Keyed Hash Function Using Hyper Chaotic System With Time-Varying Parameters Perturbation

Secure hash function plays an important role in cryptography. This paper constructs a hash algorithm using the hyperchaotic Lorenz system, which serves as a sponge function to absorb input message via multiple parameters time-varying perturbation. First, the input message is divided into four 1D arrays, to generate four perturbation sequences via parameter updating rule, the perturbed parameters are still within their significant intervals, to make the system remain a hyperchaotic state. Each iteration of the discrete hyperchaotic system uses updated parameters, and the last state variable values are extracted to generate a len-bit hash value by transformation algorithm. The algorithm is so flexible that it can generate 256, 512, 1024 or longer hash value through parameter switcher. The experimental evaluation and comparison demonstrated the hash function's resistance to differential attack and second pre-image attack. The proposed hash function can be applied in the identification, information integrity, and figure signature.