A Novel Design of Cryptographic SP-Network Based on Gold Sequences and Chaotic Logistic Tent System

Substitution permutation network (SP-network) is a chain of linked mathematical primitives used in block cipher algorithms. The proposed novel design of cryptographic SP-network consists of three cryptographic primitives: substitution box, permutation box, and random key sequences, including one key whitening operation. A new design is being proposed for each cryptographic primitive. The cryptographic strength of the proposed SP-network is evaluated by employing various standard tests; strict avalanche criterion, differential approximation probability, bit independent criterion, linear approximation probability, nonlinearity test, unified averaged changed intensity, histogram analysis, and coefficient correlation tests. The outcomes of the investigations validate that the designed cryptosystem is stable for secure communication and attains better cryptographic strength as compared with other state-of-the-art techniques.