Hyperchaotic system-based pseudorandom number generator

Pseudorandom sequences are very important in the field of cryptography. The characteristics such as non-linearity and random-like behaviours make chaotic systems suited to generate pseudorandom sequences. However, most of chaosbased pseudorandom number generators have a typical shortcoming. That is, the finite precision in all processors may cause the chaotic systems to degenerate into a periodic function or a fixed point. To overcome this shortcoming, a hyperchaos-based generator is proposed. First, a new hyperchaotic system with bigger Lyapunov exponent is constructed. Then the self-shrinking generator, which is superior to many other linear feedback shift register-based generators, is used to perturb the hyperchaotic sequences to decrease the period degeneration and improve the performance of the sequences. The proposed generator is named as hyperchaos with self-shrinking perturbance generator (H-SSP generator). The analysis results show that the H-SSP generator has better performance.