarios and widely used evaluation metrics such as bijectivity, nonlinearity (NL), strict avalanche criteria (SAC), bit independence criteria (BIC), differential probability (DP) and linear probability (LP) are considered for the analysis. Taking into account these metric values, the study also presents a detailed performance comparison of the proposed s-boxes with recent studies from the last 5 years in the literature. The fact that the nonlinearity degree of 75 % of the produced s-boxes is higher than 103, which is the average limit value in the literature, also confirms the method's efficiency, proven reliable by the analysis results. When all these results are evaluated together, they confirm that the proposed method is highly effective in generating robust s-boxes and that these s-boxes can be reliably used in modern cryptographic systems.
AtıfScopus21WoS23İncele - MakaleAçık Erişim2025Scopus SJRQ1An efficient 2D hyper chaos and DNA encoding-based s-box generation method using chaotic evolutionary improvement algorithm for nonlinearity
Garipcan, Ali Murat; Aydin, Yılmaz; Özkaynak, Fatih
In this study, an innovative substitution box (s-box) method is proposed, which combines the complexity and unpredictability of chaotic systems with the natural randomness and security features of Deoxyribonucleic Acid (DNA) encoding, in response to the increasing security requirements in the field of modern cryptography. This method, based on the integration of a two-dimensional (2D) hyper-chaotic Vincent map (VM) and DNA encoding techniques, aims to produce secure and high-performance s-boxes. To evaluate the reliability of the s-boxes, fundamental cryptographic criteria such as nonlinearity (NL), strict avalanche criterion (SAC), differential probability (DP), linear approximation probability (LAP), and bit independence criterion (BIC) are considered. Additionally, a novel chaos-based evolutionary optimization algorithm is proposed to optimize the NL criterion of the s-boxes. This algorithm offers a cost-effective and highly efficient alternative compared to classical metaheuristic methods, providing a balanced structure between security and performance. Experimental findings and comparison results demonstrate that the proposed s-boxes offer effective and reliable solutions for modern cryptographic applications, such as secure data transmission and storage. From a broader perspective, the study makes a meaningful contribution to the literature in the field of data security by presenting a high-performance s-box design meeting the security requirements of cryptographic systems and is resilient against current threats.
AtıfScopus25WoS26OpenAlex23İncele - MakaleAçık Erişim2025Scopus SJRQ1A novel post-processing approach for improving minimum nonlinearity in S-boxes: A case study based on 2D hyper chaotic Schaffer transformation map
Aydın, Yılmaz; Garipcan, Ali Murat; Özkaynak, Fatih
Substitution boxes (s-boxes), providing nonlinearity in block cipher algorithms, constitute a fundamental security layer against linear and differential cryptanalysis attacks. In this study, an innovative s-box generation method is proposed by integrating a 2D hyper-chaotic Schaffer map (SM) with biomolecular DNA-based encoding techniques. Furthermore, to enhance the security of s-box structures, a novel post-processing algorithm is developed, aiming to simultaneously optimize both the average (NLavg) and minimum (NLmin) nonlinearity levels by targeting linear components. Unlike traditional meta-heuristic methods, the proposed algorithm avoids random exploration across large search spaces, instead identifying dominant linear components through Walsh spectrum analysis and applying targeted permutation operations to suppress their effects. This strategy not only increases the NLavg value but also balances the contribution of each Boolean function to security, thereby establishing a homogeneous and consistent security structure across all input–output combinations. Comparative experimental analyses with existing methods demonstrate that the proposed approach outperforms prior techniques in terms of both cryptographic security metrics and computational efficiency. In this respect, the study presents an advanced s-box design framework, characterized by high nonlinearity and a balanced spectral distribution, suitable for integration into modern block cipher systems.
AtıfScopus12WoS13OpenAlex13İncele - DüzeltmeAçık Erişim2024Scopus SJRQ1Correction to: A Novel Secure S-box Design Methodology Based on FPGA and SHA-256 Hash Algorithm for Block Cipher Algorithms (Arabian Journal for Science and Engineering, (2024), 10.1007/s13369-024-09251-8)
Aydin, Yilmaz; Garipcan, Ali Murat; Özkaynak, Fatih
In the original publication, Table 1 was published with wrong values. The corrected table is given below. This has been updated in the original article. (Table presented.) 8 × 8 s-box component obtained through the proposed scheme 0 1 2 3 4 5 6 7 8 9 A B C D E F 0 7 16 40 37 222 29 204 225 65 81 156 199 63 42 44 197 1 158 2 11 117 30 134 106 209 24 78 152 141 215 251 160 36 2 249 6 228 75 233 198 132 203 147 100 176 97 214 43 239 59 3 146 47 200 49 79 195 188 201 184 85 218 151 213 154 76 253 4 17 196 26 120 105 130 45 115 186 4 224 145 118 252 138 208 5 255 10 5 129 236 91 21 162 216 109 72 27 243 207 89 13 6 124 86 206 179 192 172 235 68 28 230 74 54 99 80 139 143 7 182 234 108 149 94 168 177 3 64 250 46 41 9 191 232 136 8 84 210 88 205 23 15 95 56 50 83 107 190 98 242 103 19 9 60 169 101 181 114 174 69 82 119 112 247 244 128 51 96 1 A 123 90 150 93 32 159 57 237 170 52 231 202 125 217 155 73 B 189 31 66 14 194 62 227 104 140 165 153 131 20 12 211 245 C 111 102 183 142 137 113 187 254 133 77 116 122 161 110 38 173 D 39 18 87 148 175 121 35 193 70 229 92 55 166 219 163 171 E 185 8 126 135 127 223 240 58 53 22 248 246 167 67 48 212 F 241 144 221 178 220 34 71 0 61 164 180 157 226 238 25 33
AtıfScopus1İncele - MakaleAçık Erişim2024Scopus SJRQ1A new chaotic system and its practical applications in substitution box and random number generator
Artuğer, Fırat; Özkaynak, Fatih
One of the successful practical applications of chaos theory and nonlinear dynamics is chaos-based cryptology studies. In this study, a new chaotic system is proposed. The proposed chaotic system generator model has a simple algorithmic structure. In addition to, generated chaotic systems have rich dynamics. It has been examined whether this system has potential advantages, especially for information security applications. As a result of the analysis and experimental studies, it is seen that the study makes many contributions to the literature. The simple mathematical generator structure has the potential to reduce computational complexity, which is an important problem for cryptology applications. One of the most comprehensive studies has been realized for chaos-based substitution box designs. 70,000 different substitution box structures have been generated. It has been known that the highest nonlinearity value that can be achieved for designs that transform chaotic system outputs into substitution box structures is 106.75 today. It has been shown that this value may be higher. The new highest nonlinearity value is calculated as 107. Side channel analysis has been examined for substitution box structures with the highest nonlinearity value among the substitution boxes generated in the study. Analysis results show that the proposed new substitution box structures may have an advantage for application-oriented attacks. Among the generated substitution box structures, 289 substitution box structures with a nonlinearity value of 106 and above are presented as a public dataset for researchers to use. In addition, 3 different random sequences with a length of 1 million-bit were produced with the proposed map, and the NIST SP 800–22 test was applied. Test results for all datasets were successful. In this way, the proposed map can also be used as a random number generator.
AtıfScopus13İncele - MakaleAçık Erişim2024Scopus SJRQ1A new algorithm to generate aes-like substitution boxes based on sine cosine optimization algorithm
Artuğer, Fırat; Özkaynak, Fatih
Symmetric encryption approaches are generally used for data encryption. One of the basic requirements for symmetric encryption algorithms to provide security is strong s-box structures. Because s-box is a nonlinear unit in these encryption algorithms and provides the requirement called confusion. In this article, a new technique is developed to produce effective s-boxes like the 16*16 s-box structure used in the AES algorithm. In the proposed method, the sine cosine algorithm (SCA), one of the recently developed optimization algorithms, is used. SCA is a suitable option for generating strong s-boxes because of its strong randomness and ease of implementation. The proposed method first uses a logistic map to generate the initial population. Then, the nonlinearity value is optimized with the help of the sine cosine algorithm. The proposed method reaches the highest nonlinearity value (112) by relocating 126 values in the s-box structure produced initially. Looking at the results, it is seen that the proposed method gives better results than other optimization-based s-box creation methods. This new method has significant potential to improve the security of symmetric encryption algorithms and make data encryption processes stronger.
AtıfScopus19WoS22OpenAlex24İncele - MakaleYayıncıda açık erişim2024Scopus SJRQ2A new post-processing approach for improvement of nonlinearity property in substitution boxes
Artuğer, Fırat; Özkaynak, Fatih
The main reason that makes chaos theory attractive for cryptology studies is the unpredictable nature of chaotic systems. However, the fact that the statistical and cryptographical properties of cryptographic primitives based on the values obtained as a result of the electronic circuit implementation of a chaotic system are not as good as the designs based on mathematical transformations has occupied the agenda of researchers. One of the most striking examples of this problem in practical applications is substitution-box (s-box) structures. While the nonlinearity value is 112 for s-box designs based on mathematical transformations, this value is in the range of 103–106.75 for s-box designs based on random (chaotic) transformations. Thanks to the post-processing algorithm proposed in this study, it has been shown that this problem can be resolved and the nonlinearity values of chaos-based s-box structures can be improved up to 111.5. It is thought that the proposed post-processing algorithm may have various potential contributions not only to improve the nonlinearity criterion of s-box structures but also to other information security applications such as cryptographic random number generators in future studies.
AtıfScopus19WoS13OpenAlex16İncele - Kitap BölümüAçık Erişim2023Scopus SJRQ4The Effects of Knowledge Extraction Approaches on Cryptanalysis Studies and Analysis of the Success of Chaos-Based Countermeasures
Bürhan, Yücel; Özkaynak, Fatih
Each new approach and scientific progress provides many advantages and innovations from theory to practice yet, its disadvantages should be evaluated comprehensively from different perspectives. In this study, the effects of knowledge extraction approaches on the cryptanalysis process have been evaluated. It is known that the secret key of the encryption algorithm can be obtained by using knowledge extraction approaches, especially with application oriented attacks such as side channel analysis. It is known that chaotic masks can be used as a countermeasure to prevent the success of these attacks. In this study, side-channel analyzes of the chaos-based substitution box structures that have been proposed in recent years have been carried out. The side channel analysis results of the existing studies in the literature have been carried out for the first time in this study. The results obtained showed that the approaches in the field of knowledge extraction should be handled more comprehensively in the cryptanalysis processes, and also pointed out that a new evaluation criterion should be analyzed for future studies for chaos-based design studies.
AtıfScopus2OpenAlex2İncele - MakaleAçık Erişim2023Scopus SJRQ2Chaotic quantization based JPEG for effective compression of whole slide images
Artuğer, Fırat; Özkaynak, Fatih
In today’s digital world, effectively transferring data from one point to another is an important problem. For this reason, the development of various new compression algorithms and making existing solutions more effective are examined in detail by researchers. In this study, a new method is proposed to improve the performance of JPEG algorithm. The proposed method includes an approach based on chaotic systems. Chaotic systems contain a strong entropy source. This powerful source of entropy has strong practical applications in obtaining statistically robust random values. In this study, a method is proposed to obtain quantization tables effectively by taking advantage of this potential of chaotic systems. The obtained results showed that the compression performance can be increased at the same quality factors. The proposed approach has been tested on the whole slide image (WSI) dataset. Looking at the analysis results, an average of 2.43% higher accuracy was achieved compared to the JPEG algorithm. It is thought that these results can provide an advantage especially in transferring high-dimensional images such as the DICOM standard, where the JPEG algorithm is used in practical applications.
AtıfScopus5WoS4OpenAlex7İncele - MakaleAçık Erişim2022Görüntü Sıkıştırma Algoritmalarının Performans Analizi İçin Değerlendirme Rehberi
Özkaynak, Fatih; Artuger, Firat
Teknolojinin ilerlemesiyle birlikte artan görüntülerin etkili bir şekilde depolanması ve bir iletişim ağı üzerinden daha hızlı bir şekilde iletilmesi ciddi bir problem haline gelmiştir. Bu problemi çözmek için geçmişten günümüze görüntü sıkıştırma algoritmaları geliştirilmektedir. Bu algoritmaların performansını doğru bir şekilde değerlendirmek oldukça önemli bir konudur. Bu makalede, sıkıştırılmış görüntülerin kalitesini değerlendirmek için yaygın biçimde kullanılan Ortalama Kare Hatası (Mean Square Error-MSE), Kök Ortalama Kare Hatası (Root Mean Square Error-RMSE), Tepe Sinyal Gürültü Oranı (Peak Signal-to-Noise Ratio-PSNR), Yapı Benzerlik İndeksi Yöntemi (Structure Similarity Index Method-SSIM), Yapısal Farklılık (Structural Difference-DSSIM), Özellikler Benzerlik İndeksi Matrisi (Features Similarity Index Matrix-FSIM) yöntemleri açıklanmıştır. Çalışmanın özgün yönlerinden biri bu metriklerin kullanımını detaylandırmak için çeşitli test görüntüleri üzerinde adım adım uygulanması açıklanmış bir rehber niteliğinde olmasıdır. Görüntülerin ne kadar sıkıştırıldığını hesaplamak için ise Sıkıştırma oranı(Compression ratio-CR) ve Piksel başına düşen bit sayısı(-Bits per Pixel-Bpp) yöntemleri kullanılarak sonuçlar tartışılmış ve ileride bu konuda çalışmayı planlayan araştırmacılar için önerilerde bulunulmuştur.
AtıfTR Dizin4
İncele - MakaleAçık Erişim2022A Method to Improve the Performance of JPEG Algorithm
Özkaynak, Fatih; Artuger, Firat
JPEG is one of the most widely used methods for image compression. In the JPEG image compression method, the quantization table used in the quantization step plays an important role. The quantization table significantly determines the quality of the image and the amount of compression. Therefore, the creation of the quantization table is seen as an optimization problem. In this article, rate-distortion approach, human visual system approach and meta-heuristic approaches have been explained in order to create more effective quantization tables. Then, a new table was obtained by taking the average of the neighbors of that value instead of each value in the JPEG quantization table. The results were tested on 5 different images using different quality factors. It has been found that the proposed table increases the compression ratio by 3.52% compared to the standard JPEG table, almost without sacrificing the quality of the images.
AtıfOpenAlex1İncele - MakaleAçık Erişim2022Scopus SJRQ1A method for generation of substitution box based on random selection
Artuğer, Fırat; Özkaynak, Fatih
Two basic requirements must be met to encrypt data. These requirements are confusion and diffusion properties. In particular, block cipher algorithms are based on a cryptographic component known as substitution-box to provide the need for confusion. Therefore, attack scenarios generally focus on this cryptographic component. There are alternative design approaches for substitution-box design. It is known that each design approach has several advantages and disadvantages. In this study, an alternative method is proposed to address the problems of the substitution-box design approach based on random selection. The success of the proposed method has been tested in three different scenarios. Analysis results for these three scenarios showed that generated substitution-box provides performance increase for nonlinearity criterion from s-box design criteria. Successful results achieved; It points out that improvement cryptographic components can be used in a variety of practical applications such as block ciphers, masks to prevent side-channel attacks, random number generators, and image encryption algorithms.
AtıfScopus29WoS25OpenAlex35İncele - MakaleAçık Erişim2022Scopus SJRQ1SBOX-CGA: substitution box generator based on chaos and genetic algorithm
Artuğer, Fırat; Özkaynak, Fatih
What makes artificial intelligence techniques so remarkable in the field of computer science is undoubtedly their success in producing effective solutions to difficult computational problems. In particular, metaheuristic optimization algorithms are a unique example of using artificial intelligence techniques to generate approximate solutions to problems that cannot be solved in polynomial time, called NP. Obtaining a substitution box (s-box) structure that will satisfy the desired requirements in cryptography is an example of these NP problems. In the literature, it is a hot topic to optimize the s-box structures obtained from chaotic entropy sources with heuristic algorithms to improve their cryptographic properties. The study with the highest nonlinearity value (110.25) based on optimization algorithms to date has been published in 2020. In this study, a method with a higher nonlinearity value than the algorithms previously proposed in the literature is developed. It has been shown that the nonlinearity value can be increased to 111.75. These results will be a basis for new research on the chaos-based s-box literature and will motivate new studies to develop alternative optimization algorithms in the future to obtain s-box structures based on the random selection equivalent to the AES s-box.
AtıfScopus47WoS35OpenAlex49İncele - Proje2021Kaotik Entropi Kaynakları Ve Optimizasyon Algoritmaları Kullanılarak Gürbüz Anahtar Üreteçlerinin Tasarımı Ve Mobil Platformlar Için Pratik Uygulamalarının Geliştirilmesi
Özkaynak, Fatih; Bürhan, Yücel; Aydın, Yılmaz; Durmuş, Beyzanur; Çakıl, Ahmet Can; Metin, Zülfiye Beyza; Kaya, Ömer
Son yirmi yılda, kaos temelli şifreleme, kaotik sistemlerin pratik uygulamaları arasında en dikkat çekici konulardan biri olmuştur. Literatürde binlerce çalışma vardır. Ancak bu çalışmalar incelendiğinde iki temel kategori ön plana çıkmaktadır. Birinci kategorideki çalışmalar kaotik sistemlerin zengin rastgelelik dinamiklerini kullanan yeni şifreleme protokollerini önerirken, ikinci kategorideki çalışmalar ise bu ilk kategoride önerilenlerin güvenlik zayıflıklarını analiz etmektedir. Bu iki karşıt durum birçok araştırmacının kaos temelli kriptolojiye şüphe ile yaklaşmasına neden olmaktadır. Proje önerisinde bu problemleri adresleyebilmek için kaotik sistemlerin rasgelelik karakteristiklerin optimizasyon algoritmaları yardımıyla iyileştirilmesi, fiziksel klonlanamaz fonksiyonlar ve çeşitli son işlem teknikleri ile elde edilen çıktıların görüntü şifreleme algoritmasına dönüştürülmesi planlanmıştır. Proje sonunda iki farklı fiziksel klonlanamaz fonksiyon kullanılarak önerilen görüntü şifreleme mimarinin hem masaüstü hem de mobil versiyonları gerçekleştirilmiştir. PUF donanımlarının kriptolojik uygunluğunun incelenmesi, kaotik yer değiştirme kutusu yapılarının yan kanal analizlerine karşı direncinin araştırılması ve kaotik entropi kaynaklarına çeşitli son işlem teknikleri uygulanarak kriptolojik açıdan daha başarılı tasarımlar elde edilebileceğinin gösterilmiş olması proje önerisinin diğer önemli çıktılarıdır. Tüm bu çıktılar kapsamında bir yüksek tezi, yüksek etki faktörlü iki araştırma makalesi ve bir uluslararası konferans bildirisi yayınlanmıştır. Proje sonuçları TÜBİTAK 1001 ve 1005 projelerine ön çalışma çıktısı olarak katkı sunmuştur.
- MakaleAçık Erişim2021Scopus SJRQ1An effective method to improve nonlinearity value of substitution boxes based on random selection
Artuğer, Fırat; Özkaynak, Fatih
In today's digital society, new design alternatives are needed for substitution box structures, which has critical importance in developing secure information systems that are resistant to algebraic and application attacks, as new attacks negatively affect designs based on mathematical transformations. Although random selection-based substitution box structures are a good alternative against algebraic and application attacks, the low value of nonlinearity criterion is an important problem. Solution suggestions using optimization algorithms have been proposed to address this problem. “Information Sciences 523 (2020) 152–166” is the study that reached the highest nonlinearity value based on optimization algorithms to date. However, the high computational costs of optimization algorithms are another challenge that must be overcome. In this study, it has been shown that the nonlinearity values of random (chaotic) selection substitution box structures can be improved as much as mathematically based designs by using a method that is too simple to compare with optimization algorithms. It has been shown that the nonlinearity value can be improved up to 110 for random selection-based substitution box designs. Although this nonlinearity value is the highest achievable value in the literature based on the random selection principle, the fact that it requires only 2×255×255 processes in the worst case has been evaluated as an important success of the proposed method compared to other design approaches. Other advantages of the proposed method are that the improved substitution box structures are resistant to side-channel attacks, simple structure, easy hardware implementation, and successful results in practical applications such as image encryption. It is believed that all these results will be a motivation for new post-processing techniques to be designed in the future for random selection-based substitution box designs.
AtıfScopus42WoS30OpenAlex42İncele - MakaleAçık Erişim2020Scopus SJRQ2A novel method for performance improvement of chaos-based substitution boxes
Artuğer, Firat; Özkaynak, Fatih
Symmetry plays an important role in nonlinear system theory. In particular, it offers several methods by which to understand and model the chaotic behavior of mathematical, physical and biological systems. This study examines chaotic behavior in the field of information security. A novel method is proposed to improve the performance of chaos-based substitution box structures. Substitution box structures have a special role in block cipher algorithms, since they are the only nonlinear components in substitution permutation network architectures. However, the substitution box structures used in modern block encryption algorithms contain various vulnerabilities to side-channel attacks. Recent studies have shown that chaos-based designs can offer a variety of opportunities to prevent side-channel attacks. However, the problem of chaos-based designs is that substitution box performance criteria are worse than designs based on mathematical transformation. In this study, a postprocessing algorithm is proposed to improve the performance of chaos-based designs. The analysis results show that the proposed method can improve the performance criteria. The importance of these results is that chaos-based designs may offer opportunities for other practical applications in addition to the prevention of side-channel attacks.
AtıfScopus55WoS44OpenAlex56İncele - MakaleAçık Erişim2010Scopus SJRQ2A method for designing strong S-Boxes based on chaotic Lorenz system
Özkaynak, Fatih; Özer, Ahmet Bedri
It is important to design cryptographically strong S-Boxes in order to design secure systems. In this study, a strong, chaos-based S-Box design is proposed. Continuous-time Lorenz system is chosen as the chaotic system. Proposed methodology is analyzed and tested for the following criteria: Bijective property, nonlinearity, strict avalanche criterion, output bits independence criterion and equiprobable input/output XOR distribution. The results of the analysis show that the proposed cryptosystem is a highly reliable system suitable for secure communication. (C) 2010 Elsevier B.V. All rights reserved.
AtıfWoS192OpenAlex235İncele