Block Cipher’s Substitution Box Generation Based on Natural Randomness in Underwater Acoustics and Knight’s Tour Chain

Abstract

The protection of confidential information is a global issue, and block encryption algorithms are the most reliable option for securing data. The famous information theorist, Claude Shannon, has given two desirable characteristics that should exist in a strong cipher which are substitution and permutation in their fundamental research on “Communication Theory of Secrecy Systems.” block ciphers strictly follow the substitution and permutation principle in an iterative manner to generate a ciphertext. The actual strength of the block ciphers against several attacks is entirely based on its substitution characteristic, which is gained by using the substitution box (S-box). In the current literature, algebraic structure-based and chaos-based techniques are highly used for the construction of S-boxes because both these techniques have favourable features for S-box construction but also various attacks of these techniques have been identified including SAT solver, linear and differential attacks, Gröbner-based attacks, XSL attacks, interpolation attacks, XL-based attacks, finite precision effect, chaotic systems degradation, predictability, weak randomness, chaotic discontinuity, and limited control parameters. The main objective of this research is to design a novel technique for the dynamic generation of S-boxes that are safe against the cryptanalysis techniques of algebraic structure-based and chaos-based approaches. True randomness has been universally recognized as the ideal method for cipher primitives design because true random numbers are unpredictable, irreversible, and unreproducible. The biggest challenge we faced during this research was how can we generate the true random numbers and how can true random numbers utilized for strengthening the S-box construction technique. The basic concept of the proposed technique is the extraction of true random bits from underwater acoustic waves and to design a novel technique for the dynamic generation of S-boxes using the chain of knight’s tour. Rather than algebraic structure- and chaos-based techniques, our proposed technique depends on inevitable high-quality randomness which exists in underwater acoustics waves. The proposed method satisfies all standard evaluation tests of S-boxes construction and true random numbers generation. Two million bits have been analyzed using the NIST randomness test suite, and the results show that underwater sound waves are an impeccable entropy source for true randomness. Additionally, our dynamically generated S-boxes have better or equal strength, over the latest published S-boxes (2020 to 2021). According to our knowledge first time, this type of research has been conducted, in which natural randomness of underwater acoustic waves has been used for the construction of block cipher’s substitution box.

Construction and Optimization of Dynamic S-Boxes Based on Gaussian Distribution

“…The results of the SAC analysis for the sample S-box are presented in Table 6. [27] 112 [44] 106 [28] 112 [46] 106 [29] 110 [47] 106 [9] 106 [48] 106 [38] 110 [49] 108 [39] 110 [50] 108 [40] 108 [51] 110…”

A Robust Steganographic Algorithm based on Linear Fractional Transformation and Chaotic Maps

“…The variations of the Lyapunov exponent of the sine map are shown in Fig. 2(b) Study regarding the combinations of onedimensional chaotic maps shows that by introducing suitable combinations of such maps, the chaotic range can be enhanced [19]. In the next section, we discuss such combinations in detail.…”

“…Consequently, the study and analysis of chaos-based steganographic techniques have gained popularity in recent years. However, it has been observed that some chaos-based methods are vulnerable to statistical analysis because of the limited chaotic range of the used maps [16][17][18][19][20]. To overcome this issue, authors of [19] proposed a nonlinear combination of one-dimensional chaotic maps that enhances the chaotic range of the resulting system.…”

“…However, it has been observed that some chaos-based methods are vulnerable to statistical analysis because of the limited chaotic range of the used maps [16][17][18][19][20]. To overcome this issue, authors of [19] proposed a nonlinear combination of one-dimensional chaotic maps that enhances the chaotic range of the resulting system. Such systems are applied in image encryption applications, but to the best of our knowledge, they have not been applied in steganographic methods yet.…”

Elevating Network Security: A Novel S-Box Algorithm for Robust Data Encryption

“…Security analysis demonstrated that the newly constructed S-Box is effective and defiant to the various threats in network security. An other work [16] identified various attacks over the cyber security products including Gröbner-based attacks, linear and differential attacks, SAT solver, XL-based attacks, interpolation attacks etc. The focus of the reported research was to design a novel algorithm for dynamic generation of S-Boxes which could defy the various algebraic structure-based and chaos-based cryptanalysis techniques.…”