Analysis and improvement of a chaos-based Hash function construction

The construction of a new Hash function attracts much attention recently. In Kwok and Tang (2005) [Kwok HS, Tang WKS. A chaos-based cryptographic Hash function for message authentication. Int J Bifurcat Chaos 2005;15:4043–50], a chaos-based Hash function has been proposed. In this paper, the potential flaws in the original algorithm are analyzed in detail, and then the corresponding improving measures are proposed. We enhance the influence that each bit of the final Hash value is closely related to all the bits of the message or key and a single bit change in message or key results in great changes in the final Hash value. Simulation results show that the proposed improving algorithm has strong diffusion and confusion capability, good collision resistance, extreme sensitivity to message and secret key.