Abstract: A Hash function algorithm based on variable parameter cascade chaos is put forward aiming at the possible risk on the letting out of cascade chaos key and the deficiency of present Hash function. That is the status variable of another chaos system as the parameter perturbation is introduced to a Hash function cascade driving system, and the safe variable parameter cascade chaos system is realized with the control of turbulence intensity. The Hash function composed in this way not only obeys the variable parameter characteristic of chaos rules, but also possesses the feature of crosstalk step by step between the cascade subsystems. It can effectively reduce the risk of short period behavior caused by the finite computer precision and digital quantization possible, and it has great significance to improve the complexity and strong collision resistance of the compression function’s internal structure. The experimental results show that compared with other chaotic Hash algorithm and SHA-3 algorithm, this algorithm has high sensitivity to initial conditions, nice chaos and diffusion ability, strong collision resistance, simple and flexible algorithm, and strong controllability of variable parameter system; and it has a favorable prospect in the field of chaos secure communication, digital signature, etc.

Key words: cascade chaos, Hash function, parameter perturbation, Lyapunov index, anti collision