A New Substitution Box From Quranic Maqamat

Permutation extraction plays an important role in cryptographic component design, especially in generating substitution boxes (S-Boxes) for block cipher algorithms to ensure nonlinearity and security against cryptanalysis. Although extensive research has explored various mathematical and algorithmic methods for S-Box construction, the integration of alternative structured data sources for generating diverse permutations is still underexplored. This research proposes a new method of generating cryptographic permutations derived from Quranic maqamat audio data, aimed at constructing abundant and diverse S-Boxes for block cipher applications. The proposed method starts with the extraction of permutations from 70 Quranic audio samples, recorded in a controlled environment. These samples consist of ten selected verses from Juz’ Amma, each recited in seven maqamat styles, namely Bayyati, Hijjaz, Rast, Jiharkah, Nahawand, Soba, and Sikah, with a sampling frequency of 44,100 Hz. The feature extraction process applies Discrete Wavelet Transform to identify high-frequency components, followed by permutation entropy analysis to assess randomness, retaining only segments with entropy values above 0.7. Rank encoding is used to transform these high-entropy segments into structured permutations, serving as the foundation for S-Box construction. From the extracted permutations, a large collection of S-Boxes is generated and assessed using nonlinearity, differential uniformity, and avalanche effect to evaluate cryptographic strength. A comparative analysis is conducted to measure the performance and quality of S-Boxes produced from each maqamat, focusing on the proportion of high-quality S-Boxes relative to total generated permutations. The abundance of generated S-Boxes allows flexible selection according to desired security levels and forms the foundation for a proposed 256- bit encryption model, utilizing a 16x16-bit substitution box constructed by combining two 8x8 S-Boxes. The encryption framework modifies standard AES operations, including SubBytes, ShiftRows, MixColumns, and key scheduling, to adapt to the larger substitution box and enhance complexity. This research contributes a new structured method for permutation extraction aimed at cryptographic use, a diverse collection of S-Boxes evaluated across different maqamat, and an alternative high-capacity encryption model, offering a novel pathway for advancing S-Box construction and block cipher design through non-conventional data sources.