An irreversible word-wise PRNG based on 2D hyper chaotic map and dynamic strong S-Box

Abstract This paper proposes a word-wise pseudo-random number generator (PRNG) based on a 2D non-degenerate hyperchaotic map (2D-NDHCM) with adaptive perturbation. First, a 2D-NDHCM is constructed and its dynamic behavior is analyzed; the results demonstrate its good randomness, sensitivity to initial conditions, and wide chaotic parameter range. The initial key is then converted into the initial conditions for the 2D-NDHCM and iterated with impulse injection to generate random word-wise integers of the desired length, which are further substituted using a dynamic strong S-Box. The PRNG is evaluated through security analysis and experimental statistics. The results show that it satisfies the criteria of irreversibility, independence, and strong randomness, demonstrating its suitability for cryptographic applications.