Abid Mahboob¹, Muhammad Asif², Rana Muhammad Zulqarnain^3,*, Imran Saddique⁴, Hijaz Ahmad⁵, Sameh Askar⁶

CMC-Computers, Materials & Continua, Vol.77, No.2, pp. 2565-2578, 2023, DOI:10.32604/cmc.2023.040371

Abstract Nowadays, one of the most important difficulties is the protection and privacy of confidential data. To address these problems, numerous organizations rely on the use of cryptographic techniques to secure data from illegal activities and assaults. Modern cryptographic ciphers use the non-linear component of block cipher to ensure the robust encryption process and lawful decoding of plain data during the decryption phase. For the designing of a secure substitution box (S-box), non-linearity (NL) which is an algebraic property of the S-box has great importance. Consequently, the main focus of cryptographers is to achieve the S-box with a high value of… More >

Tao Hu¹, Cheng Huang², Sergiy Reutskiy^3,*, Jun Lu⁴, Ji Lin^5,*

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.2, pp. 1521-1548, 2024, DOI:10.32604/cmes.2023.030449

Abstract A novel accurate method is proposed to solve a broad variety of linear and nonlinear (1+1)-dimensional and (2+1)- dimensional multi-term time-fractional partial differential equations with spatial operators of anisotropic diffusivity. For (1+1)-dimensional problems, analytical solutions that satisfy the boundary requirements are derived. Such solutions are numerically calculated using the trigonometric basis approximation for (2+1)-dimensional problems. With the aid of these analytical or numerical approximations, the original problems can be converted into the fractional ordinary differential equations, and solutions to the fractional ordinary differential equations are approximated by modified radial basis functions with time-dependent coefficients. An efficient backward substitution strategy that… More >

Yi-Li Huang¹, Fang-Yie Leu^1,2,*, Ruey-Kai Sheu¹, Jung-Chun Liu¹, Chi-Jan Huang^2,3

CMC-Computers, Materials & Continua, Vol.77, No.1, pp. 1143-1164, 2023, DOI:10.32604/cmc.2023.037161

Abstract Currently, data security mainly relies on password (PW) or system channel key (SK_CH) to encrypt data before they are sent, no matter whether in broadband networks, the 5th generation (5G) mobile communications, satellite communications, and so on. In these environments, a fixed password or channel key (e.g., PW/SK_CH) is often adopted to encrypt different data, resulting in security risks since this PW/SK_CH may be solved after hackers collect a huge amount of encrypted data. Actually, the most popularly used security mechanism Advanced Encryption Standard (AES) has its own problems, e.g., several rounds have been solved. On the other hand, if… More >

Musheer Ahmad¹, Reem Ibrahim Alkanhel^2,*, Naglaa F. Soliman², Abeer D. Algarni², Fathi E. Abd El-Samie³, Walid El-Shafai^3,4

Computer Systems Science and Engineering, Vol.47, No.2, pp. 2361-2380, 2023, DOI:10.32604/csse.2023.038439

Abstract Patient privacy and data protection have been crucial concerns in E-healthcare systems for many years. In modern-day applications, patient data usually holds clinical imagery, records, and other medical details. Lately, the Internet of Medical Things (IoMT), equipped with cloud computing, has come out to be a beneficial paradigm in the healthcare field. However, the openness of networks and systems leads to security threats and illegal access. Therefore, reliable, fast, and robust security methods need to be developed to ensure the safe exchange of healthcare data generated from various image sensing and other IoMT-driven devices in the IoMT network. This paper… More >

Amjad Hussain Zahid¹, Muhammad Junaid Arshad², Musheer Ahmad^3,*, Naglaa F. Soliman⁴, Walid El-Shafai^5,6

CMC-Computers, Materials & Continua, Vol.75, No.2, pp. 3011-3026, 2023, DOI:10.32604/cmc.2023.037516

Abstract A substitution box (S-Box) is a crucial component of contemporary cryptosystems that provide data protection in block ciphers. At the moment, chaotic maps are being created and extensively used to generate these S-Boxes as a chaotic map assists in providing disorder and resistance to combat cryptanalytical attempts. In this paper, the construction of a dynamic S-Box using a cipher key is proposed using a novel chaotic map and an innovative tweaking approach. The projected chaotic map and the proposed tweak approach are presented for the first time and the use of parameters in their working makes both of these dynamic… More >

Nabilah Abughazalah¹, Mohsin Iqbal², Majid Khan^3,*, Iqtadar Hussain^4,5

CMC-Computers, Materials & Continua, Vol.74, No.3, pp. 6523-6534, 2023, DOI:10.32604/cmc.2022.031859

Abstract The substitution box, often known as an S-box, is a nonlinear component that is a part of several block ciphers. Its purpose is to protect cryptographic algorithms from a variety of cryptanalytic assaults. A MultiCriteria Decision Making (MCDM) problem has a complex selection procedure because of having many options and criteria to choose from. Because of this, statistical methods are necessary to assess the performance score of each S-box and decide which option is the best one available based on this score. Using the Pythagorean Fuzzy-based Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method, the major… More >

Suha Q. AL-Shahrabalee^*, Hussein Alaa Jaber

Journal of Renewable Materials, Vol.11, No.3, pp. 1485-1498, 2023, DOI:10.32604/jrm.2023.025011

Abstract Cancerous diseases and diseases resulting from bacteria and fungi are some of the pressures that humans face. Therefore, the development of biomaterials that are resistant to cancerous diseases, bacteria, and fungi has become one of the requirements of the medical field to extend the life of the biomaterial and fight pathogens after implanting these materials inside the human body. One of the important biomaterials used in the field of orthopedics is hydroxyapatite. In this research, Nano substituted hydroxyapatite was prepared by the wet precipitation method, including replacing 5% of the calcium ions with neodymium, cerium, magnesium, and zinc ions in… More > Graphic Abstract

Hafeez ur Rehman^1,*, Tariq Shah¹, Mohammad Mazyad Hazzazi², Ali Alshehri³, Bassfar Zaid⁴

CMC-Computers, Materials & Continua, Vol.73, No.2, pp. 2913-2930, 2022, DOI:10.32604/cmc.2022.028765

Abstract Elliptic curves (ECs) are deemed one of the most solid structures against modern computational attacks because of their small key size and high security. In many well-known cryptosystems, the substitution box (S-box) is used as the only nonlinear portion of a security system. Recently, it has been shown that using dynamic S-boxes rather than static S-boxes increases the security of a cryptosystem. The conferred study also extends the practical application of ECs in designing the nonlinear components of block ciphers in symmetric key cryptography. In this study, instead of the Mordell elliptic curve (MEC) over the prime field, the Galois… More >

Muhammad Fahad Khan^1,2,*, Khalid Saleem¹, Mohammed Alotaibi³, Mohammad Mazyad Hazzazi⁴, Eid Rehman², Aaqif Afzaal Abbasi², Muhammad Asif Gondal⁵

CMC-Computers, Materials & Continua, Vol.73, No.2, pp. 2679-2696, 2022, DOI:10.32604/cmc.2022.027655

Abstract Internet of Things is an ecosystem of interconnected devices that are accessible through the internet. The recent research focuses on adding more smartness and intelligence to these edge devices. This makes them susceptible to various kinds of security threats. These edge devices rely on cryptographic techniques to encrypt the pre-processed data collected from the sensors deployed in the field. In this regard, block cipher has been one of the most reliable options through which data security is accomplished. The strength of block encryption algorithms against different attacks is dependent on its nonlinear primitive which is called Substitution Boxes. For the… More >

Muhammad Samiullah¹, Waqar Aslam¹, Saima Sadiq², Arif Mehmood¹, Gyu Sang Choi^3,*

CMC-Computers, Materials & Continua, Vol.72, No.1, pp. 1645-1670, 2022, DOI:10.32604/cmc.2022.021019

Abstract While designing and developing encryption algorithms for text and images, the main focus has remained on security. This has led to insufficient attention on the improvement of encryption efficiency, enhancement of hyperchaotic sequence randomness, and dynamic DNA-based S-box. In this regard, a new symmetric block cipher scheme has been proposed. It uses dynamic DNA-based S-box connected with MD5 and a hyperchaotic system to produce confusion and diffusion for encrypting color images. Our proposed scheme supports various size color images. It generates three DNA based S-boxes for substitution namely DNA_1_s-box, DNA_2_s-box and DNA_3_s-box, each of size . Next, the 4D hyperchaotic… More >